Developmental and geographic variation in stress hormones in wild Belding's ground squirrels (Spermophilus beldingi)

Developmental and geographic variation in stress hormones in wild Belding's ground squirrels (Spermophilus beldingi).

Extensive research has been conducted on the role of glucocorticoids in regulating growth, mobilizing energy, responding to stressors and modulating learning and memory. However, little is known about the production of corticoids during early development in free-living animals, particularly during sensitive periods of acquisition of important behaviors. In a four-year study of Belding's ground ...

Early auditory experience and the ontogeny of alarm-call discrimination in Belding's ground squirrels (Spermophilus beldingi).

Because young ground squirrels are vulnerable to predation, selection would favor the early ability to respond to alarm calls. This requires discrimination of classes of alarm calls from each other as well as from non-alarm calls. Pre-emergent auditory experience may influence the development of discrimination. As a means of determining when Belding's ground squirrels (Spermophilus beldingi) ca...

Bile constituents in hibernating golden-mantled ground squirrels (Spermophilus lateralis)

BACKGROUND Golden-mantled ground squirrels (S. lateralis) are anorexic during the winter and survive by exploiting hibernation to reduce energetic demands. The liver normally plays a critical role in fueling and regulating metabolism and one might expect significant changes in hepatobiliary function with hibernation. We analyzed bile collected from animals in summer, animals in winter that were...

Hibernation effects on memory in European ground squirrels (Spermophilus citellus).

Effects of hibernation on memory were tested in European ground squirrels (Spermophilus citellus). The animals were trained in summer to successfully accomplish two tasks: a spatial memory task in a maze and an operant task on a feeding machine. One group hibernated normally, and the other was prevented from hibernation by maintaining ambient temperature at 22 degrees C. In spring, the same tas...

Individual variation in the antisnake behavior of California ground squirrels (Spermophilus beecheyi)