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Open Access Research Article Issue
Population genomic data reveal low genetic diversity, divergence and local adaptation among threatened Reeves’s Pheasant (Syrmaticus reevesii)
Avian Research 2024, 15 (1): 100156
Published: 30 December 2023
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Population genomic data could provide valuable information for conservation efforts; however, limited studies have been conducted to investigate the genetic status of threatened pheasants. Reeves’s Pheasant (Syrmaticus reevesii) is facing population decline, attributed to increases in habitat loss. There is a knowledge gap in understanding the genomic status and genetic basis underlying the local adaptation of this threatened bird. Here, we used population genomic data to assess population structure, genetic diversity, inbreeding patterns, and genetic divergence. Furthermore, we identified candidate genes linked with adaptation across the current distribution of Reeves’s Pheasant. The present study assembled the first de novo genome sequence of Reeves’s Pheasant and annotated 19,458 genes. We also sequenced 30 individuals from three populations (Dabie Mountain, Shennongjia, Qinling Mountain) and found that there was clear population structure among those populations. By comparing with other threatened species, we found that Reeves’s Pheasants have low genetic diversity. Runs of homozygosity suggest that the Shennongjia population has experienced serious inbreeding. The demographic history results indicated that three populations experienced several declines during the glacial period. Local adaptative analysis among the populations identified 241 candidate genes under directional selection. They are involved in a large variety of processes, including the immune response and pigmentation. Our results suggest that the three populations should be considered as three different conservation units. The current study provides genetic evidence for conserving the threatened Reeves’s Pheasant and provides genomic resources for global biodiversity management.

Open Access Research Article Issue
Using non-destructive sampling to evaluate the population genomic status of captive Brown Eared Pheasants
Avian Research 2023, 14 (2): 100078
Published: 13 January 2023
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Evaluating the genetic status of threatened species is an essential task in conservation genetics. However, the genetic status of threatened species has been mostly evaluated through techniques that fail to estimate genetic diversity at the whole genomic level. Next generation sequencing can meet this demand, but high quality samples such as blood or muscle tissues are required. However, it is difficult to collect such samples from threatened species because sampling work may impact their health. Therefore, it is essential to design a workflow to evaluate the whole genomic status of threatened species using non-destructive sampling. Even though non-destructive sampling has been used in traditional barcoding technique, the barcoding technique cannot evaluate the whole genomic status. Brown Eared Pheasant (Crossoptilon mantchuricum) is an endangered species, with captive populations maintained in Taiyuan Zoo, China, and Europe. However, the genetic diversity, inbreeding pattern, and mutation load of these two populations are unclear. To uncover the genetic status of these two captive populations, we applied 2b-RAD technology to evaluate the genomic status of these populations using feathers as samples. The feathers could be collected by non-destructive sampling. The results indicate that the Taiyuan Zoo population has a lower genetic diversity and higher inbreeding coefficient than the European population. The Taiyuan Zoo population has lethal mutations when homozygous. The current project uses a non-destructive sampling technique to evaluate the whole genomic status of the two captive populations, providing a paradigm for conservation genetics, which will facilitate the development of conservation biology.

Open Access Research Article Issue
Predicting the non-breeding distributions of the two Asian subspecies of Black-tailed Godwit using morphological information
Avian Research 2023, 14 (1): 100069
Published: 01 November 2022
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Until recently, Limosa limosa melanuroides was thought to be the only subspecies of Black-tailed Godwit in the East Asian–Australasian Flyway. For this reason, all previous occurrences and counts of Black-tailed Godwits in the flyway have been assigned to melanuroides. However, a larger-bodied subspecies, bohaii, has recently been discovered in the flyway. As a result, the occurrence of Black-tailed Godwits in the flyway needs to be reconsidered such that the specific distribution of each subspecies becomes known. To this end, we developed a simple discriminant function to assign individuals to subspecies based on their bill and wing length. Cross-validation with individuals known to be bohaii or melanuroides, based on molecular analysis, showed the developed function to be 97.7% accurate. When applied to measurements of godwits captured at 22 sites across 9 countries in East–Southeast Asia and Australia, we found that bohaii and melanuroides occurred at most sites and overlapped in their distribution from Kamchatka to Australia. We examined photos from all along the flyway to verify this surprising result, confirming that both subspecies co-occur in most locations. Based on these results, we hypothesise that bohaii and melanuroides from the west of their breeding ranges mostly migrate over Chinese mainland. Birds of both subspecies from the east of their ranges are expected to migrate along the Pacific Ocean. We encourage ringing groups in East–Southeast Asia and Australia to use this simple method to keep adding knowledge about Black-tailed Godwits in the East Asian–Australasian Flyway.

Open Access Research Article Issue
Identification of annual routines and critical stopover sites of a breeding shorebird in the Yellow Sea, China
Avian Research 2022, 13 (4): 100068
Published: 31 October 2022
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Pied Avocets (Recurvirostra avosetta) are common migratory shorebirds in the East Asian–Australasian Flyway. From 2019 to 2021, GPS/GSM transmitters were used to track 40 Pied Avocets nesting in northern Bohai Bay to identify annual routines and key stopover sites. On average, southward migration of Pied Avocets started on 23 October and arrived at wintering sites (mainly in the middle and lower reaches of the Yangtze River and coastal wetlands) in southern China on 22 November; northward migration started on 22 March with arrival at breeding sites on 7 April. Most avocets used the same breeding sites and wintering sites between years, with an average migration distance of 1124 ​km. There was no significant difference between sexes on the migration timing or distance in both northward and southward migration, except for the departure time from the wintering sites and winter distribution. The coastal wetland of Lianyungang in Jiangsu Province is a critical stopover site. Most individuals rely on Lianyungang during both northward and southward migration, indicating that species with short migration distances also heavily rely on a few stopover sites. However, Lianyungang lacks adequate protection and is facing many threats, including tidal flat loss. We strongly recommend that the coastal wetland of Lianyungang be designated as a protected area to effectively conserve the critical stopover site.

