Variation in lekking costs in blackbuck (Antilope cervicapra): Relationship to lek-territory location and female mating patterns

We studied variation in lekking costs in an Indian antelope, the blackbuck Antilope cervicapra, in relation to female mating patterns. We tested the h ypothesis that central males had a higher mating success and faced higher c osts than peripheral males. We used continuous focal animal sampling to est imate time-activity budgets of individually identified central and peripher al lekking males and bachelor males. Scan sampling was used to estimate the time spent on the lek by central and peripheral males and to monitor femal e visits to the lek. We mapped lek-territories and monitored territory addi tions, territory turnover, and the location of matings. We found that centr al males faced higher costs than peripheral males. Central males foraged le ss, spent more time on the lek and tended to have higher fighting rates tha n peripheral males. Corresponding to this difference in costs, mating benef its were also greater for central males. Our results suggest that lek-terri tory location may be an important cue in female choice. Male mating success was skewed and 90% of matings observed occurred in the lek-centre. Further more, three of the five most successful males previously held territories i n the lek-periphery where they were not observed to mate. Territory turnove r was higher in the centre than in the periphery and males tended to move t owards the centre while shifting territories. Based on these findings, we s uggest that central and peripheral males follow two different strategies in response to a female preference for central territories: while central mal es may try to maximise encounters with oestrous females by investing heavil y in lekking, peripheral males seem to attempt to maximise their chances of gaining central territories by not compromising on foraging time and inves ting less in lekking. Since we did not directly measure male phenotype, its role in explaining the patterns we found remains to be studied.