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Animals are predicted to shrink and shape‐shift as the climate warms, declining in size, while their appendages lengthen. Determining which types of species are undergoing these morphological changes, and why, is critical to understanding species responses to global change, including potential adaptation to climate warming. We examine body size and bill length changes in 25 shorebird species using extensive field data (> 200,000 observations) collected over 46 years (1975–2021) by community scientists. We show widespread body size declines over time, and after short‐term exposure to warmer summers. Meanwhile, shorebird bills are lengthening over time but shorten after hot summers. Shrinking and shape‐shifting patterns are consistent across ecologically diverse shorebirds from tropical and temperate Australia, are more pronounced in smaller species and vary according to migration behaviour. These widespread morphological changes could be explained by multiple drivers, including adaptive and maladaptive responses to nutritional stress, or by thermal adaptation to climate warming. [ABSTRACT FROM AUTHOR]

Epidermal cell proliferation and differentiation during formation of the beak in tadpoles of Rana dalmatina. Acta Zoologica (Stockolm). The beak utilized in tadpoles of R. dalmatina for crushing vegetables is formed of cornified cell layers. A row of large wedge‐like cells forms a central pile that produces the sharp corneous lamina of the beak. The labial and oral surfaces of the beaks also accumulate corneous material during proliferation and differentiation of keratinocytes from the epidermis to form a sheath around the central corneous cells. Corneocytes are shed during the growth of tadpoles. Electron microscopy reveals that keratin and mucus granules are main components of these keratinocytes. Electron‐dense organelles of unknown composition and with inside lamellae are also present. Using immunohistochemistry after post‐injection of 5BrdU, a marker of cell proliferation, the main timing of formation of the beak has been determined. After 2–5 h from injection, labelled nuclei of keratinocytes are seen in the basal layer, and sparse suprabasal labelled nuclei are detected after 5 h. Labelled keratinocytes are seen in suprabasal layers at 2 days post‐injection. At 5 and 6 days labelled keratinocytes are present in central corneous cells and in the lateral shell of corneocytes forming the labial and oral beak sides. Shedding a complete stratum corneum likely takes more days, but this depends on feeding usage. [ABSTRACT FROM AUTHOR]

At the top of many ecosystems, raptors, also known as birds of prey, hold major influence. They shape their surroundings through their powerful hunting skills and complex interactions with their environment. This study investigates the beak morphology of four prominent raptor species, Golden eagle (Aquila chrysaetos), Common buzzard (Buteo buteo), Peregrine falcon (Falco peregrinus) and Common kestrel (Falco tinnunculus), found in Türkiye. By employing geometric morphometric methods, we investigate shape variations in the beaks of these species to unravel the adaptive significance of their cranial structures. This analysis reveals distinct beak morphologies among the studied raptors, reflecting adaptations to their feeding habits, hunting techniques and ecological niches. The results from Principal component analysis and Canonical variate analysis demonstrate significant differences in beak morphology between the Falconiformes and Accipitriformes clades, as well as among all three groups. The overall mean beak shapes of Golden Eagles are quite similar to Common Buzzards, with both species having longer beaks. In contrast, Falcons exhibit a distinctly different beak morphology, characterized by wider and shorter beaks. Changes in beak shape can lead to changes depending on the skull. It is thought that skull shape variations among predator families may have an impact on beak shape. These findings highlight the importance of integrating morphometric analyses with ecological insights to enhance our understanding of the evolutionary processes shaping raptor beak morphology. [ABSTRACT FROM AUTHOR]

There is insufficient data about the migratory duck Anas crecca, especially the beak and oropharyngeal cavity roof. This study aimed to characterize the beak and palatine adaptations and relate the morphological features with the species-specific feeding behavior of A. crecca collected near Lake Nasser (Egypt). Our study was carried out with the help of gross, scanning electron microscopy (SEM), and morphometric analysis. The lower median papillary teeth-like region corresponded to the lower papillary region in terms of food particle capture. The serrated gnathotheca surface exhibited transverse, wedge-like, cap-like, and serrated border-like processes. The lower mandibular space had four spaces: the rostral smooth, the middle folded, the long sublingual, and the caudal sublaryngeal space. The palate showed two major regions, the rostral long beak (beak nail, middle part, and the caudal papillary part) and the connecting region. The choana consists of the rostral narrow part, which has rostral non-papillated and caudal papillated parts, and the caudal papillated wide part, which has three papillary rows. The infundibular plate had numerous small papillae and sphenopterygoid salivary gland openings. Functionally, the beak plays an important role in the sieving filter feeding mechanism, and the palate is involved in the fixation of the captured food particles inside the oral cavity. Consequently, beak and palate structures exhibit anatomical adaptations for efficiently filtering feeding mechanisms. [ABSTRACT FROM AUTHOR]

This study gives the first data on the body and beak morphometric characteristics, age, and genetic structure of neon flying squid, a rarely caught cephalopod in the Adriatic Sea. We identified specimens as recently resurrected Ommastrephes caroli species using two mitochondrial markers, 16S ribosomal RNA gene and cytochrome c oxidase subunit I gene. Overall, 23 juveniles (3 females, 3 males, and 17 unsexed), with a dorsal mantle range of 65–152 mm, were caught in September 2020 in the waters of the Korčula Channel, island of Palagruža, and island of Jabuka, thus providing the most abundant sample of this species in the Mediterranean waters. The length–weight relationship showed an isometric growth. The results of the beak/length regressions suggest hood length is a useful characteristic for biomass estimation studies, as it showed a good linear fit to the dorsal mantle length. Statolith growth increments were easily visible and statolith microstructure analysis was successfully used to determine the age of 22 individuals. The estimated age ranged from 36 to 64 days (mean = 48 days). The back-calculation analysis showed that the squid hatched during July and August 2020, indicating that O. caroli spawns during the warmer, summertime period. Considering the size and age of the caught individuals, the Adriatic Sea could represent a potential feeding ground for this species. The genetic structure analyses indicate the existence of separate Atlantic and Mediterranean/Adriatic subclusters; however, this warrants further investigation. [ABSTRACT FROM AUTHOR]

