Mammalian predators and vegetated nesting habitat drive reduced protected area nesting success of Kentish plovers, Yellow Sea region, China

Protected areas provide essential habitats for wildlife by conserving natural and semi-natural habitats and reducing human disturbance. However, whether breeding birds vulnerable to nest predation can benefit from strict land management in the protected area is unclear. Here, we compare the nesting performance of two groups of a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus), in the protected area (Liaohekou Natural Reserve, hereinafter PA), and the control non-protected area (non-PA) around the Liaohekou Natural Reserve, in the north of the Yellow Sea, China, and identify which environmental factors, such as nesting habitat and nest materials, influence the daily nest survival rate (DSR). We found similar nesting habitats in both study areas, dominated by bare land or Suaeda salsa grassland. However, DSR was lower in PA (0.91 ± 0.01) than in non-PA (0.97 ± 0.01). Kentish plovers nesting in areas with vegetation cover experienced lower DSR than in bare lands in both areas, and nests built with materials of S. salsa sticks had the lowest DSR in the bare land. Data from infrared cameras confirmed relatively higher predator abundances and nest predation rates by nocturnal mammals, such as Eurasian badgers (Meles meles), in PA than in non-PA, and this pattern was especially evident for plover nests located in S. salsa grassland. Our results suggest that Liaohekou Natural Reserve protected area may not necessarily provide safe nesting sites for Kentish plovers due to the abundance of generalist mammal nest predators. However, the PA includes about 80% of the nests from both locations. This means the contribution of the total number of successful nests continues to be much higher within PA, with the benefit for the species that this brings in terms of conservation. The variation and mechanisms underlying differences in the nest predator communities of PA and non-PA deserve further study

Systematic revision of the ‘diminutive’ Kentish Plover (Charadriidae:<i> Charadrius</i>) with the resurrection of <i>Charadrius seebohmi </i>based on phenotypic and genetic analyses

The Kentish Plover Charadrius alexandrinus Linnaeus 1758 is a common shorebird in Eurasia and North Africa that breeds in a variety of habitats, exhibits different extents of migratory behaviour and is an emerging model species of breeding system evolution. Here we focus on the resident population found across the southern tip of India and Sri Lanka, and re-evaluate its systematic status based on phenotypic and genetic distinctiveness from a sympatric migrant, Charadrius alexandrinus sensu stricto, and the recently elevated closely related Charadrius dealbatus in East Asia. We show that the Sri Lankan and South Indian (South Asian) population differs in body size, moulting pattern and plumage coloration from C. alexandrinus and C. dealbatus. Furthermore, based on two mitochondrial, two sex-linked and 11 autosomal microsatellite markers from 378 individuals, we show that these three taxa have moderate genetic differentiation (Fst 0.078–0.096). The South Asian taxon is sister to the clade of C. alexandrinus sensu stricto and C. dealbatus with an estimated divergence time of 1.19 million years ago. We also examined ornithological records of major museum collections in Asia, Europe and North America for the south Asian taxon to evaluate its biogeographical and taxonomic status. Based on differences in genotype, phenotype, allochronic migratory pattern and breeding range, we resurrect the most suitable synonym, Charadrius alexandrinus seebohmi Hartert and Jackson, 1915, and elevate the nomen to the species level with the proposed English name ‘Hanuman Plover’.</p

Systematic revision of the ‘diminutive’ Kentish Plover (Charadriidae:<i> Charadrius</i>) with the resurrection of <i>Charadrius seebohmi </i>based on phenotypic and genetic analyses

The Kentish Plover Charadrius alexandrinus Linnaeus 1758 is a common shorebird in Eurasia and North Africa that breeds in a variety of habitats, exhibits different extents of migratory behaviour and is an emerging model species of breeding system evolution. Here we focus on the resident population found across the southern tip of India and Sri Lanka, and re-evaluate its systematic status based on phenotypic and genetic distinctiveness from a sympatric migrant, Charadrius alexandrinus sensu stricto, and the recently elevated closely related Charadrius dealbatus in East Asia. We show that the Sri Lankan and South Indian (South Asian) population differs in body size, moulting pattern and plumage coloration from C. alexandrinus and C. dealbatus. Furthermore, based on two mitochondrial, two sex-linked and 11 autosomal microsatellite markers from 378 individuals, we show that these three taxa have moderate genetic differentiation (Fst 0.078–0.096). The South Asian taxon is sister to the clade of C. alexandrinus sensu stricto and C. dealbatus with an estimated divergence time of 1.19 million years ago. We also examined ornithological records of major museum collections in Asia, Europe and North America for the south Asian taxon to evaluate its biogeographical and taxonomic status. Based on differences in genotype, phenotype, allochronic migratory pattern and breeding range, we resurrect the most suitable synonym, Charadrius alexandrinus seebohmi Hartert and Jackson, 1915, and elevate the nomen to the species level with the proposed English name ‘Hanuman Plover’.</p

