Energy Expenditures of Caribou Responding to Low-Altitude Jet Aircraft.
Abstract
We evaluated responses in daily energy expenditure of caribou (Rangifer tarandus) to low-flying military jet aircraft overflights. Simulation modeling was used to assess effects on energy balance and conception success. In captive caribou at the Large Animal Research Station, activity counts (ACs) from a motion sensing radio transmitter mounted on a neck-collar were highly correlated with caribou activity, and with the incremental energy cost (IEC) of activities. Average daily metabolic rate (ADMR) was estimated as the product daily IEC (IEC24) times seasonal resting metabolic rate. Radio collared female caribou of the Delta Herd, 5 controls and 5 treatments (i.e., overflown), carried animal noise monitors and were overflown in April (late winter), June (post-calving) and July-August (insect season). Caribou responded with linear increases in AC, IEC24 and ADMR in response to increasing daily sound dose; the response was significant for post-calving females. Computer simulation of caribou energetics and fecundity, based on the Porcupine Caribou Model (CARIBOU), predicted that, for the sound exposures of the field study, changes in energy expenditure, forage intake, energy balance and consequent pregnancy rate were small. Although we project no significant decrease in fecundity and thus, herd productivity in response to the sound exposure due to low-flying jet overflights in this study, we nonetheless, recommend that early post-calving caribou not be subjected to repeated low-altitude jet aircraft overflights until it is determined that indirect responses associated with caribou movement carry no reproductive cost.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1993
- Accession Number
- ADA292322
Entities
People
- Bret R. Luick
- Julie A. Kitchens
- Michael D. Smith
- Robert G. White
- Stephen M. Murphy
Organizations
- University of Alaska Fairbanks