A heightened vigilance state alters mechanics of jump backs in kangaroo rats (D deserti)


Meeting Abstract

131-3  Tuesday, Jan. 7 14:00 – 14:15  A heightened vigilance state alters mechanics of jump backs in kangaroo rats (D. deserti) SCHWANER, MJ*; FREYMILLER, GA; CLARK, RW; MCGOWAN, CP; University of Idaho, Moscow, ID; San Diego State University, San Diego, CA; San Diego State University, San Diego, CA; University of Idaho, Moscow, ID schw1900@vandals.uidaho.edu

Predation pressures shape most animals’ morphology and behavior. In the presence of a predator, animals have been shown to increase vigilance. Kangaroo rats, a bipedal hopping desert rodent, are known to exhibit a series of stereotyped anti-snake behaviors, such as head bobbing, foot drumming, and jump backs. During jump backs, animals make sudden jumps backwards without changing body or head orientation. These behaviors occur in response to predators, but also to novel objects. According to literature, in a vigilant state, kangaroo rats increase their performances; however, the difference in mechanics of these behaviors is less well studied. We hypothesized that kangaroo rats would respond faster, jump higher during jump backs, and perform more jump backs when experiencing a heightened vigilance state due to exposure to a predator. To test this, we collected data in the Mojave Desert (CA) using high-speed video examining jump height, take-off time, and number of jump backs by kangaroo rats that were in a heightened vigilance state after exposure to sidewinder rattlesnakes and individuals that did not see a snake before their encounter with a novel object. Comparing performance in both behavioral states showed that kangaroo rats in a state of higher vigilance performed more jump backs (4 – 9) in series and jump higher (0.10 – 0.26 m) compared to animals in less vigilant behavioral state (1 – 2 jumps in series, 0.06 – 0.18 m). That behavioral state can alter performance, suggests that laboratory studies might underestimate an animals’ predator escape ability in the wild.

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