Age data are crucial for understanding and managing target species in commercial and recreational fisheries. Octopus catches are increasing worldwide, yet ageing methods are still in their infancy. Octopus age is estimated by counting growth increments in stylets and beaks. These increments have been validated as daily in some species or assumed to be daily in other species. Here, we conducted an age validation study on both the stylets and beaks of a commercial octopus species (Octopus berrima). Subsequently, we compared and assessed the readability of growth increments in beaks and stylets of wild-caught O. berrima. We found that increment periodicity was nondaily for both structures, with increment periodicity also varying between structures (0.75 increments per day for stylets and 0.53 increments per day for beak). This study highlights the importance of validating increment periodicity for different octopus species and for both stylets and beaks to obtain accurate age and growth data. Without accurate age data, a species may be incorrectly managed with the potential for negative effects on the sustainability of wild populations. [ABSTRACT FROM AUTHOR]

This study gives the first data on the body and beak morphometric characteristics, age, and genetic structure of neon flying squid, a rarely caught cephalopod in the Adriatic Sea. We identified specimens as recently resurrected Ommastrephes caroli species using two mitochondrial markers, 16S ribosomal RNA gene and cytochrome c oxidase subunit I gene. Overall, 23 juveniles (3 females, 3 males, and 17 unsexed), with a dorsal mantle range of 65–152 mm, were caught in September 2020 in the waters of the Korčula Channel, island of Palagruža, and island of Jabuka, thus providing the most abundant sample of this species in the Mediterranean waters. The length–weight relationship showed an isometric growth. The results of the beak/length regressions suggest hood length is a useful characteristic for biomass estimation studies, as it showed a good linear fit to the dorsal mantle length. Statolith growth increments were easily visible and statolith microstructure analysis was successfully used to determine the age of 22 individuals. The estimated age ranged from 36 to 64 days (mean = 48 days). The back-calculation analysis showed that the squid hatched during July and August 2020, indicating that O. caroli spawns during the warmer, summertime period. Considering the size and age of the caught individuals, the Adriatic Sea could represent a potential feeding ground for this species. The genetic structure analyses indicate the existence of separate Atlantic and Mediterranean/Adriatic subclusters; however, this warrants further investigation.

A 2-year-old male budgerigar (Melopsittacus undulatus) died after a 1-day history of fracture of the rostral rhinotheca with pale mucous membranes, dyspnea, dull mentation, and ataxia. Histopathology revealed an infiltrative neoplasm composed of interweaving streams of spindle cells effacing the dermis and bone of the rostral upper beak as well as a ganglion and two cranial nerves. No visceral metastasis was observed. Neoplastic cells exhibited strong cytoplasmic immunolabeling for alpha-smooth muscle actin (α-SMA) and lacked immunolabeling for S100, Melan-A, PNL2, and cytokeratin AE1/AE3. These findings were consistent with a locally invasive leiomyosarcoma Leiomyosarcomas arise from the smooth muscle and are locally invasive with rare metastases. In birds, leiomyosarcomas are mostly reported to arise from the spleen, gastrointestinal, and reproductive tracts. In the case report herein, we describe the histological and immunohistochemical features of a primary beak leiomyosarcoma in a budgerigar associated with a fracture located at the rostral rhinotheca. Leiomyosarcoma arising from the beak has not been described in the literature.

The knob serves as both a sexual indicator of a goose’s maturity and a significant packaging attribute that garners consumer attention. However, studies regarding the morphological, anatomical and histological traits of different breeds and ages on the on knob in goose are lacking. In this study, six breeds with typical goose knob types were selected, and their knob size, morphological, anatomical and histological traits were characterized. The results showed that: Knob was more prominent in gander than in female goose, and the difference was the most obvious in Magang goose. Wanxi white goose and Shitou goose had the largest knob bulge, while Magang goose and Sichuan white goose were smaller. The total knob volume of Wanxi White goose and Shitou goose was significantly higher than that of other breeds, regardless of male or female (p < 0.05). The beak volume of Wanxi White goose and gander was significantly higher than that of other goose breeds (p < 0.05). Furthermore, the observation revealed that the “knob” primarily consisted of skin-derived tissue and bony protrusions. As age advances, the knob of both male and female geese undergoes synchronous development, with the knob of male geese typically surpassing that of their female counterparts during the same period. The growth rate of knob in male goose was the fastest from 70 to 120 days of age, and slowed down from 300 to 500 days of age. The growth rate of knob in female goose was slower than that in male goose. There were essential differences in the composition of Yangzhou goose knob and Magang goose knob. The subcutaneous tissue of Magang goose was rich, and the thickness of epidermis, dermis and various layers was significantly smaller than that of Yangzhou goose (p < 0.05). With the growth of goose knob, the cells of the epidermal spinous layer became denser and gradually condensed into an overall structure, and there was a clear boundary between the dermis and epidermis after adult. In adulthood, the fiber fascicle network was staggered and dense, with greater toughness and elasticity, and the stratum corneum, epidermis, reticular layer, dermis and other skin structural layers became thicker. [ABSTRACT FROM AUTHOR]

The study of ontogenetic organisms can help us fully understand the law of morphology change and the correlation between the function and morphology of the structure of organisms. To explore the pattern of growth change in U. edulis beak, this study used geometric morphometric methods to analyze the differences in beak size and morphology in different sexes and ontogenetic stages, revealing its ecological implications. Results show some differences in the size of different sexes´ beaks of U. edulis in the ontogenetic process; the beak of female individuals is larger than that of male individuals, but the differences in the beak morphology of different sexes were not significant (P > 0.05). Principal component analysis and a thin-plate spline deformation mesh show that the beak morphology from immature to mature presents different developmental stages; in the ontogenetic process, the hood and wing of the upper and lower beak become larger, the crest protrudes more, the jaw angle gradually becomes smaller, and the rostrum of the upper beak is sharper; however, the rostrum of the lower beak gradually blunted. The multiple regression analysis shows that the morphology change of the upper beak is small in the immature stage, the morphology change is larger in the maturing and mature stages, the pattern of morphology change in the maturing and mature stages is similar, the morphology change of the lower beak is large in the immature and mature stages, the morphology change is small in the mature stage, and the morphology change trend is significantly different in the ontogenetic process. The beak morphology of U. edulis had different growth patterns during different ontogenetic stages. Beaks also showed an allometric growth, possibly related to the feeding and environmental changes during the ontogenetic stage of U. edulis, helping it to grow and develop.

