Avian Research最新文献

{"title":"Seasonal acclimatization and temperature acclimation in small passerine birds is achieved via metabolic adjustments","authors":"Yujie XuanYuan ,&nbsp;Ran Chen ,&nbsp;Jieheng Xu,&nbsp;Jiacheng Zhou,&nbsp;Ming Li,&nbsp;Jinsong Liu","doi":"10.1016/j.avrs.2023.100084","DOIUrl":"10.1016/j.avrs.2023.100084","url":null,"abstract":"<div><p>Temperature and other environmental factors play an integral role in the metabolic adjustments of animals and drive a series of morphological, physiological, and behavioral adaptions essential to survival. However, it is not clear how the capacity of an organism for temperature acclimation translates into seasonal acclimatization to maintain survival. Basal metabolic rate (BMR), evaporative water loss (EWL), and energy budget were measured in the Chinese Hwamei (<em>Garrulax canorus</em>) following winter and summer acclimatization, and in those acclimatized to 15 ​°C (cold) and 35 ​°C (warm) under laboratory conditions for 28 days. In addition to the above indicators, internal organ masses, as well as state 4 respiration and cytochrome <em>c</em> oxidase (COX) activity were also measured for the liver, skeletal muscle, heart, and kidney. Both winter-acclimatized and cold-acclimated birds exhibited significantly higher BMR, EWL, and energy budget, as well as organ masses, state 4 respiration, and COX activity compared with the summer-acclimatized and warm-acclimated birds. This indicated that the Chinese Hwamei could adapt to seasonal or just temperature changes through some physiological and biochemical thermogenic adjustments, which would be beneficial to cope with natural environmental changes. A general linear model showed that body mass, BMR, GEI, state 4 respiration in the liver and kidney, and COX activity in the skeletal muscle, liver, and kidney were significantly affected by temperature and acclimation. A positive correlation was observed between BMR and each of the other parameters (body mass, EWL, energy budget, heart dry mass, kidney dry mass, state 4 respiration) in the muscle, heart, and kidney and also between BMR and COX activity in the muscle and kidney. The results suggested that similar to seasonal acclimatization, Chinese Hwameis subjected to temperature acclimation also exhibited significant differences in metabolism-related physiological and biochemical parameters, depending on the temperature. The data also supported the prediction that metabolic adjustment might be the primary means by which small birds meet the energetic challenges triggered by cold conditions.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47771307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feeding ecology of a highly aerial bird during its long breeding season","authors":"Sandra Fernandes ,&nbsp;Vanessa A. Mata ,&nbsp;Luis P. da Silva","doi":"10.1016/j.avrs.2022.100073","DOIUrl":"10.1016/j.avrs.2022.100073","url":null,"abstract":"<div><p>Pallid Swifts (<em>Apus pallidus</em>), as other swifts, are birds extremely adapted to an aerial lifestyle, showing unique adaptations that allow them to fly almost continuously. The diet of these non-stopping high-altitudinal aerial birds has been mostly studied through techniques that fail to produce highly resolved prey identifications, and for that have been replaced by molecular techniques, such as DNA metabarcoding. Faecal samples of Pallid Swifts were monthly collected from a colony in the north of Portugal during the breeding season. DNA from the faecal samples was used to sex the birds and to identify the arthropods present in the diet through DNA metabarcoding. From the detected prey items, 74 families were identified belonging to 16 orders, with Hymenoptera and Hemiptera being the most frequently consumed. There were seasonal variations in diet richness, composition and prey size. Regarding the diet of males and females, although no differences were found between the diet of males and females in terms of composition and richness, there were differences in the size of arthropods preyed by the different sexes, with males feeding on larger arthropods. The large seasonal variation in Pallid Swifts' diet during the breeding season is probably a result of spatiotemporal variation in aerial prey, of which swifts likely predate opportunistically. Although no significant differences were detected in diet richness and composition between sexes, the fact that males consumed larger prey may suggest the existence of sexual dietary segregation in this group of birds. At last, several pest species were found in these swifts’ diet, which, if studied through DNA metabarcoding, can be used to monitor small arthropods, including airborne pests.