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ABSTRACT Neophobia, avoidance of novel stimuli, is an ecologically and evolutionarily relevant behavioural trait that varies among individuals and across species. Especially among wild animals, the neuromolecular mechanisms underlying individual variation in neophobia have not been well characterised. We examined three neophobic behaviours in captive female and male Eurasian tree sparrows (Passer montanus) from a wild population introduced to the USA in 1870: responses towards novel objects, novel foods, and repeated presentations of the same initially novel object. We compared transcriptomic patterns associated with neophobia in three brain regions, the striatum, dorsal hippocampus, and rostral hippocampus, using differential expression and co‐expression network analyses. We found that the striatum and hippocampus had distinct transcriptomic profiles, as did the rostral and caudal subregions of the hippocampus, supporting recent hypotheses that these subregions are functionally specialised. Despite the absence of sex differences in neophobic behaviours, neophobia‐associated gene modules revealed sex‐specific patterns within brain regions. For females, neophobic behaviours more strongly correlated with gene modules in the caudal hippocampus, a region involved in stress and anxiety, whereas for males, neophobic behaviours correlated with gene modules in the rostral hippocampus, a region that may play a larger role in spatial cognition. These modules exhibited significant overlap, suggesting that neophobic behaviours in both females and males are driven by shared neurobiological mechanisms, though they exhibit sex‐specific patterns of brain region localization. Further, this work highlights the importance of examining both male and female animals in neurobiological research.
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Beak wiping stereotypies are correlated with neophobia and lack of enrichment in captive house sparrows (Passer domesticus)
Behavioural syndromes are suites of correlated behaviours at the population or species level that can affect how wild animals respond to their environments, including potentially stressful situations such as captivity. In this study, we assessed whether beak wiping, a stereotyped anxiety-linked behaviour where birds wipe their beaks on a perch in a “windshield wiper” motion, was correlated with another anxiety-linked behaviour, neophobia to- wards novel objects presented with food, in captive house sparrows (Passer domesticus). We predicted that more neophobic sparrows would also exhibit more beak-wiping stereotypies. We analyzed 1 h long control videos (when sparrows were presented with a normal food dish only; n = 54) from three previous neophobia studies to assess beak wiping frequency, mean beak wiping bout duration, and total bout duration. Sparrows’ reluctance to feed in the presence of novel objects was significantly correlated with the mean duration of beak wiping bouts during control trials. We also found that simple enrichment (rubber perches, manzanita branch perches, and/or artificial pine branches) decreased both the frequency and duration of beak wiping. These findings suggest that high neophobia and high levels of stereotypy may arise due to similar neuroendocrine mechanisms and reflect a “high anxiety” behavioural syndrome. This work also highlights the importance of providing species-appropriate environmental enrichment to decrease the prevalence of stereotypic behaviours in captive songbirds.
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- Award ID(s):
- 2237423
- PAR ID:
- 10665138
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Behavioural Brain Research
- Volume:
- 503
- Issue:
- C
- ISSN:
- 0166-4328
- Page Range / eLocation ID:
- 116075
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1016/j.bbr.2026.116075
