Ctenophorus (FITZINGER,1843)

Soldatenagamen

MELVILLE, J., SCHULTE, J.A. & A. LARSON (2001): A molecular phylogenetic study of ecological diversification in the Australian lizard genus Ctenophorus. - Journal of Experimental Zoology: Molecular and Developmental Evolution, 291(4): 339-353.

THOMPSON, G.G. & P.C. WITHERS (2005): The relationship between size-free body shape and choice of retreat for Western Australian Ctenophorus (Agamidae) dragon lizards. - Amphibia-Reptilia, 26 (1): 65-72.

WYLIE, D.R., HOOPS, D., ASPDEN, J.W. & A.N. IWANIUK (2016): Zebrin II Is Expressed in Sagittal Stripes in the Cerebellum of Dragon Lizards (Ctenophorus sp.). - Brain Behav. Evol., 88: 177–186.

Aldolase C, also known as zebrin II (ZII), is a glycolytic enzyme that is expressed in cerebellar Purkinje cells of the vertebrate cerebellum. In both mammals and birds, ZII is expressed heterogeneously, such that there are sagittal stripes of Purkinje cells with high ZII expression (ZII+) alternating with stripes of Purkinje cells with little or no expression (ZII–). In contrast, in snakes and turtles, ZII is not expressed heterogeneously; rather all Purkinje cells are ZII+. Here, we examined the expression of ZII in the cerebellum of lizards to elucidate the evolutionary origins of ZII stripes in Sauropsida. We focused on the central netted dragon (Ctenophorus nuchalis) but also examined cerebellar ZII expression in 5 other dragon species ( Ctenophorus spp.). In contrast to what has been observed in snakes and turtles, we found that in these lizards, ZII is heterogeneously expressed. In the posterior part of the cerebellum, on each side of the midline, there were 3 sagittal stripes consisting of Purkinje cells with high ZII expression (ZII+) alternating with 2 sagittal stripes with weaker ZII expression (ZIIw). More anteriorly, most of the Purkinje cells were ZII+, except laterally, where the Purkinje cells did not express ZII (ZII–). Finally, all Purkinje cells in the auricle (flocculus) were ZII–. Overall, the parasagittal heterogeneous expression of ZII in the cerebellum of lizards is similar to that in mammals and birds, and contrasts with the homogenous ZII+ expression seen in snakes and turtles. We suggest that a sagittal heterogeneous expression of ZII represents the ancestral condition in stem reptiles which was lost in snakes and turtles.

Ctenophorus caudicinctus (GÜNTHER, 1875)

Ring-tailed Bicycle-dragon / Ring-tailed Dragon

BRADSHAW, S.D., SAINT GIRONS, H. & F.J. BRADSHAW (1991): Patterns of breeding in two species of agamid lizards in the arid subtropical Pilbara region of Western Australia. – Gen. Comp. Endocr., 82: 407-422.

DOODY, J.S., CHERRIMAN, S. & J. TURPIN (2015): Natural history notes: Ctenophorus reticulatus (Western Netted Dragon), Ctenophorus caudicinctus (Ring-tailed Dragon), and Egernia eos (Central Pygmy Spiny-tailed Skink). predation. – Herpetol. Rev., 46 (3): 433.

DOODY, J.S. & B. SCHEMBRI (2014): Natural history notes: Ctenophorus caudicinctus (Ring-tailed Dragon). Predation. – Herpetol. Rev., 45 (3): 494-495.

PIANKA, E.R. (2014): Notes on the ecology and natural history of Ctenophorus caudicinctus (Agamidae) in Western Australia. – West. Aust. Nat., 29 (3): 226-230.

STORR, G.M. (1967): Geographic races of the agamid lizard Amphibolurus caudicinctus. – J. Proc. R. Soc. West. Aust., 50: 49-56.

Ctenophorus clayi (STORR, 1967)

Black-shouldered Ground-dragon

GREER, A.E. (1987): Observations on the osteology and natural history of the agamid lizard Ctenophorus clayi. - West. Aust. Nat., 17(1): 5-7.

STORR, G.M. (1966): The Amphibolurus reticulates species group (Lacertilia, Agamidae) in Western Australia. – J. Proc. Roy. Soc. W.Aust., 49: 17-25.

Ctenophorus cristatus (GRAY, 1841)

Crested Bicycle-dragon / Crested Dragon

GOLDBERG, S.R. (2009): Notes on reproduction of the Crested Dragon, Ctenophorus cristatus (Squamata: Agamidae) from Western Australia. – Bull. Mary. Herp. Soc., 45 (4): 111-113.

GRAY, J.E. (1841): Description of some new species and four new genera of reptiles from Western Australia, discovered by John Gould, Esq. - Ann. Mag. Nat. Hist. (1) 7: 86-91.

PIANKA, E.R. (1971): Notes on the biology of Amphibolurus cristatus and Amphibolurus scutulatus. – West. Aust. Nat., 12: 36-41.

Ctenophorus decresii (DUMÉRIL & BIBRON, 1837)

Tawny Creviced-dragon / Tawny Dragon

DUMÉRIL, A.M.C. & G. BIBRON (1837): Description of Ctenophorus decresii. – In: “Erpétologie Générale ou Histoire Naturelle Complete des Reptiles”. Vol. 4. Libr. Encyclopédique Roret, Paris, 570 pp.

GIBBONS, J.R.H. (1977): Comparative ecology and behaviour of lizards of the Amphibolurus decresii species complex. Thesis. University of Adelaide, South Australia.

GIBBONS, J.R.H. (1979): The hind leg pushup display of the Amphibolurus decresii species complex (Lacertilia: Agamidae). – Coipeia, 1979: 29-40.

GIBBONS, J.R.H. & H.B. LILLYWHITE (1981): Ecological segregation, color matching, and speciation in lizards of the Amphibolurus decresii species complex (Lacertilia: Agamidae). – Ecology, 62 (6): 1573–1584.The Amphibolurus decresii complex comprises three species, A. decresii, A. fionni, and A. vadnappa, having restricted distribution in South Australia and extreme western New South Wales, Australia. Adults of all three species are similar in appearance, apart from color and patternd ifferences, particularlyi n males, and are restrictedt o rocky outcrops. Amphibolurusd ecresii and A. vadnappa are partially sympatric, but are ecologically segregated according to the color of rocks on which they perch. Amphibolurusd ecresii is found on rocks whicha re predominantlyp inkishy ellow, whereas A. vadnappa is found on rocks which are dark reddish brown. Each species appears camouflaged on its respective mineral type which it prefers in choice tests. Amphibolurus fionni is allopatric from the other species and exhibits variable coloration in its "substrate races." It has a distinctive color pattern of its own, but resembles one or the other species in areas where rocky habitats are correspondingly similar. Studies of reflectivity of lizard skin demonstrate that the dorsal coloration on the back, tail, and legs is relatively labile. Maximum blanching occurs at high body temperatures. Lability is correlated with latitude, southern populations being darker and possessing less lability than northern populations. The dorsal coloration is thought to be importanti n thermoregulationR. eflectancef rom dorsolateral patterns of lizards shows little lability (<3% at all visible wavelengths) and matches the reflectance of respective mineral backgrounds. These patterns also resemble the colors and shapes of lichens that grow upon the rocks. Both dorsal and dorsolateral coloration are believed to have camouflage functions, but the latter appears more important because (1) it matches the substrate more closely, and (2) it does not change appreciably with body temperature. Evidence suggests that species comprising the A. decresii complex evolved from a common ancestor in South Australia. With respect to A. decresii and A. vadnappa, a model of ecological speciation is proposed involving divergent color adaptation and possibly sympatric or parapatric populations. Color divergence and substrate matching seen in populations of A. fionni conceivably reflect evolutionary processes similar to those that promoted speciation of A. decresii and A. vadnappa.

HARLOW, P.S. (2000): Incubation temperature determines hatchling sex in Australian rock dragons (Agamidae: Genus Ctenophorus). – Copeia, 2000 (4): 958-964.

HOUSTON, T.F. (1974): Revision of the Amphibolurus decresii complex (Lacertilia: Agamidae) of South Australia. – Transactions R. Soc. S. Aust., 98 (2): 49-60.

McFADDEN, M. & P.S. HARLOW (2007): Captive reproduction and longevity in tawny crevice (Ctenophorus decresii) and central netted dragons (C. nuchalis). - Herpetofauna (Sydney), 37 (1): 22-26.

MCLEAN, C.A., MOUSSALLI, A., SASS, S. & D. STUART-FOX (2013): Taxonomic assessment of the Ctenophorus decresii complex (Reptilia: Agamidae) reveals a new species of Dragon Lizard from Western New South Wales. - Records of the Australian Museum. 65(3): 51–63.

We describe a new species of agamid lizard, Ctenophorus mirrityana sp.nov. currently known from two disjunct populations in western New South Wales. The species is a member of the C. decresii species complex, and was formerly recognized as an outlying population of C. decresii due to similarities in dorsal colour pattern and adjacent distributions. Previous work documented deep molecular divergence, across multiple loci, with no genetic admixture between the new species and proximal C. decresii populations. We find that the new species differs in morphology from all other members of the species complex and is characterized by distinct male throat and lateral coloration, a small head size relative to snout-vent length, a large number of labial scales, and a lack of tubercular scales. We also identify two geographically structured lineages (northern and southern) within C. decresii as requiring further taxonomic investigation, based on notable genetic and morphological (including colour) divergence. We find that divergence in coloration is associated with genetic and body form differentiation within the C. decresii species complex.

McLEAN, C.A., MOUSSALLI, A. & D. STUART-FOX (2014): Local adaptation and divergence in colour signal conspicuousness between monomorphic and polymorphic lineages in a lizard. – J. Evol. Biol., 27 (12): 2654-2664.