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47272235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Altitudinal migration behavior patterns of birds on the eastern slope of Mt. Gongga, China","authors":"Ian Haase ,&nbsp;Zhengwei Liu ,&nbsp;Shangmingyu Zhang,&nbsp;Zhehan Dong,&nbsp;Yuwen Cheng,&nbsp;Kaize Feng,&nbsp;Kexin Peng,&nbsp;Jianghong Ran,&nbsp;Yongjie Wu","doi":"10.1016/j.avrs.2023.100114","DOIUrl":"https://doi.org/10.1016/j.avrs.2023.100114","url":null,"abstract":"<div><p>Many bird species in montane regions exhibit altitudinal migration behavior; however, altitudinal migration of birds is still understudied, especially in Asia. Mt. Gongga (7556 ​m) is the highest peak of the Hengduan Mountains in Southwest China. The steep elevation gradient and the high bird diversity make the eastern slope of Mt. Gongga (Hailuo Valley) an ideal place for studying the altitudinal migration behavior patterns of birds. We synchronously recorded the local bird diversity, temperature and humidity at two sites (1800 and 3000 ​m a.s.l.) during three migration seasons from September 2020 to June 2021 to identify birds exhibiting altitudinal migration behavior. During our surveys, we recorded 146 bird species in total and 20 passerine bird species were altitudinal migrants according to our altitudinal migration formula. Among those 20 altitudinal migrant species, eight bird species displayed a typical altitudinal migration pattern (upward migration during the breeding season and downward migration during the non-breeding season). Moreover, temperature was correlated with the daily number of individuals (DNI) at each study site. Therefore, increasing temperatures possibly caused upward migration of birds (DNI decreased at 1800 ​m and increased at 3000 ​m) and vice versa. To further elaborate, the Rufous-gorgeted Flycatcher (<em>Ficedula strophiata</em>), the species with the most prominent altitudinal migration behavior, initiated upward migration at a temperature of 11–12 ​°C at 1800 ​m and initiated downward migration at a temperature of 12–13 ​°C at 3000 ​m. Besides, humidity was positively correlated with the DNI. Therefore, increasing humidity (equals to increasing rainfall or snow) possibly caused downward migration of birds (DNI increased) and vice versa. Furthermore, bird species exhibiting a typical altitudinal migration behavior pattern are feeding on insects. Thus, the spatial and temporal changes of the invertebrate biomass might be an important ecological driver for the altitudinal migration of invertivorous (birds eating invertebrates) birds. This study provides fundamental data for the altitudinal migration of birds in the Hengduan Mountains and shows how altitudinal migration is seasonally dynamic across an elevational gradient in a subtropical mountain region.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49780139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migration routes and differences in migration strategies of Whooper Swans between spring and autumn","authors":"Ji-Yeon Lee ,&nbsp;Hyung-Kyu Nam ,&nbsp;Jin-Young Park ,&nbsp;Seung-Gu Kang ,&nbsp;Nyambayar Batbayar ,&nbsp;Dong-Won Kim ,&nbsp;Jae-Woong Hwang ,&nbsp;Otgonbayar Tsend ,&nbsp;Tseveenmyadag Natsagdorj ,&nbsp;Jugdernamjil Nergui ,&nbsp;Tuvshintugs Sukhbaatar ,&nbsp;Wee-Haeng Hur ,&nbsp;Jeong-Chil Yoo","doi":"10.1016/j.avrs.2023.100113","DOIUrl":"https://doi.org/10.1016/j.avrs.2023.100113","url":null,"abstract":"<div><p>Long-distance migratory birds travel more rapidly in spring than in autumn, as they face temporal breeding constraints. However, several species travel slower in spring owing to environmental influences, such as food availability and wind conditions. GPS trackers were attached to 17 Whooper Swans (<em>Cygnus cygnus</em>) inhabiting northeastern Mongolia, to determine their migration routes and stopover sites in spring and autumn. Differences between spring and autumn migrations, migration-influencing parameters, and the effect of spring stopover site temperatures were analyzed. Six swans completed perfect tours between their wintering and breeding sites, and these data were used for analysis. Spring migration lasted 57 days, with 49.2 days spent at 3.7 stopover sites. Autumn migration lasted 21.5 days, with 17.5 days spent at 1.0 stopover sites. Thus, the swans traveled more rapidly in autumn than in spring. Migration distance, number of stopovers, migration speed, and straightness were important migration determinants in both spring and autumn. Migration distance, stopover duration, number of stopovers, daily travel speed, travel duration, and migration speed differed significantly between spring and autumn. During spring migration, the temperature at the current stopover sites and that at the future stopover sites displayed significant variations (<em>t</em> ​= ​1585.8, df ​= ​631.6, <em>p</em> ​&lt; ​0.001). These findings are critical for the conservation and management of Whooper Swans and their key habitats in East Asian regions, and the data are anticipated to make a particularly significant contribution toward developing detailed management plans for the conservation of their key habitats.