New Zealand Journal of Zoology abstracts

---

Effects of vaccination against gonadotrophin-releasing hormone (GnRH) on the social status of brushtail possums in captivity

S. E. JOLLY¹
S. SCOBIE
P. E. COWAN²

Manaaki Whenua - Landcare Research
P.O. Box 69
Lincoln 8152, New Zealand
1Present address: 5 Howitt Court, Werribee, Victoria, Australia.
2Present address: Manaaki Whenua - Landcare Research, P.O. Box 11052, Palmerston North, New Zealand (to whom all correspondence should be addressed).

Abstract  Options for the biological control of brushtail possums (Trichosurus vulpecula) are being evaluated in the hope of finding a cost-effective, long-term solution to the problem of reducing numbers of possums as hosts of bovine tuberculosis and as threats to conservation values. Methods of inhibiting possum reproduction by affecting sex steroid levels are among the options. However, this may result in behavioural changes. In some species, a loss of status by dominant animals allows subordinates to breed more successfully. This paper describes how social hierarchies in captive groups of possums are affected by vaccination of dominant females against gonadotrophin-releasing hormone (GnRH) to block all centrally controlled steroid hormone release. Ten groups consisting of two females and one male were established in pens, and the dominance status of each animal was measured by recording the outcome of social interactions during monthly observations. The dominant female in each pen was vaccinated against GnRH with a series of three immunisations. Social hierarchies remained unchanged over the 2-4 months after vaccination of the dominant females. We therefore conclude that methods of biological control that disrupt sex steroid production could be considered for possum control once these findings are confirmed by similar observations on wild possums.

Keywords  brushtail possums; Trichosurus vulpecula; dominance; social behaviour; reproduction; GnRH vaccination; biological control

Received 1 April 1996; accepted 27 May 1996

New Zealand Journal of Zoology, 1996, Vol. 23: 325-330

0301-4223/2304-0325 $2.50/0   (c) The Royal Society of New Zealand 1996

PDF file of entire paper: medium quality (395K); (scanned from paper original: notes about this process)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page