This project is investigating the influence of oestrid (nasal bot and warble) fly harassment on the behaviour and distribution of Bathurst caribou.  Given the current decline of the Bathurst barren-ground (Rangifer tarandus groenlandicus) herd in the Northwest we will investigate whether conditions on the post-calving/summer range may be contributing to the decline. Summer is a critical time for caribou to support calves &  replenish protein & energy reserves.  One factor that may preclude the ability of caribou to obtain adequate forage is harassment by biting & parasitic insects, including oestrid flies, mosquitoes, & black flies. Insect harassment alters habitat use and activity budgets of caribou, potentially leading to reduced forage intake and elevated energy expenditures. In this project we will develop an empirically-based index that relates oestrid activity to weather, habitat, time of day and time of year. 
Our work will involve:

• Data collection during six sampling sessions July-August 2007 & 2008.

• CO2-baited Malaise traps to collect insects at 2-hr intervals and portable weather station and light meter to record weather variables at 10-min intervals.

• Count models to analyze activity/abundance of mosquitoes & black flies relative to weather and temporal variable. We will use a logistic regression to model presence/absence of oestrid flies.

Insect trap and caribou (L. Witter)

Leslie Witter's Master's thesis completed, September 2010. See Reports.