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49862924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aviary measurements of dominance and affiliation between members of mixed-species birds flocks in southern China","authors":"Jichong Chen ,&nbsp;Estelle Meaux ,&nbsp;Caiyun Li ,&nbsp;Aiwu Jiang ,&nbsp;Eben Goodale","doi":"10.1016/j.avrs.2023.100139","DOIUrl":"https://doi.org/10.1016/j.avrs.2023.100139","url":null,"abstract":"<div><p>In mutualistic interactions, all parties are usually considered to benefit; yet there may be asymmetries in mutualisms where some partners/individuals benefit more than others. Such is thought to be the case in mixed-species flocks of birds, where following species are thought to benefit more than leading species, and leading species may not be able to escape the association if they are subordinate to other species. We measured dominance and affiliation patterns of a mixed-species flock system of southern China in an aviary where these variables could be measured in a standardized way. In eight wild-caught flocks, the leading species, David's Fulvetta (<em>Alcippe davidi</em>), was usually among the more subordinate flock members (ranking 9 of 13 species, with the the most dominant species ranked number one, and dominance measured by normalized David's scores). Dominance was strongly influenced by body mass, and not by bill length or the number of individuals. Female fulvettas in particular tended to be among the most subordinate individuals in the flock. There was evidence of a negative relationship between a species pair's affiliation, measured as the percentage of all observations in which these two species were found perching together, and their difference in ranking in the dominance hierarchy, particularly when some ground species, which are not likely to remain in flocks long term, were removed from the analysis. Species pairs that had more pronounced differences in their dominance rankings were less likely to be affiliated, which is consistent with the idea that subordinate species may avoid dominants. David's Fulvetta is a strong information provider, so other species are likely benefitted in this relationship. Our data suggest one reason that fulvettas stay in flocks is that they may be subordinate and therefore have little control over who associates with them.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2053716623000658/pdfft?md5=04c9a0c047a13f97a67aa1afc1efa1ce&pid=1-s2.0-S2053716623000658-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91685476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antipredatory call behavior of lapwing species in an Afrotropical environment","authors":"Fatima R. James ,&nbsp;Chioma I. Okafor ,&nbsp;Samuel T. Osinubi ,&nbsp;Shiiwua A. Manu ,&nbsp;Samuel Ivande ,&nbsp;Taiwo C. Omotoriogun","doi":"10.1016/j.avrs.2023.100137","DOIUrl":"https://doi.org/10.1016/j.avrs.2023.100137","url":null,"abstract":"<div><p>Predation is an important source of natural selection on prey species and has resulted in adaptations such as antipredator vocal signals, which can alert others to the presence of predators and solicit cooperative attack. Although vocal alarm signals of birds have been well studied, they are poorly known in tropical African species. To address this lack of information, the antipredatory signals and responses of two lapwings (Wattled Lapwing <em>Vanellus senegallus</em> and Spur-winged Lapwing <em>Vanellus spinosus</em>) to potential predators were investigated using data collected from focal observation, distance measurements, focal recordings, and playback experiment. The lapwing calls elicited to predators were classified as alarm or mobbing calls based on whether the calls elicited alert behavior or attack from other lapwings. Discriminant linear analysis (DLA) was used to compare the time and frequency parameters of the call types measured in Raven PRO. Also, lapwings’ responses to intruders, alert and start distance, time of day, and latency, as well as the effects of flock size and distance to cover were examined. About 48% of all calls was correctly classified by DLA. The best predictors of call type for the lapwings were maximum frequency and high frequency. Both alarm and mobbing calls were elicited by African Wattled Lapwings to dogs and humans. Mobbing calls were elicited to intruders by the Spur-winged Lapwings. Alert distance was positively associated with start distance, and differed between morning and evening in both lapwings. With scarce information from tropical Africa, this study put in perspective vocal and antipredator behavior of lapwing species in Africa.