Individual differences in the preferred neck-resting position of Caribbean flamingos (Phoenicopterus ruber)

Abstract

When resting, flamingos often lay their heads along their backs. While in this position they must curve their necks to either the right or left of their midline. Observations of captive Caribbean flamingos at the Philadelphia Zoo (Philadelphia, PA, USA) were conducted in order to determine if individual birds would display consistent preferences in neck-resting position over multiple observations. While individual birds were shown to vary greatly in regards to the strength and direction of their preferences, a significant flock-level preference towards neck resting to the right was obtained. Analysis of individual flamingos revealed that 5 out of 17 birds displayed preferences that significantly differed from chance, with each of these birds preferring to rest their necks to the right. From the present data we can conclude that flamingos display behavioural laterality of neck-resting position at both the level of the group and that of the individual.

Why do flamingos stand on one leg?

“…Similarly, individual binomial tests comparing the observed instances of resting while standing on the right and left leg for each bird failed to reveal significant lateral biases at the level of the individual (P40.05, two-tailed). Thus, it can be concluded that, unlike their own neck resting behavior [Anderson et al, 2009], and the preferred resting leg stances of several other bird species [Randler, 2007], Caribbean flamingos do not display individual or group level lateral preferences in leg stance while resting.…”

“…First, we sought to determine whether flamingos resting on one leg display individual or flock level lateral preferences in leg stance. As we have recently shown both individual and flock level lateral preferences in neck resting position, with most birds preferring to curve their necks to the right of their bodies when resting their heads on their backs [Anderson et al, 2009] (see Fig. 1), such preferences in leg stance seemed possible.…”

“…Permission to observe the flock was granted by both the Saint Joseph's University Institutional Animal Care and Use Committee, and the Philadelphia Zoo, which provided demographic information for each bird prior to the start of the study. As previous research has suggested that flamingos typically rest around midday [e.g., Bildstein et al, 1991;Anderson et al, 2009], observations for each study described in this report were made from public viewing areas between 11:00 a.m. and 3:30 p.m. (EST). As birds were inaccessible when in the indoor enclosure, all observations made were of birds in the outdoor areas.…”

Preferred neck-resting position predicts aggression in Caribbean flamingos (Phoenicopterus ruber)

“…In order to achieve this positioning they curve their necks to either the right or left of their midline. Previously we have shown both individual and flock-level laterality of preferred neck-resting direction, with most birds preferring to rest their necks to their right (Anderson, Williams, & O'Brien, 2009). As laterality has been shown to play a role in social cohesion (e.g., Rogers & Workman, 1989) and aggression (e.g., Vallortigara, Cozzutti, Tommasi, & Rogers, 2001), here we attempted to determine whether a flamingo's preferred neck-resting direction could be used to predict involvement in aggressive encounters.…”

“…In a recent study we tested for potential lateral asymmetry in the resting behaviours of Caribbean flamingos (Phoenicopterus ruber) (Anderson et al, 2009). When flamingos rest they lay their heads on their backs.…”