Population differences in visual environment can lead to divergence in multiple components of animal coloration including signalling traits and colour patterns important for camouflage. Divergence may reflect selection imposed by different receivers (conspecifics, predators), which depends in turn on the location of the colour patch. We tested for local adaptation of two genetically and phenotypically divergent lineages of a rock-inhabiting lizard, Ctenophorus decresii, by comparing the visual contrast of colour patches to different receivers in native and non-native environments. The lineages differ most notably in male throat coloration, which is polymorphic in the northern lineage and monomorphic in the southern lineage, but also differ in dorsal and lateral coloration, which is visible to both conspecifics and potential predators. Using models of animal colour vision, we assessed whether lineage-specific throat, dorsal and lateral coloration enhanced conspicuousness to conspecifics, increased crypsis to birds or both, respectively, when viewed against the predominant backgrounds from each lineage. Throat colours were no more conspicuous against native than non-native rock but contrasted more strongly with native lichen, which occurs patchily on rocks inhabited by C. decresii. Conversely, neck coloration (lateral) more closely matched native lichen. Furthermore, although dorsal coloration of southern males was consistently more conspicuous to birds than that of northern males, both lineages had similar absolute conspicuousness against their native backgrounds. Combined, our results are consistent with local adaptation of multiple colour traits in relation to multiple receivers, suggesting that geographic variation in background colour has influenced the evolution of lineage-specific coloration in C. decresii.

McLEAN, C.A., STUART-FOX, D. & A. MOUSSALLI (2014): Phylogeographic structure, demographic history and morph composition in a colour polymorphic lizard. – J. Evol. Biol., 27 (10): 2123-2137.

In polymorphic species, population divergence in morph composition and frequency has the potential to promote speciation. We assessed the relationship between geographic variation in male throat colour polymorphism and phylogeographic structure in the tawny dragon lizard, Ctenophorus decresii. We identified four genetically distinct lineages, corresponding to two polymorphic lineages in the Northern Flinders Ranges and Southern Flinders Ranges/Olary Ranges regions respectively, and a monomorphic lineage in the Mt Lofty Ranges/Kangaroo Island region. The degree of divergence between these three lineages was consistent with isolation to multiple refugia during Pleistocene glacial cycles, whereas a fourth, deeply divergent (at the interspecific level) and monomorphic lineage was restricted to western New South Wales. The same four morphs occurred in both polymorphic lineages, although populations exhibited considerable variation in the frequency of morphs. By contrast, male throat coloration in the monomorphic lineages differed from each other and from the polymorphic lineages. Our results suggest that colour polymorphism has evolved once in the C. decresii species complex, with subsequent loss of polymorphism in the Mt Lofty Ranges/Kangaroo Island lineage. However, an equally parsimonious scenario, that polymorphism arose independently twice within C. decresii, could not be ruled out. We also detected evidence of a narrow contact zone with limited genotypic admixture between the polymorphic Olary Ranges and monomorphic Mt Lofty Ranges regions, yet no individuals of intermediate colour phenotype. Such genetic divergence and evidence for barriers to gene flow between lineages suggest incipient speciation between populations that differ in morph composition.

OSBORNE, L. (2005): Information content of male agonistic displays in the territorial tawny dragon (Ctenophorus decresii). – J. Ethol., 23 (2): 189-197.

Two potential signals used during male–male agonistic encounters were examined for signal content in the territorial agamid lizard Ctenophorus decresii, or tawny dragon. Males have black chest patches, which are apparent when they posture during agonistic encounters. Patches are not condition or size dependent. The area of the patches is positively associated with levels of aggression and likelihood of winning a fight. The patch thus functions as a “badge of status” indicating male aggression. The complex dynamic displays given by males contain information on male endurance and size. The number of push-ups given during a display reflects the aggressiveness of an animal. There was no relationship between patch size and endurance. There is some overlap in the content of the two signals, both contain information on aggressiveness, suggesting that they may function as back-up signals. The multiple-message hypothesis is not ruled out as endurance and size are only related to the dynamic displays. However, it is not clear that endurance is an important determinant of contest outcomes in this species, and so it is not certain that the receiver uses this information.

OSBORNE, L. (2005): Rival recognition in the territorial tawny dragon (Ctenophorus decresii). - Acta Ethol., 8 (1): 45-50.

The ability to discriminate between familiar and unfamiliar conspecifics is important in territorial animals as it allows animals to distinguish neighbours from nonneighbours. This prevents wasting time and energy in unnecessary aggressive interactions. I investigated the ability of adult males of a territorial lizard, the tawny dragon (Ctenophorus decresii), to distinguish familiar from unfamiliar rivals in a laboratory setting. Males significantly reduced their aggression levels in repeat interactions with familiar rivals and increased their aggression levels towards unfamiliar males. The time taken for interactions to be settled was also significantly lower towards familiar than unfamiliar males. The results of this study suggest that adult male tawny dragons can discriminate familiar from unfamiliar conspecifics. Furthermore, animals were presented with three new rivals in succession and showed a robust ability to discriminate between familiar and unfamiliar males.

OSBORNE, L., UMBERS, K.D.L., BACKWELL, P.R.Y. & J.S. KEOGH (2012): Male tawny dragons use throat patterns to recognize rivals. – Naturwissenschaften, 99 (10): 869-872.

The ability to distinguish between familiar and unfamiliar conspecifics is important for many animals, especially territorial species since it allows them to avoid unnecessary interactions with individuals that pose little threat. There are very few studies, however, that identify the proximate cues that facilitate such recognition in visual systems. Here, we show that in tawny dragons (Ctenophorus decresii), males can recognize familiar and unfamiliar conspecific males based on morphological features alone, without the aid of chemical or behavioural cues. We further show that it is the colour pattern of the throat patches (gular) that facilitates this recognition.

RANKIN K. & D. STUART-FOX (2015): Testosterone-induced expression of male colour morphs in females of the polymorphic Tawny Dragon Lizard, Ctenophorus decresii. - PLoS ONE 10(10): e0140458, doi:10.1371/journal.pone.0140458.

Many colour polymorphisms are present only in one sex, usually males, but proximate mechanisms controlling the expression of sex-limited colour polymorphisms have received little attention. Here, we test the hypothesis that artificial elevation of testosterone in females of the colour polymorphic tawny dragon lizard, Ctenophorus decresii, can induce them to express the same colour morphs, in similar frequencies, to those found in males. Male C. decresii, express four discrete throat colour morphs (orange, yellow, grey and an orange central patch surrounded by yellow). We used silastic implants to experimentally elevate testosterone levels in mature females to induce colour expression. Testosterone elevation resulted in a substantial increase in the proportion and intensity of orange but not yellow colouration, which was present in a subset of females prior to treatment. Consequently, females exhibited the same set of colour morphs as males, and we confirmed that these morphs are objectively classifiable, by using digital image analyses and spectral reflectance measurements, and occur in similar frequencies as in males. These results indicate that the influence of testosterone differs for different colours, suggesting that their expression may be governed by different proximate hormonal mechanisms. Thus, caution must be exercised when using artificial testosterone manipulation to induce female expression of sexlimited colour polymorphisms. Nevertheless, the ability to express sex-limited colours (in this case orange) to reveal the same, objectively classifiable morphs in similar frequencies to males suggests autosomal rather than sex-linked inheritance, and can facilitate further research on the genetic basis of colour polymorphism, including estimating heritability and selection on colour morphs from pedigree data.

STUART-FOX, D.M. & G.R. JOHNSTON (2005): Experience overrides colour in lizard contests. – Behaviour, 142 (3): 329-350.

We examined the role of conspicuous coloration in male-male contests for two species of Australian dragon lizards, Ctenophorus decresii and C. vadnappa, in which conspicuous coloration has a demonstrated predation cost. We conducted contests in which the overall conspicuousness of male coloration was manipulated using paints that matched the spectral reflectance of the lizards, as well as natural (control) contests. There was little evidence for an influence of colour on contest outcome or aggression levels for either species when all experiments were considered. However, we found a significant effect of trial order and experience on contest outcome and aggression levels (the same pair of males was used for both types of contest), despite a 2-3 week interval between contests. When we examined only the first trial between unfamiliar males, we found that male C. vadnappa that had been painted to appear more conspicuous consistently won. Comparison with the natural trials suggests that the aspect of colour manipulation that was responsible for this result was the ‘hue’ of the throat: males with yellower throats consistently beat males with bluer throats in both natural and painted trials. The difference in coloration of flank markings also predicted the difference in aggression scores between contestants in the natural trials. These results suggest that although colour is important in opponent assessment and in determining contest outcome in C. vadnappa, previous agonistic experience can override the effects of colour and have a long-lasting influence on aggressive behaviour.

UMBERS, K.D.L., OSBORNE, L. & J.S. KEOGH (2012): The Effects of Residency and Body Size on Contest Initiation and Outcome in the Territorial Dragon, Ctenophorus decresii. – PlosOne 7 (10): e47143 5 pp.

Empirical studies of the determinants of contests have been attempting to unravel the complexity of animal contest behaviour for decades. This complexity requires that experiments incorporate multiple determinants into studies to tease apart their relative effects. In this study we examined the complex contest behaviour of the tawny dragon (Ctenophorus decresii), a territorial agamid lizard, with the specific aim of defining the factors that determine contest outcome. We manipulated the relative size and residency status of lizards in contests to weight their importance in determining contest outcome. We found that size, residency and initiating a fight were all important in determining outcomes of fights. We also tested whether residency or size was important in predicting the status of lizard that initiated a fight. We found that residency was the most important factor in predicting fight initiation. We discuss the effects of size and residency status in context of previous studies on contests in tawny dragons and other animals. Our study provides manipulative behavioural data in support of the overriding effects of residency on initiation fights and winning them.

YEWERS, M. (2016): The function and evolution of colour polymorphism in the Tawny Dragon Lizard. Thesis. University of Melbourne. 245 pp.

