Behavioral stages interact with intrinsic and extrinsic factors to shape White-tailed Deer ( Odocoileus virginianus ) neonate mortality

Many mammalian neonates adopt behavioral survival strategies, such as predator avoidance and close parental proximity, to mitigate mortality risks during early development. For White-tailed Deer (Odocoileus virginianus), these strategies progress across three behavioral stages: hider, follower, and post-follower, each with distinct risks. Despite the critical effect of each stage on survival, the influence of intrinsic traits, landscape features, and anthropogenic activity across these stages remains poorly understood. We addressed this knowledge gap by evaluating factors influencing survival in 399 neonate White-tailed Deer across three behavioral stages in two landscapes in Missouri, USA, from 2015 to 2019. Mortality risks varied significantly across stages using time-dependent and competing risks hazard models. In the hider stage, higher birth mass reduced natural mortality risks, while greater trail density in forested areas lowered risk, likely by altering predator movement. During the follower stage, male neonates had higher mortality risks than females, likely attributable to increased activity levels in males. In the post-follower stage, road density increased mortality risk in fragmented landscapes, possibly due to predator presence and vehicle collisions. These results indicate that neonate survival depends on the dynamic interaction between intrinsic and environmental factors, which vary across developmental stages. By linking survival to behavioral stages, our findings provide insights into how early-life strategies mediate the effects of landscape and individual traits, offering broader insights into how species adapt to human-altered ecosystems. Understanding the interplay of behavioral stages and environmental risks can contribute to ecological frameworks for understanding species adaptations to human-altered and rapidly changing ecosystems.