| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
RESEARCH |
1 Department of Zoology, University of Melbourne, Victoria 3010, Australia and 2 Goonderoo, MS472275, Queensland, Springsure, 4722, Australia
Correspondence should be addressed to M B Renfree; Email: m.renfree{at}zoology.unimelb.edu.au
The tammar wallaby (Macropus eugenii) is a small, promiscuous, macropodid marsupial. Females usually produce a single young each year and there is a clear dominance hierarchy between adult males. The dominant male usually mates first and then guards the female to prevent access to her by other males. In this study, agonistic encounters and mating behaviour were observed to determine male dominance hierarchies in six groups of captive tammars consisting of a total of 23 males and 50 females. Mating behaviour was observed immediately post-partum when females were in oestrus and was correlated with plasma testosterone concentrations. Male mating sequences were recorded, and the paternity of offspring was determined by using seven macropodid marsupial microsatellites. Rates of sexual checking and aggression by males housed with females in oestrus in the non-breeding season were lower than in the breeding season. These males also had lower concentrations of testosterone, but were still able to sire young. High testosterone concentrations neither ensured dominance nor appeared to control directly the level of sexual activity. Females usually mated with more than one male. The dominant male most often secured the initial copulation (60%), but the first-mating male did not always secure parentage, with second and third matings resulting in as many young as first matings. Using these data, we were unable to discount first sire, last sire or equal chance models of paternity in this species. Half the young (50%) were sired by the dominant
male, but of the remaining progeny, the ß male sired more (35%) than
and
males (15%). Dominance therefore is only a moderately effective predictor of paternity in the tammar. Although the dominant males gained most first matings and individually sired half of the offspring, the subdominant males still contributed significantly to the population, at least in captivity.
This article has been cited by other articles:
![]() |
D B B P Paris, D A Taggart, G Shaw, P D Temple-Smith, and M B Renfree Changes in semen quality and morphology of the reproductive tract of the male tammar wallaby parallel seasonal breeding activity in the female Reproduction, September 1, 2005; 130(3): 367 - 378. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |