Spatio-temporal composition of aquatic birds communityin Juluapan Lagoon, Colima, Mexican Central Pacific / Composición espacio-temporal de las aves acuáticas en la laguna Juluapan, Colima, en el Pacífico Central Mexicano

Abstract Introduction: Aquatic birds (AB) are usually associated with wetlands, which provide refuge, food, and/or nesting sites for resident and migratory species. Despite their ecological importance, there is little knowledge on AB in some tropical environments, such as those found on the Colima coast. Objective: To investigate the spatial and temporal composition of the AB community in Juluapan Lagoon, Colima, Central Mexican Pacific. Methods: Monthly counts were conducted between June 2017 and May 2018 during low-tide conditions to record habitat use by AB. Species richness and bird counts were obtained to compare sampling areas; mean richness and number of individuals were compared between seasons. Results: We detected 53 species and 5 750 individuals. The highest species richness and relative abundance values were obtained in winter at the lagoon area farthest from the connection with the marine system, where anthropogenic activity is lower. Diversity was greater in zones 2 and 3 in spring, summer, and fall. Muddy flats were the most used environment, and the most frequent activity was resting. Nesting activity was only recorded in the middle of the lagoon at the mangrove during spring. "Shorebirds" and "waders" were the most dominant groups in the bird community of the Juluapan lagoon. Conclusions: This coastal wetland is a site of great biological importance for aquatic birds; thus, conservation measures should be implemented, and there should be a continuous study of the effects of anthropogenic pressure.

Resumen Introducción: Las aves acuáticas (AA) son usualmente relacionadas a los humedales debido a que éstos funcionan como sitios de refugio, alimentación y anidación de diferentes especies residentes y migratorias. Sin embargo, el conocimiento sobre las aves acuáticas en algunos humedales es nulo. Objetivo: Investigar la composición espacio-temporal de la comunidad de AA en la laguna Juluapan, Colima, en el Pacífico Central Mexicano. Métodos: Entre junio de 2017 y mayo de 2018 se llevaron a cabo conteos mensuales en condiciones de marea baja para registrar el uso de hábitat de las AA. Se obtuvieron valores de riqueza de especies y número de individuos para realizar comparaciones entre zonas de muestreo, así como el promedio del número de especies y número de individuos para comparaciones entre temporadas. Resultados: Se registraron un total de 53 especies y 5 750 individuos. Los valores de riqueza de especies y densidad de individuos fueron más altos durante invierno, en la zona más alejada al ambiente marino, donde la actividad antropogénica es menor. La diversidad tuvo valores más altos en la zona 2 y 3, durante primavera, verano y otoño. El ambiente más explotado por las aves fueron las planicies lodosas; y el descanso fue la actividad más frecuente. Asimismo, la actividad de anidación sólo se registró en el manglar de la zona media durante primavera. Las "aves playeras" y "aves zancudas" fueron los grupos más predominantes en la comunidad de aves de la laguna Juluapan. Conclusiones: Este humedal costero es un sitio de gran importancia biológica para aves acuáticas, por lo que resulta necesario la implementación de medidas de conservación, así como el estudio de los efectos por la presión antropogénica.

Phylogenetic relationships of the Mangrove Hummingbird, "Amazilia" boucardi (Apodiformes: Trochilidae) of Costa Rica / Relaciones filogenéticas del Colibrí manglero "Amazilia" boucardi (Apodiformes: Trochilidae) de Costa Rica

Abstract Introduction: A recent revision of the generic classification of the Trochilidae based on DNA sequences revealed many inconsistencies with the current generic classification, largely based on plumage characters subject to homoplasy, especially in the Trochilini, the largest tribe. A thorough generic reorganization brought the classification into accord with the phylogeny, but due to lack of genetic data, two species remained unclassified. One of these was the Mangrove Hummingbird, "Amazilia" boucardi, endemic to Costa Rica and included in the IUCN red list of threatened species. Objective: To obtain molecular evidence to clarify the generic relationships of "A." boucardi. Methods: We isolated DNA from tissues of this species and amplified 4 nuclear and 4 mitochondrial fragments and compared these with homologous fragments from 56 species in the Trochilini, constructing phylogenetic trees with maximum likelihood and Bayesian methods. Results: Our phylogenetic analyses confirmed the placement of boucardi in the Trochilini and definitely excluded it from Amazilia but placed it with high confidence in the genus Chrysuronia Bonaparte, 1850, within which its closest relative is C. coeruleogularis, which also inhabits mangroves. Conclusions: Our genetic data based on nuclear and mitochondrial regions clearly indicate the relationship of A. boucardi and L. coeruleogularis. Moreover, it is also supported by their habitat distribution in the mangroves of the Pacific coast of Costa Rica and Western Panama. Therefore, we suggested to exclude A. boucardi as "incertae sedis".

Resumen Introducción: Una revisión reciente de la clasificación de la familia Trochilidae con base en secuencias de ADN demostró muchas incongruencias con la clasificación genérica previa, que había sido hecho con base en caracteres del plumaje muy sujetos a homoplasia, especialmente en la tribu más grande, Trochillini. Una reorganización de los géneros logró llevar su clasificación genérica a la concordancia con la filogenia, pero debido a la ausencia de datos genéticos, dos especies permanecieron sin clasificar. Una de estas fue el colibrí de manglar Amazilia boucardi, una especie endémica de Costa Rica, considerada como amenazada en la lista roja de la UICN. Objetivo: Obtener evidencia molecular para esclarecer las relaciones genéricas de A. boucardi. Métodos: Se aisló ADN de tejidos de esta especie y se amplificaron 4 fragmentos de ADN del núcleo y 5 de la mitocondria, y se compararon con fragmentos homólogos de 56 especies en la tribu Trochillini, generando árboles filogenéticos con métodos de máxima verosimilitud y bayesiano. Resultados: Los análisis filogénticos obtenidos confirmaron la ubicación de boucardi en Trochilini y definitivamente la excluyó del género Amazilia, pero la ubicó con un alto grado de confianza en el género Chrysuronia Bonaparte, 1850, dentro los cuales su pariente más cercano es C. coeruleogularis, que también habita manglares. Conclusiones: Nuestros datos genéticos basados en regiones nucleares y mitocondriales indican claramente la relación entre A. boucardi and L. coeruleogularis. Es más, lo anterior se sustenta por su distribución en los manglares de la costa Pacífica de Costa Rica y oeste de Panamá. Por lo tanto, sugerimos excluir a A. boucardi como "incertae sedis".

Earliest evidence of avian primary feather moult.

Feather moulting is a crucial process in the avian life cycle, which evolved to maintain plumage functionality. However, moulting involves both energetic and functional costs. During moulting, plumage function temporarily decreases between the shedding of old feathers and the full growth of new ones. In flying taxa, a gradual and sequential replacement of flight feathers evolved to maintain aerodynamic capabilities during the moulting period. Little is known about the moult strategies of non-avian pennaraptoran dinosaurs and stem birds, before the emergence of crown lineage. Here, we report on two Early Cretaceous pygostylian birds from the Yixian Formation (125 mya), probably referable to Confuciusornithiformes, exhibiting morphological characteristics that suggest a gradual and sequential moult of wing flight feathers. Short primary feathers interpreted as immature are symmetrically present on both wings, as is typical among extant flying birds. Our survey of the enormous collection of the Tianyu Museum confirms previous findings that evidence of active moult in non-neornithine pennaraptorans is rare and likely indicates a moult cycle greater than one year. Documenting moult in Mesozoic feathered dinosaurs is critical for understanding their ecology, locomotor ability and the evolution of this important life-history process in birds.

A review of predator exclusion fencing to create mainland islands in Hawai'i.

Background: Invasive species are the primary threat to island ecosystems globally and are responsible for approximately two-thirds of all island species extinctions in the past 400 years. Non-native mammals-primarily rats, cats, mongooses, goats, sheep, and pigs-have had devastating impacts on at-risk species and are major factors in population declines and extinctions in Hawai'i. With the development of fencing technology that can exclude all mammalian predators, the focus for some locations in Hawai'i shifted from predator control to local eradication. Methods: This article describes all existing and planned full predator exclusion fences in Hawai'i by documenting the size and design of each fence, the outcomes the predator eradications, maintenance issues at each fence, and the resulting native species responses. Results: Twelve predator exclusion fences were constructed in the Hawaiian Islands from 2011-2023 and six more were planned or under construction; all were for the protection of native seabirds and waterbirds. Fences ranged in length from 304-4,877 m and enclosed 1.2-640 ha. One-third of the 18 fences were peninsula-style with open ends; the remaining two-thirds of the fences were complete enclosures. The purpose of twelve of the fences (67%) was to protect existing bird populations, and six (33%) were initiated for mitigation required under the U.S. Endangered Species Act. Of the six mitigation fences, 83% were for the social attraction of seabirds and one fence was for translocation of seabirds; none of the mitigation fences protected existing bird populations. Rats and mice were present in every predator exclusion fence site; mice were eradicated from five of six sites (83%) where they were targeted and rats (three species) were eradicated from eight of 11 sites (72%). Mongoose, cats, pigs, and deer were eradicated from every site where they were targeted. Predator incursions occurred in every fence. Rat and mouse incursions were in many cases chronic or complete reinvasions, but cat and mongoose incursions were occasional and depended on fence type (i.e., enclosed vs. peninsula). The advent of predator exclusion fencing has resulted in great gains for protecting existing seabirds and waterbirds, which demonstrated dramatic increases in reproductive success and colony growth. With threats from invasive species expected to increase in the future, predator exclusion fencing will become an increasingly important tool in protecting island species.

Intersexual patterns of the digestive tract and body size are opposed in a large bird.

The appropriate structure of the digestive tract is crucial for individual adaptation to ecological conditions. In birds, the length of the small intestine, responsible for food absorption, is generally believed to be positively correlated with body size. In this study, we investigated the variation in small intestine length in the White Stork (Ciconia ciconia), a monomorphic species without visible sexual dimorphism, but characterized by differing parental efforts, which can be reflected by the small intestine lengths between the sexes. We examined the relationship between small intestine length and body size within the sexes. Our findings show that male White Storks have significantly shorter small intestines than females, despite having larger body sizes than the latter. Furthermore, we found a significant relationship between body size and small intestine length, but it was of a different nature in the two sexes. Males exhibited a previously unreported phenomenon, whereby increasing body size was associated with shortening small intestines, whereas females exhibited the opposite pattern. These novel findings shed light on the anatomical adaptations of the digestive tract in birds.

Leach's storm-petrel (Hydrobates leucorhous), a long-lived seabird shows flexible, condition-dependent, feeding strategies in response to poor chick condition.

BACKGROUND: Parent-offspring conflict represents the sensitive balance of resource allocation between self-maintenance and reproduction. Two strategies have been proposed to better understand how species manage this conflict. In fixed-level feeding behavior, parents feed offspring consistent quantities of food; while flexible feeding shows plasticity in parental allocation based on offspring need. Life-history theory predicts that parents of long-lived species prioritize their survival and may favor the fixed-level hypothesis to maximize lifetime reproductive success. In this study, we highlight the natural variation of parent-offspring allocation strategies within a unique population of Leach's storm-petrels (Hydrobates leucorhous), and through month-long food supplementation and restriction manipulations, we investigate how chick condition affects parental provisioning during the chick-rearing period of reproduction. RESULTS: We show that the parents upregulated chick feeding frequency of nutritionally deprived chicks, resulting in a larger total amount of food delivered during the study period. Additionally, the proportion of nights when both parents fed was highest in restricted chicks, and the proportion of nights when neither parents fed was lowest in restricted chicks, suggesting that storm-petrel parents shorten their foraging bouts to deliver food more often when their chicks are in relatively poor condition. CONCLUSIONS: Our results support that Leach's storm-petrels use a flexible-level feeding strategy, suggesting that parents can assess offspring condition, and respond by feeding chicks at higher frequencies. These data provide insight on how a long-lived seabird balances its own energetic demands with that of their offspring during the reproductive period.

Gut fungi of black-necked cranes (Grus nigricollis) respond to dietary changes during wintering.

BACKGROUND: Migratory birds exhibit heterogeneity in foraging strategies during wintering to cope with environmental and migratory pressures, and gut bacteria respond to changes in host diet. However, less is known about the dynamics of diet and gut fungi during the wintering period in black-necked cranes (Grus nigricollis). RESULTS: In this work, we performed amplicon sequencing of the trnL-P6 loop and ITS1 regions to characterize the dietary composition and gut fungal composition of black-necked cranes during wintering. Results indicated that during the wintering period, the plant-based diet of black-necked cranes mainly consisted of families Poaceae, Solanaceae, and Polygonaceae. Among them, the abundance of Solanaceae, Polygonaceae, Fabaceae, and Caryophyllaceae was significantly higher in the late wintering period, which also led to a more even consumption of various food types by black-necked cranes during this period. The diversity of gut fungal communities and the abundance of core fungi were more conserved during the wintering period, primarily dominated by Ascomycota and Basidiomycota. LEfSe analysis (P < 0.05, LDA > 2) found that Pyxidiophora, Pseudopeziza, Sporormiella, Geotrichum, and Papiliotrema were significantly enriched in early winter, Ramularia and Dendryphion were significantly enriched in mid-winter, Barnettozyma was significantly abundant in late winter, and Pleuroascus was significantly abundant in late winter. Finally, mantel test revealed a significant correlation between winter diet and gut fungal. CONCLUSIONS: This study revealed the dynamic changes in the food composition and gut fungal community of black-necked cranes during wintering in Dashanbao. In the late wintering period, their response to environmental and migratory pressures was to broaden their diet, increase the intake of non-preferred foods, and promote a more balanced consumption ratio of various foods. Balanced food composition played an important role in stabilizing the structure of the gut fungal community. While gut fungal effectively enhanced the host's food utilization rate, they may also faced potential risks of introducing pathogenic fungi. Additionally, we recongnized the limitations of fecal testing in studying the composition of animal gut fungal, as it cannot effectively distinguished between fungal taxa from food or soil inadvertently ingested and intestines. Future research on functions such as cultivation and metagenomics may further elucidate the role of fungi in the gut ecosystem.

Evaluation of an autonomous acoustic surveying technique for grassland bird communities in Nebraska.

Monitoring trends in wildlife communities is integral to making informed land management decisions and applying conservation strategies. Birds inhabit most niches in every environment and because of this they are widely accepted as an indicator species for environmental health. Traditionally, point counts are the common method to survey bird populations, however, passive acoustic monitoring approaches using autonomous recording units have been shown to be cost-effective alternatives to point count surveys. Advancements in automatic acoustic classification technologies, such as BirdNET, can aid in these efforts by quickly processing large volumes of acoustic recordings to identify bird species. While the utility of BirdNET has been demonstrated in several applications, there is little understanding of its effectiveness in surveying declining grassland birds. We conducted a study to evaluate the performance of BirdNET to survey grassland bird communities in Nebraska by comparing this automated approach to point count surveys. We deployed ten autonomous recording units from March through September 2022: five recorders in row-crop fields and five recorders in perennial grassland fields. During this study period, we visited each site three times to conduct point count surveys. We compared focal grassland bird species richness between point count surveys and the autonomous recording units at two different temporal scales and at six different confidence thresholds. Total species richness (focal and non-focal) for both methods was also compared at five different confidence thresholds using species accumulation curves. The results from this study demonstrate the usefulness of BirdNET at estimating long-term grassland bird species richness at default confidence scores, however, obtaining accurate abundance estimates for uncommon bird species may require validation with traditional methods.

A(H2N2) and A(H3N2) influenza pandemics elicited durable cross-reactive and protective antibodies against avian N2 neuraminidases.

Human cases of avian influenza virus (AIV) infections are associated with an age-specific disease burden. As the influenza virus N2 neuraminidase (NA) gene was introduced from avian sources during the 1957 pandemic, we investigate the reactivity of N2 antibodies against A(H9N2) AIVs. Serosurvey of healthy individuals reveal the highest rates of AIV N2 antibodies in individuals aged ≥65 years. Exposure to the 1968 pandemic N2, but not recent N2, protected against A(H9N2) AIV challenge in female mice. In some older adults, infection with contemporary A(H3N2) virus could recall cross-reactive AIV NA antibodies, showing discernable human- or avian-NA type reactivity. Individuals born before 1957 have higher anti-AIV N2 titers compared to those born between 1957 and 1968. The anti-AIV N2 antibodies titers correlate with antibody titers to the 1957 N2, suggesting that exposure to the A(H2N2) virus contribute to this reactivity. These findings underscore the critical role of neuraminidase immunity in zoonotic and pandemic influenza risk assessment.