In order to better understand the morphological growth characteristics of beak and fisheries biology, polynomial growth model was established for the relationship between mantle length and body mass for Loligo beka collected from fishery independent surveys by trawl net in the Bohai Bay from Jul. to Nov. 2021, and the size at first maturity was estimated. Wilcoxon rank-sum test was employed to analyze the influence of maturity and gender on the morphologic growth of beak. In addition, multivariate statistical analysis based on the principal components were applied to establish the relationships between morphologic straits of beak and mantle length or weight for Loligo beka. The analyses showed that polynomial growth model was more suitable for fitting the relationship between mantle length and body mass, and the sizes at first maturity was estimated at (3.522±0.009) cm, (3.505±0.026) cm and (3.513±0.016) cm for female, male and total Loligo beka, respectively. There were obvious differences in the morphologic between upper beak and lower beak. Some ratios between beak length indices, such as hood length and crest length, were nearly consistent with the change of sex and sexual maturity, but others were different, such as the ratios between upper crest length and upper rostrum length and between upper hood length and upper lateral wall length, and there were significant differences in gender and sexual maturity, respectively. Taking the coefficient of determination and Akaike's information criterion (AIC) as the criterion of goodness-of-fit, the optimal relationships between morphologic indices of beak versus mantle length or weight were established by means of stepwise multiple linear regression. The information above mentioned suggested that the behavior of fishing Loligo beka with shorter than 3.513 cm in mantle length should been forbidden. The ratio of upper hood length and upper crest length could be used as stable beak index of the morphological characteristics of Loligo beka, the ratios between upper crest length and upper rostrum length and between upper hood length and upper lateral wall length could be used as the indexes of gender and sexual maturity, respectively. Besides, the relationships described by stepwise multiple linear function were more suitable for predicting the mantle length or weight on the basis of data of beak for Loligo beka. [ABSTRACT FROM AUTHOR]

Introduction For birds of prey, the integrity of the beak is extremely important for defence, hygiene, socialization and especially, feeding. This paper describes successful trans‐sinus fixation of a lateral deviation of the mandible in a hawk (Caracara plancus). Case report The patient was presented with malnutrition and dehydration due to severe left lateral deviation of gnathotheca, with significant malocclusion. Fixation was performed with a 1.0‐mm pin and 0.4‐mm cerclage, applying contralateral traction to the deviation. The placement of the cerclage enabled full opening of the beak to allow feeding in the postoperative period. At 21 days after surgery, occlusion was perfect and the patient had recovered normal beak function. When clinical follow‐up indicated that the bird would be able to survive in the wild, it was released. Conclusion Trans‐sinus fixation was effective in correcting lateral deviation of the gnathotheca in a hawk (C. plancus).

BackgroundAvian keratin disorder (AKD) is an epizootic of debilitating beak deformities, first documented in black-capped chickadees (Poecile atricapillus) in Alaska during the late 1990s. Similar deformities have now been recorded in dozens of species of birds across multiple continents. Despite this, the etiology of AKD has remained elusive, making it difficult to assess the impacts of this disease on wild populations. We previously identified an association between infection with a novel picornavirus, Poecivirus, and AKD in a small cohort of black-capped chickadees.MethodsTo test if the association between Poecivirus and AKD holds in a larger study population, we used targeted PCR followed by Sanger sequencing to screen 124 symptomatic and asymptomatic black-capped chickadees for Poecivirus infection. We further compared the efficacy of multiple non-terminal field sampling methods (buccal swabs, cloacal swabs, fecal samples, and blood samples) for Poecivirus screening. Finally, we used both in situ hybridization and a strand-specific expression assay to localize Poecivirus to beak tissue of AKD-positive individuals and to determine if virus is actively replicating in beak tissue.ResultsPoecivirus was detected in 28/28 (100%) individuals with AKD, but only 9/96 (9.4%) asymptomatic individuals with apparently normal beaks (p

Pyrenestes finches are unique among birds in showing a non-sex-determined polymorphism in bill size and are considered a textbook example of disruptive selection. Morphs breed randomly with respect to bill size, and differ in diet and feeding performance relative to seed hardness. Previous breeding experiments are consistent with the polymorphism being controlled by a single genetic factor. Here, we use genome-wide pooled sequencing to explore the underlying genetic basis of bill morphology and identify a single candidate region. Targeted resequencing reveals extensive linkage disequilibrium across a 300 Kb region containing the insulin-like growth factor 1 (IGF1) gene, with a single 5-million-year-old haplotype associating with phenotypic dominance of the large-billed morph. We find no genetic similarities controlling bill size in the well-studied Darwin's finches (Geospiza). Our results show how a single genetic factor may control bill size and provide a foundation for future studies to examine this phenomenon within and among avian species.

For well over half of the 150 years since the discovery of the neural crest, the special ability of these cells to function as a source of species-specific pattern has been clearly recognized. Initially, this observation arose in association with chimeric transplant experiments among differentially pigmented amphibians, where the neural crest origin for melanocytes had been duly noted. Shortly thereafter, the role of cranial neural crest cells in transmitting species-specific information on size and shape to the pharyngeal arch skeleton as well as in regulating the timing of its differentiation became readily apparent. Since then, what has emerged is a deeper understanding of how the neural crest accomplishes such a presumably difficult mission, and this includes a more complete picture of the molecular and cellular programs whereby neural crest shapes the face of each species. This review covers studies on a broad range of vertebrates and describes neural-crest-mediated mechanisms that endow the craniofacial complex with species-specific pattern. A major focus is on experiments in quail and duck embryos that reveal a hierarchy of cell-autonomous and non-autonomous signaling interactions through which neural crest generates species-specific pattern in the craniofacial integument, skeleton, and musculature. By controlling size and shape throughout the development of these systems, the neural crest underlies the structural and functional integration of the craniofacial complex during evolution.