Colour polymorphic species are model systems to investigate the evolutionary processes that maintain intraspecific diversity within a population. Colour polymorphism occurs when two or more discrete, genetically inherited colour forms coexist within an interbreeding population. Almost ubiquitously, colour morphs differ in morphological, behavioural, ecological, life history and/or physiological traits in addition to colour that often form alternative strategies. Each strategy has optimal trait combinations that allow morphs to maximise fitness. Variation in the trait composition of morph-specific strategies has important implications for understanding life-history trade-offs and the maintenance of polymorphism within populations. Differences in morph composition and correlated traits between populations can also promote divergence and ultimately speciation. In this thesis, I investigate the evolutionary maintenance of colour polymorphism in the tawny dragon lizard, Ctenophorus decresii. I do so in two distinct ways; by assessing colour vision differences between genetically and geographically distinct monomorphic and polymorphic lineages, and by comparing a range of traits that could differentially affect the fitness of morphs within a colour polymorphic population. In the south of their range, male tawny dragons are monomorphic for throat coloration whereas in the north of their range, they are polymorphic. There are four discrete male colour morphs in polymorphic populations that vary in the presence/absence of yellow and orange coloration; the yellow morph, orange morph, grey morph and orange-yellow morph (a yellow background with a central orange patch). Throat colour is heritable, fixed for life, and is an important sexual signal. ii Males of the monomorphic southern lineage express ultraviolet (UV)-blue throat coloration, unlike males of the polymorphic northern lineage. Lineages meet at a narrow contact zone where genotypic admixture suggests potential barriers to gene flow and incipient speciation. I determined the cone photoreceptor spectral sensitivities using microspectrophotometry and opsin expression of the two lineages, to see if they differ, particularly in sensitivity to UVblue wavelengths. I confirmed the presence of four single cone classes in both lineages and provide the first evidence of UV visual sensitivity in agamid lizards. However, whether the lineages differ in UV-blue sensitivity remains unresolved. Within a polymorphic northern population, I assessed a combination of traits associated with each colour morph. I found morph-specific alternative strategies differentiated by consistencies in behaviour and hormones. The orange morph has an aggressive strategy with high levels of androgens while the grey morph has a cautious strategy with low levels of baseline androgens. The yellow morph has a conditional strategy where its aggression depends on the colour of the intruder and exhibits a stress-induced androgen increase. The orange-yellow morph similarly shows aggression conditional on the colour of the intruder but it is the boldest with high levels of androgens. Morphs did not differ in performance (bite force) or space use, and there was no relationship between spatial arrangement and relatedness. However, genetic structure based on microsatellite markers indicated weak genetic differentiation between morphs. Therefore, there are minimal barriers to gene flow between morphs. Instead, frequency-dependent selection is likely to be maintaining polymorphism in the tawny dragon lizard.

Ctenophorus dualis (STORR, 1965)

Spotted Sand-dragon, Spotted Dragon

Ctenophorus femoralis (STORR,1965)

Long-tailed Sand-dragon

BELL, C.J., MEAD, J.I. & M. HOLLENSHEAD (2009): Sand shimmying as predator avoidance behaviour in two agamid lizards, Ctenophorus reticulatus and Ctenophorus femoralis. – West. Aust. Nat., 27 (1): 54-55.

GREER, A.E. (1989): Observations on the osteology and natural history of the agamid lizard Ctenophorus femoralis. – West. Aust. Nat., 18 /1): 21-23.

STORR, G.M. (1965): The Amphibolurus maculatus species-group (Lacertilia, Agamidae) in Western Australia. – J. Royal Soc. West. Australia, 48 (2): 45-54.

Ctenophorus fionni (PROCTER,1923)

Peninsula Crevis-dragon / Peninsula Dragon

JOHNSTON, G. (2000): Population density and habitat use in the Peninsula Dragon Lizard (Ctenophorus fionni). - Herpetofauna (Sydney), 30 (1): 34-36.

JOHNSTON, G. (2005): Natural history notes: Ctenophorus fionni (Peninsula Dragon Lizard). Cannibalism. – Herpetol. Rev., 36 (2): 175.

JOHNSTON, G. (2011): Growth and survivorship as proximate causes of sexual size dimorphism in peninsula dragon lizards Ctenophorus fionni. – Aust. Ecol., 36 (2): 117-125

Males and females differ in body size in many animals, but the direction and extent of this sexual size dimorphism (SSD) varies widely. Males are larger than females in most lizards of the iguanian clade, which includes dragon lizards (Agamidae). I tested whether the male larger pattern of SSD in the peninsula dragon lizard, Ctenophorus fionni, is a result of sexual selection for large male size or relatively higher mortality among females. Data on growth and survivorship were collected from wild lizards during 1991–1994.The likelihood of differential predation between males and females was assessed by exposing pairs of male and female lizards to a predator in captivity, and by comparing the frequency of tail damage in wild-caught males and females. Male and female C. fionni grew at the same rate, but males grew for longer than females and reached a larger asymptotic size (87 mm vs. 78 mm). Large males were under-represented in the population because they suffered higher mortality than females. Predation may account for some of this male-biased mortality. The male-biased SSD in C. fionni resulted from differences in growth pattern between the sexes. The male-biased SSD was not the result of proximate factors reducing female body size. Indeed SSD in this species remained male-biased despite high mortality among large males. SSD in C. fionni is consistent with the ultimate explanation of sexual selection for large body

PROCTER, J. B. (1923): On new and rare reptiles and batrachians from the Australian region. - Proc. Zool. Soc. London, 1923: 1069-1077.

Several interesting collections from the Australian Region have recently been received by the British Museum (Nat. Hist.). I .shall include four in this one paper, and limit it for the sake of brevity to notes on rarities and descriptions of new species.

Ctenophorus fordi (STORR, 1965)

Mallee Sand-dragon / Mallee Dragon

COGGER, H.G. (1974): Thermal relations of the malle dragon Amphibolurus fordi (Lacertilia: Agamidae). – Australian Journal of Zoology, 22 (3): 319-339.

A field study of the thermal relationships of the small agamid lizard A. fordi has been carried out in two areas of mallee in central western New South Wales, where this lizard occurs only in close association with the grass Triodia scariosa. The body temperatures characteristic of various phases in this lizard's die1 cycle have been determined. The behavioural techniques employed to regulate temperature are described; they are similar to those used by a wide range of diurnal heliothermic lizards in other regions. The total effect of these thermoregulatory responses is to maintain an internal thermal environ- ment approaching homoiothermy while the lizard is active. For A. fordi the eccritic body temperature determined from animals in the field is 36.9+-0.16C. Lowering of activity thermal levels occurs in winter, and can be induced at any time by even mild starvation.

COGGER, H.G. (1978): Reproductive cycles, fat body cycles and socio-sexual behavior in the Mallee dragon, Amphibolurus fordi (Lacertrilia: Agamidae). – Aust. J. Zool., 26: 653-672.

GARCÍA, J.E., ROHR, D. & A.G. DYER (2013): Trade-off between camouflage and sexual dimorphism revealed by UV digital imaging: the case of Australian Mallee dragons (Ctenophorus fordi). – J. Exp. Biol., 216 (22): 4290-4298.

Colour patterns displayed by animals may result from the balance of the opposing requirements of sexual selection through display and natural selection through camouflage. Currently, little is known about the possibility of the dual purpose of an animal colour pattern in the UV region of the spectrum, which is potentially perceivable by both predators and conspecifics for detection or communication purposes. Here, we implemented linearised digital UV photography to characterise and quantify the colour pattern of an endemic Australian Agamid lizard classically regarded as monomorphic when considering data from the visible region of the spectrum. Our results indicate a widespread presence of UV elements across the entire body of the lizards and these patterns vary significantly in intensity, size and frequency between sexes. These results were modelled considering either lizard or avian visual characteristics, revealing that UV reflectance represents a trade-off between the requirements of sexual displaying to conspecifics and concealment from avian predators

GOLDBERG, S.R. (2008): Longitudinal variation in timing of the testicular cycle of the Mallee dragon, Ctenophorus fordi (Squamata: Agamidae) from Australia. – Bull. Mary. Herp. Soc., 44 (4): 138-140.

OLSSON, M. (2001): 'Voyeurism' prolongs copulation in the dragon lizard Ctenophorus fordi. – Behav. Ecol. Sociobiol., 50 (4): 378-381.

Risk of sperm competition is becoming increasingly appreciated as a determinant of male reproductive behavior in evolutionary ecology. That is, a male is under selection to adjust his ejaculate investments into a female depending on the mating histories of both. I investigated such behavior in the Australian Mallee dragon lizard (Ctenophorus fordi). Females in this species mate repeatedly and apparently indiscriminately with several partners in succession. Intuitively, a male mating subsequent to a rival should mate longer if doing so transfers more competing spermatozoa or seminal fluids that may act as paternity guards. I tested the prediction that males mate longer with females known to have mated recently with other males in a simple experiment using wildcaught lizards kept in outdoor enclosures. Males allowed to observe a female’s first copulation with rival males and then copulate with the same female remained in copula 60% longer (15.9 s on average) than the males in the first matings (9.9 s on average). In the reciprocal trials in which males in females’ second copulations could not observe the first male’s copulation, second males did not mate for longer than first males. Furthermore, copula duration was positively correlated with transferred ejaculate volume. Thus, the results suggest that males may prolong copulation to become more competitive when under increased risk of sperm competition.

PIANKA, E.R. 2013. Notes on the ecology and natural history of two uncommon terrestrial agamid lizards Ctenophorus clayi and C. fordi in the Great Victoria Desert of Western Australia. – West. Aust. Nat., 29 (2): 85-93.

ULLER, T., ISAKSSON, C. & M. OLSSON (2006): Immune challenge reduces reproductive output and growth in a lizard. – Funct. Ecol., 20 (5): 873-879.

1. A fundamental assumption in evolutionary immunology is that the immune system is costly to develop, maintain or activate. 2. Two plausible costs of activation of the immune system are decreased resources for growth and reproductive investment. However, few studies have estimated direct effects of an immune challenge, in particular in ectotherm vertebrates. We studied the consequences of an immune challenge in reproductive female dragons, Ctenophorus fordi, and in their offspring by exposing lizards to bacterial lipopolysaccharides (LPS). 3. The immune challenge led to decreased reproductive investment in terms of egg mass, but with no effect on probability of future reproduction. 4. Maternal immune challenge did not influence the response of their offspring to the same challenge. However, juveniles that were induced to mount an immune response had a higher thermal preference and showed reduced growth, but the magnitude of the growth effect was dependent on the date of oviposition, indicating maternal effects on offspring immunity. 5. Our results suggest that costs of immune activation may be important in shaping growth and reproductive strategies in ectotherms.

ULLER, T., ODIERNA, G. & M. OLSSON (2008): Sex ratio variation and sex determination in the mallee dragon Ctenophorus fordi. – Integr. Zool., 3 (3): 157-165.