Genetic diversity of astroviruses detected in wild aquatic birds in Hong Kong.

Wild waterfowl serve as a reservoir of some astroviruses. Fecal samples from wild waterfowl collected at Hong Kong's Marshes were tested using pan-astrovirus reverse transcription-PCR. Positive samples underwent subsequent host identification using DNA barcoding. Based on deduced partial sequences, noteworthy samples from three astrovirus groups (mammalian, avian and unclassified astroviruses) were further analyzed by next-generation sequencing. One sample of Avastrovirus 4 clade, MP22-196, had a nearly complete genome identified. The results of ORF2 phylogenetic analysis and genetic distance analysis indicate that Avastrovirus 4 is classified as a distinct subclade within Avastrovirus. MP22-196 has typical astrovirus genome characteristics. The unique characteristics and potential differences of this genome, compared to other avian astrovirus sequences, involve the identification of a modified sgRNA sequence situated near the ORF2 start codon, which precedes the ORF1b stop codon. Additionally, the 3' UTR of MP22-196 is shorter than other avian astroviruses. This study expands our understanding of the Avastrovirus 4 clade.

Phylogenetic and mutational analysis of H10N3 avian influenza A virus in China: potential threats to human health.

In recent years, the avian influenza virus has emerged as a significant threat to both human and public health. This study focuses on a patient infected with the H10N3 subtype of avian influenza virus, admitted to the Third People's Hospital of Kunming City on March 6, 2024. Metagenomic RNA sequencing and polymerase chain reaction (PCR) analysis were conducted on the patient's sputum, confirming the H10N3 infection. The patient presented severe pneumonia symptoms such as fever, expectoration, chest tightness, shortness of breath, and cough. Phylogenetic analysis of the Haemagglutinin (HA) and neuraminidase (NA) genes of the virus showed that the virus was most closely related to a case of human infection with the H10N3 subtype of avian influenza virus found in Zhejiang Province, China. Analysis of amino acid mutation sites identified four mutations potentially hazardous to human health. Consequently, this underscores the importance of continuous and vigilant monitoring of the dynamics surrounding the H10N3 subtype of avian influenza virus, utilizing advanced genomic surveillance techniques.

Comparison of Manual Restraint With and Without Sedation on Outcomes for Wild Birds Undergoing Decontamination.

The decontamination process for plumage-contaminated wild birds, such as those affected by oil spills, is lengthy and involves manual restraint and manipulation of all body parts. Birds commonly react to this in ways that suggest they are extremely stressed (eg, struggling, vocalizing). We proposed to reduce stress during the wash process using sedation and hypothesized that the use of sedation would not negatively impact survival. Contaminated birds in need of washing were randomly selected to be either sedated (butorphanol 2 mg/kg IM + midazolam 1 mg/kg IM and flumazenil 0.1 mg/kg IM for reversal) or not sedated at 3 US rehabilitation centers over the course of 1 year. Response to sedation was rated on a scale of 0-4 with 0 as no effect to 4 as excessively sedate. Data such as cloacal temperatures at various time points, lengths of various portions of the wash process, preening behavior in the drying pen, and disposition were collected. No statistical differences were found between sedated and nonsedated birds for any of the data points collected, including survival. There was a significant association between birds with higher cloacal temperatures in the drying pen and with birds held longer in the drying pen with improved survival; however, these findings were unrelated to whether the birds were sedated. Our findings show that sedation with butorphanol 2 mg/ kg IM and midazolam 1 mg/kg IM reversed with flumazenil 0.1 mg/kg IM can be used during the wash process for wild birds without adverse effects. Careful attention must be given to heat support for all birds while drying to prevent hypothermia.

Predictability of ecological and evolutionary dynamics in a changing world.

