干旱区生态环境知识资源中心

The yellow-nosed cotton rat (Sigmodon ochrognathus) previously was known only from extreme southwestern New Mexico in the Peloncillo and Animas mountains. Here I document S. ochronathus at 3 localities from the Big Burro and Mogollon mountains in southwestern New Mexico. My northernmost capture represents an extra-limital record of 160 kin north of prior records in southern New Mexico and represents the northernmost Occurrence in North America. Lack of intensive mammalian surveys in the region render it difficult to interpret my recent captures, but the most parsimonious explanation is that captures likely represent overlooked populations. I captured S. ochrognathus in grassy areas ungrazed by domestic livestock along die Gila River. Understanding the use of limited grassland habitats along arid rivers by terrestrial vertebrates in the region is important because many of these grasslands have been converted to agricultural lands or are grazed by livestock.