Ibis最新文献

The Hoopoe Starling Fregilupus varius is an extinct species of the Sturnidae that was endemic to Réunion Island in the Indian Ocean. The species rapidly disappeared in the middle of the 19th century, primarily because of overexploitation by humans. We generated an approximately 11× coverage genome to reconstruct the demographic history of the Hoopoe Starling and compared these results with the demographic histories of other starlings and myna species. Our analyses confirmed the close affinities of the Hoopoe Starling with the genera Sturnia, Leucopsar and Sturnornis, and revealed that it went through a strong population bottleneck during its evolutionary history, but that its effective population size was not particularly low when compared with other extinct or critically endangered species of birds.

This report covers the period October 2022 to September 2023. The 55th Report appeared in Ibis 165: 360–363.

The following changes have been made to the British List.

The following subspecies are added to the British List in accordance with earlier iterations of the IOC World Bird List (https://www.worldbirdnames.org):

The Eider subspecies Somateria mollissima faeroeensis is recognized as a valid taxon by the IOC, with birds breeding in Shetland, Orkney and the Outer Hebrides apparently pertaining to this taxon, with the new annotation being:

The release of versions 13.1 and 13.2 of the IOC World Bird List results in a number of changes to the British List. These include:

Tibetan Sand Plover Charadrius atrifrons is split from Lesser Sand Plover C. mongolus (re-named Siberian Sand Plover) based on phenotypic differences and phylogenetic analysis. The new annotation is:

Historically, bird taxonomy was largely based on morphology, but in recent decades molecular genetic and bioacoustic data have been used to refine species limits, resulting in the recognition of many new species-level taxa, both through the elevation of subspecies to species status and through the identification and designation of new taxonomic units. Many of these new species are difficult to identify in the field and necessitate a pragmatic approach from rarities committees. For example, if systematic revisions result in a split leaving a restricted range resident species with limited or no long-distance vagrancy potential and a highly-migratory sister species with high vagrancy potential then the burden of assessment proof need not consider elimination of the resident taxon if this is difficult or impossible under field conditions (and if the escape potential of this taxon is also negligible) e.g. the recent splits of Himalayan Bluetail Tarsiger rufilatus from Red-flanked Bluetail T. cyanurus and Salim Ali's Swift Apus salimalii, Blyth's Swift A. leuconyx, and Cook's Swift A. cooki from Pacific Swift A. pacificus. Obviously, if identification is possible by obtaining a DNA sample or through acoustic recordings then confirmation is desirable, but the absence of these need not be a barrier to formal acceptance to the British List. Therefore, BOURC will take a pragmatic approach to any such species pairing or groups on a case-by-case basis, where it is overwhelmingly likely that a record pertains to one cryptic species and not others; when this is not the case, the species group will be added to Appendix 4 (Ibis 164: 909–910).

Traditionally, records of vagrants considered by rarities committees will have been found and identified in the field by human observers supplemented by field notes; historically often the specimen of the bird would have been provided too. In recent decades submissions have usually also included supporting ‘rich media’ in the

The Nicobar Bulbul Ixos nicobariensis is an endemic species found across the central Nicobar Islands whose systematic position has been debated for many decades. Its current placement in the genus Ixos is tentative and is based on morphological similarities and geographical affinities to other members of the genus. We used mitochondrial and nuclear markers to examine its phylogenetic relationship to other members of Ixos and Hypsipetes. Our results indicate that the Nicobar Bulbul is sister to members of the genus Hypsipetes, and not Ixos. We further discuss the origin of this species based on the results of our study.

A robust understanding of the mechanisms driving demographic change in wild animal populations is fundamental to the delivery of effective conservation interventions. Demographic change can be driven by variation in adult survival, recruitment of juveniles into the breeding population or breeding productivity – the number of fledglings produced per breeding pair. Across Europe, low breeding productivity in wader populations has been a significant driver of population decline, increasing the importance of gathering accurate data on breeding productivity. Monitoring wader breeding productivity is challenging because finding nests can be time-consuming and requires experienced fieldworkers; wader chicks are nidifugous and difficult to count due to their cryptic behaviour; and waders often have high re-laying rates following nest failure, meaning that hatching or fledging can be highly asynchronous. This paper reviews approaches to estimating breeding productivity where fieldworkers either record the agitation or alarm-calling behaviour of adults with dependent young, make direct observations of broods on survey visits, or both. Using a systematic literature search (restricted to Europe where most of these studies have taken place) we identified 38 peer-reviewed papers which used this approach. The productivity metrics produced can be divided into the following categories: (i) ‘Hatching Success’ (HS), (ii) ‘Fledging Success’ (FS) and (iii) ‘Young Fledged Per Pair’ (YFP), from the coarsest to the most precise. The first two metrics are most often used when direct observations of broods are not possible due to the behaviour of broods or vegetation structure; YFP is preferred if brood counts are possible. Design of an appropriate metric depends on (i) whether accurate brood counts are possible; (ii) whether adults exhibit diagnostic agitation behaviour when young are present; (iii) whether individual breeding territories are separable; (iv) whether re-nesting rates are assumed to be high; and (v) the availability of experienced surveyors (particularly where behavioural observations are required). Globally there are many wader species for which the methods described here could provide valuable information and we hope this review encourages further development or adoption of these methods.

