Exploring object neophobia in wild nesting house wrens

CARRO, MARIANA E.; FERNÁNDEZ, GUSTAVO J

Maine

Congreso; Northeast Natural History Conference; 2021

Association for Field ornithologists and Wilson Ornithological Society

Neophobia is an aversive behavior towards novelobjects or places. Many animals show some degree of aversion to novelty, andneophobia can shape their responses to the environment. Here, we examine theindividual variation in the response of nesting southern house wrens (Troglodytes aedon bonariae) to a novelobject, and assess the relationship of these responses with the individualaggressiveness and the risk-taking responses when there is a potential threatnear the nest. Also, we evaluate the effect of age and body size and conditionon the responses of individuals. The study was conducted in GeneralLavalle, Buenos Aires province, Argentina, during the 2014 and 2015 breedingseasons (September-January). A total of 17 breeding pairs were tested. Theindividuals used in these experiments were captured, banded (those that werenot previously marked), weighed and their tarsus was measured. We used playbackexperiments to characterize the aggressive response of males and exposed thenest to a threat during egg-laying to assess the aggressive response offemales. During the nestling rearing period, when nestling were 10-days old, weplace a piece of white paper around the entrance of the nest. We measured thelatency to enter of both males and females as a measure of avoidance to thenovel object. The response to a potential risk near the nest was measured asthe latency to enter the nest of males and females when an observer waspositioned 10 m from the nest. Males and females differed in their response tothe novel object. The response of males was positively related to theirresponse to a threat to the nest. In addition, individuals in better condition shorterlatency to entry the nest in presence of the novel object. The response offemales, on the other hand, was mostly explained by the age of the individuals,with older females being more likely to explore the novel object. The resultsshow that neophobia seems to respond not only to individual characteristics butmay also be influenced by life history strategies, responding to the relativecosts and benefits for each sex.