Cumulative long-term investment in vocalization and mating success of fallow bucks, Dama dama

We carried out behavioural observations to investigate the function of long -term investment in vocal display by fallow bucks during the breeding seaso n. The measures of long-term investment used were the date of initiation of vocal activity, the number of days vocal during the breeding season, and t he proportion of time spent vocalizing. We analysed data from 3 years (1993 _1995) to assess' the relationship between the date of initiation of vocal activity, and the number of days vocal, and age, dominance rank and mating success. Observations from a sample of focal males in 1996 were used to det ermine the effect of the proportion of time; vocal during the breeding seas on on dominance rank and mating success. The majority of socially immature males (less than or equal to 3 years old) did not vocalize; among socially mature males (greater than or equal to 4 years old), dominance rank was mor e important than age in explaining variation in vocal activity. The onset o f vocal activity by fallow bucks was not a direct consequence of the presen ce of mating opportunities since the first males became vocal more than 3 w eeks before any matings occurred. Long-term investment in vocal activity di d not alter the dominance relationships that had been established between m ales before they became vocal. When we considered all mature males from 3 y ears of observations, the majority of matings were achieved by those that h ad high rank, initiated vocal activity early during the breeding season and remained vocal on most days. For the 1-year sample of mature males, the fa ctor most highly correlated with mating success was the proportion of time that males spent vocalizing during the mt. Thus we have shown a strong rela tionship between the time invested in vocal;display by fallow bucks and the ir mating success. (C) 1999 The Association for the Study of Animal Behavio ur.