Recent evidence suggests that many Australian agamids show temperature-dependent sex determination (TSD) with variation in sex determining mechanisms among closely related taxa. However, as shown in other vertebrates, sex ratios can also be influenced by genetic or phenotypic differences among females in their propensity to produce sons or daughters, and these influences might confound any thermal effects of incubation per se. To address these issues, we investigated the determinants of sex ratios in the mallee dragon Ctenophorus fordi, together with a detailed analysis of karyotypes. There was no detectable variation in sex ratios arising from variation among females, clutches or incubation temperatures, which might indicate genetic sex determination for this species. However, there was no evidence of cytologically distinct sex chromosomes using standard banding techniques. The sex ratio pattern in C. fordi strongly contrasts with the results for the congener Ctenophorus pictus, where sex ratios show variation among females. Thus, Australian agamids offer promising opportunities to address fundamental issues in sex ratio biology.

ULLER, T. & M. OLSSON (2006): No seasonal sex-ratio shift despite sex-specific fitness returns of hatching date in a lizard with genotypic sex determination. – Evolution, 60 (10): 2131-2136.

Sex allocation theory predicts that mothers should adjust their sex-specific reproductive investment in relation to the predicted fitness returns from sons versus daughters. Sex allocation theory has proved to be successful in some invertebrate taxa but data on vertebrates often fail to show the predicted shift in sex ratio or sex-specific resource investment. This is likely to be partly explained by simplistic assumptions of vertebrate life-history and mechanistic constraints, but also because the fundamental assumption of sex-specific fitness return on investment is rarely supported by empirical data. In short-lived species, the time of hatching or parturition can have a strong impact on the age and size at maturity. Thus, if selection favors adult sexual-size dimorphism, females can maximize their fitness by adjusting offspring sex over the reproductive season. We show that in mallee dragons, Ctenophorus fordi, date of hatching is positively related to female reproductive output but has little, if any, effect on male reproductive success, suggesting selection for a seasonal shift in offspring sex ratio. We used a combination of field and laboratory data collected over two years to test if female dragons adjust their sex allocation over the season to ensure an adaptive match between time of hatching and offspring sex. Contrary to our predictions, we found no effect of laying date on sex ratio, nor did we find any evidence for within-female between-clutch sex-ratio adjustment. Furthermore, there was no differential resource investment into male and female offspring within or between clutches and sex ratios did not correlate with female condition or any partner traits. Consequently, despite evidence for selection for a seasonal sex-ratio shift, female mallee dragons do not seem to exercise any control over sex determination. The results are discussed in relation to potential constraints on sex-ratio adjustment, alternative selection pressures, and the evolution of temperature-dependent sex determination.

ULLER, T. & M. OLSSON (2009): Offspring size-number trade-off in a lizard with small clutch sizes: tests of invariants and potential implications. – Evol. Ecol., 23 (3): 363-372.

Models of small clutch sizes predict a number of invariant relationships between means and variances of measures of reproductive investment. However, empirical tests of the models have been lagging behind theoretical work. We tested the predictions using data on the mallee dragon, Ctenophorus fordi, a species where the basic assumptions of the models are likely to be fulfilled. Some, but not all, qualitative predictions of the models were shown to hold true, but the data fitted poorly to quantitative predictions. The patterns of deviation from theory may suggest the presence of a lower, and potentially an upper, limit on egg mass. We also argue that multiple and non-independent allocation decisions between total reproductive effort, growth and maintenance, and offspring sizenumber allocation could be important factors in the evolution of size-number strategies in lizards and thus need to be taken into account in theoretical models. The present study shows the potential to use small clutch size models to gain further insights into reproductive investment and allocation decisions in squamates.

ULLER, T., SCHWARTZ, T., KOGLIN, T. & M. OLSSON (2013): Sperm storage and sperm competition across ovarian cycles in the dragon lizard, Ctenophorus fordi. – J. Exp. Zool., 319A (7): 404-408.

Female sperm storage can influence male reproductive success and may favour males that produce sperm that remain viable across several ovarian cycles. Here we show that sperm are viable in the female reproductive tract across ovarian cycles in the mallee dragon, Ctenophorus fordi. Based on experimental mating trials, we show that stored sperm were generally less likely to fertilize eggs than recently inseminated sperm. The fertilization success of stored sperm increased with male body size relative to rivals. This may be due to differences in ejaculate volume or sperm number transferred by males of different sizes. However, there was no evidence that copulation time, which is correlated with ejaculate volume, contributed to fertilization success. We suggest that sperm storage across ovarian cycles may be common in small, multi-clutched lizards and that its impact on selection on male phenotypes could contribute to the evolution of lizard mating systems.

Ctenophorus gibba (HOUSTON, 1974)

Bulldust Ground-dragon

HOUSTON, T.F. (1974): Amphibolurus gibba, a new dragon lizard (Lacertilia: Agamidae) from northern South Australia. – Transactions R. Soc. S. Aust., 98 (4): 209-212.

HOUSTON, T.F. (1976): Vertebrate type-specimens in the South Australian Museum. III. Reptiles. - Rec. South Austral. Mus., 17: 181-187.

Ctenophorus isolepis (FISCHER, 1881)

Military Sand-dragon / Military Dragon

DALY, B.G., DICKMAN, C.R. & M.S. CROWTHER (2007): Selection of habitat components by two species of agamid lizards in sandridge desert, central Australia. – Aust. Ecol., 32 (7): 825-833.

We studied the use and selection of habitat components by two species of agamid (dragon) lizards in the Simpson Desert, Queensland, Australia. Both the military dragon (Ctenophorus isolepis) and central netted dragon (Ctenophorus nuchalis) were captured in pitfall traps surrounded by areas of open sand, but the mean coverage of spinifex (Triodia basedowii) was greater (35%) around traps capturing C. isolepis than around those capturing its congener (approx. 8%). Direct observations of free-ranging lizards confirmed that C. isolepis spent most time in, or within 30 cm of, spinifex hummocks, whereas C. nuchalis primarily perched in dead wood. Both species spent most (_75%) of the time they were observed at rest, with little time spent feeding or moving. Ctenophorus isolepis spent 67% of its time in shade and was active in temperatures between 37.5°C and 43.3°C, whereas C. nuchalis spent 81% of its time in open sun and was active between 35.9°C and 48.1°C.Transect surveys at observation sites showed that open sand was the dominant habitat component available to both species. However, sand was under-used compared with its availability. Ctenophorus isolepis instead showed strong selection for spinifex cover and C. nuchalis for dead wood; shrub cover was little used. We discuss several mechanisms that may drive the observed pattern of habitat selection, but cannot specify which is the most important. However, the results indicate clear partitioning of habitat between the two species, and suggest that this segregation may facilitate coexistence at local and regional scales.

DALY, B.G., DICKMAN, C.R. & M.S. CROWTHER (2008): Causes of habitat divergence in two species of agamid lizards in arid central Australia. - Ecology (Washington, D.C.), 89 (1): 65-76.

The deserts of central Australia contain richer communities of lizards than any other arid regions, with the highest diversity occurring in sand dune habitats dominated by hummock-forming spinifex grasses. To investigate the mechanisms that permit coexistence, we studied two species of coexisting agamid lizards that exhibit striking divergence in their use of habitat in the Simpson Desert of central Australia. Here, the military dragon Ctenophorus isolepis is restricted primarily to sites providing >30% cover of hard spinifex Triodia basedowii, whereas the central netted dragon C. nuchalis occurs in areas with much sparser (<10%) cover. We constructed four mechanistic models to explain this pattern and then derived hypotheses to test them. One hypothesis, that competition restricts each species to its preferred habitat, was rejected after dyad encounters in field enclosures failed to elicit any habitat shift or any overt interactions between the species. Our next hypotheses were that each species exhibits preferences for different thermal environments or different prey types and that each selects the habitats that maximize access to them. Both were supported. C. isolepis preferred lower temperatures when active and specialized in eating ants <5 mm long and selected spinifex dominated areas where these requirements were met. In contrast, C. nuchalis preferred higher temperatures and a diversity of prey, both of which were available mostly in open areas. Finally, we used plasticine models to test the hypothesis that each species faced lower risk of predation in its selected habitat. This was partly supported, as models of both species were attacked more often in the open than under spinifex cover. The results show that habitat divergence occurs along several, probably covarying, niche axes. We suggest that different levels of spinifex cover provide the template for a broad range of ecological interactions, allowing lizard species to partition biotic and abiotic resources and achieve the extraordinarily high levels of local diversity that are observed.

DICKMAN, C.R., LETNIC, M. & P.S. MAHON (1999): Population dynamics of two species of dragon lizards in arid Australia: the effects of rainfall. – Oecologia, 119: 357-366.

Military Sand-dragon / Military Dragon


Ctenophorus isolepis citrinus (STORR, 1965)

Military Sand-dragon / Military Dragon


Ctenophorus isolepis gularis (STERNFELD, 1925)

Military Sand-dragon / Military Dragon

Ctenophorus maculatus (GRAY, 1831)

Spotted Sand-dragon / Spotted Dragon

CHAN, R., STUART-FOX, D.M. & T.S. JESSOP (2009): Why are females ornamented? A test of the courtship stimulation and courtship rejection hypotheses. – Behav. Ecol., 20 (6): 1334-1342.

Female ornamentation was initially thought to reflect genetic correlation with the more elaborate male trait. However, this cannot explain female-specific ornamentation, such as the conspicuous coloration displayed by females of many species during breeding. Females may exhibit distinctive, reproductive coloration to 1) advertise receptivity and stimulate male courtship or 2) advertise nonreceptivity when gravid to reduce male courtship, harassment, and potentially costly copulations. We tested both hypotheses in the Lake Eyre dragon lizard (Ctenophorus maculosus) by quantifying female coloration, using spectroradiometry and a model of lizard color perception, and male and female behavior across the female reproductive cycle. Females develop bright orange coloration on their throat and abdomen during the breeding season, whereas males remain cryptically colored. The onset of orange coloration was associated with enlarging follicles, acceptance of copulations, and escalation of male courtship. Rather than fading once females were no longer receptive, however, the intense orange coloration remained until oviposition. Furthermore, despite maximal coloration associated with nonreceptivity, males persisted with courtship and copulation attempts, and females increased rejection behaviors comprising lateral displays and flipping onto their backs (to prevent forced intromission), both of which emphasize the conspicuous ventrolateral coloration. These apparently costly rejection behaviors did not reduce male harassment but did decrease the frequency of potentially costly copulations. These results suggest that 1) males do not determine female receptivity based on coloration alone and 2) the potentially costly rejection behaviors may have evolved to reduce the direct costs of mating.

