Date of Graduation

Spring 5-29-2009

Document Type


Degree Name

Master of Science in Biology


College of Arts and Sciences



First Advisor

Scott Nunes

Second Advisor

Karen Francis

Third Advisor

Patricia Schulz


Maternal behavior is an important behavior because it influences whether or not raising one’s offspring is successful. Maternal experience is positively correlated with successful maternal behavior. This association is evident when comparing first-time mothers with mothers who have prior experience raising young. Life experience not related to raising young can also positively influence maternal behavior. In this work, the hypothesis that is tested is whether or not maternal experience enhances the ability of a female to assess the threat level of a situation. The model species used to conduct the study is the Belding ground squirrel (Spermophilus beldingi), and the study is conducted in an alpine meadow near Yosemite’s Tioga Lake, which is the native habitat of the model species. To test the hypothesis, the research team conducts intruder tests in which an unfamiliar male in a cage is placed in a female’s maternal territory. Responses to the intruder male are recorded for multiparous adult, primiparous adults, and primiparous yearling females. As the breeding season progresses, all three female types learn to respond appropriately, but in the early breeding season, the primiparous yearling females do not show appropriate cautionary activity toward the intruder. Instead, they are passive, and they only observe the intruder male. However, primiparous adults do also show appropriate activity early in the breeding season, which indicates that maternal experience can also be learned through life experience.

Included in

Biology Commons