Nuthatches (genus Sitta; family Sittidae) are a passerine genus with a predominantly Nearctic and Eurasian distribution. To understand the phylogenetic position of Sitta and phylogenetic relations within this genus, we sequenced the complete mitochondrial genomes of three Sitta species (S. himalayensis, S. nagaensis, and S. yunnanensis), which were 16,822–16,830 bp in length and consisted of 37 genes and a control region. This study recovered the same gene arrangement found in the mitogenomes of Gallus gallus, which is considered the typical ancestral avian gene order. All tRNAs were predicted to form the typical cloverleaf secondary structures. Bayesian inference and maximum likelihood phylogenetic analyses of sequences of 18 species obtained a well-supported topology. The family Sittidae is the sister group of Troglodytidae, and the genus Sitta can be divided into three major clades. We demonstrated the phylogenetic relationships within the genus Sitta (S. carolinensis + ((S. villosa + S. yunnanensis) + (S. himalayensis + (S. europaea + S. nagaensis)))).

The breeding ecology of birds is the cornerstone of bird life-history theory, and breeding success directly affects the survival and development of populations. We studied the breeding ecology of a secondary cavity-nesting bird, the chestnut-vented nuthatch Sitta nagaensis, in southwestern China from March to June in 2020, 2021, and 2022. In total, 16 nests in nest boxes and 19 nests in natural cavities were studied. The nesting habitat was mainly Pinus yunnanensis forest (68.4%), and the nest trees were mainly P. yunnanensis and pear Pyrus spp. Cavities made by woodpeckers and knot holes were used as nest sites, and the nuthatches plastered the hole entrance with mud. The nesting material was mainly pine bark. The clutch size was 3.47 ± 0.56 (range 2–4, n = 30), with an incubation period of 16.06 ± 0.91 days (range 15–19 days, n = 18). The nestling period was 20.88 ± 1.90 days (range 18–23 days, n = 23), and both parents fed the nestlings.

The complete mitochondrial genome sequence of the Ptyas mucosus was sequenced and reported for the first time using muscle tissue. The total length is 17 151 bp and sequence analysis showed its structure is in accordance with other snakes. The complete mitochondrial genome contains 2 rRNA genes, 21 tRNA genes, 13 protein-coding genes (PCGs), 2 control regions and 1 putative origin of L-strand replication. The gene order and nucleotide composition of P. mucosus are very similar with E. bimaculata, E. anomala and E. schrenckii. A phylogenetic tree of mitochondrial genomes indicated P. mucosus had the most closely relationship with E. bimaculata, and formed a monophyletic group with E. bimaculata, E. anomala and E. schrenckii.

The Spectacled Fulvetta (Fulvetta ruficapilla sordidior) is an endemic bird species to the southwest mountains of China, distributing from 1250 to 2500 m in the widespread broadleaved evergreen forest and occasionally in secondary scrubs. The present study describes its breeding biology for the first time. Fieldwork was conducted in the springs of 2017 and 2018 on Humashan Mountain, a hill mainly covered by secondary forest located at the eastern marginal of Kunming, the capital of Yunnan Province in Southwest China. This bird was found to initiate egg-laying mainly in March, and most nestlings fledged in late April and May. There were 16 nests found in total, which were located mainly in the dense shrubs at a height of 0.99 ± 0.40 m (n = 15). Of the 11 active nests, clutch size averaged 2.73 ± 0.45 (n = 11). Focal observations were made on nests; the incubation lasted for 13.67 ± 0.47 days (n = 3) with a notably high nest attendance, i.e., eggs were incubated 84.23% of the observation time. Nestlings fledged at 13.00 ± 0.71 days (n = 4), and parents feeding frequency increased as the nestlings grew. Overall, the cumulative hatching and fledgling rates were 71.43% and 35.71%, resulting in a nesting success rate of 45.45%.

In this study, we first sequenced and described the complete mitochondrial genome and phylogeny of Psittacula alexandri. The whole genome of P. alexandri was 16,883?bp in length, and contained 14 protein-coding genes, 22 transfer RNA genes, 2 ribosome RNA genes, and 1 non-coding control regions. The overall base composition of the mitochondrial DNA was 30.87% for A, 22.36% for T, 32.82% for C, and 13.95% for G, with a GC content of 46.77%. A phylogenetic tree strongly supported that P. alexandri closely related with Eclectus roratus by highly probability.

This study investigated the gut microbiota of three captive hornbill species ( Anthracoceros albirostris, Buceros bicornis, Rhyticeros undulatus ) at the Nanning Zoo. Fecal samples were aseptically collected from 30 hornbills, and 16S rRNA high-throughput sequencing was employed to analyze the composition, diversity, and potential functions of the gut microbiota. The influence of host taxonomic status, sex, and captive environment on the gut microbiota was explored. The results revealed that the dominant phyla in the gut microbiota of all three hornbill species were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Although no significant differences were detected in the gut microbiota composition among different species and sexes, LEfSe analysis indicated significant enrichment of Erysipelotrichaceae and Lactobacillus_hayakitensis_DSM_18933_JCM_14209 in the Oriental Pied Hornbill group, as well as Clostridiales, Paenibacillaceae, and Paenibacillus_xylanilyticus in the Great Hornbill group. PICRUSt analysis indicated that the functional genes of the gut microbiota in all three hornbill species were primarily enriched in metabolic pathways, showing similar relative abundances. This study suggests that the gut microbiota characteristics of hornbills align with those of omnivorous birds. The homogenization of food resources in a captive environment may weaken the impact of host differences on the gut microbiota. The research findings provide a scientific basis for the health management of captive hornbills and the microecological assessment of wild population habitats.