the fitzpatrick report using social media Scared skinks eavesdrop on wary weavers

any make scolding calls at secrets to be discovered. PhD student predators to warn other individ- Anthony Lowney is working on describing anthony lowney uals – often their close relatives the diverse community that uses A Kalahari tree skink vigilant and near its –M of a threat. Other birds may eavesdrop nests as refugia in the weaver nest refuge. on these signals because predator-related harsh Kalahari environment. Not all of the information can be particularly valuable. many birds, mammals, reptiles and insects by a distinctive alarm call, likely to be the Some species even hijack these calls. that use the weaver nests live in harmony. equivalent of shouting ‘! Falcon! For example, Fork-tailed Drongos use false One of the more common residents is the Falcon!’ To test whether the skinks react to alarm calls to steal food from other birds. shy Kalahari tree skink, which shares a this change in the weavers’ calls, Anthony Birdwatchers also exploit this phenom- common enemy with Sociable Weavers: performed an experiment that used re- enon to lure skulking species out of cover; the small but ferocious Pygmy Falcon. cordings of weaver alarm and chatter calls. ‘spishing’ mimics alarm calls. But we are As the adage advises, ‘the enemy of Observing skink reactions from a distance, not the only mammals to benefit from my enemy is my friend’, and Kalahari tree he played the social chatter and the skinks bird calls; chipmunks, for example, use skinks appear to take this concept to foraged and basked normally, even when parid alarm calls in decisions about where heart by using information from Soci­ no weavers were present. But when he to forage. able Weavers to reduce the predation risk played the weaver alarm calls, the skinks’ Eavesdropping between widely differ- posed by Pygmy . Anthony has behaviour changed dramatically: they ent species is an exciting field of study spent a lot of time watching skinks on lifted and turned their heads, seemingly and the ecology of information transfer trees. He observed that more skinks bask scanning for approaching danger, and within animal communities still has many in the open and venture farther from the soon fled into cover. colony tree when they have hundreds of Skinks therefore appear to use the Sociable Weaver eyes to warn them of an weavers as an early-warning system by approaching falcon. When the weavers eavesdropping on their calls. Being warned are away foraging, the skinks stay closer to by potentially hundreds of observant cover and fewer are observed. weavers is a useful risk-management To confirm this theory, Anthony com- strategy for skinks. This information facili- pared the skinks’ reactions to a human tates the skinks coexistence with Pygmy approach when weavers were present and Falcons at Sociable Weaver colonies, help- when the weavers were away from the ing them to avoid lethal encounters. This colony. In the birds’ absence, acting as the work is a first step towards demonstrating human ‘predator’ Anthony could approach the potential importance of information to within three metres of a skink before use in determining the outcomes of inter­ it fled into cover. However, with weavers actions between species that associate present, he could seldom get within eight with Sociable Weaver nests. Future work is metres of them because the weavers likely to unveil more subtleties within this raised the alarm and fled to safety, with complex multi-player system. the skinks following suit. Interestingly, ROBERT THOMSON skinks don’t flee before the weavers react, indicating that when weaver information For more information, contact is available, the skinks use it and trust it. The Director, FitzPatrick But what cues are the weavers using? Institute of African Ornithology, Anyone who has visited a Sociable University of Cape Town, Weaver colony can attest that the weavers Rondebosch, South 7701. robert thomson chatter a lot. However, when a Pygmy Fal- E-mail [email protected], A Pygmy Falcon with a skink meal. con approaches, the chattering is replaced tel. +27 (0)21 650 3291 or visit www.fitzpatrick.uct.ac.za

18 african birdlife