Carnivore Territoriality and Sociality: Optimal Behavior for Gray Wolves in the Northern Rocky Mountains

PhD Dissertation, Sarah Sells

Monitoring is a critical, yet challenging, management tool for gray wolves (Canis lupus) in Montana and Idaho. Since delisting of wolves in 2011, monitoring results help each state set management objectives and communicate with stakeholders and the public. Monitoring any large carnivore is challenging, however, due to their elusive nature and naturally low densities. This is particularly true for wolves in Montana and Idaho due to expanding populations, decreasing funding for monitoring, and changing behavioral dynamics with harvest.

Abundance estimates are a key component of monitoring. In Montana, abundance is estimated based on area occupied, average territory size, and annual average pack size. Area occupied is estimated with a Patch Occupancy Model (POM). Reliability of abundance estimates, however, hinge on key assumptions about territory size, territory overlap, and pack size. Assumptions of fixed territory size and minimal overlap are simplistic. In reality, territories vary spatiotemporally, and likely even more so under harvest. Meanwhile, pack size estimates assume all packs are located and accurately counted each year, which is no longer possible due to the number of packs and declining funding for monitoring.

The goal of my research is to provide tools for managing wolves in the Northern Rocky Mountains (NRM). My objectives are to develop mechanistic territory and group size models based on a suite of theoretical models tested on real data. This approach will allow me to identify the mechanisms driving territorial and social behaviors of wolves in the NRM, yielding models predictive at any spatiotemporal scale in absence of abundant empirical data. Alongside POM, the models I develop will help accurately estimate abundance of wolves through biologically based, spatially explicit predictions for territory size, location, and overlap and group size. In addition, my objectives are to make novel contributions to the field of theoretical behavioral ecology. I will formally test hypotheses of causal mechanisms of territorial and social behavior of a large carnivore. Furthermore, the mechanistic models I develop will be useful for predicting territorial and social behaviors of other carnivores without abundant empirical data.