Western oregons columbian black-tailed deer (cbtd odocoileus hemionus columbianus) survey trends and hunter harvest numbers have been showing consistent declines since the mid-1990S

Federal Grant Award Summary

The U.S. Department of the Interior Fish and Wildlife Service awarded the State of Oregon Department of Fish and Wildlife (ODFW) a Wildlife Restoration and Basic Hunter Education and Safety formula grant (CFDA 15.611) totaling $745,892 effective July 1, 2025, through June 30, 2026. Under this award, ODFW will conduct research to develop and validate methods for accurately estimating Columbian black-tailed deer (CBTD) population demographics—including population size, age structure, and sex ratios—in western Oregon. The project responds to documented population declines since the mid-1990s attributed to habitat loss and changes in forest management practices that have reduced early successional habitat and deer forage availability, particularly on federally owned lands.

ODFW will test the efficacy of multiple estimation methods and modeling approaches and implement a large-scale pilot of these methods across western Oregon to support informed wildlife management decisions. This research will provide critical demographic data on fawn recruitment rates, adult female survival, and population dynamics to inform harvest management decisions and conservation strategies. The grant-funded work builds on previous ODFW research documenting low recruitment and survival rates in the region and directly supports the Wildlife Restoration program's core mission of wildlife conservation, management research, and population surveys.

Changes in habitat and forest management practices in recent decades has reduced the availability of open and early successional habitat where high quality deer forage is abundant, particularly on federally owned lands. Previous research conducted in the region by odfw has documented low rates of fawn recruitment and relatively low survival of adult females (clark 2022 ruprecht ET AL. 2024). Wildlife managers at odfw and other agencies require estimates of the populations demographic rates (e.g., SEX ratio, age structure, and survival) and an understanding of the ecological processes that drive population dynamics to make informed decisions such as setting harvest numbers. The aims of this research are to test the efficacy of several methods and modeling approaches to accurately estimate cbtd population size, age structure, and SEX ratios, and to implement a large scale pilot of these methods across western oregon.