Date: 01/28/09
Contact: C. Douglas Nielsen
Phone: (702) 486-5127, ext. 3500

JANUARY WARMING BUT NOT FOOLING WILDLIFE

Mild mid-January temperatures may be fooling southern Nevada residents, but they’re not fooling wildlife. If you’ve lived in the Mojave Desert for a while, you know that brief warm spells in the middle of winter are just a passing phase, leading us to venture out and dig in the dirt and look for animals. But spring flowers aren’t in the nurseries yet, and hibernating animals are not emerging.

Christy Klinger, diversity biologist for the Nevada Department of Wildlife (NDOW) says that you will still see some rodents in the daytime and some bats at night that are active year-round, but hibernating species are not fooled. They know that the continuous warm temperatures of spring are several weeks off. Some bats may be triggered to come out of “torpor” (lowered body temperature and metabolism) for a short time, but will return to their hibernation roosts. The flowers which attract insects, bats’ primary food source, have not yet come out. Migrating bird species aren’t fooled either.

Some reptiles may come out on a warm day to bask in the sun but will go right back into “brumation” (reptile hibernation) until the warmth is guaranteed, said Polly Conrad, NDOW reptile biologist. Conrad added that likewise, some desert tortoises do not enter their burrows until about November if there is a prolonged warm period in the fall. Still, being active while food sources are not available is dangerous to wildlife. Studies of phenology, which tells how plants grow and animals move with the seasons, indicate this to be a concern if global warming changes temperature regimes. If animal activity is not closely timed to the availability of both plant and animal food sources, some wildlife species may go hungry.

You are not likely to see distinctive changes in the behavior of larger either. Bighorn sheep and deer do not hibernate during the winter months. Instead they actively seek food and shelter. The only difference that a few warm days may make is that they will need to pursue water more.

Fish will be only slightly affected by temporary warm temperatures, according to NDOW angler educator Chris Pietrafeso. Pond and lake temperatures will likely remain stable throughout the winter, with very little warming of water at the top and at the shorelines. It takes prolonged periods of warming for water warmed by the sun to mix with deeper, cold water. Nevertheless, this could mean increased luck for the angler who seeks out those shallow warm pockets. But don’t expect cold-water trout to come jumping.

The Nevada Department of Wildlife (NDOW) protects, restores and manages fish and wildlife, promotes fishing, hunting, and boating safety. NDOW’s wildlife and habitat conservation efforts are primarily funded by sportsmen’s license and conservation fees and a Federal surcharge on hunting and fishing gear. Support wildlife and habitat conservation in Nevada by purchasing a hunting, fishing, or combination license. For more information, visit www.ndow.org.