The Chihuahuan Desert has been overgrazed by livestock ranching since the 16th century. This has changed the structure and dynamics of the ecosystem, and native species have developed physiological adaptations to survive these vegetation changes. We evaluated the changes in packed cell volume (PCV) and plasma protein of Dipodomys merriami, Merriam's kangaroo rats, inhabiting shrubland and grassland areas at Mapimí Biosphere Reserve, Chihuahuan Desert, Mexico. We captured 57 individuals from two vegetation types in March–April for two years. We found higher kangaroo rat packed cell volume in grassland than shrubland. However, the plasma protein/packed cell volume ratios were not significantly different between rats from both vegetation types, suggesting that an increase in PCV is a consequence of dehydration. Monitoring the packed cell volume can be a useful and rapid screening tool to assess responses to changes in habitat degradation in arid areas.

自16世纪以来，奇瓦瓦沙漠一直被牧场放牧。这改变了生态系统的结构和动态，原生物种已发展出生理适应性以适应这些植被变化。我们评估了Dipodomys merriami的包装细胞体积（PCV）和血浆蛋白的变化，是墨西哥墨西哥奇瓦瓦沙漠Mapimí生物圈保护区的灌木丛和草原地区的Merriam袋鼠大鼠。在两年的三月至四月，我们捕获了来自两种植被类型的57个人。我们发现草原上的袋鼠大鼠堆积细胞数量比灌木地更高。然而，两种植被类型的大鼠之间血浆蛋白/包装细胞体积比没有显着差异，这表明PCV的增加是脱水的结果。监测包装细胞的体积可以是一种有用的快速筛选工具，用于评估对干旱地区栖息地退化变化的响应。