Energy Expenditures of Caribou Responding to Low-Altitude Jet Aircraft.
Final technical rept. Apr 89-Sep 93,
ALASKA UNIV FAIRBANKS INST OF ARCTIC BIOLOGY AND MUSEUM
Pagination or Media Count:
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.
- *MILITARY AIRCRAFT
- *LOW ALTITUDE
- *JET AIRCRAFT
- COMPUTERIZED SIMULATION
- COUNTING METHODS
- ENERGY CONSUMPTION
- DAILY OCCURRENCE
- RADIO TRANSMITTERS
- Flight Control and Instrumentation
- Anatomy and Physiology