Precipitation explains Wood Thrush (Hylocichla mustelina) occupancy patterns in Northern Costa Rica / Patrones de ocurrencia del Zorzal del Bosque (Hylocichla mustelina) explicados por la precipitación en el Norte de Costa Rica

Abstract Introduction: The Wood Thrush is a migratory bird that has experienced dramatic declines in its populations in recent decades. This species overwinters in forest fragments with intermediate levels of habitat modification in Central America. However, more studies detailing the use of remnant forests through time are needed to elucidate the threats this species faces in the wintering grounds. Objective: To understand the effects of environmental and forest structure variables on the occupancy of Wood Thrush in Northern Costa Rica. Methods: The study area was the Área de Conservación Guanacaste (ACG), located in Northern Costa Rica, in December 2016, and during the 2018-2019 migration season. We estimated Wood Thrush occupancy and detection probability in four locations of ACG (dry forest, cloud forest, and two locations in the wet forest) using single-season occupancy models. We also estimated Wood Thrush occupancy and probability of persistence in different months in three vegetation types (open area, secondary forest, and old-growth forest) in the wet forest of ACG using a multi-season occupancy model approach. Results: Wood Thrush occupancy was best described by precipitation in the four locations of the ACG; the probability of occupancy increased with precipitation. The average occupancy of Wood Thrushes varied with vegetation type: open area with shrubs and forest edge (0.69 ± 0.09), secondary forest (0.46 ± 0.1), and old-growth forest (0.61 ± 0.1). Wood Thrush probability of persistence responded partially to changes in precipitation, with an unexpected increase in persistence when the rainfall continued decreasing in the season. Conclusion: Wood Thrush occupancy was best predicted by changes in precipitation considering a larger spatial scale. Its probability of persistence partially varied with precipitation. An increase in persistence closer to Spring migration might be explained by the start of the breeding season of resident birds, potentially reducing territorial conflicts and conserving energy before migration. The long-term protection of wet forests in Northern Costa Rica is of paramount importance for the conservation of Wood Thrushes in their wintering grounds.

Resumen Introducción: El Zorzal del Bosque es un ave migratoria que ha experimentado caídas dramáticas en sus poblaciones en las últimas décadas. Esta especie pasa el invierno en fragmentos de bosque con niveles intermedios de modificación de hábitat en Centroamérica. Sin embargo, se necesitan más estudios que detallen el uso de los bosques remanentes a lo largo del tiempo para dilucidar las amenazas que enfrenta esta especie en las zonas de invernada. Objetivo: Comprender los efectos de variables ambientales y de estructura del bosque en la ocurrencia del Zorzal del Bosque en el Norte de Costa Rica. Métodos: El área de estudio fue el Área de Conservación Guanacaste (ACG), ubicada en el Norte de Costa Rica, en diciembre de 2016, y en la temporada migratoria 2018-2019. Estimamos la ocurrencia y la probabilidad de detección del Zorzal del Bosque en cuatro ubicaciones de ACG (bosque seco, bosque nuboso y dos ubicaciones en el bosque húmedo) utilizando modelos de ocurrencia de una sola temporada. También estimamos la ocurrencia del Zorzal del Bosque y la probabilidad de persistencia en diferentes meses en tres tipos de vegetación (área abierta, bosque secundario y bosque primario) en el bosque húmedo de ACG utilizando un enfoque de modelo de ocurrencia multi-estacional. Resultados: La ocurrencia del Zorzal del Bosque estuvo mejor descrita por la precipitación en las cuatro localidades del ACG; la probabilidad de ocurrencia aumentó con las precipitaciones. La ocurrencia media de zorzales varió con el tipo de vegetación: área abierta con arbustos y borde de bosque (0.69 ± 0.09), bosque secundario (0.46 ± 0.1) y bosque primario (0.61 ± 0.1). La probabilidad de persistencia del zorzal respondió parcialmente a cambios en la precipitación, con un aumento inesperado en la persistencia cuando las precipitaciones continuaron disminuyendo en la temporada. Conclusión: La ocurrecia del Zorzal del Bosque varió con la precipitación considerando una escala espacial mayor. Su probabilidad de persistencia varió parcialmente con la precipitación. Un aumento en la persistencia más cerca de la migración de primavera podría explicarse por el inicio de la temporada de reproducción de las aves residentes, lo que podría reducir los conflictos territoriales y conservar energía antes de la migración. La protección a largo plazo de los bosques húmedos en el norte de Costa Rica es de suma importancia para la conservación de los Zorzales del Bosque en sus zonas de invernada.

Diversity and Interactions between Picobiine Mites and Starlings.

