BURROWS OF DESERT TORTOISES (GOPHERUS AGASSIZII) AS THERMAL REFUGIA FOR HORNED LARKS (EREMOPHILA ALPESTRIS) IN THE MOJAVE DESERT.

Walde, Andrew D.; Walde, Angela M.; Delaney, David K.; Pater, Larry L.

The Mojave Desert is one of the driest and hottest deserts in North America. One would expect that birds living in this desert would be specialists adapted to survive such an environment. However, most of the avifauna present in the Mojave Desert range into cooler, more-humid regions. We report observations of horned larks (Eremophila alpestris) using burrows of the desert tortoise (Gopherus agassizii) during summer as refugia from hot above-ground temperatures. We show that horned larks appear selective of the micro-environment they choose and that burrows are the coolest, most-humid, microsites available. By using burrows of desert tortoises, horned larks may reduce evaporative water loss by ≤65% and they may avoid physiological stress, or potentially death. Additional research should investigate the importance of burrows of desert tortoises to other species as it is likely to provide a key microhabitat to many species that reside in the Mojave Desert.

MOJAVE Desert; NORTH America; TESTUDINIDAE; HORNED lark; ECOLOGICAL niche; ANIMAL species

Southwestern Naturalist, 2009, Vol 54, Issue 4, p375

0038-4909

Academic Journal

10.1894/MH-41.1