Territorial defence depends on highly interrelated factors such as food abundance and conspecific density. We used Dupont's Lark Chersophilus duponti as a model species to evaluate the response of a territorial bird to a foreign male playback, examining how conspecific density, habitat quality and male body condition impact responses. The study was conducted in central Spain with variable male density. Response (yes/no), latency time, distance to the playback speaker, and the number of songs and other vocalizations were monitored for 5 min. Habitat quality was estimated using BlueNDVI vegetation index extracted from high-resolution drone imagery, which is a proxy for arthropod prey biomass. Conspecific density (Kernel Density Estimator) and male body condition were calculated to assess their effect on response and intensity. We applied generalized linear mixed models (GLMMs) to determine which factors predicted the response and its intensity. There was a greater response probability in areas with a higher density of conspecifics and in areas of poorer habitat quality (i.e. lower BlueNDVI values). In contrast, latency time was longer in areas with lower conspecific density. Intrasexual communication (singing and calling rates) increased with habitat quality. Intraspecific communication (other vocalizations) increased in poorer quality habitats and at a higher density of conspecifics. Body condition was not related to any variables. Our results suggest that male density, sometimes used as an indicator of an area being well conserved for the species, may reflect areas of poorer habitat quality occupied by unpaired floater males, whereas paired territorial males would occupy and defend higher quality areas, leading to lower density.

Establishing methods that allow for more focused management of wildlife under predator pressure may increase the efficiency of managing problematic predators. Non-invasive dietary analysis and identification of conservation-sensitive prey in the diet of ‘culprit’ predator individuals could help to facilitate this and is worthy of exploration. Recently on Phillip Island, Australia, Little Ravens Corvus mellori have emerged as a prominent predator on the clutches of burrow-nesting Little Penguins Eudyptula minor. We tested the feasibility of using non-invasive PCR approaches targeting the penguin mitochondrial 16S rRNA marker gene to establish whether penguin DNA could be detected in raven faecal samples, potentially enabling the identification of culprit ravens missed by extensive field observation. Using a metabarcoding approach, we examined the feasibility of non-invasively establishing other dietary items via high-throughput amplicon sequencing. We documented components of raven diet using the universal mitochondrial 16S rRNA, insect-specific ‘Chiar’ 16S rRNA and plant ITS2. The assemblage of dietary items did not differ with raven culprit status (i.e. a raven previously observed preying upon penguin), sex or date. Penguin was detected in the diet of some individuals classified observationally as non-culprits. Although some cases may conceivably have been false detections, other explanations include missed depredation events, consumption via scavenging or through secondary consumption (e.g. eating invertebrates that have consumed penguin). While this study found metabarcoding unreliable for unambiguous assigning of raven culprit status, at least as we implemented it, it may hold promise complementing observations if consumption via scavenging can be distinguished from direct depredation.

The vocal activity and detectability of tropical birds are subject to high levels of temporal heterogeneity, but quantifying patterns of diel and day-to-day variation in complex systems is challenging with traditional point count methods. As a result, research concerning stochastic temporal effects on tropical bird assemblages is limited, typically offering only broad conclusions, such as that overall activity is highest in the first few hours of the morning and some species are active at different times of the day. Passive acoustic monitoring introduces several advantages for studying temporal variation, particularly by enabling simultaneous and continuous data collection across adjacent sites. Here, we employed autonomous recording units to quantify temporal variation in bird vocal activity and observed species richness at an Amazonian reserve in Madre de Dios, Peru, a region featuring some of Earth's richest, most complex bird assemblages. We manually annotated 18 dawn hour recordings, collected simultaneously from three separate days at the same six sites, which represent various microhabitats and bird community compositions. We documented significant and consistent temporal variation in avian vocal activity levels and observed species richness within the dawn hour and across days. We found that temporal effects were stronger for vocal activity than for observed species richness and that vocal activity patterns over the course of the dawn hour varied between species. Our results indicate that overlooked temporal variation in Amazonian soundscapes may obfuscate the results of surveys that do not sufficiently account for temporal variables with simultaneous monitoring. While manual analysis of large volumes of soundscape data remains challenging, such data should be collected to supplement traditional surveys whenever possible. Rapid advances in the automated processing of acoustic data could lead to more efficient methods for reducing temporal bias and improving the calibration and accuracy of tropical bird surveys.