The subfamily Picobiinae (Acariformes: Syringophilidae) comprises obligate and permanent parasites of birds found exclusively in the quills of contour feathers. We studied associations of picobiine mites with birds of the family Sturnidae (Aves: Passeriformes) across the Palaearctic, Afrotropical, Oriental, and Oceanian zoogeographical regions. Among the 414 examined bird individuals belonging to 44 species (35.2% of all sturnids), 103 individuals from 24 species (54.5% of examined species) were parasitised by quill mites. The diversity of mites was represented by five species, including one newly described, Picobia malayi Patan and Skoracki sp. n. Statistical analysis of the Picobiinae-Sturnidae bipartite network demonstrated a low connectance value (Con = 0.20) and high modularity, with significant differences in the H2' specialisation index compared to null model values. The network structure, characterised by four distinct modules, highlighted the specificity and limited host range of the Picobiinae-Sturnidae associations. The distribution of Picobia species among starlings was congruent with the phylogeny of their hosts, with different mites parasitising specific clades of starlings. Additionally, the findings suggest that the social and breeding behaviours of starlings influence quite a high prevalence. Finally, our studies support the validity of museum collections to study these parasitic interactions.

Microbial DNA extraction method for avian feces and preen oil from diverse species.

As DNA sequencing technology continues to rapidly improve, studies investigating the microbial communities of host organisms (i.e., microbiota) are becoming not only more popular but also more financially accessible. Across many taxa, microbiomes can have important impacts on organismal health and fitness. To evaluate the microbial community composition of a particular microbiome, microbial DNA must be successfully extracted. Fecal samples are often easy to collect and are a good source of gut microbial DNA. Additionally, interest in the avian preen gland microbiome is rapidly growing, due to the importance of preen oil for many aspects of avian life. Microbial DNA extractions from avian fecal and preen oil samples present multiple challenges, however. Here, we describe a modified PrepMan Ultra Sample Preparation Reagent microbial DNA extraction method that is less expensive than other commonly used methodologies and is highly effective for both fecal and preen oil samples collected from a broad range of avian species. We expect our method will facilitate microbial DNA extractions from multiple avian microbiome reservoirs, which have previously proved difficult and expensive. Our method therefore increases the feasibility of future studies of avian host microbiomes.

A sex chromosome polymorphism maintains divergent plumage phenotypes between extensively hybridizing yellowhammers (Emberiza citrinella) and pine buntings (E. leucocephalos).

Under allopatric speciation, populations of a species become isolated by a geographic barrier and develop reproductive isolation through genetic differentiation. When populations meet in secondary contact, the strength of evolved reproductive barriers determines the extent of hybridization and whether the populations will continue to diverge or merge together. The yellowhammer (Emberiza citrinella) and pine bunting (E. leucocephalos) are avian sister species that diverged in allopatry on either side of Eurasia during the Pleistocene glaciations. Though they differ greatly in plumage and form distinct genetic clusters in allopatry, these taxa show negligible mitochondrial DNA differentiation and hybridize extensively where they overlap in central Siberia, lending uncertainty to the state of reproductive isolation in the system. To assess the strength of reproductive barriers between taxa, we examined genomic differentiation across the system. We found that extensive admixture has occurred in sympatry, indicating that reproductive barriers between taxa are weak. We also identified a putative Z chromosome inversion region that underlies plumage variation in the system, with the 'pine bunting' haplotype showing dominance over the 'yellowhammer' haplotype. Our results suggest that yellowhammers and pine buntings are currently at a crossroads and that evolutionary forces may push this system towards either continued differentiation or population merging. However, even if these taxa merge, recombination suppression between putative chromosome Z inversion haplotypes may maintain divergent plumage phenotypes within the system. In this way, our findings highlight the important role hybridization plays in increasing the genetic and phenotypic variation as well as the evolvability of a system.

A chromosome-level genome assembly of the common eider, Somateria mollissima (Linnaeus, 1758).

The common eider, Somateria mollissima mollissima (Chordata; Aves; Anseriformes; Anatidae), is a large sea duck with a circumpolar distribution. We here describe a chromosome-level genome assembly from an individual female. The haplotype-resolved assembly contains one pseudo-haplotype spanning 1205 megabases (with both Z and W sex chromosomes) and one pseudo-haplotype spanning 1080 megabases. Most of these two assemblies (91.13% and 93.18%, respectively) are scaffolded into 32 autosomal chromosomal pseudomolecules plus Z and W for pseudo-haplotype one. The BUSCO completeness scores are 94.0% and 89.9%, respectively, and gene annotations of the assemblies identified 17,479 and 16,315 protein coding genes. Annotation of repetitive sequences classify 17.84 % and 14.62 % of pseudo-haplotype one and two, respectively, as repeats. The genome of the common eider will be a useful resource for the widely distributed northern species in light of climate change and anthropogenic threats.

A reference genome, mitochondrial genome and associated transcriptomes for the critically endangered swift parrot ( Lathamus discolor).

The swift parrot ( Lathamus discolor) is a Critically Endangered migratory parrot that breeds in Tasmania and winters on the Australian mainland. Here we provide a reference genome assembly for the swift parrot. We sequence PacBio HiFi reads to create a high-quality reference assembly and identify a complete mitochondrial sequence. We also generate a reference transcriptome from five organs to inform genome annotation. The genome was 1.24 Gb in length and consisted of 847 contigs with a contig N50 of 18.97 Gb and L50 of 20 contigs. This study provides an annotated reference assembly and transcriptomic resources for the swift parrot to assist in future conservation genomic research.

Direct evidence of frugivory in the Mesozoic bird Longipteryx contradicts morphological proxies for diet.

