Barve Sahas, La Sorte Frank A
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America.
Cornell Laboratory of Ornithology, Cornell University, Ithaca, New York, United States of America.
PLoS One. 2016 May 5;11(5):e0154871. doi: 10.1371/journal.pone.0154871. eCollection 2016.
Food availability is known to influence parental care and mating systems in passerine birds. Altricial chicks make uni-parental care particularly demanding for passerines and parental investment is known to increase with decreasing food availability. We expect this to limit uni-parental passerines to habitats with the most consistent food availability. In passerine birds, species having uni-parental care are primarily female-only parental care (female-only care) and most passerine birds with female-only care are frugivores. We predict that frugivorous passerines with female-only care should be restricted to the most stable habitats characterized by longer fruiting season length. At a global scale, female-only care frugivores were distributed in areas with significantly longer fruiting seasons than non-female-only care frugivores. Female-only care species richness had a stronger spatial relationship with longer fruiting season than non-female-only care species richness. Verifying the lack of a phylogenetic signal driving this pattern, our findings indicate that the geographic distribution of female-only care, a geographically and phylogenetically widespread parental care system, is restricted by an extrinsic factor: fruiting season length. This reinstates the importance of food availability on the evolution and maintenance of parental care systems in passerine birds.
众所周知，食物可获得性会影响雀形目鸟类的亲代抚育和交配系统。晚成雏使得单亲抚育对雀形目鸟类来说格外艰巨，而且已知亲代投资会随着食物可获得性的降低而增加。我们预计这会将单亲雀形目鸟类限制在食物可获得性最稳定的栖息地。在雀形目鸟类中，进行单亲抚育的物种主要是仅由雌性进行亲代抚育（仅雌性抚育），并且大多数进行仅雌性抚育的雀形目鸟类是食果动物。我们预测，进行仅雌性抚育的食果雀形目鸟类应被限制在以结果季节更长为特征的最稳定栖息地。在全球范围内，进行仅雌性抚育的食果动物分布在结果季节明显长于非仅雌性抚育的食果动物的地区。进行仅雌性抚育的物种丰富度与较长结果季节的空间关系比非仅雌性抚育的物种丰富度更强。通过验证不存在驱动这种模式的系统发育信号，我们的研究结果表明，仅雌性抚育这种在地理和系统发育上广泛存在的亲代抚育系统的地理分布受到一个外在因素的限制：结果季节长度。这再次强调了食物可获得性在雀形目鸟类亲代抚育系统的进化和维持中的重要性。
