Research, Connect, Protect



Life history

Gestational length in the koala, Phascolarctos cinereus

Gifford, A, Fry, G, Houlden, BA, Fletcher, TP & Deane, EM 2002, Animal Reproduction Science, vol. 70, no. 1, pp. 261-266.

A koala born at Taronga Zoo was found to have a gestational period of at least 50 and up to 77 days, considerably longer than the typical gestational length of 30-35 days.

Read more ...

Growth and development of the koala from birth to weaning

Blanshard, WH 1991, in Lee, AK, Handasyde, KA & Sanson, GD (ed.), Biology of the Koala, Surrey Beatty and Sons, Chipping Bay, pp. 193-202.

Several observations of the developmental changes in the physical appearance, dentition and behaviour of koalas during the 12-month period from birth to weaning have been compiled and documented.

Read more ...

Growth and mortality of koala pouch and back young

O’Callaghan, P 1996, Proceedings from the Conference on the Status of the Koala in 1996, Brisbane, Australian Koala Foundation, pp. 101-109.

The systematic management and monitoring of captive koala populations presents a unique opportunity for learning about the growth and mortality of koala pouch and back young. In this report, a number of learnings about the factors affecting the development of juvenile koalas from the Lone Pine Koala Sanctuary koala population are documented.

Read more ...

Relationships between morphometric variables and age for captive individuals may not accurately estimate the age of free-ranging juvenile koalas (Phascolarctos cinereus)

Tucker, GM, Clifton, ID & McKillup, SC 2012, Australian Journal of Zoology, vol. 60, no. 1, pp. 173-179.

The development and application of a model for determining the ages of free-ranging juvenile Queensland koalas based on morphometric variables suggests that similar models based on data obtained from captive animals may not be suitable for estimations of age of wild koalas.

Read more ...

Seasonal oestrous cycle activity of captive female koalas in south-east Queensland

Ballantyne, K, Lisle, A, Mucci, A, Johnston, SD 2015, Australian Mammalogy, vol. 37, pp. 245-252.

Over a four-year period, 33 mature, captive female koalas were investigated regarding the seasonality of their oestrous behaviour, with the potential impacts of rainfall, temperature and photoperiod explored specifically. Findings revealed noticeable seasonality in behavioural oestrus, as well as a significant correlation between oestrous cycle activity and both average monthly temperature and photoperiod.

Read more ...

Sexual maturity, factors affecting the breeding season and breeding in consecutive seasons in populations of overabundant Victorian koalas (Phascolarctos cinereus)

McLean, N & Handasyde, KA 2006, Australian Journal of Zoology, vol. 52, pp. 385-392.

At sexual maturity, female koalas in Victorian koala populations had an average age of 24.4 months, head length of 125 mm and body mass of 6.6 kg. The length and timing of the breeding season differed significantly between the island populations and inland populations, with those in island populations commencing earlier and lasting longer than those in inland populations.  More male offspring were born earlier in the breeding season than females, and Chlamydia appeared to affect the frequency of breeding in consecutive seasons.

Read more ...

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Johnston, SD, McGowan, MR, O’Callaghan, PO, Cox, R & Nicolson, V 2000, Journal of Reproduction and Fertility, vol. 120, no. 1, pp. 49-57.

This study described the oestrous cycles of both non-mated and mated female koalas in terms of relationships between oestrus, oestrous behaviours, the appearance of the external genitalia, and concentrations of the reproductive steroids oestradiol and progestogen.

Read more ...