Diet is one of the most important aspects of an animal's ecology, as it reflects direct interactions with other organisms and shapes morphology, behavior, and other life history traits. Modern birds (Neornithes) have a highly efficient and phenotypically plastic digestive system, allowing them to utilize diverse trophic resources, and digestive function has been put forth as a factor in the selectivity of the end-Cretaceous mass extinction, in which only neornithine dinosaurs survived.1 Although diet is directly documented in several early-diverging avian lineages,2 only a single specimen preserves evidence of diet in Enantiornithes, the dominant group of terrestrial Cretaceous birds.3 Morphology-based predictions suggest enantiornithines were faunivores,4,5,6 although the absence of evidence contrasts with the high preservation potential and relatively longer gut-retention times of these diets. Longipteryx is an unusual Early Cretaceous enantiornithine with an elongate rostrum; distally restricted dentition7; large, recurved, and crenulated teeth8; and tooth enamel much thicker than other paravians.9 Statistical analysis of rostral length, body size, and tooth morphology predicts Longipteryx was primarily insectivorous.4,5 Contrasting with these results, two new specimens of Longipteryx preserve gymnosperm seeds within the abdominal cavity interpreted as ingesta. Like Jeholornis, their unmacerated preservation and the absence of gastroliths indicate frugivory.10 As in Neornithes,11 complex diets driven by the elevated energetic demands imposed by flight, secondary rostral functions, and phylogenetic influence impede the use of morphological proxies to predict diet in early-diverging avian lineages.

Assessing the global prevalence of wild birds in trade.

Trade represents a significant threat to many wild species and is often clandestine and poorly monitored. Information on which species are most prevalent in trade and potentially threatened by it therefore remains fragmentary. We used 7 global data sets on birds in trade to identify species or groups of species at particular risk and assessed the extent to which they were congruent in terms of the species recorded in trade. We used the frequency with which species were recorded in the data sets as the basis for a trade prevalence score that was applied to all bird species globally. Literature searches and questionnaire surveys were used to develop a list of species known to be heavily traded to validate the trade prevalence score. The score was modeled to identify significant predictors of trade. Although the data sets sampled different parts of the broad trade spectrum, congruence among them was statistically strong in all comparisons. Furthermore, the frequency with which species were recorded within data sets was positively correlated with their occurrence across data sets, indicating that the trade prevalence score captured information on trade volume. The trade prevalence score discriminated well between species identified from semi-independent assessments as heavily or unsustainably traded and all other species. Globally, 45.1% of all bird species and 36.7% of globally threatened bird species had trade prevalence scores ≥1. Species listed in Appendices I or II of CITES, species with large geographical distributions, and nonpasserines tended to have high trade prevalence scores. Speciose orders with high mean trade prevalence scores included Falconiformes, Psittaciformes, Accipitriformes, Anseriformes, Bucerotiformes, and Strigiformes. Despite their low mean prevalence score, Passeriformes accounted for the highest overall number of traded species of any order but had low representation in CITES appendices. Geographical hotspots where large numbers of traded species co-occur differed among passerines (Southeast Asia and Eurasia) and nonpasserines (central South America, sub-Saharan Africa, and India). This first attempt to quantify and map the relative prevalence in trade of all bird species globally can be used to identify species and groups of species that may be at particular risk of harm from trade and can inform conservation and policy interventions to reduce its adverse impacts.

Análisis de la prevalencia mundial de aves silvestres en el mercado Resumen El mercado representa una amenaza importante para muchas especies silvestres y a menudo es clandestino y mal vigilado. Por ello, la información sobre las especies más presentes en el mercado y bajo amenaza potencial todavía está fragmentada. Utilizamos siete conjuntos de datos mundiales sobre aves comercializadas para identificar especies o grupos de especies bajo riesgo especial y evaluamos hasta qué punto eran congruentes en cuanto a las especies registradas en el comercio. Utilizamos la frecuencia con la que las especies se registraban en los conjuntos de datos como base para una puntuación de prevalencia del comercio que se aplicó a todas las especies de aves a nivel mundial. Para validar la puntuación de prevalencia del comercio, realizamos búsquedas bibliográficas y cuestionarios para elaborar una lista de especies que se sabe son objeto de comercio intenso. Modelamos la puntuación para identificar los predictores significativos del mercado. Aunque los conjuntos de datos muestrearon partes distintas del amplio espectro del mercado, la congruencia entre ellos fue estadísticamente robusta en todas las comparaciones. Además, la frecuencia con la que se registraron las especies dentro de los conjuntos de datos se correlacionó positivamente con su presencia en todos los conjuntos de datos, lo que indica que la puntuación de prevalencia del mercado captó información sobre el volumen de este. La puntuación de prevalencia del mercado distinguió entre las especies identificadas a partir de evaluaciones semiindependientes como objeto de comercio intenso o insostenible y todas las demás especies. A nivel mundial, el 45.1% de todas las especies de aves y el 36.7% de las especies de aves amenazadas mundialmente tenían puntuaciones de prevalencia del mercado ≥1. Las especies incluidas en los Apéndices I o II de CITES, las especies con una amplia distribución geográfica y los no paseriformes tendieron a tener puntuaciones elevadas de prevalencia del mercado. Los órdenes de especies con puntuaciones medias de prevalencia del mercado elevadas fueron Falconiformes, Psittaciformes, Accipitriformes, Anseriformes, Bucerotiformes y Strigiformes. A pesar de su baja puntuación media de prevalencia, los Passeriformes representaron el mayor número total de especies comercializadas de todos los órdenes, pero tuvieron una baja representación en los apéndices de CITES. Los puntos calientes geográficos en los que coexisten un gran número de especies comercializadas difieren entre los paseriformes (Sudeste Asiático y Eurasia) y los no paseriformes (centro de Sudamérica, África subsahariana e India). Este primer intento de cuantificar y cartografiar la prevalencia relativa en el comercio de todas las especies de aves a escala mundial puede utilizarse para identificar especies y grupos de especies que pueden correr un riesgo especial de sufrir daños a causa del comercio y puede servir de base para intervenciones políticas y de conservación destinadas a reducir sus efectos adversos.

