Hand rearing affects emotional responses but not basic cognitive performance in European starlings

Abstract

Hand rearing is a common procedure in behavioural research on birds. While likely to produce tamer experimental animals, there is a risk that it could induce pathological changes in brain and behaviour similar to those seen in mammals that have experienced maternal separation. We explored the effects of hand rearing on the cognitive and behavioural development of European starlings, Sturnus vulgaris, to assess the generality of results obtained from hand-reared animals. Two groups of age-matched birds were created from the same wild population: one hand-reared from 10 days posthatch and one brought into the laboratory as independent juveniles. These groups were compared on a battery of neuropsychological tasks designed to probe different aspects of cognitive function including learning, perseverative cognition, interval timing, neophobia and impulsivity. There was no evidence for cognitive impairment in the hand-reared birds. They did not have reduced learning speed, impairments in accuracy or precision of interval timing or pathological perseverative cognition compared to the wild-caught birds. Additionally, there was no evidence that birds that developed stereotypies in laboratory cages (predominantly the wild-caught birds) had any cognitive impairments, although this may be because no birds had severe, crystallized stereotypies. There was some evidence that hand-reared birds were less neophobic and less impulsive than wild-caught birds, suggesting that hand rearing might alter emotionally mediated decision making in a direction usually associated with reduced developmental stress in mammals. This study therefore supports the use of hand rearing as an experimental procedure in behavioural research on passerine birds.

A marker of biological ageing predicts adult risk preference in European starlings, Sturnus vulgaris

“…Additionally, in previous studies on separate cohorts of starlings, we found only limited associations between developmental telomere attrition and learning ability (Bateson, Brilot, et al 2015; Nettle, Andrews, et al 2015). We note however that greater developmental telomere attrition was associated with slower autoshaping performance in one of these cohorts (Nettle, Andrews, et al 2015), but also that this measure may reflect differences in neophobia rather than purely cognitive ability (Feenders and Bateson 2013). Similarly, risk preference among aged rats was not associated with performance in a spatial learning task (Gilbert et al 2012).…”

“…18 °C; 40% humidity; 15:9 h light:dark cycle) fitted with 2 wooden perches and 2 water bottles and a water bath, and allowing acoustic and visual contact. The testing apparatus within each cage has been previously described in detail elsewhere (Feenders and Bateson 2013). Briefly, each cage was fitted with an overhead surveillance camera and custom-built operant panel comprising 3 horizontally aligned 4 cm diameter pigeon pecking keys, which could be transilluminated, and a central food hopper connected to an external pellet dispenser delivering 45 mg, grain-based rodent pellets (TestDiet, Richmond, IN).…”

“…Operant training procedures followed those outlined by Feenders and Bateson (2013). First, birds were exposed to pellet rewards delivered to the hopper (2 pellets every 200 ± 50 s for 80 trials daily) until they reliably consumed the pellets.…”

T-pattern analysis for the study of temporal structure of animal and human behavior: A comprehensive review

“…Results demonstrated that wild-caught starlings showed higher numbers of T-patterns indicating more route-tracing (Feenders and Bateson, 2012). Interestingly, some evidence showed that hand-reared starlings were noticeably less neophobic and less impulsive than wild-caught ones (Feenders and Bateson, 2013).…”

A high-accuracy, time-saving method for extracting nest watch data from video recordings

“…Current software, such as EthoVision XT (Noldus Information Technology, 2013), is often used in laboratory-based settings to track the movement and behaviour of rodents and other captive animals (Noldus et al 2001;e.g., Fonio et al 2009;Bechstein et al 2014). To our knowledge, this software has not been employed on free-living animals, and the only work with birds has been in captive settings (e.g., Feenders and Bateson 2013;Wood 2013). One potential advantage to this software is that it can be used with pre-existing video and does not require any specialized recording equipment.…”