Genetic, phenotypic and ecological differentiation suggests incipient speciation in two Charadrius plovers along the Chinese coast

BackgroundSpeciation with gene flow is an alternative to the nascence of new taxa in strict allopatric separation. Indeed, many taxa have parapatric distributions at present. It is often unclear if these are secondary contacts, e.g. caused by past glaciation cycles or the manifestation of speciation with gene flow, which hampers our understanding of how different forces drive diversification. Here we studied genetic, phenotypic and ecological aspects of divergence in a pair of incipient shorebird species, the Kentish (Charadrius alexandrinus) and the White-faced Plovers (C. dealbatus), shorebirds with parapatric breeding ranges along the Chinese coast. We assessed divergence based on molecular markers with different modes of inheritance and quantified phenotypic and ecological divergence in aspects of morphometric, dietary and climatic niches.ResultsOur integrative analyses revealed small to moderate levels of genetic and phenotypic distinctiveness with symmetric gene flow across the contact area at the Chinese coast. The two species diverged approximately half a million years ago in dynamic isolation with secondary contact occurring due to cycling sea level changes between the Eastern and Southern China Sea in the mid-late Pleistocene. We found evidence of character displacement and ecological niche differentiation between the two species, invoking the role of selection in facilitating divergence despite gene flow.ConclusionThese findings imply that ecology can indeed counter gene flow through divergent selection and thus contributes to incipient speciation in these plovers. Furthermore, our study highlights the importance of using integrative datasets to reveal the evolutionary history and assist the inference of mechanisms of speciation

Parental cooperation in a changing climate: fluctuating environments predict shifts in care division

Aim: Parental care improves the survival of offspring and therefore has a major impact on reproductive success. It is increasingly recognized that coordinated biparental care is necessary to ensure the survival of offspring in hostile environments, but little is known about the influence of environmental fluctuations on parental cooperation. Assessing the impacts of environmental stochasticity, however, is essential for understanding how populations will respond to climate change and the associated increasing frequencies of extreme weather events. Here we investigate the influence of environmental stochasticity on biparental incubation in a cosmopolitan ground-nesting avian genus. Location: Global. Methods: We assembled data on biparental care in 36 plover populations (Charadrius spp.) from six continents, collected between 1981 and 2012. Using a space-for-time approach we investigate how average temperature, temperature stochasticity (i.e. year-to-year variation) and seasonal temperature variation during the breeding season influence parental cooperation during incubation. Results: We show that both average ambient temperature and its fluctuations influence parental cooperation during incubation. Male care relative to female care increases with both mean ambient temperature and temperature stochasticity. Local climatic conditions explain within-species population differences in parental cooperation, probably reflecting phenotypic plasticity of behaviour. Main conclusions: The degree of flexibility in parental cooperation is likely to mediate the impacts of climate change on the demography and reproductive behaviour of wild animal populations.</p

First breeding record of the black‐headed penduline tit (Remiz macronyx) in China

Abstract Black‐headed penduline tit (Remiz macronyx) is a poorly known bird species mainly distributed in Iran, Turkmenistan, and Kazakhstan. The distribution of black‐headed penduline tit is disjointed and fragmented, and it occurs only along lakes or rivers surrounded by extensive reedbeds. Four subspecies of R. macronyx have been recognized (macronyx, neglectus, nigricans, and ssaposhnikowi). The ssaposhnikowi subspecies was previously known to occur only around lakes in southeastern Kazakhstan. In this study, we reported the first confirmed breeding record of R. m. ssaposhnikowi in the Nalati wetland, Ili, Xinjiang, China, extending the distribution range of the black‐headed penduline tit by 350 km to the east. We also obtained new information about the morphology and breeding behavior of R. m. ssaposhnikowi, which can be useful for the taxonomy of penduline tits, especially in distinguishing black‐headed penduline tits from Eurasian penduline tits (R. pendulinus)

