How temperature, humidity, and burrow selection affect evaporative water loss in desert tortoises

摘要

By combining field behavior and microclimate measurements with biophysical models, I assessed the value of underground burrows as thermal refuge for desert tortoises (Gopherus agassizii) and their additional advantage for water conservation. Between 1000-1200 h, humidity was significantly higher and temperature and predicted evaporative water loss (EWL) lower inside burrows than on the surface. Greater burrow length and smaller entrances were correlated with greater burrow humidity. Furthermore, the range of variation in humidity. temperature and EWL over 24 h was greater on the surface than inside burrows. Thus. Surface conditions would be more favorable during certain times of day.