Territorial and mating strategies of males in a lekking population of blackbuck Antilope cervicapra

Abstract

Territoriality associated with lek-mating systems is unique in that males defend small, heavily clustered territories that lack resources usually thought to attract females, such as food and water. Females visit these male aggregations (leks) solely for the purpose of mating. Males compete intensively to defend mating territories and male mating success is typically highly skewed. Males in this system face the complex problem of making decisions on how much effort to allocate towards territory defence and mate attraction efforts versus maintenance activities and how to time this effort, as the duration of territory tenure in relation to the peak in number of females visiting the lek has important fitness consequences. Associated with the high variance in mating success, there is extensive variation in the behaviour of males holding territories on leks. In my thesis, I attempt to understand this variation in male lekking behaviour, by examining patterns of territorial investment in relation to patterns of expected payoffs, estimating underlying hormone correlates and analysing the social context of male territorial decisions. Using a lekking population of blackbuck (Antilope cervicapra) as a model system, I took an integrative approach to study the variation in male territorial and mating behaviour on lek. In the first chapter, I investigated a principal blackbuck lek to understand the fine scale patterns of variation in male territorial investment and test whether they may arise from associated variation in mating benefits. I found that patterns of male investment in lek attendance, signalling and interactions closely track patterns in payoffs, supporting the hypothesis, that due to the large costs of lekking-related behaviour males should tailor their investment in this behaviour to predictable cues of mating benefits...