More fruits, more birds? How plant traits attract birds feeding in urban green spaces during winter

Abstract

Rapid urban development poses drastic changes in bird biodiversity. Trees in urban green spaces play an essential role in bird conservation, providing crucial nesting sites and food resources. The fruits of woody plants offer food resources for birds throughout most of the year, especially during winter. However, the dominant traits of woody plants that attract frugivorous birds to feed in urban green spaces during winter remain poorly understood. To evaluate the interaction network between frugivorous birds and heterogeneous woody plant species, and figure out how plant structure traits, fruit morphological traits, and fruit nutritional traits influence the diversity of frugivorous birds, a pilot sampling survey of frugivorous birds on 10 native woody plant species was conducted on a university campus in Hangzhou, China. The results show that (1) most frugivorous birds interact specifically with certain plant species in urban green spaces during winter; (2) plant-frugivorous birds interaction network showed a significantly low level of connectance, specialization, and nestedness; (3) in all functional traits of woody plants, fruit abundance (FA) contributes most to the richness and abundance of frugivorous birds; (4) in 3 types of functional traits, plant structure traits play dominant roles in determining the richness and abundance of frugivorous birds, with explanatory power of 24.43 % and 34.0 %, respectively. Moreover, combining plant structure traits and fruit traits can better explain the diversity of frugivorous birds. This study expands our knowledge of the effect of plant and fruit traits in attracting frugivorous bird diversity in urban green spaces during winter, which can provide insights for woody plant selection and planting design to conserve bird species diversity in urban areas.