Contrasting timing of parturition of chital Axis axis and gaur Bos gaurus in tropical South India – the role of body mass and seasonal forage quality

摘要: Seasonal variation in forage availability and quality is understood to affect the annual timing of parturition large herbivores. In India–where seasonal monsoonal rains define quality–chital Axis axis exhibit stronger seasonality than larger gaur Bos gaurus. We hypothesized that this difference can be explained by requirements determined body mass. developed a model simulate changes leaf biomass nitrogen content based on plant available moisture nutrients, calibrated our with field data. Our results show minimum required lactating was throughout year, but chital for less 40% i.e. during early wet season, which coincides peak period births. The three four month spread births, begins dry implies highest also important females replenish maternal reserves future reproduction help maximize growth rate neonates. This indicates low synchrony births suggests predator swamping influencing their parturition. As rain exhibits temporal variation, we analyzed under different rainfall patterns while keeping total constant. found between durations how long satisfy similar all simulated patterns. insensitivity variable lends support hypothesis mass one plausible explanation strategies among herbivores species. Many animals live environments where food follow cyclical variation. temperate zone, adequate quantity only summer not winter. tropical regions rainfall, abundant high season replaced season. influence mammalian (Rutberg 1987, Wittemyer et al. 2007). ‘seasonality’ proposes