JESSOP, T.S., CHAN, R. & D.M. STUART-FOX (2009): Sex steroid correlates of female-specific colouration, behaviour and reproductive state in Lake Eyre dragon lizards, Ctenophorus maculosus. – J. Comp. Physiol., 195A (7): 619-630.

In some species, females develop bright colouration to signal reproductive status and exhibit behavioural repertoires to incite male courtship and/or reduce male harassment and forced copulation. Sex steroids, including progesterone and testosterone, potentially mediate female reproductive colouration and reproductive behaviour. We measured associations among plasma proWles of testosterone and progesterone with variation in colour expression and reproductive behaviour, including unique courtship rejection behaviours, in female Lake Eyre dragon lizards, (Ctenophorus maculosus). At onset of breeding, progesterone and testosterone increased with vitellogenesis, coincident with colour intensiWcation and sexual receptivity, indicated by acceptance of copulations. As steroid levels peaked around the inferred ovulation time, maximal colour development occurred and sexual receptivity declined. When females were gravid and exhibited maximal mate rejection behaviours, progesterone levels remained consistently high, while testosterone exhibited a discrete second peak. At oviposition, signiWcant declines in plasma steroid levels, fading of colouration and a dramatic decrease in male rejection behaviours co-occurred. Our results indicate a generally concordant association among steroid levels, colouration, behaviour and reproductive events. However, the prolonged elevation in progesterone and a second peak of testosterone was unrelated to reproductive state or further colour change, possibly suggesting selection on females to retain high steroid levels for inducing rejection behaviours.


STORR, G.M. (1965): The Amphibolurus maculates species-group (Lacertilia, Agamidae) in Western Australia. – J. Royal Soc. West. Australia, 48 (2): 45-54.


Ctenophorus maculates maculatus (GRAY, 1831)

Spotted Sand-dragon / Spotted Dragon


Ctenophorus maculates badius (STORR, 1965)

Spotted Sand-dragon / Spotted Dragon

STORR, G.M. (1965): The Amphibolurus maculatus species-group (Lacertilia, Agamidae) in Western Australia. – J. Royal Soc. West. Australia, 48 (2): 45-54.

Ctenophorus maculates dualis (STORR, 1965)

Spotted Sand-dragon / Spotted Dragon

STORR, G.M. (1965): The Amphibolurus maculatus species-group (Lacertilia, Agamidae) in Western Australia. – J. Royal Soc. West. Australia, 48 (2): 45-54.


Ctenophorus maculates griseus (STORR, 1965)

Spotted Sand-dragon / Spotted Dragon

STORR, G.M. (1965): The Amphibolurus maculatus species-group (Lacertilia, Agamidae) in Western Australia. – J. Royal Soc. West. Australia, 48 (2): 45-54.

Ctenophorus maculosus (MITCHELL, 1948)

Salt-Lake Ground-dragon / Lake Eyre Dragon

Ctenophorus mckenziei STORR, 1981

Dwarf Bicycle-dragon

PETERSON, M., SHEA, G.M. & B. MILLER (1994): Notes on the morphology and biology of Ctenophorus mckenziei (Storr, 1981) (Squamata: Agamidae). – Transactons of the Royal Society of South Australia, 118 (3/4): 237.

STORR, G.M. (1981): Three new agamid lizards from Western Australia. – Rec. West. Aust. Mus., 8 (4): 599-607.

Ctenophorus nuchalis (DE VIS, 1884)

Australische Bodenagame / Central Netted Dragon,Central Netted Ground-dragon

BRADSHAW, S.D. & G. DE'ATH (1991): Variation in condition indices due to climatic and seasonal factors in an Australian desert lizard, Amphibolurus nuchalis. – Aust. J. Zool., 39 (4): 373-385.

The precise nature of the allometric relationships between body size and body mass, water content and solid matter was derived from a sample of over 700 lizards of the agamid species Amphibolurus nuchalis ( = Ctenophorus inermis), collected during 1969-82 at Shark Bay in Western Australia. Three condition indices relating each variable to body size, as expressed by snout-vent length, were derived from these allometric relationships for male, female and juvenile lizards. The formation of condition indices was compared to analysis of covariance as a method of analysis of such data. Variation in these indices with weather and season over the period of the study were investigated by means of regression models. Variation between days within trips was relatively small, suggesting a time scale for physiological change of greater than 3-4 days. Ascribing cause to specific weather and seasonal factors was difficult, due to the high colinearity of the explanatory variables. The influence of temperature and rainfall on the condition indices was evident in the model, however, and accords well with physiological data for this species. The extent to which the condition indices could be predicted by a combination of weather and seasonal variables was encouraging, and suggests that the method may have general utility in the study of changes in body composition and condition of free-ranging animals.

BRADSHAW, S.D., SAINT GIRONS, H. & F.J. BRADSHAW (1991): Patterns of breeding in two species of agamid lizards in the arid subtropical Pilbara region of Western Australia. – Gen. Comp. Endocr., 82: 407-422.

DALY, B.G., DICKMAN, C.R. & M.S. CROWTHER (2007): Selection of habitat components by two species of agamid lizards in sandridge desert, central Australia. – Aust. Ecol., 32 (7): 825-833.

The population dynamics of two species of agamid (dragon) lizards were studied in the Simpson Desert, central Australia, over a period of 7 years, and modelled in relation to rainfall. Both species have annual life cycles, with adults predominating during the breeding season in spring and summer and juveniles predominating in other seasons. Within years, juvenile abundance in both species in autumn and winter was related most strongly to rainfall in the preceding summer and autumn. This pattern suggests that rainfall enhances survival, growth and possibly clutch size and hatching success. Between years, however, rainfall drove successional change in the dominant plant species in the study area, spinifex Triodia basedowii, causing in turn a shift in the relative abundance of the two species. Thus, the central netted dragon Ctenophorus nuchalis was most numerous in 1990 when vegetation cover was <10%, but declined dramatically in abundance after heavy rainfall at the end of that year. In contrast, the military dragon C. isolepis achieved greatest abundance following heavy rains in the summers of 1990 and 1994, when spinifex cover increased to >20%, and remained numerically dominant for much of the study. We suggest that drought-wet cycles periodically reverse the dominance of the two species of Ctenophorus, and perhaps of other lizard species also, thus enhancing local species diversity over time. Further long-term studies are needed to document the population dynamics of other species, and to identify the factors that inuence them.

GARLAND, T.J.R. (1985): Ontogenetic and individual variation in size, shape and speed in the Australian agamid lizard Amphibolurus nuchalis. - J. Zool., Lond., A 207: 425-439.

The present study investigates relationships among size, shape and speed in the Australian agamid lizard Amphibolurus nuchalis. Maximal running speed, body mass, snout-vent length, tail length, fore- and hind limb spans and thigh muscle mass were measured in 68 field-fresh individuals spanning the entire ontogenetic size range (1.3 48 g). Relative lengths of both foreand hind limbs decrease with increasing body mass ( = negative allometry), whereas relative tail length and thigh muscle mass increase with body mass ( = positive allometry). Repeatable and significant differences in maximal running speed exist among individuals. Maximal running speed scales as (body mass)O'161, and 590,; of the variation in maximal speed was related to body mass. Based on the results of the present and previousstudies, data on scaling of body proportions alone appear inadequate to infer scaling relationships of functional characters such as top speed. Surprisingly, individual variation in maximal speed is not related to individual variation in shape (relative limb, tail and body lengths). These components of overall shape are not independent; individuals tended to have either relatively long or relatively short limbs, tails and bodies for their body mass. Even the significant difference in multivariate shape between adult males and females has no measurable consequences for maximal speed. Speeds of field-fresh animals did not vary on a seasonal basis, and eight weeks of captivity had no effect on maximal running speeds. Gravid females and long-term (obese) captive lizards were both approximately 12q; slower than field-fresh lizards.

HEATWOLE; H. (1970): Thermal ecology of the Desert dragon Amphibolurus inermis. – Ecol. Monogr., 40: 425-457.

KLAGES, H.G. (1982): Pflege und Nachzucht der australischen Bodenagame Amphibolurus nuchalis (Reptilia: Sauria: Agamidae). – Salamandra, Frankfurt/Main, 18 (1/2): 65-70. (00.074)

Zusammenfassung:
Es wird über die Haltung und erstmalige Nachzucht der Agame Amphibolurus nuchalis berichtet. Ein erstes Gelege wurde im September, weitere im Oktober und im November erhalten, von denen sich das erste als unbefruchtet erwies. Bei 27°C dauerte es 75 bis 79 Tage bis zum Schlupf der Jungen. In den ersten neun Tagen nach dem Schlupf wird keine Nahrung angenommen.

McFADDEN, M. & P.S. HARLOW (2007): Captive reproduction and longevity in tawny crevice (Ctenophorus decresii) and central netted dragons (C. nuchalis). - Herpetofauna (Sydney), 37 (1): 22-26.

NAGY, K.A. & S.D. BRADSHAW (1995): Energetics, osmoregulation, and food consumption by free-living desert lizards, Ctenophorus (= Amphibolurus) nuchalis. – Amphibia-Reptilia, 16 (1): 25-35.

RANKIN, P.R. (1977): Burrow plugging in the Netted Dragon Amphibolurus nuchalis with reports on the occurrence in three other Australian agamids. – Herpetofauna, Vic. Australia, 9 (1): 18-22.

RICE, G.E. & S.D. BRADSHAW (1980): Changes in dermal reflectance and vascularity and their effects on thermoregulation in Amphibolurus nuchalis (Reptilia: Agamidae). – J. Comp. Physiol., 135 (2): 139-146.

STERNFELD, R. (1919): Neue Schlangen und Echsen aus Zentralaustralien. - Senckenb. Biol., 1 (3): 76-83.

VIS, C.W. de (1884): On new species of Australian lizards. - Proc. Roy. Soc. Queensland, 1: 97-100.

Ctenophorus ornatus (GRAY, 1845)

Ornate Crevice-dragon / Ornate Dragon

BARBOUR, H.R., ARCHER, M.A., HART, N.S., THOMAS, N., DULOP, S.A., BEAZLEY, L.D. & J. SHAND (2002): Retinal characteristics of the ornate dragon lizard Ctenophorus ornatus. – J. Comp. Neurol., 450: 334-344.

