Flamingo Research in the Anderson Lab
Flamingos are among the most beautiful and highly gregarious of avian species. Despite the popular interest in flamingos (think lawn ornaments), their general apprehension of people as well as the seclusion and oft aversive conditions of their preferred haunts have historically made them relatively difficult to study in the wild (see Brown, 1959), and thus many basic questions about the behavior of these fascinating birds have remained under-investigated.
Indeed, research on captive flamingo flocks is necessary to address a variety of issues that cannot be easily investigated in the wild (King, 2008). In particular, tracking the behaviors of individual birds over time is much more readily done in a zoological setting (but see Childress et al., 2004), and thus my students and I have been engaged in observational studies of the captive flock of Caribbean flamingos (Phoenicopterus ruber) at the Philadelphia Zoo (Philadelphia, PA, USA). We have also employed webcams focused on both captive and wild flocks around the globe in an effort to examine various flock-level behaviors.
While we are interested in all aspects of flamingo behavior, many studies have focused on flamingo resting behaviors, as rest is itself an easily observable, fairly stable behavioral state. When flamingos rest they lay their heads on their backs. This forces the birds to curve their necks to either the right or left of their individual center of gravity. We have demonstrated that many of the Philadelphia Zoo's Caribbean flamingos display a lateral side preference when choosing the direction in which to rest their necks, and that this preference is fairly consistent across time (Anderson, Williams, & O’Brien, 2009; Anderson, Williams, & Bono, 2010; Williams & Anderson, 2012). Moreover, while a great deal of variability in the direction and strength of this preference exists across birds, the majority of birds tend to rest their necks to the right. Interestingly, this preference has also been demonstrated in another captive population of Caribbean flamingos (Anderson, Urbine, Wilson, & Calabro, 2011) and in a wild population of Lesser flamingos (Phoeniconaias minor) (Anderson, 2009), suggesting that it may generalize to other flamingo groups (but see Hughes, Cauthen & Driscoll, 2014), but additional research is necessary to further investigate this possibility. While the function of such lateral preferences at the individual level is commonly thought to be one of task sharing and reduction in neural redundancy across the brain's two hemispheres (e.g., Rogers, 2000), population-level lateral behavioral asymmetries have been tougher to explain, but may involve enhancement of social cohesion (e.g., Rogers & Workman, 1989) or coordination (e.g., Bisazza, Cantalupo, Capocchiano, & Vallortigara, 2000), among other possibilities. The presence of such a population-level lateral preference in the highly gregarious Caribbean flamingo (e.g., Anderson et al., 2009) lends support to these types of explanations. We have also obtained further evidence of the role of population-level laterality in social cohesion by demonstrating that those flock members that do not conform to the rightward neck-resting standard, instead preferring to rest their necks to the left, are more likely to be involved in aggressive encounters (as either initiator or target) with their fellow birds (Anderson et al., 2010). Moreover, we have shown that individual Caribbean flamingos that are more strongly pair-bonded with their partners tend to differ less from their partners in terms of neck-resting directional preference than do those individuals with weaker pair-bond strengths (Williams & Anderson, 2012).
Another, more familiar, resting behavior displayed by Caribbean flamingos is their tendency to rest while standing on one leg. Surprisingly, while many hypotheses had been proposed to explain why flamingos engage in this behavior, little empirical evidence supporting any of the primary hypotheses had been put forth. Thus, research by the Anderson lab attempted to test several hypotheses in an effort to answer the age-old question of why flamingos stand on one leg. Our results have shown that unipedal resting serves a thermoregulatory function in flamingos (Anderson & Williams, 2010; Bouchard & Anderson, 2011; but see Harker & Harker, 2010), although there may be other benefits to the behavior as well.
More recent projects have focused on the relationship between laterality and health in flamingos (Anderson & Ialeggio, 2014), and have attempted to obtain evidence of lateral preferences in behaviors other than neck-resting (Peluso & Anderson, 2014). In addition, we have been investigating the relationship between various environmental (weather) variables and agonistic behavior in flamingos (Peluso, Royer, Wall, & Anderson, 2013), as well as the existence and impact of social dominance hierarchies in captive flamingo flocks (Royer & Anderson, 2014). Future research is needed to replicate all of our previous findings in other captive and wild populations, as well as in flamingo species other than Phoenicopterus ruber in order to ensure that our observed effects generalize to other flamingo groups.
Our research on Caribbean flamingo resting behavior and efforts to answer the age-old question, "Why do flamingos stand on one leg?" has gained substantial media attention, and has been featured in SJU Magazine (Spring 2009, page 7), the Philadelphia Inquirer (July 28, 2008 pages A1 & A6), BBC Earth News (August 13, 2009) USA TODAY’s On Deadline (August 13, 2009), LiveScience (September 17, 2009), The New York Times (August 23, 2011 pages D1 & D2), WHYY's The Pulse (June 5, 2014), and numerous other media outlets.
It is my hope that by investigating the behavior of flamingos we will come to reach a better understanding of these iconic birds, the workings and evolution of general behavioral processes, and perhaps even ourselves.