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49780128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of constant light and dark conditions on the locomotor activity, body mass, and body temperature rhythms of Eurasian Tree Sparrows (Passer montanus)","authors":"Lirong Zuo ,&nbsp;Ibrahim M. Ahmad ,&nbsp;Yuanyuan Liu ,&nbsp;Limin Wang ,&nbsp;Shu Fang ,&nbsp;Dongming Li","doi":"10.1016/j.avrs.2023.100126","DOIUrl":"10.1016/j.avrs.2023.100126","url":null,"abstract":"<div><p>Light is an essential environmental cue influencing the endogenous circadian clocks that regulate behavioral and physiological processes in animals. Despite extensive research on the circadian rhythms of avian behavior and physiology, the mechanisms by which they adapt and adjust to abnormal photoperiod conditions, such as artificial light, have yet to be fully elucidated. Here, the circadian rhythms of the body mass, activity, and core and peripheral body temperatures of the Eurasian Tree Sparrow (<em>Passer montanus</em>, ETS)—a diurnal passerine—were examined under three different lighting conditions: constant light (LL), constant darkness (DD), and normal light–dark cycles (LD). Our results showed that the activity, body mass, core, tarsometatarsus, and eye temperatures of the ETSs varied significantly with treatment, time, and the interaction between treatment and time; however, there was no significant change in body mass in response to the interaction between time and treatment. Under LD conditions, the ETSs exhibited significant circadian rhythms in activity and core, tarsometatarsus, and eye temperatures. Under LL conditions, only the core temperature exhibited significant rhythmicity. Under DD conditions, there were no significant circadian rhythms in activity, body mass, and eye temperature; however, the core and tarsometatarsus temperatures remained rhythmic. Our results indicate that the core body temperature rhythm of ETS is endogenous and can be maintained under abnormal photoperiods. In contrast, the activity and body surface temperature, uncoupled from the core body temperature under abnormal photoperiod conditions, strongly depend on light. These results differ from those of other diurnal avian species, suggesting a unique coping mechanism of ETS in response to an abnormal photoperiod.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43741540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation in reproductive life-history traits of Chinese Bulbuls (Pycnonotus sinensis) along the urbanization gradient in Hangzhou, China","authors":"Xingmin Chen ,&nbsp;Qin Zhang ,&nbsp;Sisi Lan ,&nbsp;Qin Huang ,&nbsp;Shuihua Chen ,&nbsp;Yanping Wang","doi":"10.1016/j.avrs.2023.100100","DOIUrl":"10.1016/j.avrs.2023.100100","url":null,"abstract":"<div><p>Urbanization brings new selection pressures to wildlife living in cities, and changes in the life-history traits of urban species can reflect their responses to such pressures. To date, most of the studies investigating the impacts of urbanization on avian life-history traits are conducted in Europe and North America, while such studies are often lacking in quickly developing countries in Asia (e.g., China). In this study, we examined the variations in reproductive life-history traits of Chinese Bulbuls (<em>Pycnonotus sinensis</em>) along the urbanization gradient in Hangzhou, China. We detected 234 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to 2013. We collected data on seven life-history traits (laying date, incubation period, nestling period, clutch size, egg volume, hatching success rate, and fledging success rate). We used infrared cameras to record the number of feedings per hour as the measure of food resources for the nestlings. We measured nest predation pressure by monitoring 148 natural breeding nests during breeding seasons and 54 artificial nests immediately after breeding seasons. We then calculated the urbanization synthetic index (USI) as a measure of the level of urbanization and examined its relationship with the seven life-history traits. We found that Chinese Bulbuls laid eggs significantly earlier with increasing USI. However, the other six life-history traits did not vary significantly with the USI. Moreover, the feeding frequency of chicks increased significantly with the USI, but the nest predation pressure of Chinese Bulbuls decreased significantly with the USI. Increased food resources and reduced nest predation pressure in cities may lead to earlier laying date of Chinese Bulbuls. Further study should test whether the earlier laying date of Chinese Bulbuls is the result of phenotypic plasticity or genetic change.