Quantifying species biases among multidata sources on illegal wildlife trade and its implications for conservation.

Unsustainable wildlife consumption and illegal wildlife trade (IWT) threaten biodiversity worldwide. Although publicly accessible data sets are increasingly used to generate insights into IWT, little is known about their potential bias. We compared three typical and temporally corresponding data sets (4204 court verdicts, 926 seizure news reports, and 219 bird market surveys) on traded birds native to China and evaluated their possible species biases. Specifically, we evaluated bias and completeness of sampling for species richness, phylogeny, conservation status, spatial distribution, and life-history characteristics among the three data sets when determining patterns of illegal trade. Court verdicts contained the largest species richness. In bird market surveys and seizure news reports, phylogenetic clustering was greater than that in court verdicts, where songbird species (i.e., Passeriformes) were detected in higher proportions in market surveys. The seizure news data set contained the highest proportion of species of high conservation priority but the lowest species coverage. Across the country, all data sets consistently reported relatively high species richness in south and southwest regions, but markets revealed a northern geographic bias. The species composition in court verdicts and markets also exhibited distinct geographical patterns. There was significant ecological trait bias when we modeled whether a bird species is traded in the market. Our regression model suggested that species with small body masses, large geographical ranges, and a preference for anthropogenic habitats and those that are not nationally protected were more likely to be traded illegally. The species biases we found emphasize the need to know the constraints of each data set so that they can optimally inform strategies to combat IWT.

Cuantificación del sesgo por especies entre fuentes de datos múltiples para el mercado ilegal de fauna y lo que implica para la conservación Resumen El consumo insostenible y el comercio ilegal de fauna y flora silvestres amenazan la biodiversidad en todo el mundo. Aunque los conjuntos de datos de acceso público se utilizan cada vez más para obtener información sobre el mercado ilegal de especies silvestres, se sabe poco sobre su posible sesgo. Comparamos tres conjuntos de datos típicos con correspondencia temporal (4,204 sentencias judiciales, 926 informes de noticias sobre incautaciones y 219 encuestas sobre mercados de aves) de aves autóctonas de China objeto de comercio y evaluamos sus posibles sesgos por especie. En concreto, evaluamos el sesgo y la exhaustividad del muestreo de la riqueza de especies, la filogenia, el estado de conservación, la distribución espacial y las características del ciclo vital entre los tres conjuntos de datos a la hora de determinar los patrones del mercado ilegal. Las sentencias judiciales contenían la mayor riqueza de especies. En los estudios de mercado de aves y en los informes de noticias sobre incautaciones, la agrupación filogenética fue mayor que en las sentencias judiciales, donde las especies de aves canoras (Passeriformes) se detectaron en mayor proporción en los estudios de mercado. El conjunto de datos de noticias sobre decomisos contenía la mayor proporción de especies de alta prioridad para la conservación, pero la menor cobertura de especies. En todo el país, todos los conjuntos de datos informaron sistemáticamente de una riqueza de especies relativamente alta en las regiones sur y suroeste, pero los mercados revelaron un sesgo geográfico septentrional. La composición por especies en los veredictos judiciales y en los mercados también mostró patrones geográficos distintos. Hubo un sesgo significativo de rasgos ecológicos cuando modelamos si una especie de ave se comercializa en el mercado. Nuestro modelo de regresión sugería que las especies con masas corporales pequeñas, grandes áreas de distribución geográfica y preferencia por los hábitats antropogénicos y las especies que no están protegidas a nivel nacional tenían más probabilidades de ser objeto de comercio ilegal. Los sesgos de las especies que hallamos resaltan la necesidad de conocer las limitaciones de cada conjunto de datos para poder informar de manera óptima las estrategias de lucha contra el comercio ilegal de especies silvestres.

A review of commercial captive breeding of parrots as a supply-side intervention to address unsustainable trade.