BAVERSTOCK, P.R. (1975): Effect of variations in rate of growth on physiological parameters in the lizard Amphibolurus ornatus. – Comparative Biochem. Physiol. (A), 51 (3): 619-631.

BAVERSTOCK, P.R. (1978): The probable basis of the relationship between growth rate and winter mortality in the lizard Amphibolurus ornatus (Agamidae). - Oecologia (Heidelberg), 37 (1): 101-107.

BAVERSTOCK, P.R. & S.D. BRADSHAW (1975): Variation in rate of growth and adrenal corticosteroidogenesis in field and laboratory populations of the lizard Amphibolurus ornatus. – Comparative Biochem. Physiol. (A), 52 (3): 557-565.

BEAZLEY, L.D., SHEARD, P.W., TENNANT, M., STARAC, D. & S.A. DUNLOP (1997): Optic nerve regenerates but does not restore topographic projections in the lizard Ctenophorus ornatus. – Journal of Comparative Neurology, 377 (1): 105-120.

BRADSHAW, F.J. & S.D. BRADSHAW (1996): Arginine vasotocin: locus of action along the nephronj of the ornate dragon lizard, Ctenophorus ornatus. – General and Comparative Endocrinology, 103 (3): 281-289.

BRADSHAW, S.D. & SHOEMAKER, V.H. (1967): Aspects of water and electrolyte changes in a field population of Amphibolurus lizards. – Comp. Biochem. Physiol., 20: 855-865.

FERGUSSON, B., BRADSHAW, C.D. & J.R. CANNON (1985): Hormonal control of femoral gland secretion in the lizard, Amphibolurus ornatus. – Gen. Comp. Endocrinol., 57: 371-376.

HARLOW, P.S. (2000): Incubation temperature determines hatchling sex in Australian rock dragons (Agamidae: Genus Ctenophorus). – Copeia, 2000 (4): 958-964.

LeBAS, N.R. (2001): Microsatelite determionation of male reproductive success in a natural population of the territorial ornate dragon, Ctenophorus ornatus. – Mol. Ecol., 10: 193-203.

LeBAS, N.R. (2002): Mate choice, genetic incompatibility, and outbreeding in the ornate dragon lizard, Ctenophorus ornatus. – Evolution 56 (2): 371-377.

LeBAS, N.R. & N.J. MARSHALL (2000): The role of colour in signalling and male choice in the agamid lizard Ctenophorus ornatus. – Proc. R. Soc. London B. 267: 445-452.

LeBAS, N.R. & N.J. MARSHALL (2001): No evidence of female choice for a condition-depended trait in the Agamid lizard, Ctenophorus ornatus. – Behaviour 138: 965-980.Female choice has rarely been documented in reptiles. In this study we examined the variation, condition-dependence and female preference for a range of male morphological and colour traits in the agamid lizard, Ctenophorus ornatus. Colour traits were measured with reectance spectrophotometry which allows the accurate quanti. cation of colour traits independent of the human visual system. All the colour traits varied greatly in brightness but only the throat showed high variationin the spectral shape. For the morphological traits, chest patch size showed the highest amount of variation and was also condition-dependent.Males with a larger chest patch also had a patch which was a darker black. Female mate choice trials were conducted on male chest patch size and body size, which is the trait females have preferred in other lizard species. Females showed no preference, measured as spatial association, for larger males or males with bigger chest patches. In post-hoc tests females did not prefer males with brighter throats or darker chests. Our . ndings suggest that females show no spatial discrimination between males on the basis of a range of traits most expected to in influence female choice.

LeBAS, N.R. & P.B.S. SPENCER (2000): Polymorphic microsatellite markers in the ornate dragon lizard, Ctenophorus ornatus. - Molecular Ecology, 9 : 365–378.

LEVY, E., KENNINGTON, W.J., TOMKINS, J.L. & N.R. LeBAS (2010): Land clearing reduces gene flow in the granite outcrop-dwelling lizard, Ctenophorus ornatus. – Molec. Ecol., 19 (19): 4192-4203.

An important question for the conservation of species dwelling in fragmented habitats is whether changes to the intervening landscape create a barrier to gene flow. Here, we make use of the spatial distribution of the granite outcrop-dwelling lizard, Ctenophorus ornatus, to compare inferred levels of gene flow between outcrops in a nature reserve with that between outcrops in the adjacent agricultural land. Genetic variation, relatedness and subdivision were compared within groups of individuals from different outcrops similar in size and distance apart at each site. In the agricultural land, we found significantly lower genetic variation within outcrops and greater genetic differentiation between outcrops than in the reserve. Further, the rate at which genetic divergence between outcrops increased over geographical distance was significantly greater in the agricultural land than in the reserve. We also found that individuals were more closely related within outcrops but more distantly related between outcrops in the cleared land. These effects occur over a small spatial scale with an average distance between outcrops of less than five kilometres. Thus, even though land clearing around the outcrops leaves outcrop size unchanged, it restricts gene flow, reducing genetic variation and increasing population structure, with potentially negative consequences for the long-term persistence of the lizards on these outcrops.

LEVY, E., KENNINGTON, W.J., TOMKINS, J.L. & N.R. LeBAS (2012): Phylogeography and population genetic structure of the ornate dragon lizard, Ctenophorus ornatus. – PLOS One 7 (10): e46351: 1-11.

Species inhabiting ancient, geologically stable landscapes that have been impacted by agriculture and urbanisation are expected to have complex patterns of genetic subdivision due to the influence of both historical and contemporary gene flow. Here, we investigate genetic differences among populations of the granite outcrop-dwelling lizard Ctenophorus ornatus, a phenotypically variable species with a wide geographical distribution across the south-west of Western Australia. Phylogenetic analysis of mitochondrial DNA sequence data revealed two distinct evolutionary lineages that have been isolated for more than four million years within the C. ornatus complex. This evolutionary split is associated with a change in dorsal colouration of the lizards from deep brown or black to reddish-pink. In addition, analysis of microsatellite data revealed high levels of genetic structuring within each lineage, as well as strong isolation by distance at multiple spatial scales. Among the 50 outcrop populations’ analysed, non-hierarchical Bayesian clustering analysis revealed the presence of 23 distinct genetic groups, with outcrop populations less than 4 km apart usually forming a single genetic group. When a hierarchical analysis was carried out, almost every outcrop was assigned to a different genetic group. Our results show there are multiple levels of genetic structuring in C. ornatus, reflecting the influence of both historical and contemporary evolutionary processes. They also highlight the need to recognise the presence of two evolutionarily distinct lineages when making conservation management decisions on this species.

WILLIAMS, D.L. (2016): Regenerating reptile retinas: a comparative approach to restoring retinal ganglion cell function. - Eye, 31: 167-172.

Transection or damage to the mammalian optic nerve generally results in loss of retinal ganglion cells by apoptosis. This cell death is seen less in fish or amphibians where retinal ganglion cell survival and axon regeneration leads to recovery of sight. Reptiles lie somewhere in the middle of this spectrum of nerve regeneration, and different species have been reported to have a significant variation in their retinal ganglion cell regenerative capacity. The ornate dragon lizard Ctenophoris ornatus exhibits a profound capacity for regeneration, whereas the Tenerife wall lizard Gallotia galloti has a more variable response to optic nerve damage. Some individuals regain visual activity such as the pupillomotor responses, whereas in others axons fail to regenerate sufficiently. Even in Ctenophoris, although the retinal ganglion cell axons regenerate adequately enough to synapse in the tectum, they do not make long-term topographic connections allowing recovery of complex visually motivated behaviour. The question then centres on where these intraspecies differences originate. Is it variation in the innate ability of retinal ganglion cells from different species to regenerate with functional validity? Or is it variances between different species in the substrate within which the nerves regenerate, the extracellular environment of the damaged nerve or the supporting cells surrounding the regenerating axons? Investigations of retinal ganglion cell regeneration between different species of lower vertebrates in vivo may shed light on these questions. Or perhaps more interesting are in vitro studies comparing axon regeneration of retinal ganglion cells from various species placed on differing substrates.

Ctenophorus pictus PETERS,1866

Painted Grounnd-dragon / Painted Dragon

HANSSON, A. & M. OLSSON (2018): Incubation temperature and parental identity determine sex in the Australian agamid lizard Ctenophorus pictus. – Ecol. Evol., 2018, 8: 9827–9833.

Sex determination in Australian agamid lizards shows a complex framework of different mechanisms, varying even among closely related taxa. It is clear that discrete classification of these species as either having genetic (GSD) or environmental sex determination (ESD) does not agree with empirical data. Although many species in this group show temperature-dependent sex determination (TSD), recent evidence suggests additional genetic or epigenetic effects. A proposed model explaining the adaptive significance and evolution of TSD in short-lived agamids predicts that selection will favor temperature-biased sex ratios in species with intense male-male competition. Here, we use experimental incubation at (near) constant temperatures to test whether the sex of Australian painted dragons (Ctenophorus pictus) is influenced by temperature, building on previous research yet to have reached an agreement regarding the role of temperature in this species. In this study, incubation temperature and parental identity affected hatchling sex suggesting that environment and genetics may work in concert to determine sex in this species. Although our results are consistent with TSD, our data cannot rule out a temperature-by-sex effect on egg or hatchling mortality. However, our findings together with the observed differences of sex determination systems in closely related species within this genus may provide novel opportunities to address fundamental questions in the evolution of sex determination systems.

HEALEY, M. & M. OLSSON (2008): Territory acquisition in a polymorphic lizard: an experimental approach. – Aust. Ecol., 33 (8): 1015-1021.

Males of the colour polymorphic Australian painted dragon lizard Ctenophorus pictus occur in red or yellow head colouration. In a previous experiment, we showed that red is associated with a higher probability of winning staged contests for resources (females or space) and that manipulation of male colouration by painting males in the opposing morph changed the dynamics of staged interactions by prolonging them 30-fold. Thus, colour is linked to behavioural differences between males and is involved in information transfer between competing males.This inherent red dominance could result in yellow males being marginalized to poorer quality territories in terms of access to females, food, perch sites or shade. With an experiment in the wild, we test to what extent this prediction is upheld, and how colour manipulation affects morph-specific success in territory acquisition when male body size, territory quality and emergence time from hibernation are controlled through manipulation or randomization. There was no significant effect of colour category per se, although on average red males remained closer to the release sites (our proxy for territory acquisition ability) than yellow males and artificially altered morphs moved the furthest away. There was a significant interaction effect between colour category and experimental release position, which may be linked to differences in how exposed (or not) these positions were and morph-specific ability to cope with such exposure (e.g. ‘boldness’). Our data show that territory acquisition success is not merely a function of competitive ability but a composite outcome of a suite of factors, including signal perception.

