Multi-dimensional niche differentiation of two sympatric breeding secondary cave-nesting birds in Northeast China using DNA metabarcoding.

Niche theory predicts that ecologically similar sympatric species should show differentiation in at least one of the main niche dimensions (time, space, and/or food). Here, we combined observations of breeding timing, nest site selection, and diet (the latter determined using DNA metabarcoding) to analyze the niche overlap and differentiation between two sympatric secondary cavity-nesting birds, the Japanese Tit Parus minor and the Yellow-rumped Flycatcher Ficedula zanthopygia. The results showed that (1) there were significant differences in the first egg laying date, length of the egg laying period, incubation date, and hatching date between tits and flycatchers, and the breeding time of flycatchers peaked later (about 30 days) than that of tits; (2) the two species had a large overlap in nest site selection, although the canopy coverage and shrub density of flycatchers were significantly higher than those of tits; and (3) the niche overlap in diet was minimal, with both species heavily relying on Lepidoptera (39.6% and 63.7% for tits and flycatchers, respectively), but with flycatchers consuming significantly higher percentages of Lepidoptera, Diptera, and Coleoptera than tits. The results indicate that these two sympatric secondary cavity-nesting species have significant niche differentiation in breeding time and diet, but little differentiation in nest site selection.

The complete mitochondrial genome of the Yellow-rumped Flycatcher (Ficedula zanthopygia) from Maorshan, China.

The Yellow-rumped Flycatcher (Ficedula zanthopygia) is a secondary cavity nesting bird and widely distributed in China, Mongolia, Russia and Korea. In this study firstly sequenced the mitotic genome of the Yellow-rumped Flycatcher (Ficedula zanthopygia) gathered at Maorshan, China, using Illumina high-throughput sequencing technology, and then annotated the assembly. The total length of the complete mitochondrial genome is 16,730 bp and it consists of 13 protein-coding, 22 tRNA, 2 rRNA genes, and 1 control region (CR). The CR is 1148 bp in length. The nucleotide composition is 29.59% A, 14.75% T, 32.13% G, 23.54% C. The result of phylogenetic analysis showed that there is close genetic relationship among Ficedula zanthopygia and Ficedula hyperythra.