Date of Award

Fall 2025

Project Type

Thesis

Program or Major

Natural Resources and Environmental Studies

Degree Name

Master of Science

First Advisor

Remington J Moll

Second Advisor

Joshua J Millspaugh

Third Advisor

Rebecca J Rowe

Abstract

As human activity and development continue to alter natural landscapes, large ungulates are increasingly exposed to changing habitat structures, altered mortality risks, and climate-related stressors. These ecological shifts can influence their survival, behavior, and population dynamics. Understanding how such complex and evolving conditions shape demographic trends in these species is critical for effective management. In this thesis, I examined two ecologically and culturally important ungulate species, white-tailed deer (Odocoileus virginianus) and moose (Alces alces), across human-modified environments. Specifically, I analyzed how intrinsic factors, behavioral development, and landscape composition influence stage-specific mortality in deer neonates and population parameters in moose in northeastern North America. In Chapter 1, I investigated how behavioral stages interact with intrinsic (mass, sex) and extrinsic (road density, trail density) factors to influence white-tailed deer neonate survival. Using telemetry data from 399 neonates monitored at two sites in Missouri between 2015 and 2019, I applied time-dependent and competing risks Cox proportional hazard models to estimate survival and cause-specific mortality across three early-life behavioral stages: hider, follower, and post-follower. Survival varied meaningfully by stage: during the hider stage, both greater birth mass and increased trail density were associated with reduced mortality; males experienced increased mortality in the follower stage; and increased road density was associated with elevated mortality during the post-follower stage. These results demonstrate that variation in neonate survival arises from the interaction of behavioral stage, intrinsic factors and the spatial configuration of anthropogenic landscape features. In Chapter 2, I examined demographic patterns of moose across three regions in New Hampshire. Using over 80,000 detections from 257 camera traps collected between 2022 and 2024, I applied the Random Encounter and Staying Time (REST) model to estimate region-specific densities of bulls, cows, and calves. From these, I derived adult sex ratios (bull:cow) and productivity ratios (calf:cow) as a proxy for reproductive output. Results revealed substantial spatiotemporal variation in both adult sex ratio and productivity. The White Mountains maintained bull-biased sex ratios throughout the study, while the North and Central/Southwest regions exhibited dynamic shifts that transitioned toward cow-biased sex ratios by 2024. Productivity was lowest in areas experiencing elevated winter tick (Dermacentor albipictus) pressure – a stressor that has been intensified by warming winter conditions. These findings suggest that adult sex ratio and productivity in moose populations are likely shaped by region-specific factors, aligning with adult density trends observed in hunter harvest surveys in New Hampshire. This thesis demonstrates how demographic patterns in large ungulates are shaped by the combined effect of behavior, physiology, and spatial context. The integration of stage-specific and non-invasive approaches advances ecological understanding and informs conservation strategies in human-altered ecosystems.

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