Search Results (73)

Community-sourced biodiversity imagery has expanded rapidly in the past decade, facilitating analyses of ecology on unprecedented spatial scales. Proliferation of these databases has also helped to reveal understudied or previously overlooked aspects of many species’ basic biology. The Evening Grosbeak (Hesperiphona vespertina) is considered to be a species of conservation concern, and many aspects of its diet have yet to be investigated, including how its diet varies seasonally and across its large North American range. The Evening Grosbeak’s striking plumage, frequent occurrences at bird feeders, and nomadic behavior all make them popular targets of bird photographers and a prime species for study using large community-sourced archives. We reviewed more than 50,000 photographs of Evening Grosbeaks archived in the Macaulay Library, a large public database, to gain a more detailed understanding of the diet of this species. While most Evening Grosbeak images found in the Macaulay Library depicted birds foraging at bird feeders, 1075 images were found to be of birds consuming natural (non-feeder) food items. We mapped the location of these natural dietary items to four distinct regions within the Evening Grosbeak’s geographical range and found a diet consisting of at least 96 species of plants from 25 families, 1 species of insect, and 2 species of lichen from 1 family. Despite the high diversity of dietary items we identified, richness estimators suggest even greater diversity of dietary foods exists, especially in the Pacific Northwest. Using these data and published literature on the Evening Grosbeak’s diet, we discuss the characteristics of preferred Evening Grosbeak dietary items, as well as the advantages and limitations of using community-science data for such analyses. To our knowledge, this is the first range-wide, descriptive study of a songbird species’ diet using photographs made publicly available in a community-sourced archive. Full article

Spermatogenesis in passerine birds remains poorly characterized. Previous studies focused on the steps of spermiogenesis, while a detailed staging of the seminiferous epithelium cycle is still lacking for this order. In this study, we provide the first comprehensive histological characterization of spermatogenesis in a model passerine species, the zebra finch. We defined ten distinct steps of spermiogenesis based on acrosomal and nuclear morphology of spermatids in Periodic acid–Schiff-stained histological sections. Using this classification, we further defined seven stages of the seminiferous epithelium, encompassing cytological features associated with the programmed DNA elimination, which is unique to passerines. Our analysis revealed that seminiferous tubules of the zebra finch exhibit a mosaic organization typical of all birds examined so far. However, in this species, most stages were characterized by the presence of spermatids at three developmental steps, in contrast to the one to two steps typical of non-passerine birds. To facilitate future comparative studies, we developed a flowchart for determining the stages of the seminiferous epithelium cycle. This work establishes an essential histological framework for future research in reproductive biology of the zebra finch and other passerine species. Full article

Primordial germ cells (PGCs) are the unipotent precursors of sperm and ova, responsible for transmitting hereditary information across generations. Their ability to be isolated and cultured in vitro has opened new horizons for avian biotechnology, species conservation, and fundamental developmental research. In birds, the unique migratory pattern of PGCs—originating in the epiblast and traveling via the bloodstream to the gonads—enables their collection and manipulation during embryogenesis. Long-term in vitro culture systems have been successfully established in chickens, where defined media allow for stable proliferation and genetic modification. Applications include germline chimeras, generation of transgenic lines, recombinant protein production, and cryobanking of genetic resources. However, translating these advances to other species remains challenging due to interspecies variability in signaling requirements. Recent work in geese, ducks, quails, and zebra finches underscores the need for tailored media formulations and a better understanding of molecular regulation. This review summarizes established techniques, highlights key interspecies differences, and outlines future directions for the standardization and expansion of avian PGC culture systems to support conservation and biotechnology. Full article

Mites associated with birds comprise representatives of numerous families and display a remarkable diversity of ecological strategies, ranging from commensalism, in which the mite benefits without causing measurable harm to its host, to parasitism, which can lead to direct damage through feeding on host tissues or resources [...] Full article

