Population structure, growth and reproduction in two species of Tympanocryptis (Agamidae)

Lyn Nelson; Paul D. Cooper

doi:10.1071/ZO24034

RESEARCH ARTICLE (Open Access)

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Population structure, growth and reproduction in two species of Tympanocryptis (Agamidae)

Lyn Nelson ^A and Paul D. Cooper

^A ^*

+ Author Affiliations

- Author Affiliations

^A Research School of Biology, The Australian National University, Canberra, ACT, Australia.

^* Correspondence to: paul.cooper@anu.edu.au

Handling Editor: Steven Cooper

Australian Journal of Zoology 73, ZO24034 https://doi.org/10.1071/ZO24034

Submitted: 6 November 2024 Accepted: 14 April 2025 Published: 1 May 2025

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Two threatened species of Tympanocryptis (T. lineata and T. osbornei) (the grassland earless dragon clade) are compared for population structure, growth and reproduction from sites around the Australian Capital Territory (ACT) and near Cooma in New South Wales (NSW). Both species showed similar proportions of adults, intermediates and juveniles, as well as similar proportions of adult males and females. Growth patterns had a rapid increase in snout–vent length (SVL) in juveniles. Predicted adult SVL was the same in both species, and females in both species had greater SVL than males. In one year, the appearance of juveniles in the populations was later in T. osbornei than in T. lineata, but that may have been a result of cooler temperatures in the austral summer. Body condition was slightly better in adults of T. osbornei than T. lineata as the former were heavier and shorter. Longevity in the field was similar for both species, being slightly greater than two years, but reproduction may have occurred only once during their lifetime. Colouration associated with reproduction appeared to be the same for both species. Future work can use this information to determine how populations of Tympanocryptis sp. vary in response to environmental changes.

Keywords: conservation ecology, earless dragons, endangered species, grassland habitats, herpetology, life history, lizard biology, population biology.

References

Adolph SC, Porter WP (1993) Temperature, activity, and lizard life histories. The American Naturalist 142(2), 273-295.
| Crossref | Google Scholar | PubMed |

Adolph SC, Porter WP (1996) Growth, seasonality, and lizard life histories: age and size at maturity. Oikos 77(2), 267-278.
| Crossref | Google Scholar |

Andrews RM (1982) Patterns of growth in reptiles. In ‘Biology of the reptilia. Vol. 13’. (Eds C Gans, FH Pough) pp. 273–320. (Academic Press: New York)

Anonymous (2023) Draft national recovery plan for four grassland earless dragons (Tympanocryptis spp.) of southeast Australia. Department of Climate Change, Energy, the Environment and Water, Commonwealth of Australia, Canberra.

Atkinson D (1996) Ectothermal life-history responses to developmental temperature. In ‘Animals and temperature: phenotypic and evolutionary adaptation’. (Eds IA Johnston, AF Bennett) pp. 183–204. (Cambridge University Press: New York)

Ballinger RE (1979) Intraspecific variation in demography and life history of the lizard, Sceloporus jarrovi, along an altitudinal gradient in southeastern Arizona. Ecology 60(5), 901-909.
| Crossref | Google Scholar |

Ballinger RE, Congdon JD (1981) Population ecology and life history strategy of a montane lizard (Sceloporus scalaris) in southeastern Arizona. Journal of Natural History 15(2), 213-222.
| Crossref | Google Scholar |

Bauwens D, Diaz-Uriarte R (1997) Covariation of life-history traits in lacertid lizards: a comparative study. The American Naturalist 149(1), 91-111.
| Crossref | Google Scholar |

Bennett AF, Nagy KA (1977) Energy expenditure in free-ranging lizards. Ecology 58(3), 697-700.
| Crossref | Google Scholar |

Brown G (1988) The diet of Leiolopisma entrecasteauxii (Lacertilia, Scincidae) from southwestern Victoria, with notes on its relationship with the reproductive-cycle. Australian Wildlife Research 15(6), 605-614.
| Crossref | Google Scholar |

Bureau of Meteorology (1996–2003) Climate data online. Commonwealth of Australia. Available at http://bom.gov.au/climate/data/ [accessed 15 January 2025]

