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Foraging in the tropics: relationships among species’ abundances, niche asymmetries and body condition in an urban avian assemblage

Pagani-Núñez, Emilio; He, Chao; Wu, Yi Wei; Peabotuwage, Indika; Goodale, Eben


Chao He

Yi Wei Wu

Indika Peabotuwage

Eben Goodale


Two main theories attempt to explain species coexistence: the neutral theory considers all the species as equivalents so biodiversity is mainly regarded as a function of total available resources (i.e. niche expansion), while the niche theory stresses the relevance of differences in niche use between species (i.e. niche packing). The relative importance of these forces is under discussion and has been largely tested in natural ecosystems. However, few studies have addressed this issue in tropical-urban environments. In this work we studied niche overlap asymmetries among the most common urban resident birds, and the effect of habitat type on this pattern, in a subtropical location of South China (Nanning, Guangxi). We found differences in abundances and niche use among species and urban habitats (parks, streets and orchards). We also recorded strong asymmetries in niche use between species, which we divided into three categories: species with positive asymmetries, which showed highly specific niches and were able to exploit other species’ niches; species with neutral asymmetries, which showed high levels of niche overlap with the rest of species; and species with negative asymmetries, which showed low specificity in their niches and were unable to exploit other species’ niches. These differences in niche use correlated with differences in fat scores. Species from the first group showed higher fat scores than other two groups. Ultimately, niche asymmetries correlated with species’ body condition and mediated their differences in abundance, which supports the view that in this urban context niche theory is more appropriate than neutral theory.

Journal Article Type Article
Online Publication Date May 23, 2017
Publication Date 2017-12
Deposit Date Nov 2, 2022
Journal Urban ecosystems
Print ISSN 1083-8155
Publisher Springer
Peer Reviewed Peer Reviewed
Volume 20
Issue 6
Pages 1301-1310
Keywords Avian community, Niche overlap, Tropical Asia, Urban ecosystems
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