Mycobacterium avium subsp. hominissuis (MAH) is a zoonotic pathogen with a broad host range and diverse clinical manifestations. We report here the first documented case of MAH-induced fatal vasculitis in zebra finch (Taeniopygia guttata). Histopathological examination revealed acid-fast bacilli within macrophages and endothelial cells, primarily affecting the heart and aorta. Mycobacterial DNA was detected in cloacal swabs from affected finches and environmental samples from their housing facility. PCR targeting the rpoB gene and insertion elements IS1245 and IS901, followed by sequencing, confirmed MAH infection. MAH DNA was identified in 4 of 13 finch cloacal swabs and 7 of 28 environmental samples. This study describes a novel, highly pathogenic manifestation of MAH in birds and underscores the potential for avian involvement in environmental and zoonotic transmission. Full article

Autism spectrum disorder (ASD) encompasses a range of neurodevelopmental conditions characterized by impairments in social abilities and communication. Studying appropriate animal models can enhance our understanding of the neural mechanisms underlying these conditions, potentially leading to improved treatment and intervention strategies. Modeling impairments in linguistic development and vocal communication caused by autism had been a challenging goal for a long time. Prenatal valproic acid (VPA) treatment has been successfully used to induce ASD-like behavioral symptoms in several vertebrate species including birds. Applying VPA-treatment on songbirds, therefore, offers a promising research paradigm to model ASD. In this study, we investigated the effect of embryonic VPA treatment on song learning in the highly social zebra finch (Taeniopygia guttata). Fertilized eggs were injected with either 0.45 µmol VPA or a saline solution on day 9 of incubation, and hatchlings were allowed to stay with their parents until day 35 post-hatching to facilitate song learning from the father. Once male offsprings reached adulthood, their songs were recorded and compared to those of their fathers. VPA-exposed males exhibited significantly greater similarity to their fathers’ songs compared to control males (74% vs. 31%, respectively), suggesting a reduced ability to modify and develop their own vocal patterns as subadults. Additionally, they showed higher entropy in their songs compared to controls (−1.4 vs. −1.7), indicating more disorganized vocalizations. These findings suggest that prenatal VPA exposure disrupts typical song learning and vocal development in zebra finches, likely by affecting neural mechanisms involved in vocal learning and crystallization of the songs. Our study suggests VPA treatment in songbirds provides a useful tool to model and investigate linguistic developmental disorders related to ASD in humans. Full article

This comprehensive review examines FINCHES (Force field-based Interaction Network for Characterizing Heterotypic and Entropic Sequences). This groundbreaking computational framework enables the rapid, sequence-based prediction of intermolecular interactions in intrinsically disordered regions (IDRs) without the need for molecular simulations. The document provides detailed comparisons with other computational methods, including their mathematical foundations, specific applications, and experimental validations. We explore both the potential for advancing our understanding of disordered protein function and the inherent challenges in computationally modeling these dynamic biological systems. Additionally, we discuss computational assessment tools for interface prediction in molecular complexes, providing a comprehensive framework for evaluating IDR interaction predictions. Full article

Real-time health assessment is crucial for diagnosing emerging threats to wildlife. Point-of-care instruments now allow detailed, affordable measurements of blood metabolites (e.g., glucose, triglycerides, ketones) in free-ranging animals. Ketones, however, remain understudied, especially in relation to environmental and life-history traits. Here, we assessed blood ketone variation in male House Finches (Haemorhous mexicanus) across two seasons (summer and winter) as a function of body condition, circulating glucose, carotenoids, lipid-soluble vitamins, and habitat urbanization (urban/suburban/rural). In both seasons, the interaction between capture site and glucose concentration predicted ketone levels: urban and suburban birds showed a negative relationship, while in summer, rural birds showed a positive one. Additionally, in winter, ketone levels were negatively associated with plasma carotenoids, indicating birds with higher carotenoid levels had lower ketone concentrations. These findings suggest that similar to patterns seen in biomedical research and our previous work on carotenoids and health, ketone status can serve as a valuable indicator of nutritional condition and fat metabolism in wild birds, particularly in the context of urbanization. Full article

In recent years, many academics have addressed the issue of the intersection of the fields of Biblical studies and Cultural studies. Many academic works have emphasized the importance of the Bible in the building of cultural narratives and the need to reflect on those narratives through interpretation, placing biblical texts within originating cultural contexts. This article attempts to situate itself in that stream of work, exploring the graphic interpretation of the story of Ruth and Naomi in the graphic novel The Book of Ruth by Meredith Finch and Colin Dyer. It begins with an introduction to the characteristics of the graphic novel genre, highlighting how this medium has addressed religion and the Bible, including characters, narratives, and traditions. Subsequently, a comparative methodology is applied to examine the treatment of the biblical text in the graphic novel, contrasting the textual and graphic study conducted by Finch and Dyer. The aim is to demonstrate how the graphic novel serves as a contemporary mode of biblical text reception, creating a dialogue between the Bible and the current culture in which its texts are read. Full article