Anderson, M. J. (2009). Lateral neck-resting preferences in the Lesser Flamingo (Phoeniconaias minor). In Childress, B., Arengo, F. and Bechet, A. (eds.), Flamingo, Bulletin of the IUCNSSC/Wetlands International Flamingo Specialist Group, No. 17, December 2009. (pp. 37-39). Wildfowl &Wetlands Trust, Slimbridge, UK.
Anderson, M. J., & Ialeggio, D. M. (2014). Behavioural Laterality as a Predictor of Health in Captive Caribbean Flamingos (Phoenicopterus ruber): An Exploratory Analysis. Laterality: Asymmetries of Body, Brain and Cognition, 19, 12-36. DOI:10.1080/1357650X.2012.753453.
Anderson, M. J., Urbine, J. L., Wilson, C., & Calabro, L. (2011). Employment of web-based images and a live web cam in the examination of lateral neck-resting preferences in the American flamingo (Phoenicopterus ruber). Journal of Caribbean Ornithology, 24, 41-47. (can be found here)
Anderson, M. J., & Williams, S. A. (2010). Why do flamingos stand on one leg? Zoo Biology, 29, 365-374. DOI 10.1002/zoo.20266. [Erratum. Zoo Biology. DOI: 10.1002/zoo.21051].
Anderson, M. J., Williams, S. A., & Bono, A. J. (2010). Preferred neck resting position predicts aggression in Caribbean flamingos (Phoenicopterus ruber). Laterality: Asymmetries of Body, Brain and Cognition, 15, 629-638. DOI: 10.1080/13576500903081814.[Corrigendum. (2012). Laterality, 17 (6), 755-756].
Anderson, M. J., Williams, S. A., & O'Brien, E. H. (2009). Individual differences in preferred neck resting position of Caribbean flamingos.Laterality: Asymmetries of Body, Brain and Cognition, 14, 66-78.[Corrigendum. (2012). Laterality, 17 (6), 755-756].
Bisazza, A., Cantalupo, C., Capocchiano, M., & Vallortigara, G. (2000). Population lateralisation and social behaviour: A study with 16 species of fish. Laterality: Asymmetries of Body, Brain and Cognition, 5, 269-284.
Bouchard, L. C., & Anderson, M. J. (2011). Caribbean flamingo resting behavior and the influence of weather variables. Journal of Ornithology, 152, 307-312. DOI 10.1007/s10336-010-0586-9. [Erratum. (2013). J. Ornithol., 154, 319, DOI 10.1007/s10336-012-0913-4].
Brown, L. (1959). The Mystery of the Flamingos. Country Life, London.
Childress, B., Harper, D., Hughes, B., van den Bossche, W., Berthold, P. & Querner, U. (2004). Satellite tracking Lesser Flamingo movements in the Rift Valley, East Africa: Pilot study report. Ostrich, 75, 57-65.
Harker, T.D., & Harker, R.F. (2010). Why do birds stand on one leg? - A pilot study of exotic and native New Zealand birds. Notornis, 57, 173-177.
Hughes,A.L., Cauthen,J. & Driscoll,C. 2014. Testing for behavioral lateralization in observational data: A Monte Carlo approach applied to neck-looping in American flamingos. The Wilson Journal of Ornithology, 126: 345-352.
King, C. E. (2008). The potential contribution of captive flamingos to research (pp 61-64). In Childress, B., Arengo, F. and Bechet, A. (eds.). Flamingo, Bulletin of the IUCN- SSC/Wetlands International Flamingo Specialist Group, No. 16. December, 2008. Wildfowl & Wetlands Trust, Slimbridge, UK.
Peluso, A. I., & Anderson, M. J. (2014). The role of lateralization in feeding behavior and scratching preference in relation to social behavior in captive Caribbean flamingos (Phoenicopterus ruber). Animal Behavior and Cognition, 1, 51-65.
Peluso, A. I., Royer, E. A., Wall, M. J., & Anderson, M. J. (2013). The relationship between environmental factors and flamingo aggression examined via internet resources. Avian Biology Research, 6, 215-220.
Rogers, L. J. (2000). Evolution of hemispheric specialization: Advantages and disadvantages. Brain and Language, 73, 236-253.
Rogers, L., & Workman, L. (1989). Light exposure during incubation affects competitive behaviour in domestic chicks. Applied Animal Behaviour Science, 23, 187-198.
Royer, E. A., & Anderson, M. J. (2014). Evidence of a dominance hierarchy in captive Caribbean flamingos and its relation to pair bonding and physiological measures of health. Behavioural Processes, 105, 60-70.
Williams, S. A., & Anderson, M. J. (2012). Pair Bonding and Lateral Neck-Resting Preferences in Captive Caribbean Flamingos (Phoenicopterus ruber). Laterality: Asymmetries of Body, Brain and Cognition, 17, 565-582. DOI:10.1080/1357650X.2011.589519. [Corrigendum. (2012). Laterality, 17 (6), 755-756].
Wetlands International Flamingo Specialist Group
Caribbean flamingos at the Philadelphia Zoo
Caribbean flamingos at the Smithsonian National Zoological Park