Giant panda behaviour recognition using images

Monitoring giant panda (Ailuropoda melanoleuca) behaviour is critical for their conservation and understanding their health conditions. Currently, captive giant panda behaviour is usually monitored by their caregivers. In previous studies, researchers observed panda behaviours for short time spans over a period. However, both caregivers and researchers cannot monitor them 24-h using traditional methods of observation. In other words, animal behaviour data are difficult to collect over long periods and are prone to errors when recorded manually. Some researchers have used wearable devices such as accelerometer ear tags and collar-mounted units with a global position system (GPS) receiver and contactless devices such as depth cameras and video cameras for understanding behaviour of other animals such as primates and American white pelicans. However, the giant panda, an icon of endangered species conservation, is almost completely neglected in these studies. To monitor giant panda behaviour effectively, a fully automated giant panda behaviour recognition method based on Faster R–CNN and two modified ResNet was created. The Faster R–CNN network was able to detect panda bodies and panda faces in images. One of the modified ResNet was trained to classify their behaviour into five classes, walking, sitting, resting, climbing, and eating and the other to recognise whether the panda's eyes and mouth were opened or closed. Experiments were conducted on 10,804 images collected from over 218 pandas in various environments and illumination conditions. The experimental results were very encouraging and achieved an overall accuracy of 90% for the five panda behaviours and an overall accuracy of 84% for the subtle panda facial motions. The proposed method provides an effective way to monitor giant panda behaviour in captivity.Published versionThis work was supported by the Chengdu Research Base of Giant Panda Breeding [NO. CPB2018-02; NO. 2020CPB-C09; NO.2021CPB-C01; NO.2021CPB-B06]. The research done in the Nanyang Technological University, Singapore is under the project Development of a Computational Method for Giant Panda Identification from Images NO. CPB2018e02

The allocation between egg size and clutch size depends on local nest survival rate in a mean of bet-hedging in a shorebird

Abstract Background The allocation of resources between offspring size and number is a central question of life-history theory. Although several studies have tested the existence of this trade-off, few studies have investigated how environmental variation influences the allocation of resources to offspring size and offspring number. Additionally, the relationship between population dynamics and the offspring size and number allocation is far less understood. Methods We investigate whether resource allocation between egg size and clutch size is influenced by the ambient temperature and whether it may be related to apparent nest survival rate. We measured 1548 eggs from 541 nests of two closely related shorebird species, the Kentish Plover (Charadrius alexandrinus) and the White-faced Plover (C. dealbatus) in China, in four populations that exhibit contrasting ambient environments. We weighed females, monitored nest survival, and calculated the variance of ambient temperature. Results Although we found that egg size and clutch size were all different between the four breeding populations, the reproductive investment (i.e. total clutch volume) was similar between populations. We also found that populations with a high survival rate had relatively larger eggs and a smaller clutch than populations with a low nest survival rate. The latter result is in line with a conservative/diversified bet-hedging strategy. Conclusions Our findings suggest that plovers may increasing fitness by investing fewer, larger or many, small according local nest survival rate to make a similar investment in reproduction, and thereby may have an impact on population demography

Mammalian predators and vegetated nesting habitat drive reduced protected area nesting success of Kentish plovers, Yellow Sea region, China

Protected areas provide essential habitats for wildlife by conserving natural and semi-natural habitats and reducing human disturbance. However, whether breeding birds vulnerable to nest predation can benefit from strict land management in the protected area is unclear. Here, we compare the nesting performance of two groups of a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus), in the protected area (Liaohekou Natural Reserve, hereinafter PA), and the control non-protected area (non-PA) around the Liaohekou Natural Reserve, in the north of the Yellow Sea, China, and identify which environmental factors, such as nesting habitat and nest materials, influence the daily nest survival rate (DSR). We found similar nesting habitats in both study areas, dominated by bare land or Suaeda salsa grassland. However, DSR was lower in PA (0.91 ± 0.01) than in non-PA (0.97 ± 0.01). Kentish plovers nesting in areas with vegetation cover experienced lower DSR than in bare lands in both areas, and nests built with materials of S. salsa sticks had the lowest DSR in the bare land. Data from infrared cameras confirmed relatively higher predator abundances and nest predation rates by nocturnal mammals, such as Eurasian badgers (Meles meles), in PA than in non-PA, and this pattern was especially evident for plover nests located in S. salsa grassland. Our results suggest that Liaohekou Natural Reserve protected area may not necessarily provide safe nesting sites for Kentish plovers due to the abundance of generalist mammal nest predators. However, the PA includes about 80% of the nests from both locations. This means the contribution of the total number of successful nests continues to be much higher within PA, with the benefit for the species that this brings in terms of conservation. The variation and mechanisms underlying differences in the nest predator communities of PA and non-PA deserve further study