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47022373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"More than a simple egg: Underlying mechanisms of cold tolerance in avian embryos","authors":"Ibrahim M. Ahmad ,&nbsp;Dongming Li","doi":"10.1016/j.avrs.2023.100104","DOIUrl":"10.1016/j.avrs.2023.100104","url":null,"abstract":"<div><p>Avian embryos, which develop within eggs, exhibit remarkable tolerance to extremely low temperatures. Despite being a common trait among all birds, the mechanisms underlying this cold tolerance in avian embryos remain largely unknown. To gain a better understanding of this phenomenon and the coping mechanisms involved, we reviewed the literature on severe cold tolerance in embryos of both wild and domestic birds. We found that embryos of different bird orders exhibit tolerance to severe cold during their development. In response to cold stress, embryos slow down their heartbeat rates and metabolism. In severe cold temperatures, embryos can suspend these processes, entering a torpid-like state of cardiac arrest. To compensate for these developmental delays, embryos extend their regular incubation periods. Depending on their embryonic age, embryos of all bird species can tolerate acute severe cold regimes; only a few tolerate chronic severe cold regimes. We also discussed various extrinsic and intrinsic factors that affect the tolerance of bird embryos to low temperatures before and after incubation. Cold tolerance appears to be a heritable trait shared by wild and domestic embryos of all bird classes, regardless of egg size or development (altricial/precocial). Driven by environmental variability, cold tolerance in avian embryos is an optimal physiological and ecological strategy to mitigate the adverse effects of cold conditions on their development in response to fluctuating environmental temperatures.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42432590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vultures as a model for testing molecular adaptations of dietary specialization in birds","authors":"Yanhong Chen ,&nbsp;Ling Xiang ,&nbsp;Pan Chen ,&nbsp;Huabin Zhao","doi":"10.1016/j.avrs.2023.100128","DOIUrl":"10.1016/j.avrs.2023.100128","url":null,"abstract":"<div><p>Vultures are the only obligate scavengers among extant vertebrates. They provide valuable ecological services in ecosystems through removing carcasses, thus preventing the growth of other scavenger populations and the spread of pathogens. Moreover, their specific diets expose them to various deadly pathogens, which makes them potential candidates for studying molecular adaptations required to survive this extremely specialized scavenging habit. In this review, we summarize the morphological characteristics and behavioral habits, origin and phylogeny, and molecular adaptations to scavenging in both Old and New World vultures. The two groups of vultures share a similar appearance, indicative of convergent evolution. Vultures have experienced different degrees of specialization in their sensory organs; Old World vultures depend on sight, while New World ones depend on both smell and sight. Combined fossil records and molecular data suggest that vultures evolved independently, with distinct phylogenetic positions. We also explored their adaptation to scavenging in facial and intestinal microbiomes, gastric acid secretion and immunity. Compared with the facial microbiome, the intestinal microbiome had a lower diversity, dominated by Fusobacteria and Clostridia. The phages and single invertebrate species <em>Adineta vaga</em>, which feeds on dead bacteria and protozoa, present in the gut suggest a possible alternative defense mechanism. Several genes involved in gastric acidic secretion (including <em>ATP4B</em>, <em>SLC26A7</em> and <em>SST</em>) and immunity (including <em>BCL6</em>, <em>STING</em>, and <em>TLRs</em>) undergoing positive selection likely have essential roles in eliminating invasive pathogens and initiating an innate immune response. Taken together, this review presents the current research status of vultures and highlights the use of vultures as a model for exploring molecular adaptations of dietary specialization in birds. It also provides a theoretical basis for the study of the genetic mechanisms of vultures to scavenging, and contributes to the formulation of vulture conservation strategies.</p></div>","PeriodicalId":51311,"journal":{"name":"Avian Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44048158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}