The volume and scale of commercial captive breeding of parrots have grown dramatically in recent decades. Although it has been proposed, and is often assumed, that captive breeding can reduce pressure on wild populations, there has been little scrutiny of the scale, viability, or impacts of captive breeding to prevent overexploitation among parrots, compared with similar approaches in other threatened taxa, such as pangolins or tigers. We reviewed the primary and gray literature to quantitatively and qualitatively evaluate evidence concerning 5 criteria, established a priori, for commercial captive breeding of parrots as an effective supply-side intervention. We focused on a sample of 16 threatened parrot species that are heavily traded or for which unsustainable trade has been a factor in the decline of wild populations, representing a range of taxonomic groups, life histories, and native regions. We identified multiple major gaps in knowledge of the extent to which these criteria are met, including a lack of quantitative data on breeding productivity under current commercial breeding practices, the scale and scope of commercial breeding practices in growing parrot markets, particularly in the Middle East and Asia, and the lack of financial viability of captive breeding under effective regulation to prevent laundering or use of wild-sourced specimens as breeding stock. The capacity for captive breeding to displace demand for wild-sourced parrots varied between species, and complex interactions between trade in different species and contexts sometimes made consequences of commercial production difficult to predict. Decision makers and regulatory authorities should approach commercial captive breeding of parrots with caution and take into account knowledge gaps and cross-linkages between trade in different species to avoid unanticipated consequences from stimulating and facilitating unsustainable trade in wild-sourced parrots.

Una revisión de la cría comercial de loros en cautiverio como una intervención en la oferta para abordar el comercio no sustentable Resumen El volumen y la escala de la cría comercial de loros en cautiverio ha crecido de gran manera en las últimas décadas. Aunque se ha propuesto, y a menudo se asume, que la cría en cautiverio puede reducir la presión sobre las poblaciones silvestres, apenas se ha analizado la escala, viabilidad o impacto de este método para evitar la sobreexplotación de los loros, en comparación con enfoques similares en otros taxones amenazados, como pangolines o tigres. Revisamos la bibliografía primaria y gris para evaluar cuantitativa y cualitativamente las pruebas relativas a cinco criterios, establecidos a priori, para la cría comercial de loros en cautiverio como una intervención eficaz del lado de la oferta. Usamos una muestra de 16 especies amenazadas de loros que son objeto de intenso comercio o para las que el comercio no sustentable ha sido un factor en el declive de las poblaciones silvestre para representar una gama de grupos taxonómicos, historias de vida y regiones nativas. Identificamos múltiples vacíos importantes en el conocimiento de la medida en que se cumplen estos criterios, incluida la falta de datos cuantitativos sobre la productividad de la cría en las actuales prácticas de cría comercial, la escala y el alcance de las prácticas de cría comercial en los mercados de loros en crecimiento, especialmente en Medio Oriente y Asia, y la falta de viabilidad financiera de la cría en cautiverio bajo una regulación eficaz para evitar el lavado o el uso de especímenes de origen silvestre como plantel reproductor. La capacidad de la cría en cautiverio para desplazar la demanda de loros de origen silvestre varió según las especies y las complejas interacciones entre el comercio de diferentes especies y contextos dificultaron a veces la predicción de las consecuencias de la producción comercial. Los responsables de la toma de decisiones y las autoridades reguladoras deben abordar la cría comercial de loros en cautiverio con cautela y tener en cuenta los vacíos de conocimiento y los nexos cruzados entre el comercio de diferentes especies para evitar consecuencias imprevistas derivadas de estimular y facilitar el comercio no sustentable de loros de origen silvestre.

A framework and review of evidence of the importance of coral reefs for marine birds in tropical ecosystems.

As global heating and other anthropogenic influences alter tropical marine environments, it is unclear how marine bird populations will be impacted and whether their current roles in tropical marine ecosystems will change. Although marine birds roost and breed on tropical islands in large numbers, the direct trophic interactions between these birds and their prey across the tropics are poorly documented. We present a first framework for evaluating the dependence on and contributions of marine birds to tropical coral reef ecosystems and use it to examine the evidence for different kinds of interaction, focusing primarily on avian diets. We found 34 publications between 1967 and 2023 that presented a total of 111 data sets with enough detail for quantitative dietary analysis of tropical marine birds. Only two bird species out of 37 (5.4%) had diets of >50% coral reef fishes and only one, the Pacific Reef Egret, appeared to depend almost entirely on reef-based production. Marine birds are also prey for other marine organisms, but insufficient data are available for quantitative analysis. Evidence for indirect effects of birds in tropical marine environments is stronger than for direct dependence on coral reefs, particularly in relation to nutrient concentration and the fertilisation impacts of guano on corals. Dispersal of propagules (e.g. seeds, spores, invertebrate eggs) by bathing, drinking, resting or foraging birds is under-studied and poorly documented. Although the degradation of coral reefs appears unlikely to have a significant direct impact on food availability for most marine bird populations, indirect effects involving marine birds may be disrupted by global environmental change.

The Morphological and Molecular Characterization of the Avian Trematodes Harrahium obscurum and Morishitium dollfusi (Digenea: Cyclocoelidae) from the Middle Volga Region (European Russia).

