Seasonal changes in haematocrit in captive koalas (Phascolarctos cinereus)
Cleva, GM, Stone, GM & Dickens, RK 1994, Australian Journal of Zoology, vol. 42, no. 2, pp. 233-236.
Distinct changes in microhaematocrit (ratio of red blood cell volume to the total blood volume) with season were observed in captive koalas, with raised levels in the winter and reduced values during the summer. Additionally, microhaematocrit was negatively correlated with the lowest and highest temperatures in the day. No associations of the differences in haematocrit with variations in body weight, plasma osmolarity or the concentration of plasma protein were discovered.
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Seasonal reproduction in wild and captive male koala (Phascolarctos cinereus) populations in south-east Queensland
Camryn D. AllenA,H, Deidré L. de VilliersB, Brett D. ManningB, David S. DiqueB, Michelle BurridgeC, Mandy L. ChaferC, Vere N. NicolsonC, Sophia C. JagoC, Allan J. McKinnonB, Rosemary J. BoothB, Jeff J. McKeeD, Michael J. PyneE, Yeng Peng ZeeA, Geoff Lundie-JenkinsB, Peter TheilemannB, Richard J. WilsonF, Frank N. CarrickG and Stephen D. JohnstonA
A School of Animal Studies,The University of Queensland, Gatton, Qld 4343, Australia
B Environmental Protection Agency, Brisbane, Qld 4000, Australia.
C Dreamworld, Coomera, Qld 4209, Australia.
D Mobile Disease Ecology Unit, Ecosure, West Burleigh, Qld 4219, Australia.
E Currumbin Wildlife Sanctuary, Currumbin, Qld 4223, Australia.
F Department of Mathematics, The University of Queensland, St Lucia, Qld 4072, Australia.
G Centre for Mined Land Rehabilitation,The University of Queensland, St Lucia, Qld 4072, Australia.
H Corresponding author. Email:
ABSTRACT
The effects of breeding season (late spring to early autumn) on south-east Queensland male koala fertility were examined to improve the efficacy of the AI procedure and to determine the practicality of using free-range animals as semen donors for a genome resource bank. Seasonal changes in male koala reproductive function were assessed in a wild free-range population (n=14; obtained every 6 weeks from January to November 2005), a necropsied healthy wild population (n=84; obtained monthly from September 2004 to August 2005) and a captive population (n=7; obtained monthly from October 2005 to October 2006). Reproductive parameters investigated included body weight, coat score, sternal gland area and activity, testosterone secretion, reproductive anatomy volume and semen quality (before and after cryopreservation).Collectively these findings show that reproduction in male koalas from south-eastQ ueensland changes seasonally and that winter appears to be the optimal season in which to collect semen samples by electroejaculation. While it was possible to repeatedly collect semen from free-range koalas for future genetic management via potential storage in a genome resource bank, the survival of these spermatozoa after cryopreservation was poor and will require further improvement.
Seasonal reproduction in wild and captive male koala (Phascolarctos cinereus) populations in south-east Queensland
Allen, CD, de Villiers, DL, Manning, BD, Dique, DS, Burridge, M, Chafer, ML, Nicolson, VN, Jago, SC, McKinnon, AJ, Booth, RJ, McKee, JJ, Pyne, MJ, Peng Zee, Y, Lundie-Jenkins, G, Theilemann, P, Wilson, RJ, Carrick, FN & Johnston, SD 2010, Reproduction, Fertility and Development, vol. 22, no. 1, pp. 695-709.
Male koalas exhibit seasonal changes in anatomical and physiological characteristics relating to fertility and reproduction. These seasonal variations have implications for artificial insemination (AI) programmes, as semen samples collected from wild koalas during winter appear to retain the highest quality after thawing from cryopreservation.
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