HEALEY, M. & M. OLSSON (2009): Too big for his boots: Are social costs keeping condition-dependent status signalling honest in an Australian lizard? – Aust. Ecol., 34 (6): 636-640.

Australian painted dragon lizards Ctenophorus pictus occur in three head colours (red, orange and yellow) that differ in their level of aggression (reds being most aggressive), hormone profile (reds having higher testosterone levels) and in their frequency in our study population over time. They are also polymorphic in bib colour; some males have a bright yellow area under the chin, while others lack this coloured area entirely. We show that red males with a bib are in better body condition than red males that lack a bib.This contrasts sharply to yellow males, in which males with a bib are in poorer condition than yellow males that lack a bib. Our analysis also shows that following exposure to a high percentage of red (more aggressive) neighbours, all males suffer a reduction in body condition, and importantly, males with a bib (regardless of their head colour) suffer a more severe loss of body condition than males that lack a bib. Finally, this condition loss is significantly higher for yellow bibbed males than for red bibbed males, suggesting that the cost of sporting a bib may be higher for them. Orange males showed a non-significant difference in condition between bib morphs. Our analysis also shows that bibbed yellow males (the morph with lower body condition), but no other morph category, declined significantly in their frequency between 2 years.

HEALEY, M. & M. OLSSON (2009): Vitamin E does not elevate survival in free-ranging lizards. – Copeia, 2009 (2): 339-341.

Free radical theory predicts that the unavoidable production of reactive molecules as a by-product of the respiratory transport chain will pathologically affect organismal function and fitness and lead to disease and a shortened life span. This suggests that free radical production may be linked to metabolic rate, which in turn relates to foraging strategies and intrinsic growth rate and could therefore be important for directing the evolution of life histories. We designed an experiment in which young lizards (Australian Painted Dragons, Ctenophorus pictus) received an implant with a- Tocophorol (Vitamin E) or control vehicle (cocoa butter). They were released into the wild and monitored for survival. Recapture rate was eight per cent for vitamin E-treated lizards and 16 per cent for controls, resulting in no significant difference in probability of being recaptured. We discuss the importance of dose-dependence and context-dependent effects of this supplementation and outline other physiological factors that may be driving mortality rates in young lizards.

HEALEY, M., ULLER, T. & M. OLSSON (2007): Seeing red: morph-specific contest success and survival rates in a colour-polymorphic agamid lizard. – Anim. Behav., 74 (2): 337-341.

Red coloration in multicoloured or polymorphic species has been associated with dominance in a number of case studies, including probability of winning in human sports. However, it is not clear at what stage during ontogeny the association between red and the probability of winning contests occurs (or being perceived as more threatening by a contradistinct rival), for example, at conception, early ontogeny or at maturation. We analysed such coloration effects in a polymorphic (red versus yellow) species of lizard, the Australian painted dragon, Ctenophorus pictus. Red males were more likely to win dyadic contests with yellow males when competing for receptive females. When contestants were repainted with a rival’s colour, there was a more than 30-fold increase in contest duration. Furthermore, when we tested for red-enhanced contest success in immature males, red was still significantly associated with winning. Thus, the association between red coloration and dominance seems to be set long before a male is naturally involved in sexual contests and could be an innate response to aid facultative fight or submission decisions, particularly in young males. To assess in situ selective benefits of the polymorphism, we released males in polymorphic and monomorphic groups. Males from polymorphic groups survived better, implying that polymorphism among neighbouring territorial males in the wild results in selective benefits.

JANSSON, N., ULLER, T. & M. OLSSON (2005): Female dragons, Ctenophorus pictus, do not prefer scent from unrelated males. – Aust. J. Zool., 53 (5): 279-282.

Female choice for genetic complementarity or unrelated males occurs in several vertebrate taxa, but only a few species per higher-order taxon have so far been studied. This is particularly the case in reptiles, where female choice traditionally has been considered to be less important than in most other vertebrates. Many species of reptiles use scent marking in relation to territory use and, consequently, females may use this information to avoid settling on genetically incompatible (e.g. related) males’ territories. We tested the response of female Australian dragon lizards, Ctenophorus pictus, to pheromones from closely related and unrelated males. Contrary to predictions, females did not prefer to associate with scent from unrelated males. The reason for the lack of differential response to related and unrelated males could be explained by weak selection against inbreeding, high dependence on visual cues, female control over copulation, or post-copulatory female choice. Alternative hypotheses are discussed in relation to the biology of the species and lizard biology in general.

MAYHEW, W.W. (1963): Observations on captive Amphibolurus pictus an Australian agamid lizard. - Herpetologica, 19 (2): 81-88. (1160)

NIEJALKE, D.P. (2006): Reproduction by a small agamid lizard, Ctenophorus pictus, during contrasting seasons. – Herpetologica, 62 (4): 409-420.

Reproduction in a population of painted dragons, Ctenophorus pictus (Agamidae), in semi-arid South Australia was studied over two years with distinctly contrasting climatic conditions. Data were collected from wild lizards to assess the influence of inter- and intra-seasonal conditions on reproductive characters of the small, short-lived lizard during a very wet year and a season with average rainfall. Females began to develop ova at the end of winter (August) and laid eggs during the spring and early summer, coinciding with the period of testicular enlargement in males. Potentially four, or possibly more, clutches of 2 to 4 eggs (mean 2.6) were produced by females each year. Egg moisture content varied considerably and ranged between 45 and 79% (mean 66%) of total egg mass. Eggs contained less moisture in the wet year (1992-93). Females containing oviducal eggs were marginally larger in the wet year of 1992-93 than in 1991-92. Eggs collected late in the reproductive season were significantly larger than those collected earlier. A 'parental investment' model can be used to explain this intra-seasonal shift in egg size. When adjustments for female size were made, reproductive investment was consistent between the two years of the study, with no difference in egg mass, clutch mass or clutch size detected. The reproductive strategy of C. pictus remained remarkably invariant considering the dramatic difference in climatic conditions between the two years of the study

OLSSON, M., HEALEY, M., WAPSTRA, E. & T. ULLER (2009): Testing the quality of a carrier: a field experiment on lizard signalers. – Evolution, 63 (3): 695-701.

OLSSON, M., SCHWARTZ, T., ULLER, T. & M. HEALEY (2007): Sons are made from old stores: sperm storage effects on sex ratio in a lizard. – Biol. Lett., 3 (5): 491-493.

Sperm storage is a widespread phenomenon across taxa and mating systems but its consequences for central fitness parameters, such as sex ratios, has rarely been investigated. In Australian painted dragon lizards (Ctenophorus pictus), we describe elsewhere that male reproductive success via sperm competition is largely an effect of sperm storage. That is, sperm being stored in the female reproductive tract outcompete more recently inseminated sperm in subsequent ovarian cycles. Here we look at the consequences of such sperm storage for sex allocation in the same species, which has genetic sex determination. We show that stored sperm have a 23% higher probability of producing sons than daughters. Thus, shifts in sex ratio, for example over the reproductive season, can partly be explained by different survival of sonproducing sperm or some unidentified female mechanism taking effect during prolonged storage.

OLSSON, M., SCHWARTZ, T., ULLER, T. & M. HEALEY (2009): Effects of sperm storage and male colour on probability of paternity in a polychromatic lizard. – Anim. Behav., 77 (2): 419-424.

Sexual selection may take place before or after mating and may involve a large number of different mechanisms, for example, overt male aggression, mate choice, sperm competition and cryptic female choice. In most species, males show similar reproductive tactics and, hence, achieve their reproductive success in the same or a similar way. Sometimes, however, males evolve alternative reproductive tactics. One such example is the polychromatic Australian painted dragon lizard, Ctenophorus pictus, in which red males beat yellow males in staged contests for females and show different emergence patterns posthibernation in the wild with red males emerging to establish territories before yellow males do (at least in some years). Here we show that yellow males have significantly larger testes in relation to body size and condition than red males and copulate for a shorter period of time. Our mating experiments further showed that sperm storage played a significant role in male reproductive success (i.e. males sired offspring in later ovarian cycles than the one in which they actually mated). Furthermore, yellow males had a three times higher probability of paternity in some situations of sperm competition than red males, suggesting that male polymorphism may be associated with different reproductive tactics.

OLSSON, M., WAPSTRA, E., HEALEY, M., SCHWARTZ, T. & T. ULLER (2008): Selection on space use in a polymorphic lizard. – Evol. Ecol. Res., 10 (4): 621-627.

Background: Polymorphism within the same species, population, and sex is an interesting problem for the evolutionary biologist, since differences in fitness between the morphs have to cancel out over evolutionary time, otherwise morphs of lower fitness would become extinct. One way this may be achieved is through the adoption of different morph-specific reproductive strategies, allowing morphs to become conditional specialists in space (co-existing) or in time (and cycle in frequency). In either case, we expect selection to be disruptive on data pooled across morphs. Question: In the annual Australian painted dragon lizard (Ctenophorus pictus; less than 10% survive to a second year), red males dominate yellow males in staged contests, and yellow males (sneakers) are superior in sperm competition trials. Here, we ask whether there is ongoing disruptive selection for red males to defend well-defined, smaller territories (dominants) and for yellow males to have larger, more loosely defined territories (sneakers). Methods: We monitored free-ranging lizards in a natural population, assigned paternity using microsatellites, and calculated selection coefficients to assess ongoing sexual directional and quadratic selection on territory size. Results and conclusions: Despite the different reproductive strategies, selection on space use in a natural population was not disruptive in either of the two years studied. Instead, there was no difference in territory size between morphs, and in one year there was ongoing directional (positive) and quadratic (stabilizing) selection on territory size applying across both morphs. Thus, divergence of male reproductive strategies in C. pictus does not seem to be related to differences in space use.

ROSE, R.J. & J. MELVILLE (2006): A new technique for measuring body color of lizards in the field. - Herpetol. Rev., 37 (2): 191-194.

RUEHLE, R. (1968): The painted dragon. – Wildl. Aust., 5: 40-42.

