CAUSE SPECIFIC MORTALITY OF DESERT BIGHORN SHEEP LAMBS IN THE FRA CRISTOBAL MOUNTAINS, NEW MEXICO, USA

摘要: Bighorn sheep (Ovis canadensis) herds have suffered recent declines across their previous range, and desert bighorn (O. c. mexicana) are listed as an endangered species in New Mexico. One factor affecting growth rates of these populations is low variable lamb recruitment. Capturing radio-collaring lambs can provide opportunities for collecting valuable information on factors potentially long term population persistence. Little available cause-specific mortality or methods obtaining such data. We tested 3 different capture techniques lambs. captured during the spring lambing seasons 2001 2002 by approaching foot restraining them hand, jumping from a helicopter firing net-gun helicopter. 6 hand ground, 4 helicopter, 11 with shoulder-mounted skid-mounted net-gun. The best technique depended specific circumstances each situation. Since we were concerned sample size considerations, our success implementation all techniques. However, hand-capture allowed us to very young that would not attempted either due stress, risk injury, cost. This may be applicable other ungulate populations. 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38