Optimising the hatching success of artificially incubated eggs for use in a conservation program for the western saw-shelled turtle (Myuchelys bellii)
Louise M. Streeting
A * , Deborah S. Bower A , Martin L. Dillon A B , Phil Spark C , Michael Gough D , Adam Skidmore E , Paul G. McDonald A , Hannah Delaney A , Adrienne Burns A , Sandy Watson A , Duminda S. B. Dissanayake F , Arthur Georges F and Donald T. McKnight A G
+ Author Affiliations
- Author Affiliations
A School of Environmental and Rural Science, University of New England, Armidale, NSW 2350, Australia.
B Northern Tablelands Local Land Services, Armidale, NSW 2350, Australia.
C North West Ecological Services, Tamworth, NSW 2340, Australia.
D Latisternum, Dubbo, NSW 2830, Australia.
E Taronga Conservation Society Australia, Mosman, NSW 2088, Australia.
F Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia.
G Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Wodonga, Vic. 3690, Australia.
Australian Journal of Zoology 70(2) 74-82 https://doi.org/10.1071/ZO22014
Submitted: 30 March 2022 Accepted: 24 October 2022 Published: 9 December 2022
© 2022 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
Artificial incubation of eggs and the release of hatchlings into the wild is a common conservation intervention designed to augment threatened turtle populations. We investigate a range of incubation temperatures to establish an optimal temperature for maximum hatching success of western saw-shelled turtle (Myuchelys bellii) eggs. We report on the influence of incubation temperature on incubation duration and hatching success and describe two experimental incubation methods which, for the same incubation temperature (27°C), resulted in 77% and 97% hatching success, respectively. Eggs were incubated at constant temperatures (27°C, 28°C and 29°C) to determine the influence of temperature on incubation period, hatchling morphology and external residual yolk. Incubation duration was negatively correlated with incubation temperature. We report on the morphology of eggs and hatchlings and show that their dimensions are positively correlated with maternal adult size and mass. A constant incubation temperature of 27°C produced the highest hatching success and smallest external residual yolk on hatching and is therefore recommended for incubation of eggs for population reinforcement programs. Our study is the first to optimise artificial incubation procedures for M. bellii and will be a valuable resource for M. bellii and other threatened freshwater turtle conservation initiatives.
Keywords: artificial incubation, Bell’s turtle, conservation, endangered species, freshwater turtle, head-starting, population augmentation, population reinforcement, wildlife management.
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