Species traits are thought to predict feeding specialization and the vulnerability of a species to extinctions of interaction partners, but the context in which a species evolved and currently inhabits may also matter. Notably, the predictive power of traits may require that traits evolved to fit interaction partners. Furthermore, local abiotic and biotic conditions may be important. On islands, for instance, specialized and vulnerable species are predicted to be found mainly in mountains, whereas species in lowlands should be generalized and less vulnerable. We evaluated these predictions for hummingbirds and their nectar-food plants on Antillean islands. Our results suggest that the rates of hummingbird trait divergence were higher among ancestral mainland forms before the colonization of the Antilles. In correspondence with the limited trait evolution that occurred within the Antilles, local abiotic and biotic conditions-not species traits-correlate with hummingbird resource specialization and the vulnerability of hummingbirds to extinctions of their floral resources. Specifically, hummingbirds were more specialized and vulnerable in conditions with high topographical complexity, high rainfall, low temperatures and high floral resource richness, which characterize the Antillean Mountains. These findings show that resource specialization and species vulnerability to extinctions of interaction partners are highly context-dependent.

Fine-grained visual classification (FGVC) is much more challenging than traditional classification tasks due to the inherently subtle intra-class object variations. Recent works are mainly part-driven (either explicitly or implicitly), with the assumption that fine-grained information naturally rests within the parts. In this paper, we take a different stance, and show that part operations are not strictly necessary – the key lies with encouraging the network to learn at different granularities and progressively fusing multi-granularity features together. In particular, we propose: (i) a progressive training strategy that effectively fuses features from different granularities, and (ii) a consistent block convolution that encourages the network to learn the category-consistent features at specific granularities. We evaluate on several standard FGVC benchmark datasets, and demonstrate the proposed method consistently outperforms existing alternatives or delivers competitive results. Codes are available at https://github.com/PRIS-CV/PMG-V2. [ABSTRACT FROM AUTHOR]

In the French Mediterranean plain, the northern extreme of its native range, the Iberian gray shrike, Lanius meridionalis, predominantly feeds on arthropods. Its type of loral plumage plays a key role in protecting its eyes while transporting large prey. The aims are to understand the role played by feathers in protecting the animal from various types of defensive prey. I combine an inspection of large insect prey types found on larders with a review of bird specimens found in museum collections to examine the morphometric characteristics of rictal feathers and culmen. In addition, precision photographs are used to observe the posture of the plumage in natura. I could identify four categories of protective feathers: clustered bristles, semi‐bristles, semi‐plumes distributed in the loral area, and semi‐plumes above the eyes. My results suggest that the Iberian gray shrike has a complex structure of loral feathers, specific to its foraging activity and prey types. The presence of these rictal bristles is probably a protection against the movements of larger prey items, which might damage loral zone of Lanius meridionalis. [ABSTRACT FROM AUTHOR]

Beak deformation, known as avian keratin disorder (AKD), can impair feeding and preening of birds, reducing their survival. This disorder is apparently caused by Poecivirus infection, although to date, the viral origin has been corroborated in only a few North American bird species. Considering that fruit-eating birds can track spatiotemporal variations in fruit abundance and that AKD may have a viral origin, the incidence of this disease can be expected to increase with flocking by birds. Therefore, we evaluated if austral thrushes (Turdus falcklandii) were attracted to urban areas when exotic plants offered fruits and if flocking of thrushes in urban areas increased the spread of AKD in this species in a Patagonian town. We fitted GPS loggers on some individuals with normal beaks in rural areas and found that they visit the town in fall. Through point count censuses, we recorded greater abundances of thrushes with normal and deformed beaks during fall-winter in urban sites than in rural sites. However, the abundance of birds with AKD declined more (78-87%) than that of individuals with normal beaks (44-52%) during the transition from fall-winter to spring-summer. In urban zones in our study area, fruits of exotic species ripen during fall, attracting austral thrushes from rural sites. Nevertheless, such an attraction for food resources may be an ecological trap for this species, as the increase in incidence of AKD in urban areas may drastically reduce the survival of birds during the most unfavorable period of the year., (© 2023 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

Carotenoid pigments produce the yellow and red colors of birds and other vertebrates. Despite their importance in social signaling and sexual selection, our understanding of how carotenoid ornamentation evolves in nature remains limited. Here, we examine the long-tailed finch Poephila acuticauda, an Australian songbird with a yellow-billed western subspecies acuticauda and a red-billed eastern subspecies hecki, which hybridize where their ranges overlap. We found that yellow bills can be explained by the loss of C(4)-oxidation, thus preventing yellow dietary carotenoids from being converted to red. Combining linked-read genomic sequencing and reflectance spectrophotometry measurements of bill color collected from wild-sampled finches and laboratory crosses, we identify four loci that together explain 53% of variance in this trait. The two loci of largest effect contain the genes CYP2J19, an essential enzyme for producing red carotenoids, and TTC39B, an enhancer of carotenoid metabolism. A paucity of protein-coding changes and an enrichment of associated upstream variants suggest that the loss of C(4)-oxidation results from cis-regulatory evolution. Evolutionary genealogy reconstruction indicates that the red-billed phenotype is ancestral and that yellow alleles at CYP2J19 and TTC39B first arose and fixed in acuticauda approximately 100 kya. Yellow alleles subsequently introgressed into hecki less than 5 kya. Across all color loci, acuticauda-derived variants show evidence of selective sweeps, implying that yellow bill coloration has been favored by natural selection. Our study illustrates how evolutionary transitions between yellow and red coloration can be achieved by successive selective events acting on regulatory changes at a few interacting genes., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Key Points: Penetrating orbital trauma from marine creatures, especially needlefish, should be considered after injuries sustained in open water. Advances in endoscopic sinus surgery have enabled surgeons to remove certain orbital foreign bodies through endoscopic endonasal approaches. 3D segmentation is a valuable pre-operative tool in complex endoscopic orbital cases., (© 2024 ARS‐AAOA, LLC.)

Cosmetic colourations of animals have been mainly studied in scenarios of sexual selection, while there has been no assessment of the partial contribution of cosmetics to the final colouration of begging-related traits. In birds, the uropygial gland is functional soon after hatching, and we experimentally investigated the effects of uropygial secretion on mouth-flange colouration in spotless starling ( Sturnus unicolor ) nestlings. Nestlings' flange colouration was measured with a spectrophotometer before and after being either cleaned of, or painted with, its own uropygial secretion. After cleaning, flanges were brighter, more UV and less yellow-red coloured (chroma). Instead, painting the mouth flanges of nestlings with their own uropygial secretion did not modify any of the considered colour components. Our findings therefore show that the uropygial secretion of nestlings alters their beak colouration and open the possibility for future research to investigate the role of uropygial secretion in reinforcing the signalling role of begging-related traits involved in parent-offspring communication.