Open Access Research Issue
Multilocus phylogeography and ecological niche modeling suggest speciation with gene flow between the two Bamboo Partridges
Avian Research 2021, 12 (1): 17
Published: 24 April 2021
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Background

Understanding how species diversify is a long-standing question in biology. The allopatric speciation model is a classic hypothesis to explain the speciation process. This model supposes that there is no gene flow during the divergence process of geographically isolated populations. On the contrary, the speciation with gene flow model supposes that gene flow does occur during the speciation process. Whether allopatric species have gene flow during the speciation process is still an open question.

Methods

We used the genetic information from 31 loci of 24 Chinese Bamboo Partridges (Bambusicola thoracicus) and 23 Taiwan Bamboo Partridges (B. sonorivox) to infer the gene flow model of the two species, using the approximate Bayesian computation (ABC) model. The ecological niche model was used to infer the paleo-distribution during the glacial period. We also tested whether the two species had a conserved ecological niche by means of a background similarity test.

Results

The genetic data suggested that the post-divergence gene flow between the two species was terminated before the mid-Pleistocene. Furthermore, our ecological niche modeling suggested that their ecological niches were highly conserved, and that they shared an overlapping potential distribution range in the last glacial maximum.

Conclusions

The allopatric speciation model cannot explain the speciation process of the two Bamboo Partridges. The results of this study supported a scenario in which speciation with gene flow occurring between the allopatric species and have contributed to our understanding of the speciation process.

Open Access Letter to the Editor Issue
An unusual homing behavior found in the Sichuan Partridge during the early brooding period
Avian Research 2020, 11 (1): 47
Published: 04 December 2020
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In this study, we report an unusual homing behavior of the Sichuan Partridge (Arborophila rufipectus) at the Laojunshan National Nature Reserve, Sichuan Province, China. Hen Sichuan Partridges led the chicks back to the nests where they hatched in the evening and roosted there over night. This behavior lasted 6.7 ± 4.3 nights (range = 1–15; n = 13) after the chicks hatched. At this stage, the hens became very vigilant to predators and human disturbance. If disturbed, they often abandoned the nests immediately and no longer returned thereafter. The ambient temperature at night during the early brooding period of Sichuan Partridge at our study site was ~ 12.4 ℃. Our findings suggest that hen Sichuan Partridges may make trade-offs between nest predation risks versus the thermoregulatory needs of their young.

Open Access Research Issue
Characterization of novel microsatellite markers of the Emei Shan Liocichla using restriction site-associated DNA sequencing
Avian Research 2017, 8 (1): 13
Published: 26 May 2017
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Background

The Emei Shan Liocichla (Liocichla omeiensis) is an endemic bird species to southwestern China with a small geographic range. However, little was known about the genetic status of this threatened species.

Methods

We applied restriction-site-associated DNA sequencing (RAD-Seq) for rapid mass identification of microsatellite markers of the Emei Shan Liocichla.

Results

A total of 11, 564 microsatellite sequences were obtained, 600 random loci were designed for screening and 24 polymorphic microsatellite loci were selected for further validation. The average allele number, average observed heterozygosity and average expected heterozygosity were relatively low in our samples, which were 6.08, 0.6618 and 0.7048, respectively, indicating that the Emei Shan Liocichla might have lost some genetic diversity. Further analyses suggested that the populations distributed on two mountains (Daxiangling and Xiaoliangshan) showed a modest degree of genetic differentiation.

Conclusions

These novel microsatellite markers provided valuable preliminary knowledge regarding the genetic status of the Emei Shan Liocichla and can be useful in further studies, as well as in the management and conservation of this species.

Open Access Research Issue
Nest predators, nest-site selection and nest success of the Emei Shan Liocichla (Liocichla omeiensis), a vulnerable babbler endemic to southwestern China
Avian Research 2016, 7 (1): 18
Published: 24 October 2016
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Background

The Emei Shan Liocichla (Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan National Nature Reserve in Sichuan, China in order to identify the precise nesting-habitat requirements of the species, and to test whether the nest-site-selection cues, preferred by the Emei Shan Liocichla, are positively associated with nest success.

Methods

We used infrared cameras to determine nest predators. We compared the microhabitat attributes between nest and random sites, as well as successful and failed nests. We used Binary Logistic Regression to determine the most important variables affecting nest-site selection of the Emei Shan Liocichla. We used the nest survival analysis in Program MARK to estimate daily nest survival rates (DSR). Nest success was calculated using the Mayfield method.

Results

In total 56 nests were found. The DSR for all nests that contained at least one egg was 0.9564 ± 0.0091 (95 % CI 0.9346–0.9711) (n = 40), while the total nest success was 27.5 %. We identified four categories of predators in 10 nest predation events, i.e. squirrels (n = 5), snakes (n = 3), raptors (n = 1) and wasps (n = 1). We found that: (1) nest predation was the primary reason for nest failure of the Emei Shan Liocichla, (2) tree cover, bamboo cover, liana abundance and distance to forest edge or gap were the most important variables affecting nest-site selection of this species, and (3) the nest-site-selection variables we measured appeared not to be positively associated with nest success.

Conclusions

Our findings suggest that the Emei Shan Liocichla tended to select nest sites near forest edges or gaps with good concealment and that nest-site selection by this species was nonrandom but not necessarily adaptive. Reducing forest-edge development and protecting bamboo stands should be effective for conservation of this species.

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