Ecological and evolutionary predictions are being increasingly employed to inform decision-makers confronted with intensifying pressures on biodiversity. For these efforts to effectively guide conservation actions, knowing the limit of predictability is pivotal. In this study, we provide realistic expectations for the enterprise of predicting changes in ecological and evolutionary observations through time. We begin with an intuitive explanation of predictability (the extent to which predictions are possible) employing an easy-to-use metric, predictive power PP(t). To illustrate the challenge of forecasting, we then show that among insects, birds, fishes and mammals, (i) 50% of the populations are predictable at most 1 year in advance and (ii) the median 1-year-ahead predictive power corresponds to a prediction R 2 of only 20%. Predictability is not an immutable property of ecological systems. For example, different harvesting strategies can impact the predictability of exploited populations to varying degrees. Moreover, incorporating explanatory variables, accounting for time trends and considering multivariate time series can enhance predictability. To effectively address the challenge of biodiversity loss, researchers and practitioners must be aware of the information within the available data that can be used for prediction and explore efficient ways to leverage this knowledge for environmental stewardship.

Ixodes ricinus as potential vector for Usutu virus.

Usutu virus (USUV) is an emerging flavivirus that is maintained in an enzootic cycle with mosquitoes as vectors and birds as amplifying hosts. In Europe, the virus has caused mass mortality of wild birds, mainly among Common Blackbird (Turdus merula) populations. While mosquitoes are the primary vectors for USUV, Common Blackbirds and other avian species are exposed to other arthropod ectoparasites, such as ticks. It is unknown, however, if ticks can maintain and transmit USUV. We addressed this question using in vitro and in vivo experiments and field collected data. USUV replicated in IRE/CTVM19 Ixodes ricinus tick cells and in injected ticks. Moreover, I. ricinus nymphs acquired the virus via artificial membrane blood-feeding and maintained the virus for at least 70 days. Transstadial transmission of USUV from nymphs to adults was confirmed in 4.9% of the ticks. USUV disseminated from the midgut to the haemocoel, and was transmitted via the saliva of the tick during artificial membrane blood-feeding. We further explored the role of ticks by monitoring USUV in questing ticks and in ticks feeding on wild birds in the Netherlands between 2016 and 2019. In total, 622 wild birds and the Ixodes ticks they carried were tested for USUV RNA. Of these birds, 48 (7.7%) carried USUV-positive ticks. The presence of negative-sense USUV RNA in ticks, as confirmed via small RNA-sequencing, showed active virus replication. In contrast, we did not detect USUV in 15,381 questing ticks collected in 2017 and 2019. We conclude that I. ricinus can be infected with USUV and can transstadially and horizontally transmit USUV. However, in comparison to mosquito-borne transmission, the role of I. ricinus ticks in the epidemiology of USUV is expected to be minor.

It's time to apply outbreak response best practices to avian influenza: A national call to action.

Cases of high pathogenicity avian influenza (HPAI) in Canada are upon us again and with reports of infection in US dairy cattle and a dairy farmer in the United States, concern has been raised. Although panic isn't helpful, this heightened level of concern is appropriate, given that reports of human infections with the H5N1 virus often indicate high mortality rates. These can range from 14 to 50%. The current devastating impact of the virus on the poultry industry, as well as its propensity to mutate are also reasons for concern. At the same time, HPAI provides an opportunity for the poultry and livestock industries to align and organize coherently for the management of all zoonotic diseases and other industry issues. To manage HPAI more effectively, it is essential to align all stakeholders under Outbreak Response Best Practices using a formal Quality Management System (QMS). The objective of this article is to describe this approach with examples drawn from management of the Walkerton waterborne disease crisis. We urge the veterinary profession to rise to the challenge of HPAI and use it as a context in which to align more coherently with national stakeholders for the prevention and management of all priority issues within the areas of Agri-food and Public Health.

