Breath rate patterns in precocial Northern Lapwing (Vanellus vanellus) chicks in the wild

Abstract

Individual-specific reaction to stressful situations may reveal various, individual-specific features, including personality. Breath rate and its change during and after handling [handling stress (HS) test] has been used to test individual response to stress. In previous laboratory research, the HS test has revealed a continuous decrease from peak values immediately after catching, which was consistent in adults of precocial and altricial species. Because of opposite trends in nestlings versus adults in altricial birds, we ask what breath rate pattern appears in precocial chicks in natural conditions? Advanced development during their early ontogeny compared to altricials could lead to breath rates similar to adults, but the effect of age, (in)experience, as well as environmental conditions, such as ambient temperature, may significantly shape breath rate patterns in chicks in different ways than in adults. In this study, we examined patterns in breath rate in response to HS in chicks of different age in a precocial wader, the Northern Lapwing (Vanellus vanellus) in the wild. Factors responsible for variation were simultaneously identified. We show that breath rate significantly dropped after visual isolation in a textile bag, a pattern similar to that in adult birds, and increased with the age of chicks as well as with higher ambient temperature. Breath rate was individually repeatable, but did not reflect individual behaviour observed before capture. Our results suggest that, when controlled for ambient temperature and time before catching, the breath rate pattern has the potential to be used as a useful HS test for neonatal Northern Lapwing chicks in the field.