Phenology of Antler Casting and Occurance of Late-Breeding in Nebraska White-Tailed Deer

Abstract

White-tailed deer (Odocoileus virginianus) in Nebraska primarily breed in November (stimulated by photoperiod), but this season extends into December and January for unfertilized females and healthy fawns reaching the appropriate breeding weight by winter. Variation in the typical mating period can be attributed to geographic region, skewed sex ratios, and fawns reaching sexual maturity during their first year of birth. During April of 2019, we observed late season breeding by a male white-tailed deer in the central Platte River valley and documented late antler casting for this same late-copulating male. An additional male was observed in April of 2020 still retaining antlers within the region. To understand the irregularity of these observations relative to the central Platte River valley, we documented observations of early and late antler casting utilizing long-term cast antler collection and camera trap data. We were able to establish a baseline for antler casting phenology within this region to denote a shift in average casting timeframe (more than one month later than previously recorded in this region) and document early and the latest known antler casting within the literature. Herein, we detail the variation in antler casting phenology for white-tailed deer in this region, and the latest known occurrence of natural breeding in the state. Our findings help us better understand the life history of the Nebraska white-tailed deer population and can assist state wildlife biologists and property managers as they assess seasonal harvest regulations and adaptively manage the changing resource.