Responses of Caribou to Overflights by Low-Altitude Jet Aircraft

Do human activity and infrastructure disturb domesticated reindeer? The need for the reindeer’s perspective

“…While bulls and yearlings graze in separate herds during the summer and more often favour good pasture, females have been shown to prefer an undisturbed environment at the expense of forage quality (Maier et al 1998;Helle et al 2012). The difference in response between the sexes has great relevance for reindeer husbandry, where the herd is mostly made up of reproductive females, with young animals and bulls representing only a small proportion (in Sweden, on average 90 % of the reindeer over 1 year of age are females according to data from the Swedish Sami Parliament).…”

Ecological Risk Assessment Framework for Low-Altitude Overflights by Fixed-Wing and Rotary-Wing Military Aircraft

“…Various measurement methods are listed in Table 9. (Maier et al 1998) audio capture and transmission system, part of satellite tracking system for wide-ranging birds measurement of sound pressure levels in polar bear den 3 m from location of Bell UH-1B takeoff (Blix and Lentfer 1992) cumulative or probability distribution of SELs for different overflights at site e.g., Fig location of wildlife using radiotelemetry location of wildlife using satellite tracking platform transmitter terminals for wide-ranging birds distribution of individual wildlife in area of influence per unit time distribution of observations of muskoxen throughout the day on Prince of Wales Island, Northwest Territories (Miller and Gunn 1979) location-and time-specific estimation of presence of large flocks of birds via weather radar use f National Weather Service WSR-88D radar for tracking flights of roosting purple martins and estimating their density in South Carolina (Russell and Gauthreaux 1998) air movement, takeoff and landing measurement of wind speed at ground level for a distance around helicopter or fixedwing aircraft…”

“…Occasionally, researchers estimate appropriate decibel-weighting for other species (e.g., owls, Delaney et al 1999). However, acoustic responses are unknown for most wildlife species, and many animals are assumed to have a similar sensitivities to the frequencies of aircraft sound as humans (e.g., caribou, Maier et al 1998).…”

“…(Platt 1977, Awbrey andBowles 1989) time to habituation versus sound pressure or distance to aircraft avoidance behavior reduced with habituation of nesting redtailed hawks to helicopter activity (Andersen et al 1989) probability of reproductive impact, given frequency of overflight probability of nesting and fledging success for overflightinduced flushing of raptors, adjusted for habituation (Awbrey and Bowles 1989) waterfowl probability of response versus several variables probability of flight response from flock of brant, based on altitude, lateral distance, noise, aircraft type, aircraft type times altitude, aircraft noise times lateral distance (Ward et al 1999) duration of response versus flock size logistic relationship between flock size of molting brant and duration of disturbance response (Derksen et al 1992) probability of response versus habituation proportion of overflights during which black ducks reacted versus reaction rate and days of exposure when habituation appeared to occur (Conomy et al 1998 (Maier et al 1998) daily time barren-ground caribou spend resting in late winter, negatively related to time-averaged noise level (Maier et al 1998) daily distance moved by post-calving barren-ground caribou correlated to SEL for loudest overflight of day (Maier et al 1998) level of response versus altitude percentages of barren ground caribou displaying behavioral responses at different overflight altitudes (Calef et al 1976) level of response versus frequency of overflights woodland caribou calf survival (no. survey periods that cow was accompanied by calf) negatively correlated with number of jet overflights reported < 1 km from an animal's location per day (relationship significant during the calving and immediate postcalving periods for the females known to have calved and for all females) (Harrington and Veitch 1992) number of resting bouts of barren-ground caribou related to number of overflights (Maier et al 1998) mean duration of resting bouts of barren-ground caribou negatively related to number of overflights (Maier et al 1998) response related to behavior prior to overflight traveling and feeding caribou were similar in their level of response; caribou at river crossings were more reactive than traveling or feeding animals, and resting animals were less reactive (Calef et al 1976) responses of caribou and muskoxen depend on previous activity of animals (Miller and Gunn 1979) more rapid running reaction of caribou and longer duration when animals walking prior to overflight, compared to animals feeding and standing or lying (Harrington and Veitch 1991) level of effects versus habituation bighorn sheep and mule deer habituate to low-level aircraft noise with...…”

“…of the Air Force 1995, F-2) peak sound levels for different overflight events (4 nautical mile audible flight path; factors include height, slant distance, power setting [takeoff, cruise, approach]) (U. S. Navy 1998) relationship between sound pressure and distance from flight track relationship between measures of sound pressure correlation between loudest overflight of day and average sound level during military training in Alaska (Maier et al 1998) extrapolation of ground-level noise to that in burrow SELs in small mammal burrows average 2.4 dB lower than at 1.2 m above surface, with significant attenuation above 1300 Hz SELs in kit fox dens are attenuated significantly above 500 Hz; the function is in ; more attenuation expected with bent burrows a sound pressure level of 95 dBA is not lowered in a lizard burrow of 4 cm of fine compacted sand (Brattstrom and Bondello 1983) extrapolation of sound exposure associated with one power setting to another noise levels are typically 7 to 10 dB(A) lower for approach power settings than for takeoffs and normal cruising speeds (U. S. Navy 1988) extrapolation of sound exposure from one aircraft to another…”