As biodiversity declines, wildlife conservation focuses on in situ and ex situ management strategies. Zoo-based breeding programmes are often designed to contribute to the conservation of species that are threatened in the wild. Diet contributes to the reproductive success, disease status and longevity of all animals. It is near-impossible to replicate a species' diet in captivity using only the species they consume in the wild, but the nutritional composition of a wild diet, if known, can be closely matched using commercially available foods for which the nutritional composition has been calculated. Ecological research has identified food items of importance in the diet of many species. However, the nutritional composition of these food items is rarely evaluated, even though the composition of wild food items is important in understanding the dietary adaptations and requirements of wildlife. In contrast, the nutritional requirements of domestic species are well researched and can be used to predict a range of plausible nutrient requirements of some wild species, especially those with similar life histories. Access to wild populations provides further opportunities for nutritional science to determine the requirements of individual species. Small-scale dietary experimentation undertaken at conservation institutions may show positive effects on health and welfare but is rarely published in the scientific literature. This review describes current standards in nutritional management of birds and recommends pathways for filling knowledge gaps. Research on mammals has dominated the nutrition literature, so there is a relative lack of nutritional management information for birds. We combine concepts of domestic animal nutrition with recent findings on the nutritional requirements of birds to provide a foundation for further studies of avian nutrition. We call for the broader zoological community to share data and collaborate on nutritional research to support conservation institutions in nutritional management of wild birds.

Migratory birds must fit three costly life-history events within the annual cycle, reproduction, moult and migration, to minimize their overlap and maximize survival and breeding success. However, some seabirds, such as Cory's Shearwater Calonectris borealis, overlap body moult and breeding, with flight feather renewal occurring in late chick-rearing. In contrast, the moult patterns of non-breeding adult (sabbatical) and immature Cory's Shearwaters, which also attend the colony during the breeding season, remain poorly understood. Furthermore, the potential implications of life-stage and breeding status trade-offs on moult status and colony attendance in non-breeders has rarely been investigated. Surveying different areas within one colony between June and September 2013 and 2014, we studied the age and breeding status composition of birds attending the breeding colony and scored moult of their body (breast and upper-neck), wing and tail feathers. We found that in addition to breeders (n = 165), 57.6% of the birds (n = 389) attending the colony were 4- to 10-year-old immatures (n = 132) and adult sabbatical shearwaters (n = 92). Sabbaticals and 8- to 10-year-old immatures (n = 28) were present at the colony during incubation, whereas only three sabbatical birds and no 8- to 10-year-old immatures were captured in late chick-rearing. Conversely, 4- to 7-year-old immatures arrived later in the season but were still present in late chick-rearing. Sabbatical and 8- to 10-year-old immatures were moulting body feathers at the same time as adult breeders, whereas, among 4- to 7-year-old immatures, older birds moulted earlier than younger birds. A larger proportion of sabbatical birds were replacing tail feathers compared with adult breeders. However, there was no evidence that sabbaticals or 8- to 10-year-old immatures differed in wing moult from adult breeders until August. Overall, our study shows that colony attendance by non-breeding adults and immatures is widespread in this population. The synchronous moult schedule of flight and body feathers across age groups at different life-history stages may suggest that this aspect of moult is controlled by environmental conditions.

Biodiversity, ecosystem services and human health are becoming increasingly integrated in the ‘One Health’ concept, including recognition of the impacts of biodiversity loss on human health. Birds have considerable potential to benefit human health through their contributions to ecosystem functioning, recreation, and provision of pest control and pollination services, commonly referred to as ecosystem services. To synthesize the pathways through which birds facilitate human health, a scoping review methodology was employed to search the primary literature for relevant information. Of the 125 articles containing empirical evidence that were categorized, reported benefits included tangible materials (e.g. food, income) and resiliency (e.g. supportive ecosystem services; 80%), aesthetic, cultural, recreational, socio-economic and spiritual benefits (65%), psychological benefits (25%), regulation of transmission and prevalence of infectious diseases (11%), and physiological benefits (10%). Direct and indirect health benefits provided by birds are discussed in this review, facilitating the proposal of a new pathway categorization. The health contributions of any taxon must be given greater attention with the aim of supporting conservation and to support the sustainable use of wild species.