Neophobia is an animal's avoidance of novelty. Animals tend to respond to novel objects by increasing their latency to approach the objects, and they eventually habituate after repeated exposure by attenuating this increased approach latency. Interestingly, the physiological stress response does not appear to have a causal link to neophobia, although acute stress can prevent animals from habituating to novel objects, possibly through a permissive effect. Chronic stress can induce an anxiety‐like state in animals, while often disrupting the ability to respond to acute stress. We thus hypothesized that chronic stress may increase neophobia and tested this by inducing chronic stress in wild‐caught European starlings (
Animals often avoid novel objects, a behavior known as neophobia. We examined behavioral responses of captive European starlings to novel objects placed at their food dishes. Exposure occurred concurrently to food reintroduction following overnight fasting. Behavior was analyzed for 10 min via video recording. We expected an increase in avoidance behavior compared with trials in which food was reintroduced without a novel object. Seven of 10 novel objects increased latency to approach the dish. In contrast to our expectations, neither prior restraint nor exogenous corticosterone changed the neophobic response to novel objects. While exposure to a novel object increased approach latency, there was no additional effect of restraining animals in a cloth bag for 15 min before food reintroduction. Furthermore, the subcutaneous injection of corticosterone did not affect approach latency by itself, nor did it affect the response to a novel object. Finally, we expected repeated exposure to the same object to extinguishing the neophobic response, and that restraint stress would prevent habituation. Our results show that European starlings habituate rapidly to exposure to a novel object, as approach latency returned to baseline within three repeated exposures to the same object. When the repeated presentation of the object was combined with prior restraint, however, the latency to approach never returned to baseline. These results reveal that neophobia in starlings is object‐specific and that, while neither acute stress nor corticosterone directly affects the behavioral response to a novel object, acute stress appears to have a permissive effect on neophobia by inhibiting habituation.
more » « less- NSF-PAR ID:
- 10121496
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Experimental Zoology Part A: Ecological and Integrative Physiology
- Volume:
- 333
- Issue:
- 2
- ISSN:
- 2471-5638
- Page Range / eLocation ID:
- p. 88-95
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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