The taxonomic status of many species of the family Cyclocoelidae is still unclear. Two species of cyclocoelids, Harrahium obscurum and Morishitium dollfusi, were collected from the air sacs of birds (Turdus merula and Tringa ochropus) inhabiting the Middle Volga region (European Russia). Here, we provide the first detailed morphological description of these cyclocoelids and combine it with the first molecular phylogenetic analysis of Cyclocoelidae from birds in Russia based on partial sequences of their 28s rDNA and coI mtDNA genes. Specimens of both flatworm species from different host individuals differ slightly in body shape and size, which probably reflects host-induced intraspecific variability. For the first time, we have shown that a stable morphological character such as the length of the vitelline fields in the studied digeneans is variable at the species level and cannot be used in their morphological diagnosis.

Life history traits and cancer prevalence in birds.

Background and objectives: Cancer is a disease that affects nearly all multicellular life, including the broad and diverse taxa of Aves. While little is known about the factors that contribute to cancer risk across Aves, life history trade-offs may explain some of this variability in cancer prevalence. We predict birds with high investment in reproduction may have a higher likelihood of developing cancer. In this study, we tested whether life history traits are associated with cancer prevalence in 108 species of birds. Methodology: We obtained life history data from published databases and cancer data from 5,729 necropsies from 108 species of birds across 24 taxonomic orders from 25 different zoological facilities. We performed phylogenetically controlled regression analyses between adult body mass, lifespan, incubation length, clutch size, sexually dimorphic traits, and both neoplasia and malignancy prevalence. We also compared the neoplasia and malignancy prevalence of female and male birds. Results: Providing support for a life history trade-off between somatic maintenance and reproduction, we found a positive relationship between clutch size and cancer prevalence across Aves. There was no significant association with body mass, lifespan, incubation length, sexual dimorphism, and cancer. Conclusions and implications: Life history theory presents an important framework for understanding differences in cancer defenses across various species. These results suggest a trade-off between reproduction and somatic maintenance, where Aves with small clutch sizes get less cancer.

Comparative Computed Tomographic Measurements of the Synsacrum in Some Birds / Mediciones Tomográficas Computarizadas Comparativas del Sinsacro en Algunas Aves

SUMMARY: The Synsacrum is constructed of pelvic bones, sacral, lumbar vertebrae and some thoracic vertebrae, and it takes the form of a thin sheet of bone which is curled downwards at the sides. This study is designed to assess the morphometric specialization of the lumbosacral portion of the vertebral section in flying and non-flying winged creatures. Several parameters (ratio of cranial/caudal parts and diameter/length) of the lumbosacral vertebral column were calculated in computed tomography (CT). The ratio of diameter/length of the synsacrum was the narrowest in ostrich while the widest was in pigeon. While the cranial/caudal ratio was the smallest in ostrich and the largest in pigeon. The parameters of penguin were closed to that of pigeon. It is supposed that this ratio is related to the bird locomotion, flying, swimming or/and strolling.

El sinsacro está formado por huesos pélvicos, sacros, vértebras lumbares y algunas vértebras torácicas, y toma la forma de una fina lámina de hueso curvada a los lados hacia abajo. Este estudio está diseñado para evaluar la especialización morfométrica de la porción lumbosacra de la sección vertebral en criaturas aladas voladoras y no voladoras. Se calcularon varios parámetros (relación de partes craneal/caudal y diámetro/longitud) de la columna vertebral lumbosacra en tomografía computarizada (TC). La relación diámetro/longitud del sinsacro fue la más estrecha en avestruz mientras que la más ancha fue en paloma. Mientras que la relación craneal/caudal fue la más pequeña en avestruz y la más grande en la paloma. Los parámetros del pingüino estaban cerrados en relación a los de la paloma. Se supone que esta relación está relacionada con la locomoción de las aves, volando, nadando y/o caminando.

Unique myoglobin adaptation to endothermy and flight since the origin of birds.

Myoglobin (Mb) mediates oxygen diffusion and storage in muscle tissue and thus is important for the energy utilization and activity of animals. Birds generally have a high body temperature, and most species also possess the capability of powered flight. Both of these require high levels of aerobic metabolism. Within endothermic mammals, bats also independently evolved flight. Although the functional evolution of myoglobins in deep-diving amniote vertebrates has been well-studied, the functional evolution of myoglobin since the origins of both birds and bats is unclear. Here, with Mb-coding sequences from >200 extant amniote species, we reconstructed ancestral sequences to estimate the functional properties of myoglobin through amniote evolution. A dramatic change in net surface charge on myoglobin occurred during the origin of Aves, which might have been driven by positively selected amino acid substitutions that occurred on the lineage leading to all birds. However, in bats, no change in net surface charge occurred and instead, the Mb genes show evidence of strong purifying selection. The increased net surface charge on bird myoglobins implies an adaptation to flight-related endothermic and higher body temperatures, possibly by reducing harmful protein aggregations. Different from the findings of net surface charge, myoglobins of extant birds show lower stability compared with other amniotes, which probably accelerates the rate of oxygen utilization in muscles. In bats and other mammals, higher stability of Mb may be an alternative pathway for adaptation to endothermy, indicating divergent evolution of myoglobin in birds and bats.

