Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa.
Biol Lett. 2010 Aug 23;6(4):475-7. doi: 10.1098/rsbl.2009.1016. Epub 2010 Feb 3.
Many animals must trade-off anti-predator vigilance with other behaviours. Some species facilitate predator detection by joining mixed-species foraging parties and 'eavesdropping' on the predator warnings given by other taxa. Such use of heterospecific warnings presumably reduces the likelihood of predation, but it is unclear whether it also provides wider benefits, by allowing individuals to reduce their own vigilance. We examine whether the presence of an avian co-forager, the fork-tailed drongo (Dicrurus adsimilis), affects rates of vigilance (including sentinel behaviour) in wild dwarf mongooses (Helogale parvula). We simulate the presence of drongos-using playbacks of their non-alarm vocalizations-to show that dwarf mongooses significantly reduce their rate of vigilance when foraging with this species. This is, to our knowledge, the first study to demonstrate experimentally that a mammal reduces vigilance in the presence of an avian co-forager.
许多动物必须在警戒捕食者和其他行为之间进行权衡。一些物种通过加入混合物种觅食群体并“偷听”其他类群发出的捕食者警告，来促进捕食者的检测。这种利用异种警告的行为推测可以降低被捕食的可能性，但目前尚不清楚它是否也通过允许个体降低自身警戒，从而提供更广泛的好处。我们研究了鸟类共觅食者——叉尾卷尾（Dicrurus adsimilis）的存在是否会影响野生矮狐猴（Helogale parvula）的警戒（包括哨兵行为）率。我们模拟了卷尾鸟的存在——播放它们的非警报叫声——结果表明，当与这种物种一起觅食时，矮狐猴的警戒率显著降低。据我们所知，这是第一个通过实验证明哺乳动物在有鸟类共觅食者存在的情况下会降低警戒的研究。
