Peer Review #2 of "Elevational pattern of bird species richness and its causes along a central Himalaya gradient, China (v0.1)" [peer_review]

2016 unpublished
To improve our understanding of mechanisms underlying biodiversity patterns, and provide valuable insights for conservation biologists, elevational pattern of bird species richness and its causes were studied along a central Himalaya gradient, China for the first time. We conducted field surveys at each of twelve elevational bands of 300 m for four times throughout the whole wet season between 1800-5400 m asl. A total of 169 breeding bird species were recorded, belonging to 11 orders, 41
more » ... s and 100 genera. Species richness patterns of overall breeding birds, large-ranged and small-ranged species were all hump-shaped, and peaked at the 2700-3000 m asl (overall), 3300-3600 m asl (largeranged species), whereas small-ranged species had two peaks, with the larger peak occurring at the 2700-3000 m asl and the smaller peak at the 3600-3900 m asl. Area and precipitation were not crucial factors in determining species richness along this gradient. Productivity, habitat heterogeneity (HH) and the mid-domain effect (MDE) all played important role in shaping elevational richness patterns of birds in individual regression analyses. In the multiple regressions, productivity and HH were strong explanatory factors for most of the bird groups, with MDE contributing to richness pattern of large-ranged species. Our results highlight the conservation necessity of primary forest and intact habitat in this montane biodiversity hotspot. PeerJ reviewing PDF | Abstract Elevational patterns of bird species richness and their causes were studied along a central Himalaya gradient for the first time in the Gyirong Valley, the longest of five canyons in the Mount Qomolangma National Nature Reserve. We conducted field surveys in each of twelve elevational bands of 300 m between 1800 and 5400 m asl four times throughout the entire wet season. A total of 169 breeding bird species were recorded, belonging to 11 orders, 41 families and 100 genera. Most of the birds (74%) were small-ranged. The species richness patterns of overall breeding birds and large-ranged birds were all hump-shaped and peaked at 2700-3000 m asl (overall) and 3300-3600 m asl (large-ranged species), whereas small-ranged species had two peaks, with the larger peak occurring at 2700-3000 m asl and the smaller peak at 3600-3900 m asl. Large-ranged species and small-ranged species contributed equally to the overall richness pattern. Based on the bivariate and multiple regression analyses, area and precipitation were not crucial factors in determining the species richness along this gradient. The mid-domain effect played an important role in shaping the richness pattern of large-ranged species. Temperature was negatively correlated with overall and large-ranged species but was positively correlated with small-ranged species. Productivity was a strong explanatory factor among all the bird groups, and habitat heterogeneity played an important role in shaping the elevational richness patterns of overall and small-ranged species. Productivity best explained the species richness patterns of overall and large-ranged birds, whereas habitat heterogeneity best explained the richness pattern 42 43 44 45 46 PeerJ reviewing PDF | (
doi:10.7287/peerj.2636v0.1/reviews/2 fatcat:cdkt3duhsrdz5pi5btr3jbwmim