Research Projects

Lekking, a mating system wherein males defend clustered territories to attract females, is exceptionally rare among mammals (less than 1% of species). The blackbuck antelope (Antilope cervicapra) exhibits an extraordinary lekking system ideal for studying multimodal signalling, territorial dynamics, and female mate choice. In this species, dominant males occupy central territories and achieve disproportionately high mating success but incur significant mortality risks from intense competition. Despite extensive observations, the proximate mechanisms driving male dominance, chemical communication, and multimodal female choice remain inadequately understood. Recent findings suggest a pheromone (meta-cresol) in male dung significantly influences mating outcomes (Nair 2019). This proposal integrates behavioural ecology, chemical ecology, and endocrinology to unravel the underlying mechanisms of lekking behaviour in blackbuck populations at Tal Chhapar Wildlife Sanctuary, Rajasthan, India. Fieldwork will exploit two annual peak rutting periods (March–April; August–October), providing robust comparative sampling opportunities. Objective 1 investigates individual variations in territorial dominance by identifying morphological (horn length), behavioural (display intensity, territory tenure), and physiological (testosterone and cortisol metabolites via faecal sampling; Jayabharathy 2014) predictors through systematic drone-based observations, standardised photography, and repeated non-invasive hormone assays, assessing variation from territory acquisition to replacement. Objective 2 assesses the role of olfactory signals in mediating male–male interactions by experimentally testing males' ability to discriminate between familiar versus unfamiliar scent marks, examining whether scent marks from dominant males function to inhibit aggression and territory encroachment by subordinate males, thus reducing costly conflicts (Gosling & Roberts 2001). Objective 3 explore how females integrate visual and olfactory cues, we will correlate male morphological traits and behaviours with female visitation rates. Further, a scent-swapping experiment between ‘popular’ and ‘unpopular’ males will test the relative importance of dung cues in female choice. The project will yield novel insights into multimodal signalling and lek dynamics, aligning with India's national conservation priorities. It will directly inform blackbuck habitat management and species conservation strategies. Findings will inform both fundamental evolutionary theory and applied conservation policy for India's arid grassland species. References Gosling, L.M. & Roberts, S.C. (2001).Scent-marking by male mammals, Adv. Stud. Behav. 30:169–217. Jayabharathy, R. (2014). Territorial and mating strategies of males in a lekking population of blackbuck, PhD thesis, IISc Bangalore. Nair, J.V. (2019). Factors affecting variation in mating success of males in a blackbuck lek, PhD thesis, NCBS-TIFR.