Abstract In the French Mediterranean plain, the northern extreme of its native range, the Iberian gray shrike, Lanius meridionalis, predominantly feeds on arthropods. Its type of loral plumage plays a key role in protecting its eyes while transporting large prey. The aims are to understand the role played by feathers in protecting the animal from various types of defensive prey. I combine an inspection of large insect prey types found on larders with a review of bird specimens found in museum collections to examine the morphometric characteristics of rictal feathers and culmen. In addition, precision photographs are used to observe the posture of the plumage in natura. I could identify four categories of protective feathers: clustered bristles, semi‐bristles, semi‐plumes distributed in the loral area, and semi‐plumes above the eyes. My results suggest that the Iberian gray shrike has a complex structure of loral feathers, specific to its foraging activity and prey types. The presence of these rictal bristles is probably a protection against the movements of larger prey items, which might damage loral zone of Lanius meridionalis.

Darwin's finches, with the primary diversity in the shape and size of their beaks, represent an excellent model system to study speciation and adaptive evolution. It is generally held that evolution depends on the natural selection of heritable phenotypic variations originating from the genetic mutations. However, it is now increasingly evident that epigenetic transgenerational inheritance of phenotypic variation can also guide evolutionary change. Several studies have shown that the bone morphogenetic protein BMP4 is a major driver of beak morphology. A recent study explored variability of the morphological, genetic, and epigenetic differences in the adjacent "urban" and "rural" populations of two species of Darwin's finches on the Galápagos Islands and revealed significant changes in methylation patterns in several genes including those involved in the BMP/TGFß pathway in the sperm DNA compared to erythrocyte DNA. These observations indicated that epigenetic changes caused by environmental fluctuations can be passed on to the offspring. Nonetheless, the mechanism by which dysregulated expression of BMP4 impacts beak morphology remains poorly understood. Here, we show that BMP4 is an intrinsically disordered protein and present a causal a link between epigenetic changes, BMP4 dysregulation and the evolution of the beak of the finch by natural selection. [ABSTRACT FROM AUTHOR]

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Introduction: For birds of prey, the integrity of the beak is extremely important for defence, hygiene, socialization and especially, feeding. This paper describes successful trans‐sinus fixation of a lateral deviation of the mandible in a hawk (Caracara plancus). Case report: The patient was presented with malnutrition and dehydration due to severe left lateral deviation of gnathotheca, with significant malocclusion. Fixation was performed with a 1.0‐mm pin and 0.4‐mm cerclage, applying contralateral traction to the deviation. The placement of the cerclage enabled full opening of the beak to allow feeding in the postoperative period. At 21 days after surgery, occlusion was perfect and the patient had recovered normal beak function. When clinical follow‐up indicated that the bird would be able to survive in the wild, it was released. Conclusion: Trans‐sinus fixation was effective in correcting lateral deviation of the gnathotheca in a hawk (C. plancus). [ABSTRACT FROM AUTHOR]

This study aimed to explore the feasibility of using an upper beak microstructure to estimate the age of purpleback flying squid (Sthenoteuthis oualaniensis). From these microstructures, the age and growth of squid caught from January to March and May to August in 2018, 2019, and 2020 in the waters surrounding the Xisha Islands in the South China Sea were determined. We found three typical growth zones (the hood region, crest region, and axis), abnormal increments (checks), and erosion in the beak examination. The average dorsal mantle length (ML) of males and females was 112.13 (±15.23 mm) and 119.67 mm (±24.50 mm), respectively, and no squid were older than 10 months. The peak hatching dates, according to back calculations, were from October to January of the next year. All sampled squid belonged to the autumn/winter cohort. Significant sex differences were found in the relationship between ML and age in squid with similar growth patterns. Exponential models best described the relationships of ML with age and body weight (BW) for both sexes. However, a linear model best described the relationship between age and upper rostrum length (URL). The maximum absolute daily growth rates (AGR) of BW were reached during days 240–270 for both sexes. The maximum AGRs in ML were reached during days 180–210 and 240–270 for males and females, respectively. The period of 120–150 days (4–5 months) was considered the sub-adult stage of S. oualaniensis in the Xisha Islands waters of the South China Sea. This study confirmed that the beak microstructure provides good age estimates for purpleback flying squid (S. oualaniensis). [ABSTRACT FROM AUTHOR]

Aiming at the problem that the edge contour extracted by the traditional edge detection operator,the Canny algorithm,is prone to produce such as redundant contour or edge contour defect,which can not meet the requirements of further research by computer vision,an edge detection algorithm is put forward and applied to the morphological study of cephalopod beak in this text. The algorithm realizes edge detection through five steps, including gray processing,filtering,binarization,constructing target connected domain and extracting edge contour. The results show that using this algorithm for edge detection can effectively distinguish signal and noise,improve the accuracy of target selection,and ensure the integrity of contour within the allowable range of error. It has a good effect in the recognition of cephalopod beak,and the pixel accuracy can reach 97. 79%. Compared with the results of Canny algorithm,the results of the improved algorithm are intuitive,complete and more accurate,which provides a new idea for the study of biological morphological characteristics such as beaks of cephalopods. [ABSTRACT FROM AUTHOR]