Christian KA, Tracy CR, Porter WP (1984) Physiological and ecological consequences of sleeping-site selection by the Galapagos land iguana (Conolophus pallidus). Ecology 65(3), 752-758.
| Crossref | Google Scholar |

Congdon JD, Dunham AE, Tinkle DW (1982) Energy budgets and life histories of reptiles. In ‘Biology of reptiles. Vol. 13’. (Eds C Gans, FH Pough) pp. 233–271. (Academic Press: New York)

Doucette LI, Duncan RP, Osborne WS, Evans M, Georges A, Gruber B, Sarre SD (2023) Climate warming drives a temperate-zone lizard to its upper thermal limits, restricting activity, and increasing energetic costs. Scientific Reports 13, 9603.
| Crossref | Google Scholar | PubMed |

Duffield GA, Bull CM (1996) Characteristics of the litter of the gidgee skink, Egernia stokesii. Wildlife Research 23(3), 337-341.
| Crossref | Google Scholar |

Dunham AE, Overall KL (1994) Population responses to environmental change: life history variation, individual-based models, and the population dynamics of short-lived organisms. American Zoologist 34(3), 382-396.
| Crossref | Google Scholar |

Forsman A, Shine R (1995) Parallel geographic variation in body shape and reproductive life history within the Australian scincid lizard Lampropholis delicata. Functional Ecology 9(6), 818-828.
| Crossref | Google Scholar |

Gould J, Beranek C, Madani G (2023) Dragon detectives: citizen science confirms photo-ID as an effective tool for monitoring an endangered reptile. Wildlife Research 51, WR23036.
| Crossref | Google Scholar |

Heatwole H, Taylor J (1987) ‘Ecology of reptiles.’ (Surrey Beatty and Sons Chipping Norton)

Langston AC (1996) The ecology and distribution of Tympanocryptis lineata pinguicolla (southern lined earless dragon) in the Australian Capital Territory, Canberra. Honours Thesis, University of Canberra, Canberra.

Madani G, Pietsch R, Beranek C (2023) Where are my dragons? Replicating refugia to enhance the detection probability of an endangered cryptic reptile. Acta Oecologica 119, 103910.
| Crossref | Google Scholar |

Mathies T, Andrews RM (1995) Thermal and reproductive biology of high and low elevation populations of the lizard Sceloporus scalaris: implications for the evolution of viviparity. Oecologia 104, 101-111.
| Crossref | Google Scholar | PubMed |

McGrath T, Guillera-Arroita G, Lahoz-Monfort JJ, Osborne W, Hunter D, Sarre SD (2015) Accounting for detectability when surveying for rare or declining reptiles: Turning rocks to find the grassland earless dragon in Australia. Biological Conservation 182, 53-62.
| Crossref | Google Scholar |

Melbourne BA (1993) The assessment of insect biodiversity. A case study: ants and carabid beetles in grasslands of the ACT. Honours Thesis, The Australian National University, Canberra.

Melville J, Goebel S, Starr C, Keogh JS, Austin JJ (2007) Conservation genetics and species status of an endangered Australian dragon, Tympanocryptis pinguicolla (Reptilia: Agamidae). Conservation Genetics 8, 185-195.
| Crossref | Google Scholar |

Melville J, Chaplin K, Hutchinson M, Sumner J, Gruber B, MacDonald AJ, Sarre SD (2019) Taxonomy and conservation of grassland earless dragons: new species and an assessment of the first possible extinction of a reptile on mainland Australia. Royal Society Open Science 6(5), 190233.
| Crossref | Google Scholar | PubMed |

Mitchell FJ (1948) A revision of the lacertilian genus Tympanocryptis. Records of the South Australian Museum 9, 57-86.
| Google Scholar |

Nelson L (2004) Thermal ecology and implications for life history variation in Tympanocryptis pinguicolla (grassland earless dragon). Ph.D thesis, The Australian National University.

Nelson LS, Cooper PD (2017) Seasonal effects on body temperature of the endangered grassland earless dragon, Tympanocryptis pinguicolla, from populations at two elevations. Australian Journal of Zoology 65(3), 165-178.
| Crossref | Google Scholar |

Nelson LS, Smith WJS, Goldie R (1996) 1996 Survey program for the eastern lined earless dragon (Tympanocryptis lineata pinguicolla). ACT Parks and Conservation Service, Canberra.