Les cas de grippe aviaire hautement pathogène (HPAI) sont de nouveau aux portes du Canada et, avec les rapports d'infection chez des bovins laitiers américains et chez un producteur laitier aux États-Unis, des inquiétudes ont été soulevées. Même si la panique n'aide pas, ce niveau d'inquiétude accru est approprié, étant donné que les rapports d'infections humaines par le virus H5N1 indiquent souvent des taux de mortalité élevés. Ceux-ci peuvent aller de 14 à 50 %. L'impact dévastateur actuel du virus sur l'industrie avicole, ainsi que sa propension à muter sont également des motifs d'inquiétude. Dans un même temps, l'HPAI offre aux secteurs de la volaille et de l'élevage l'opportunité de s'associer et de s'organiser de manière cohérente pour la gestion de toutes les maladies zoonotiques et d'autres problèmes industriels. Pour gérer l'HPAI plus efficacement, il est essentiel d'aligner toutes les parties prenantes sur les meilleures pratiques de réponse aux épidémies en utilisant un système de gestion de la qualité (QMS) formel. L'objectif de cet article est de décrire cette approche avec des exemples tirés de la gestion de la crise des maladies d'origine hydrique à Walkerton. Nous exhortons la profession vétérinaire à relever le défi de l'HPAI et à l'utiliser comme un contexte dans lequel s'aligner de manière plus cohérente avec les parties prenantes nationales pour la prévention et la gestion de toutes les questions prioritaires dans les domaines de l'agroalimentaire et de la santé publique.(Traduit par Docteur Serge Messier).

Emergence of genetic diversity and multi-drug resistant Clostridium perfringens from wild birds.

BACKGROUND: Clostridium perfringens (C. perfringens) is an important zoonotic microorganism that can cause animal and human infections, however information about the prevalence status in wild birds of this pathogenic bacterium is currently limited. RESULT: In this study, 57 strains of C. perfringens were isolated from 328 fecal samples of wild birds. All the isolates were identified as type A and 70.18% of the isolates carried the cpb2 gene. Antimicrobial susceptibility testing showed that and 22.80% of the isolates were classified as multidrug-resistant strains. The MLST analysis of the 57 isolates from wild birds was categorized into 55 different sequence types (STs) and clustered into eight clonal complexes (CCs) with an average of 20.1 alleles and the Simpson Diversity index (Ds) of 0.9812, and revealed a high level of genetic diversity within the C. perfringens populations. Interestingly, the isolates from swan goose were clustered in the same CC while isolates from other bird species were more scattered suggesting that a potential difference in genetic diversity among the C. perfringens populations associated with different bird species. CONCLUSION: C. perfringens exhibits a wide range of host adaptations, varying degrees of antimicrobial resistance, and a high degree of genetic diversity in wild birds. Understanding the prevalence, toxin type, antimicrobial resistance, and genetic diversity of C. perfringens in wildlife populations is essential for developing effective strategies for disease control and management.

Convergent evolution toward a slow pace of life predisposes insular endotherms to anthropogenic extinctions.

Island vertebrates have evolved a number of morphological, physiological, and life history characteristics that set them apart from their mainland relatives. However, to date, the evolution of metabolism and its impact on the vulnerability to extinction of insular vertebrates remains poorly understood. This study used metabolic data from 2813 species of tetrapod vertebrates, including 695 ectothermic and 2118 endothermic species, to reveal that island mammals and birds evolved convergent metabolic strategies toward a slow pace of life. Insularity was associated with shifts toward slower metabolic rates and greater generation lengths in endotherms, while insularity just drove the evolution of longer generation lengths in ectotherms. Notably, a slow pace of life has exacerbated the extinction of insular endemic species in the face of anthropogenic threats. These findings have important implications for understanding physiological adaptations associated with the island syndrome and formulating conservation strategies across taxonomic groups with different metabolic modes.

Trophic plasticity of a tropical seabird revealed through DNA metabarcoding and stable isotope analyses.

DNA metabarcoding and stable isotope analysis have significantly advanced our understanding of marine trophic ecology, aiding systematic research on foraging habits and species conservation. In this study, we employed these methods to analyse faecal and blood samples, respectively, to compare the trophic ecology of two Red-billed Tropicbird (Phaethonaethereus; Linnaeus, 1758) colonies on Mexican islands in the Pacific. Trophic patterns among different breeding stages were also examined at both colonies. Dietary analysis reveals a preference for epipelagic fish, cephalopods, and small crustaceans, with variations between colonies and breeding stages. Isotopic values (δ15N and δ13C) align with DNA metabarcoding results, with wider niches during incubation stages. Differences in diet are linked to environmental conditions and trophic plasticity among breeding stages, influenced by changing physiological requirements and prey availability. Variations in dietary profiles reflect contrasting environmental conditions affecting local prey availability.

Rat poison's long reach.

Supertoxic rodenticides are building up inside unintended targets, including birds, mammals, and insects. Scientists want to understand the damage-and limit it.