Beaks are among the few hard parts of coleoid cephalopods and are informative for species identification. Although mandible shape has been shown to be adaptive in many vertebrate taxa, it has been suggested that the shape of coleoid beaks does not bear any ecological signal. Yet, previous studies only explored beak shape in 2D and none have provided an in‐depth investigation of the potential relationship with ecological variables such as habitat use or diet.The goal of the present study was to understand whether variation in cephalopod beak shape reflects ecology and/or is more driven by phylogenetic relatedness as suggested previously.We imaged 101 lower and 108 upper beaks in 3D using underwater photogrammetry and micro‐CT scanning. Our 3D morphometric analysis conducted on 75 species of cephalopod shows that there is a significant but moderate phylogenetic signal. However, comparative phylogenetically informed analyses demonstrate that beak shape is also driven by ecology.We detected significant differences in beak shape between species inhabiting different habitats (pelagic, benthic or demersal) and of different trophic levels. Our results further suggest that beak shape variation can be summarized along a continuum between two main functions: fast closing versus hard biting.These results provide novel insights into the drivers of beak shape diversity in coleoid cephalopods and suggest that beak shape has evolved adaptively in relation to diet and habitat use. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Abstract The niche variation hypothesis (NVH) predicts that populations with wider niches exhibit greater morphological variation through increased interindividual differences in both niche and morphology. In this study, we examined niche–trait relationships in three passerine species (Cyanoderma ruficeps, Sinosuthora webbiana, and Zosterops simplex). A total of 289 C. ruficeps from 7 sites, 259 S. webbiana from 8 sites, and 144 Z. simplex from 6 sites were sampled along an elevation gradient (0–2,700 m) in Taiwan from 2009 to 2017. We measured bill traits (length, width, and depth of bill) and body size traits (length of head, tarsus, and wing) of the birds, which were reduced to four principal components (bill PC1, bill PC2, body size PC1, and body size PC2). We collected feather tissues for stable carbon and nitrogen isotope analyses to quantify their isotope niche. We quantified interindividual differences in isotope space and trait space with four diversity metrics (divergence, dispersion, evenness, and uniqueness) and tested whether interindividual differences in isotope space and trait space are positively associated. We quantified population isotope niche width by Bayesian ellipse area and population morphological variation by variances of the PCs. The results showed that individual uniqueness in isotope niche and bill morphology (average closeness of individuals within the population isotope/trait space) were positively associated across three species. Furthermore, isotope niche width and bill PC1 (reflecting the size of bill) variation at population level were also positively associated across the three species, supporting the NVH. Of the three species, C. ruficeps and S. webbiana showed stronger support for the NVH than Z. simplex, possibly due to the latter having narrower elevational distribution and a more specialized, plant‐based diet. The diversity metrics represented different aspects of interindividual differences in niche/trait space, and for the passerines, individual uniqueness appeared to play an important role in their niche–trait dynamics.

Background and aims The petaline operculum that covers the inner whorls until anthesis and the woody capsule that develops after fertilization are reproductive structures of eucalypts that protect the flower and seeds. Although they are distinct organs, they both develop from flower buds and this common ontogeny suggests shared genetic control. In Eucalyptus globulus their morphology is variable and we aimed to identify the quantitative trait loci (QTL) underlying this variation and determine whether there is common genetic control of these ecologically and taxonomically important reproductive structures. Methods Samples of opercula and capsules were collected from 206 trees that belong to a large outcrossed F2 E. globulus mapping population. The morphological variation in these structures was characterized by measuring six operculum and five capsule traits. QTL analysis was performed using these data and a linkage map consisting of 480 markers. Key results A total of 27 QTL were detected for operculum traits and 28 for capsule traits, with the logarithm of odds ranging from 2.8 to 11.8. There were many co-located QTL associated with operculum or capsule traits, generally reflecting allometric relationships. A key finding was five genomic regions where co-located QTL affected both operculum and capsule morphology, and the overall trend for these QTL was to affect elongation of both organs. Some of these QTL appear to have a significant effect on the phenotype, with the strongest QTL explaining 26.4 % of the variation in operculum shape and 16.4 % in capsule shape. Flower bud measurements suggest the expression of these QTL starts during bud development. Several candidate genes were found associated with the QTL and their putative function is discussed. Conclusions Variation in both operculum and capsule traits in E. globulus is under strong genetic control. Our results suggest that these reproductive structures share a common genetic pathway during flower bud development. [ABSTRACT FROM AUTHOR]

Compound rhamphothecae are characteristically present in the order Procellariiformes, but other birds also show this feature: ostriches, tinamous, cormorants, pelicans, herons. In Procellariiformes the shape, size and features of the rhamphotheca are not related to feeding mechanisms and/or displays (as in most birds) but with their nasal gland excretions and highly developed olfactory organ. The compound rhamphothecae are composed by several plates: the dorsal culminicorn, naricorn forming the tubes, the laterals latericorn, and premaxillary nail (upper jaw); the ramicorn and the mandibular nail (lower jaw). A nasolabial groove is present between the culminicorn and the latericorn, and caudally to the premaxillary nail. The mentolabial groove is between the ramicorn and the mandibular nail. Diomedeidae present a pseudomental fold and groove in the ventral part of the mandibular nail, the fold varies in its caudal extension. The ramicorn in Procellariidae is divided longitudinally into ventral and dorsal ramicorn by a suture. This feature is not found in other Procellariiformes except in Phoebetria palpebrata (Diomedeidae). The development and fusion of the tubes in Procellariidae vary as: a single tube, a partially fused tube, or completely separated tubes. Its extension is variable, reaching its greatest length in Macronectes giganteus. In Diomedeidae the configuration of the incurrent and excurrent apertures within or outside the tubes vary, and they present the shortest tubes. The grooves in Procellariidae vary in their development: the nasolabial groove sometimes is well marked with sutures, the ramicorn groove is always a sulcus (except for Fulmarus glacialoides) and expands cranially and/or caudally forming a triangle-shape depending on the species. In Diomedeidae the culminolabial groove presents variation at the dorsal branch, it can be: well developed, less developed or brief. Oceanitidae and Hydrobatidae present less variation. Phylogenetically, beaks of Oceanitidae and Hydrobatidae are the most basal, whereas Diomedeidae beaks derived from Procellariidae. [ABSTRACT FROM AUTHOR]

The anatomical description of the beak, oropharyngeal and nasal cavities of broad-breasted white turkey (BBWT) is unavailable in comparison with other birds. This study was conducted on five adult healthy birds (16.63 ± 5.54 Kg bwt). Beak was boat-shaped with pointed apex and was hard and rigid horny structure. The oral roof (palate) was formed of one median, two rostral, and two caudal palatine ridges. Shallow wide groove was observed between the rostral palatine ridges and lateral edges of the upper beak. The choanal slit was occupied 47.5% of the palate. There were two types of mechanical papillae distributed around the choanal slit. This slit was separated from the infundibular slit by a shallow groove. The tongue was triangular-shaped with pointed apex accompanied by V-shaped row of caudally directed lingual papillae between the body and the root. The lingual root was triangular-shaped, marked by shallow crescentic-shaped groove. The laryngeal mound was elongated pyramidal-shaped, contained glottis continued caudally by shallow longitudinal groove termed laryngeal sulcus. The nasal cavity was divided by a cartilaginous nasal septum into two symmetrical haves and opened externally by an elliptical-shaped nostril. The nostril was covered with a cartilaginous operculum which appeared as dome-shaped. Three nasal conchae were noticed within the nasal cavity: rostral, middle, and caudal nasal conchae. The middle nasal concha was the largest one, scrolled into 1 1/2 turns rostrally and scrolled 2 turns caudally. In conclusion, this study provides sufficient data on the anatomic and morphometric investigations of the nasal and oropharyngeal cavities of broad breast white turkey which may be beneficial for manipulation of head during treatment of diseases. [ABSTRACT FROM AUTHOR]