TOBLER, M., HEALEY, M. & M. OLSSON (2011): Digit ratio, color polymorphism and egg testosterone in the Australian painted dragon. - PLoS ONE, 6 (1): e16225, 1-7.

Variation in exposure to sex hormones during early development contributes to phenotypic plasticity in vertebrate offspring. As a proposed marker for prenatal sex hormone exposure and because of their association with various physiological and behavioral characteristics, digit ratio and/or digit length have received notable interest within the field of evolutionary ecology. However, the validity of digit measures as a proxy of prenatal sex hormone exposure is controversial and only few studies have provided direct evidence for the link between digit development and prenatal sex hormones. Here, we report morph- and sex-specific variation in digit ratio in wild painted dragon lizards (Ctenophorus pictus). Lizards expressing a yellow bib have significantly larger third-to-fourth toe ratios (3D:4D) than lizards without a bib. Males have significantly smaller 3D:4D than females. Furthermore, we show that experimental elevation of yolk testosterone significantly increases 3D:4D in hatchling painted dragon lizards, but has no influence on hatchling size. Our results provide direct and indirect evidence for the involvement of prenatal sex steroids in digit development and it is suggested that digit ratio may be used as a biomarker for prenatal steroid exposure in this reptilian species. As such, digit ratio may provide a useful tool to study temporal or spatial differences in the proximate hormonal mechanisms modulating physiological and behavioural phenotypes.

TOBLER, M., HEALEY, M. & M. OLSSON (2012): Digit ratio, polychromatism and associations with endurance and antipredator behaviour in male painted dragon lizards. – Anim. Behav., 84 (5): 1261-1269.

Variation in sex hormone exposure during early embryonic development contributes to individual differences in behaviour and cognitive abilities later in life. Digit ratio has gained considerable interest as a putative marker for early androgen/oestrogen exposure in behavioural ecology research. Studying digit ratio in nonhuman laboratory as well as wild vertebrate species may be useful to assess whether different traits may be influenced by a common (e.g. endocrine-related) mechanism and whether digit ratio might be used as a phenotypic indicator for behavioural or fitness-related traits. We examined whether digit ratio (third-to-fourth toe ratio; 3D:4D) may indicate a common mechanism underlying endurance and antipredator behaviour in male painted dragon lizards, Ctenophorus pictus. We have previously shown that 3D:4D is associated with the presence/absence of a yellow throat patch (bib), with males with bibs having higher 3D:4D than those without bibs. In this study we found that 3D:4D predicted antipredator behaviour with individuals with higher 3D:4D having shorter escape response times; however, 3D:4D was not associated with endurance. Endurance and antipredator behaviour were also associated with male coloration. Males expressing a bib had shorter escape response times and lower endurance than those without a bib. Moreover, males with orange head colour had lower endurance compared to yellow-headed and uncoloured males. On the basis of these results, we speculate that the associations between antipredator behaviour, endurance, 3D:4D and male sexual coloration are caused, at least partly, by different underlying mechanisms.

ULLER, T., MOTT, B., ODIERNA, G. & M. OLSSON (2006): Consistent sex ratio bias of individual female dragon lizards. – Biol. Lett., 2 (4): 569-572.

Sex ratio evolution relies on genetic variation in either the phenotypic traits that influence sex ratios or sex-determining mechanisms. However, consistent variation among females in offspring sex ratio is rarely investigated. Here, we show that female painted dragons (Ctenophorus pictus) have highly repeatable sex ratios among clutches within years. A consistent effect of female identity could represent stable phenotypic differences among females or genetic variation in sex-determining mechanisms. Sex ratios were not correlated with female size, body condition or coloration. Furthermore, sex ratios were not influenced by incubation temperature. However, the variation among females resulted in female-biased mean population sex ratios at hatching both within and among years.

ULLER, T. & M. OLSSON (2005): Continuous male presence required for fertilization in captive painted dragons, Ctenophorus pictus. – J. Exp. Zool., 303A (12): 1115-1119.

Understanding proximate determinants of reproductive events is an important issue for many biologists. In the present paper, we show that follicular recruitment and fertilization are dependent on male stimuli in long-term captive female painted dragon lizards, Ctenophorus pictus. Hibernated females kept separated from males did not initiate reproduction, despite visual contact with displaying males and repeated copulation attempts. Follicular stimulating hormone stimulated ovarian growth and female receptivity, but did not result in successful fertilization of eggs, despite repeated copulations. When housed continuously together with males, however, follicle recruitment and fertilization were achieved. Thus, not only ovarian growth, but also fertilization, is dependent on male stimuli.

Ctenophorus reticulatus GRAY, 1845

Western Netted Ground-dragon / Western Netted Dragon

BELL, C.J., MEAD, J.I. & M. HOLLENSHEAD (2009): Sand shimmying as predator avoidance behaviour in two agamid lizards, Ctenophorus reticulatus and Ctenophorus femoralis. – West. Aust. Nat., 27 (1): 54-55.

DOODY, J.S., CHERRIMAN, S. & J. TURPIN (2015): Natural history notes: Ctenophorus reticulatus (Western Netted Dragon), Ctenophorus caudicinctus (Ring-tailed Dragon), and Egernia eos (Central Pygmy Spiny-tailed Skink). predation. – Herpetol. Rev., 46 (3): 433.

GOLDBERG, S.R. (2009): Notes on reproduction of the Mulga dragon, Caimanops amphiboluroides, and the western netted dragon, Ctenophorus reticulatus, (Squamata: Agamidae) from Western Australia. – Bull. Chic. Herp. Soc., 44 (7): 114-115.

Histological analyses were conducted on gonadal material of two Australian agamid lizards, Caimanops amphiboluroides and Ctenophorus reticulatus. Caimanops amphiboluroides males from December and February were undergoing spermiogenesis. Females of C. amphiboluroides from December contained eight and ten enlarged follicles (> 4 mm), respectively. Ctenophorus reticulatus males from October, December, January and May were undergoing spermiogenesis. One female C. reticulatus from October contained corpora lutea from a previous egg clutch and concomitant yolk deposition for a subsequent clutch indicating production of multiple clutches in the same reproductive season. It appears the reproductive cycles of C. amphiboluroides and C. reticulatus most closely fit the Type I category of Heatwole and Taylor (1987) in which spermatogenesis and ovulation occur in spring.

PIANKA, E.R. (2014): Notes on the ecology and natural history of Ctenophorus reticulatus (Agamidae) in Western Australia. – Western Australian Naturalist, 30: 222-225.

Ecological data on the agamid Ctenophorus reticulatus are presented. Active early and late in the day during summer, they thermoregulate actively with an average body temperature of 34.1°C (N=34). These agamid lizards dig their own burrows, which are used as retreats. They are omnivorus dietary generalists eating ants and termites as well as plant materials. Clutch size varies from 3 to 6, averaging 4. Adult males are larger than females.

STORR, G.M. (1966): The Amphibolurus reticulates species group (Lacertilia, Agamidae) in Western Australia. – J. Proc. Roy. Soc. W.Aust., 49: 17-25.

WHITE, S.R. (1949): Some notes on the netted dragon lizard (Amphibolurus reticulates). – West Aust. Nat. Perth, 1 (8): 157-161.

Ctenophorus rufescens (STIRLING& ZIETZ,1893)

Rusty Crevice-dragon

STIRLING, E.C. & A. ZIETZ (1893): Description of Ctenophorus rufescens. – In: Scientific results of the Elder Exploring Expedition. Vertebrata. Mammalia, Reptilia. - Transactions of the Royal Society of South Australia, 16: 154-176.

Ctenophorus salinarum STORR,1966

Saltpan Ground-dragon

STORR, G.M. (1966): The Amphibolurus reticulates species group (Lacertilia, Agamidae) in Western Australia. – J. Proc. Roy. Soc. W.Aust., 49: 17-25.

Ctenophorus scutulatus (STIRLING & ZIETZ, 1893)

Lozenge-marked Bicycle-dragon / Lozenge-Marked Dragon

BOULENGER, G.A. (1904): Description of a new lizard from Western Australia. – Ann. Mag. Nat. Hist., (7) 14: 414-415.

GOLDBERG, S.R. (2007): Notes on reproduction of the lozenge-marked bicycle-dragon, Ctenophorus scutulatus and the canegrass two-line dragon, Diporiphora winneckei (Squamata: Agamidae) from Western Australia. – Bull. Mary. Herp. Soc., 43 (1): 1-3.

PIANKA, E.R. (1971): Notes on the biology of Amphibolurus cristatus and Amphibolurus scutulatus. – West. Aust. Nat., 12: 36-41.

ROSEN, N. (1905): List of the lizards in the Zoological Museum of Lund, with descriptions of new species. – Ann. Mag. Nat. Hist., (7) 16: 129-142.

STIRLING, E.C. & A. ZIETZ (1893): Description of Ctenophorus scutulatus – In: Scientific results of the Elder Exploring Expedition. Vertebrata. Mammalia, Reptilia.  - Transactions of the Royal Society of South Australia, 16: 154-176.

Ctenophorus tjantjalka JOHNSTON, 1992

JOHNSTON, G.R. (1992): Ctenophorus tjantjalka, a new dragon lizard (Lacertilia: Agamidae) from northern South Australia. –Records of the South Australian Museum (adelaide), 26 (1): 51-59.

Ctenophorus tuniluki EDWARDS & HUTCHINSON, 2023

Southern Mallee Dragon

EDWARDS, D., & HUTCHINSON, M. 2023. Sand Dragons: Species of the Ctenophorus maculatus Complex (Squamata: Agamidae) of Australia's Southern and Western Interior. Journal of Herpetology 57 (2): 176-196

Ctenophorus vadnappa HOUSTON, 1974

Red-barred Crevice-dragon

HOUSTON, T.F. (1974): Revision of the Amphibolurus decresii complex (Lacertilia: Agamidae) of South Australia. – Transactions R. Soc. S. Aust., 98 (2): 49-60.

STUART-FOX, D.M. & G.R. JOHNSTON (2005): Experience overrides colour in lizard contests. – Behaviour, 142 (3): 329-350.

Ctenophorus yinnietharra STORR,1981

Yinnietharra Crevice-dragon

STORR, G.M. (1981): Three new agamid lizards from Western Australia. – Rec. West. Aust. Mus., 8 (4): 599-607.

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