# Doe diligence: A regional analysis of antlerless deer harvest regulations in the Midwestern United States of America

## TL;DR

This study examines how changes in deer hunting regulations affect the harvest of female deer in the Midwestern US.

## Contribution

The study introduces a Bayesian hierarchical model to estimate the effects of hunting regulations on antlerless deer harvest across multiple states.

## Key findings

- Increasing antlerless harvest permits boosts harvest but effects plateau with more permits.
- The earn-a-buck program had the largest estimated increase in antlerless deer harvest.
- Licensed hunter numbers strongly correlate with antlerless deer harvest rates.

## Abstract

Wildlife management in the United States of America (US) is primarily delegated to the individual states wherein state wildlife agencies manage wildlife populations to achieve multiple and sometimes conflicting objectives. White-tailed deer (Odocoileus virginianus) are an important species in the Midwestern US whose populations are primarily managed through recreational hunting. Managers aim to adjust populations by altering the harvest of antlerless (usually female) animals by changing the number of harvest permits available, hunting season lengths, or applying incentive programs like earn-a-buck, where a hunter must harvest an antlerless deer before they may harvest an antlered deer. We estimated the effect on antlerless deer harvest from changes in these regulations and changes in the number of licensed hunters across eight states in the Midwest. We used a Bayesian hierarchical model to estimate individual state and regional (i.e., across all states) effects. We found that increasing antlerless harvest permits increased antlerless harvest; however, this effect plateaued as the number of available permits increased. Providing unlimited harvest permits increased harvest, but the same increases were achieved by minimally increasing the number of limited harvest permits. Increasing the length of hunting season had a generally positive effect on antlerless harvest but the effect was non-linear and state dependent. The earn-a-buck incentive program resulted in the largest estimated increase in harvest. Finally, the number of licensed deer hunters in a state had a strong positive effect on the number of antlerless deer harvested. Our findings show that commonly applied changes in harvest regulations have a weak effect on the number of antlerless deer harvested, highlighting the challenges facing deer managers in the Midwestern US.