干旱区生态环境知识资源中心

Seasonal wildlife observations were made along transects on 2 pastures in late seral and 2 pastures in mid seral condition in southcentral New Mexico in non-drought and drought years (1993, 1994). Remaining climax vegetation was about 64% and 57% on late seral pastures. About 37% and 32% of the climax vegetation remained on mid seral pastures. Total wildlife and total bird sightings/km(2) during tbe study period were higher (P < 0.10) on the mid compared to late seral rangelands. The same number of wildlife species were seen on the late and mid seral pastures. Sightings of scaled quail (Callipepla squamata Vigors), mourning doves (Zenaida macroura Linnaeus), pronghorn (Antilocapra americana Ord), and desert cottontails (Sylvilagus auduboni Mearns) showed no differences (P > 0.10) between late and mid seral condition rangelands. Black-tailed jackrabbit (Lepus californicus J.A. Allen) numbers were higher (P < 0.10) on mid than late seral pastures. Drought conditions in 1994 severely depressed (P < 0.01) total wildlife sightings/km(2) compared to 1993 when precipitation conditions were near average. Year effects were significant (P < 0.10) for black-tailed jackrabbit, mourning dove, raven (Corvus corax Gmelin), total songbird, total bird, and total wildlife sightings. Total wildlife sightings in 1994 were reduced by 42% compared to 1993 (256 versus 440 total sightings km(2), respectively).