Reproductive phenology of blackbuck in Velavadar National Park, India
This data set comprises calving in blackbuck from 2000-2002 in Velavadar National Park, India to examine its breeding phenology in relation to body-condition, forage abundance and quality. Seasonality poses significant nutritional constraints for ungulates. Consequently, most ungulates time their energy-demanding events like calving and lactation to the availability of abundant and high-quality nutritional resources. We investigated the reproductive phenology of blackbuck, Antilope cervicapra, in relation to resource seasonality, in a semi-arid grassland in western India. We examined whether the body-condition of females, forage abundance, and forage quality influenced the timing of blackbuck reproduction. We also used a conceptual model to explore whether blackbuck use behavioural adaptations in maternal care as an adaptive strategy to buffer the high nutritional demands of lactation. Blackbuck showed biannual calving, which occurred before (pre-monsoon) and after the rains (post-monsoon). We found statistically significant relationships, albeit small effect sizes, of body-condition, forage abundance (biomass), and moisture content of grasses on the proportion of lactating females. The biannual reproductive phenology seems more complex than a simple relationship of reproduction with body-condition and optimal nutrition supply. In the conceptual model based on our data, we propose that blackbuck females shortened their lactation time and weaned their calves sooner during the pre-monsoon calving to coincide with a period of optimal food quality, thus, ensuring sufficient nutrition for both weanlings and allowing the females to regain body-reserves. Whereas, resource availability during the post-monsoon calving likely allowed females to invest in longer lactation, weaning the calves later, as compared to the pre-monsoon calving season. Thereby, blackbuck may be maintaining biannual calving and thus increase their lifetime reproductive output.This data set is from the article accepted and in production for online publication in Journal of Zoology with DOI 10.1111/jzo.12928.
Steps to reproduce
All of this data is collected from field sampling and direct observation. This workbook contains 4 worksheets: Calving, vegetation, body-condition and rainfall. Calving and body-condition data was direct observational sampling. Forage abundance was through clipping of grass in the field and forage quality was determined through laboratory analysis. Rainfall was measured using a rain-guage. This study was carrried out in Velavadar National Park, India.