Nelson LS, Bensley N, Edwards S, Pinner L, West P (1998a) 1998 Survey and monitoring program for the eastern lined earless dragon, Tympanocryptis lineata pinguicolla, in the Majura and Jerrabomberra Valleys, ACT. ACT Department of Urban Services, Canberra.

Nelson LS, Goodisson TE, Morris BJ (1998b) 1997 Survey and monitoring program for the eastern lined earless dragon (Tympanocryptis lineata pinguicolla). ACT Department of Urban Services, Canberra.

Osborne WS, Kukolic K, Davis MS, Blackburn R (1993) Recent records of the earless dragon Tympanocryptis lineata pinguicolla in the Canberra region and a description of its habitat. Herpetofauna 23, 16-25.
| Google Scholar |

Qualls FJ, Shine R (1998) Geographic variation in lizard phenotypes: importance of the incubation environment. Biological Journal of the Linnean Society 64(4), 477-491.
| Crossref | Google Scholar |

Ratkowsky DA (1983) ‘Nonlinear regression modelling.’ (Marcel Dekker: New York)

Robertson P, Cooper P (2000) Grassland earless dragon Tympanocryptis pinguicolla national recovery plan 2000–2004. Environment Australia, biodiversity group, The Australian National University: Canberra.

Rohr DH (1997) Demographic and life-history variation in two proximate populations of a viviparous skink separated by a steep altitudinal gradient. Journal of Animal Ecology 66(4), 567-578.
| Crossref | Google Scholar |

Scott IAW, Keogh JS (2000) Conservation genetics of the endangered grassland earless dragon Tympanocryptis pinguicolla (Reptilia: Agamidae) in southeastern Australia. Conservation Genetics 1, 357-363.
| Crossref | Google Scholar |

Shine R (1980) “Costs” of reproduction in reptiles. Oecologia 46, 92-100.
| Crossref | Google Scholar | PubMed |

Shine R (1995) A new hypothesis for the evolution of viviparity in reptiles. The American Naturalist 145, 809-823.
| Crossref | Google Scholar |

Shine R, Harlow PS (1996) Maternal manipulation of offspring phenotypes via nest-site selection in an oviparous lizard. Ecology 77(6), 1808-1817.
| Crossref | Google Scholar |

Sinervo B, Adolph SC (1989) Thermal sensitivity of growth rate in hatchling Sceloporus lizards: environmental, behavioral and genetic aspects. Oecologia 78, 411-419.
| Crossref | Google Scholar | PubMed |

Smith WJS (1994) The ecology and taxonomy of the southern lined earless dragon (Tympanocryptis lineata pinguicolla). Honours Thesis. The Australian National University, Canberra.

Smith WJS, Osborne WS, Donnellan SC, Cooper PD (1999) The systematic status of earless dragon lizards, Tympanocryptis (Reptilia: Agamidae), in south-eastern Australia. Australian Journal of Zoology 47(6), 551-564.
| Crossref | Google Scholar |

Stevens TA, Evans MC, Osborne WS, Sarre SD (2010) Home ranges of, and habitat use by, the grassland earless dragon (Tympanocryptis pinguicolla) in remnant native grasslands near Canberra. Australian Journal of Zoology 58(2), 76-84.
| Crossref | Google Scholar |

Tsuji JS (1988) Thermal acclimation of metabolism in Sceloporus lizards from different Latitudes. Physiological Zoology 61(3), 241-253.
| Crossref | Google Scholar |

Van Damme R, Bauwens D, Braña F, Verheyen RF (1992) Incubation temperature differentially affects hatching time, egg survival and sprint speed in the lizard Podarcis muralis. Herpetologica 48(2), 220-228.
| Google Scholar |

Wapstra E, Swain R, Jones SM, O’Reilly J (1999) Geographical and annual variation in reproductive cycles in the Tasmanian spotted snow skink, Niveoscincus ocellantus (Squamata: Scincidae). Australian Journal of Zoology 47(6), 539-550.
| Crossref | Google Scholar |

Wapstra E, Swain R, O’Reilly J (2001) Geographic variation in age and size maturity in a small Australian viviparous skink. Copeia 2001(3), 646-655.
| Crossref | Google Scholar |