The sclerotised beaks of cephalopods have emerged as useful material to track their habitat and trophic ecology by using stable isotope analysis, because beaks grow continuously throughout their life without replacement. Here, stable isotopes of d13C and d15N in five continuous sections along the crest were measured to investigate the potential ontogenetic habitat shift and foragingecology change of Dosidicus gigas from the oceanic waters off Ecuador. In total, 90 sections from 18 upper beaks were examined with d13C values of -18.99 to -17.49‰ and d15N values of 0.69 to 7.09‰. Kruskal-Wallis test showed that there were significant differences in both isotopes between sections. The result of generalised additive models showed a significant overall decrease in both d13C and d15N values across the beak crest. The corrected standard ellipse area (SEAc) of the beak sections was 0.48 to 0.93‰2, with no high overlap between the two sections, with values ranging from 0.00 to 0.57. High individual variation of d15N values in most beak sections indicated that D. gigas in our study area appears to have a generalist food spectrum in most of its life history, except for the stage just before being captured. [ABSTRACT FROM AUTHOR]

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ABSTRACT: This study aimed to determine the effects of infrared beak treatment on the behavior and welfare of male and female turkeys reared to 12 wk of age. To do this, poults (236 males and 324 females) were assigned to one of 2 beak treatments: infrared beak treated on day of hatch (IR) or sham untreated control (C). Data collected included heterophil/lymphocyte (H/L) ratio, pecking force, feather cover, behavioral expression, and beak histology. Data were analyzed as a 2 × 2 factorial of beak treatment and gender, in a completely randomized design and analyzed using PROC MIXED (SAS 9.4). H/L ratio (indicative of a stress response) did not differ between treated and control poults during early life, except at 20 d of age when H/L ratio was higher for C poults than IR poults. Pecking force, measured as a method of monitoring pain, was different only at 1 wk of age, when IR poults pecked with more force than C poults. Feather cover was better in IR poults at 12 wk of age. Differences in behavior between treatments were minor over the 12-wk period. Overall, infrared beak treatment of commercial turkeys had minimal negative impacts on behavior and welfare. The results suggest that stress may be reduced in flocks that are beak treated and that the procedure itself does not cause a pain response.

Heat loss across the beak is an important thermoregulatory mechanism among birds, particularly in large-beaked taxa such as toucans (Ramphastidae) and hornbills (Bucerotidae). The number of species investigated remains limited, as does our understanding of how the functional significance of this pathway varies with environmental variables such as humidity, with little previous research on species inhabiting humid environments. We used infrared thermography to test the hypothesis that large (600-1300 g) Afrotropical forest hornbills use their beaks and casques as thermal radiators. We collected data over air temperatures (T air ) of 15-34 °C for wild-caught trumpeter hornbills (Bycanistes bucinator) and captive-bred silvery-cheeked hornbills (Bycanistes brevis) and black-casqued hornbills (Ceratogymna atrata). Surface temperatures of the beaks and casques (T beak ) tracked T air below 24-25 °C, but at higher T air , the T beak - T air gradient increased to maximum values of 10-12 °C. Maximum rates of beak heat loss were 2.5-3.8 W, equivalent to 31-83 % of estimated resting metabolic heat production. Facial skin showed also evidence for active regulation of heat loss. We also analysed the scaling of the inflection T air above which the T beak - T air gradient increases (T inflection ) by combining our data with published and three unpublished values. We found that T inflection decreases with increasing body mass (M b ), with the relationship best described by the linear regression model T inflection  = -9.134log 10 M b  + 50.83, with M b in g., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

AbstractAt certain intensities and durations, environmental stressors during development can result in changes in physiology that prepare organisms for future stressful conditions. Such plasticity can allow organisms to maintain good condition when confronted with a poor environment, potentially conferring an advantage in fitness. However, the physiological changes underlying these adaptive phenotypic adjustments are understudied. Using captive male zebra finches ( Taeniopygia castanotis ), we tested whether exposure to a prolonged mild stressor during development would adaptively modify their antioxidant enzyme expression, reducing oxidative damage when exposed to a high-intensity stressor in adulthood and allowing the maintenance of a secondary sexual trait. To do this, we exposed juvenile finches to either a prolonged mild heat stressor treatment (38°C) or a control temperature treatment (22°C). As adults, these finches were then exposed to either an acute high-intensity heat stressor treatment (42°C) or control temperature treatment (22°C). The beak color of males-a sexually selected trait-was quantified, as were oxidative stress parameters in the testes and liver tissues. We saw that the mild-heat-conditioned males had beaks with higher saturation and lower brightness at baseline in adulthood but that the changes in beak color in response to the high heat stressor varied. After exposure to the high heat stressor as adults, finches had higher levels of superoxide dismutase 1 and 2 in the testes and lower levels of lipid damage in the liver if they were also exposed to the mild heat conditioning as juveniles, indicating an adaptive phenotypic change.

