Age-Related Change in the Association Choices of Two Species of Juvenile Flamingos

SIMPLE SUMMARY: Flamingos are highly social birds that live in large flocks. Flamingos are commonly housed in zoological collections but can be challenging to breed regularly. The characteristic bright pink plumage colour of adult birds develops over time. Anecdotally, young flamingos have been observed to appear on the edges of flamingo flocks. Therefore, this project aimed to measure the social behaviour of juvenile flamingos and record where they were found in two zoo enclosures for two species of flamingo. This project identified that juvenile flamingos prefer to spend time with birds of their own age and are most commonly seen on the periphery of their flock. However, this can be dependent on species and situation (e.g., management impacts on flock structure). We suggest improvements to flamingo enclosures to provide quality, accessible resources for all individuals of all ages that are housed under human care. ABSTRACT: Flamingos are colonial species commonly kept in zoos, well known for their bright plumage and elaborate courtship displays. This project aimed to determine the differences in flock position and association preferences of juvenile Greater Flamingos (Phoenicopterus roseus) and Caribbean Flamingos (P. ruber) housed in the same zoological collection. Little research has been conducted on the association preferences of juvenile flamingos, especially in captive flocks, and therefore this study collected data using photographs taken throughout 2014 and 2015 to further understand association patterns. Data were collected on the age category of each juvenile flamingo observed, the age of their nearest neighbour and their position within the flock, and the location within an enclosure zone at different times of the day. The results showed that Greater Flamingo juveniles mainly associated with individuals of their own age and were most likely positioned at the periphery of their flock significantly more of the time until approximately 24 months of age. Sub-adult Greater Flamingos spent significantly more time associating with adult flamingos at the centre of the flock. In contrast, data collected on Caribbean Flamingos indicated that juveniles did not segregate themselves from the adults as distinctively. Birds aged 13–24 months were observed significantly more at the centre of the flock and had more associations with adult flamingos, in a similar manner to that observed in Greater Flamingos. Due to population management needs, juvenile Caribbean Flamingos were removed from the flock at the start of 2015 and this may have influenced the association and location preferences of the remaining young flamingos. In conclusion, these results indicated that captive juvenile flamingos were often seen away from adult birds and that sub-adult flamingos returned to the heart of their natal flock to associate significantly more with other adult individuals, potentially preparing for mate selection and breeding. Captive enclosure should therefore be spacious enough to enable young flamingos to remove themselves from adult birds so that behavioural development can be unaffected by artificially high rates of aggression.