Unanticipated Loss of Inflammasomes in Birds.

Inflammasomes are multiprotein complexes that form in response to ligands originating from pathogens as well as alterations of normal cell physiology caused by infection or tissue damage. These structures engage a robust inflammatory immune response that eradicates environmental microbes before they cause disease, and slow the growth of bona fide pathogens. Despite their undeniable utility in immunity, inflammasomes are radically reduced in birds. Perhaps most surprising is that, within all birds, NLRP3 is retained, while its signaling adapter ASC is lost, suggesting that NLRP3 signals via a novel unknown adapter. Crocodilian reptiles and turtles, which share a more recent common ancestor with birds, retain many of the lost inflammasome components, indicating that the deletion of inflammasomes occurred after birds diverged from crocodiles. Some bird lineages have even more extensive inflammasome loss, with songbirds continuing to pare down their inflammasomes until only NLRP3 and CARD8 remain. Remarkably, songbirds have lost caspase-1 but retain the downstream targets of caspase-1: IL-1ß, IL-18, and the YVAD-linker encoding gasdermin A. This suggests that inflammasomes can signal through alternative proteases to activate cytokine maturation and pyroptosis in songbirds. These observations may reveal new contexts of activation that may be relevant to mammalian inflammasomes and may suggest new avenues of research to uncover the enigmatic nature of the poorly understood NLRP3 inflammasome.

Environmental and ecological factors affecting tick infestation in wild birds of the Americas.

The Americas hold the greatest bird diversity worldwide. Likewise, ectoparasite diversity is remarkable, including ticks of the Argasidae and Ixodidae families - commonly associated with birds. Considering that ticks have potential health implications for humans, animals, and ecosystems, we conducted a systematic review to evaluate the effects of bioclimatic, geographic variables, and bird species richness on tick infestation on wild birds across the Americas. We identified 72 articles that met our inclusion criteria and provided data on tick prevalence in wild birds. Using Generalized Additive Models, we assessed the effect of environmental factors, such as habitat type, climatic conditions, bird species richness, and geographic location, on tick infestation. Our findings show that most bird infestation case studies involved immature ticks, such as larvae or nymphs, while adult ticks represented only 13% of case studies. We found birds infested by ticks of the genera Amblyomma (68%), Ixodes (22%), Haemaphysalis (5%), Dermacentor (1%), and Rhipicephalus (0.8%) in twelve countries across the Americas. Our findings revealed that temperature variation and bird species richness were negatively associated with tick infestation, which also varied with geographic location, increasing in mid-latitudes but declining in extreme latitudes. Our results highlight the importance of understanding how environmental and bird community factors influence tick infestation in wild birds across the Americas and the dynamics of tick-borne diseases and their impact on biodiversity.

Checklist of hosts, illustrated geographical range, and ecology of tick species from the genus Ixodes (Acari, Ixodidae) in Russia and other post-Soviet countries.

Hard ticks (Acari: Ixodidae) are the economically and ecologically most important blood-sucking arthropod vectors that can transmit disease agents under temperate climate. In this group, the highest number of species (currently nearing 270) belongs to the genus Ixodes. For this review, more than 400 papers related to this genus in the context of Russia were checked for data on the host records, locations of collection, as well as ecology of assigned tick species. This monograph compensates for the lack of a similarly comprehensive English-language overview of Ixodes species in the region of Russia for nearly half century, and also makes a large set of data easily available for international readers, which is especially important if the original source is difficult to access from outside this country. In addition, the data from a significant number of papers on this topic available only in the Russian language are made accessible through this work.

Exposure of wetlands important for nonbreeding waterbirds to sea-level rise in the Mediterranean.

Sea-level rise (SLR) is expected to cause major changes to coastal wetlands, which are among the world's most vulnerable ecosystems and are critical for nonbreeding waterbirds. Because strategies for adaptation to SLR, such as nature-based solutions and designation of protected areas, can locally reduce the negative effects of coastal flooding under SLR on coastal wetlands, it is crucial to prioritize adaptation efforts, especially for wetlands of international importance for biodiversity. We assessed the exposure of coastal wetlands important for nonbreeding waterbirds to projected SLR along the Mediterranean coasts of 8 countries by modeling future coastal flooding under 7 scenarios of SLR by 2100 (from 44- to 161-cm rise) with a static inundation approach. Exposure to coastal flooding under future SLR was assessed for 938 Mediterranean coastal sites (≤30 km from the coastline) where 145 species of nonbreeding birds were monitored as part of the International Waterbird Census and for which the monitoring area was delineated by a polygon (64.3% of the coastal sites monitored in the Mediterranean region). Thirty-four percent of sites were threatened by future SLR, even under the most optimistic scenarios. Protected study sites and study sites of international importance for waterbirds were, respectively, 1.5 and 2 times more exposed to SLR than the other sites under the most optimistic scenario. Accordingly, we advocate for the development of a prioritization scheme to be applied to these wetlands for the implementation of strategies for adaptation to SLR to anticipate the effects of coastal flooding. Our study provides major guidance for conservation planning under global change in several countries of the Mediterranean region.