Echidnas are commonly known as 'spiny ant-eaters', but long-beaked echidnas (Zaglossus spp.) do not eat ants, whereas short-beaked echidnas (Tachyglossus aculeatus) eat other invertebrates as well as ants. The differences in skull morphology between short- and long-beaked echidnas are related to the differences in their diets, and I tested the hypothesis that there would be differences in beak length of short-beaked echidnas from populations with different diets. Published data on diet from echidnas from different parts of Australia show that echidnas from arid and semi-arid areas (subspecies acanthion) and Kangaroo Island (subspecies multiaculeatus) principally eat ants and termites, whereas the main dietary items of echidnas from south-eastern Australia (subspecies aculeatus) and Tasmania (subspecies setosus) are ants and scarab larvae. Using museum specimens and photographs I measured skull dimensions on echidnas from different parts of Australia: acanthion and multiaculeatus have narrower skulls and shorter beaks than aculeatus and setosus , with setosus being the only Australian subspecies where beak length exceeds cranium length. Australian short-beaked echidnas fall into two groups: aculeatus and setosus from the wetter east and south-east, which eat ant and scarab larvae, and the arid and semi-arid zone acanthion and multiaculeatus , with shorter, narrower skulls, and which eat ants and termites. Echidnas occur all over Australia, but echidnas from different regions vary greatly in the length of the spines and hair. This paper shows there are also big differences in beak length. Tasmanian echidnas have the longest beaks, whereas arid zone echidnas have very short beaks. Beak length is related to diet and feeding behaviour: longer beaks are better suited to probing for scarab larvae, while short beaks are better for ploughing through the soil for ants and termites. Diet, beak length and claw lengths divide Australian echidnas into two groups. [ABSTRACT FROM AUTHOR]

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Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The beak of the jumbo squid Dosidicus gigas is a fascinating example of how seamlessly nature builds with mechanically mismatched materials. A 200-fold stiffness gradient begins in the hydrated chitin of the soft beak base and gradually increases to maximum stiffness in the dehydrated distal rostrum. Here, we combined RNA-Seq and proteomics to show that the beak contains two protein families. One family consists of chitin-binding proteins (DgCBPs) that physically join chitin chains, whereas the other family comprises highly modular histidine-rich proteins (DgHBPs). We propose that DgHBPs play multiple key roles during beak bioprocessing, first by forming concentrated coacervate solutions that diffuse into the DgCBP-chitin scaffold, and second by inducing crosslinking via an abundant GHG sequence motif. These processes generate spatially controlled desolvation, resulting in the impressive biomechanical gradient. Our findings provide novel molecular-scale strategies for designing functional gradient materials.

Raman spectroscopy has been widely applied in the analysis of biological tissues. In this study, beak cuticle was studied to investigate its compositional and secondary structural changes during the laying period and aging of laying hens. The analysis revealed markedly increased contents of amide I and amino acids (phenylalanine and tyrosine) within the beak during the intense laying period from 17 to 20 weeks. In addition, α-helical protein was also gradually synthesized in this period. The relative area ratio of 1003/1448 cm−1 (assigned to the vibrations of phenylalanine and organic C-H respectively) was confirmed as an excellent indicator for estimating the start of the laying period. This ratio increased from 0.36 to 0.42 from 17 to 20 weeks. The Raman peak at 1156 cm−1 was assigned to carotenoids in the beak. The intensities of the 1156 cm−1 peak significantly decreased during aging. The area ratio of 1156/1448 cm−1 was successfully applied to estimate ages (still within the laying period) of laying hens. This study shows the potential of using Raman spectroscopy to quantify ages and laying period of birds.

All extant birds are toothless, and recent molecular evidence suggests that edentulism in extant birds is the product of a single evolutionary transition to toothlessness on the line to crown birds in the Cretaceous. However, a fossil crown bird premaxilla from the Palaeogene of North America (assigned to the gastornithid Omorhamphus storchii) has been interpreted as bearing alveoli for teeth, an observation that would cast doubt on a single loss of teeth preceding the extant avian radiation. However, the identity of these putative alveoli has never been reinvestigated in detail. Here, we re-examine this problematic juvenile specimen, using non-invasive x-ray microtomography, enabling the assessment of the true identity of the large, alveolus-like pits on the ventral side of this premaxilla. Although superficially alveolus-like, we illustrate that these pits represent openings of large neurovascular canals communicating with both the medullary cavity as well as other canals opening along the dorsal and lateral surfaces of the upper jaw, and that none of these openings appear to represent tooth alveoli. Further, we demonstrate that claims of an adult gastornithid specimen (Gastornis parisiensis) exhibiting tooth alveoli are similarly unfounded. By rejecting the hypothesis of dentition in these gastornithids, we eliminate any lingering uncertainty regarding the persistence of teeth within the avian crown group. We illustrate the presence of similar large vascular openings along the ventral surface of the beak of juvenile Gastornis russelli/parisiensis, and smaller versions in the juvenile premaxillae of Sylviornis neocaledoniae. We suggest that the large vascular canals in gastornithid specimens such as O. storchii are a feature associated with rapid growth of the juvenile beak, allowing the attainment of a large and dorsoventrally deep beak early in ontogeny. This may have enabled young gastornithids to become autonomous early, consistent with a presumably precocial developmental strategy.

The niche variation hypothesis (NVH) predicts that populations with wider niches exhibit greater morphological variation through increased interindividual differences in both niche and morphology. In this study, we examined niche–trait relationships in three passerine species (Cyanoderma ruficeps, Sinosuthora webbiana, and Zosteropssimplex). A total of 289 C. ruficeps from 7 sites, 259 S. webbiana from 8 sites, and 144 Z. simplex from 6 sites were sampled along an elevation gradient (0–2,700 m) in Taiwan from 2009 to 2017. We measured bill traits (length, width, and depth of bill) and body size traits (length of head, tarsus, and wing) of the birds, which were reduced to four principal components (bill PC1, bill PC2, body size PC1, and body size PC2). We collected feather tissues for stable carbon and nitrogen isotope analyses to quantify their isotope niche. We quantified interindividual differences in isotope space and trait space with four diversity metrics (divergence, dispersion, evenness, and uniqueness) and tested whether interindividual differences in isotope space and trait space are positively associated. We quantified population isotope niche width by Bayesian ellipse area and population morphological variation by variances of the PCs. The results showed that individual uniqueness in isotope niche and bill morphology (average closeness of individuals within the population isotope/trait space) were positively associated across three species. Furthermore, isotope niche width and bill PC1 (reflecting the size of bill) variation at population level were also positively associated across the three species, supporting the NVH. Of the three species, C. ruficeps and S. webbiana showed stronger support for the NVH than Z. simplex, possibly due to the latter having narrower elevational distribution and a more specialized, plant‐based diet. The diversity metrics represented different aspects of interindividual differences in niche/trait space, and for the passerines, individual uniqueness appeared to play an important role in their niche–trait dynamics. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)