Esquimalt Deer Project

urban landscapes - esquimalt deer project

Esquimalt Map

Data Portal

Data type: Camera data
Camera sites: 40
Area: ~10 km2
Timespan: 2021-2024
Camera data: email us to discuss data sharing
Metadata: In progress.

Funder link: https://www.esquimalt.ca/government-bylaws/animal-control/deer/deer-management.

PROJECT OVERVIEW

We are measuring native black-tailed deer (BTD) population size and fawning rates before and after experimental treatment with birth control via immunocontraception (IC) in the Township of Esquimalt.

We deployed 40 cameras spanning the region, with locations dependent upon landowner permissions. The spacing between cameras is designed to allow for a single deer to be detected on multiple cameras, a requirement for density estimation models. This design also captures the full array of landscape heterogeneity in this region, from a gradient of high-intensity human use to low-intensity human use and high “greenness” including shrub and forest cover.

Photographs are analyzed to identify species using Timelapse Image Analyzer 2.2. For each animal detection, we record date, time, location; for BTD, we record demographic information including sex and age group (e.g., adult, fawn). For collared BTD, we also note the unique colour tag combination for individual-level identification (q.v.). Data on marked and unmarked BTD provide the basis statistical models of reproductive success and population density.

Thank you to all of the landowners who have graciously allowed us to deploy cameras in their yards, or to capture and treat deer on their properties! We could not do this without you.

DEER CAPTURE AND TREATMENT

Deer search effort was spread evenly across each landscape by allocating time and human resources systematically. Twenty control (untreated, marked) deer were captured in 2021 using field protocols approved by the University of Victoria’s Animal Care Committee, led by wildlife veterinarian Adam Hering, supported by technicians and volunteers from the University of Victoria.

The IC vaccine (PZP-22)6 was administered to 57 “Treatment” animals 2021-2022. PZP-22 time-releases the IC over a span of three years to successively prevent pregnancy with a trial efficacy of > 90% after 3 years. All marked animals were released at point of capture to mix with the unmarked population.

FUTURE STRATEGY

Population monitoring. October 30-Dec 1st as the best period to estimate density and model fawning rates, as fawns are highly discernible, deer are moving plenty (and being detected).
Pre- and Post-treatment density estimates. We have begun modelling pre- and post-treatment density estimates, to understand whether populations have changed over the research timeframe.
Fawning rate models. We are planning to model probability of fawning in relation to habitat characteristics across Esquimalt. Post-treatment estimates for 2023 will be based on fawn appearance after the fawning period in June and will take a few months thereafter to compile.

Publications are coming in 2022.