Exposición de los humedales de importancia para las aves acuáticas no reproductoras al incremento del nivel del mar en el Mediterráneo Resumen Se espera que el incremento en el nivel del mar (INM) cause cambios importantes en los humedales costeros, los cuales se encuentran entre los ecosistemas más vulnerables y son críticos para las aves acuáticas no reproductoras. Es crucial la priorización de los esfuerzos de adaptación, especialmente en los humedales con importancia internacional para la biodiversidad, ya que las estrategias de adaptación ante el INM, como las soluciones basadas en la naturaleza y la designación de áreas protegidas, pueden reducir localmente los efectos negativos de las inundaciones costeras por INM en los humedales costeros. Evaluamos la exposición de los humedales costeros con importancia para las aves acuáticas no reproductoras ante el INM proyectado en las costas del Mediterráneo en ocho países con un modelo de inundaciones costeras en el futuro bajo siete escenarios de INM para el año 2100 (de 44 a 161 cm) con un enfoque de inundación estática. Evaluamos la exposición a las inundaciones costeras bajo el INM futuro en 938 sitios costeros del Mediterráneo (≤ 30 km a partir de la costa), en donde monitoreamos a 145 especies de aves no reproductoras como parte del Censo Internacional de Aves Acuáticas y para los cuales el área de monitoreo estuvo delineada con un polígono (64.3% de los sitios costeros monitoreados en la región Mediterránea). El 34% de los sitios se vio amenazado por el INM en el futuro, incluso con los escenarios más optimistas. Los sitios de estudio protegidos y los sitios de estudio de importancia internacional para las aves acuáticas estuvieron expuestos 1.5 y 2 veces más al INM que otros sitios con el escenario más optimista. De acuerdo con esto, abogamos por el desarrollo de un esquema de priorización para aplicarse en estos humedales para la implementación de estrategias de adaptación al INM para anticipar los efectos de las inundaciones costeras. Nuestro estudio proporciona información importante para la planeación de la conservación bajo el cambio global en varios de los países del Mediterráneo.

Interspecies conflict, precarious reasoning, and the gull problem in the Gulf of Maine.

Contemporary conservation science requires mediating conflicts among nonhuman species, but the grounds for favoring one species over another can be unclear. We examined the premises through which wildlife managers picked sides in an interspecies conflict: seabird conservation in the Gulf of Maine (GOM). Managers in the GOM follow a simple narrative dubbed the gull problem. This narrative assumes Larus gulls are overpopulated and unnatural in the region. In turn, these assumptions make gulls an easy target for culling and lethal control when the birds come into conflict with other seabirds, particularly Sterna terns. Surveying historical, natural historical, and ecological evidence, we found no scientific support for the claim that Larus gulls are overpopulated in the GOM. Claims of overpopulation originated from a historical context in which rising gull populations became a nuisance to humans. Further, we found only limited evidence that anthropogenic subsidies make gulls unnatural in the region, especially when compared with anthropogenic subsidies provided for other seabirds. The risks and consequences of leveraging precarious assumptions include cascading plans to cull additional gull populations, obfuscation of more fundamental environmental threats to seabirds, and the looming paradox of gull conservation-even if one is still inclined to protect terns in the GOM. Our close look at the regional history of a conservation practice thus revealed the importance of not only conservation decisions, but also conservation decision-making.

Conflicto interespecífico, razonamiento precario y el problema de las gaviotas en el Golfo de Maine Resumen La ciencia de la conservación actual requiere mediar conflictos entre las especies no humanas, pero los fundamentos para favorecer a una especie por encima de otra pueden ser poco claros. Analizamos las premisas mediante las cuales los gestores de fauna eligen bandos en un conflicto interespecífico: la conservación de aves marinas en el Golfo de Maine (GDM). Los gestores en el GDM siguen una narrativa simple llamada el problema de las gaviotas. Esta narrativa asume que las gaviotas del género Larus no son nativas y tienen una sobrepoblación en la región. En cambio, estas suposiciones hacen que las gaviotas sean un objetivo fácil para el sacrificio y el control letal cuando las aves entran en conflicto con otras aves marinas, en particular con los charranes del género Sterna. Censamos la evidencia histórica, ecológica y de historia natural y no encontramos respaldo científico alguno para la afirmación de que hay una sobrepoblación de gaviotas Larus en el GDM. Esta afirmación se originó a partir de un contexto histórico en el que el incremento poblacional de las gaviotas se volvió una molestia para los humanos. Además, encontramos evidencia limitada de que los subsidios antropogénicos hacen que las gaviotas no sean nativas en la región, en especial cuando los comparamos con los subsidios antropogénicos proporcionados a otras aves marinas. Los riesgos y consecuencias de impulsar suposiciones precarias incluyen los planes en cascada para sacrificar poblaciones adicionales de gaviotas, la ofuscación de amenazas ambientales más fundamentales para las aves marinas y la paradoja inminente de la conservación de las gaviotas­incluso si todavía se inclinan por proteger a los charranes en el GDM. Esta mirada detallada de la historia regional de una práctica de conservación nos reveló la importancia no sólo de las decisiones de conservación, sino también de la toma de decisiones de conservación.