Coded aperture imaging (CAI) is a powerful imaging technology that has rapidly developed during the past decade. CAI technology and its integration with incoherent holography have led to the development of several cutting-edge imaging tools, devices, and techniques with widespread interdisciplinary applications, such as in astronomy, biomedical sciences, and computational imaging. In this review, we provide a comprehensive overview of the recently developed CAI techniques in the framework of incoherent digital holography. The review starts with an overview of the milestones in modern CAI technology, such as interferenceless coded aperture correlation holography, followed by a detailed survey of recently developed CAI techniques and system designs in subsequent sections. Each section provides a general description, principles, potential applications, and associated challenges. We believe that this review will act as a reference point for further advancements in CAI technologies. Full article

Urbanization has drastically transformed natural landscapes, threatening biodiversity by reducing species richness and abundance in cities. In this context, seasonal streams serve as refuge areas for various bird species. To determine the role of seasonal streams in conserving native terrestrial avifauna in Algarrobo, an expanding urban environment, we compared bird diversity in ephemeral streams (n = 18) and residential areas (n = 18). Bird counts were conducted during summer and winter. We utilized a diversity index and Generalized Linear Mixed Models (GLMMs) to assess the richness and abundance of native terrestrial birds, as well as the abundance of six migratory birds. Additionally, species accumulation curves verified whether most present species had been adequately sampled. Our results revealed that seasonal streams harbored a greater richness of native bird species than residential areas. Endemic species were also recorded in these streams. The cumulative number of bird species was higher in the seasonal stream environment compared to residential areas. During winter, a higher abundance of migratory birds (Green-backed Firecrown and Gray-hooded Sierra Finch) was observed in seasonal streams. These findings suggest that seasonal streams play a crucial role in conserving native and migratory birds. Thus, protecting and managing these habitats is essential for maintaining avian biodiversity in urbanized areas. Full article

Birds are inherently social creatures that rely on pairing to enhance their well-being. Since many bird species lack obvious physical differences between females and males, sex identification is essential for ensuring their welfare. Additionally, early determination of the sexes of birds is crucial for their breeders, especially considering that most companion birds do not display clear sexual characteristics. Molecular genetic sexing has been demonstrated to be the most reliable method for determining the sexes of monomorphic birds. The objective of the present study was to demonstrate rapid, effective, and precise identification of sex in birds through quantitative real-time PCR (qPCR) using samples obtained via a minimally invasive technique (oral swabs). This qPCR method assesses variations in gene copy numbers within conserved Z-specific genes such as CHRNA6, DDX4, VPS13A, LPAR1, and TMEM161B, which are absent from the W chromosome. A total of 34 samples were included in this study from the following 17 bird species: domestic pigeon (Columba livia domestica), domestic chicken (Gallus gallus domesticus), domestic goose (Anser anser f domesticus), domestic duck (Anas platyrhynchos domesticus), Mute swan (Cygnus olor), Budgerigar (Melopsittacus undulatus), Lovebird (Agapornis roseicollis), Cockatiel (Nymphicus hollandicus), Red-rumped parrot (Psephotus haematonotus), Rose-ringed parakeet (Psittacula krameri), African grey parrot (Psittacus erithacus), domestic Canary (Serinus canaria forma domestica), Goldfinch (Carduelis carduelis major), Gouldian Finch (Chloebia gouldiae), Red Siskin (Carduelis cucullata), Australian Zebra Finch (Taeniopygia castanotis), and Common buzzard (Buteo buteo). The results proved that the CHRNA6, DDX4, VPS13A, LPAR1, and TMEM161B genes can reveal the sexes in the Neognath birds tested. Full article

Within the framework of Rastall theory, we investigate the impact of charge on the structural development of different types of spherically symmetric anisotropic stars. To do so, we present modified field equations based upon the Finch–Skea metric potentials expressed in terms of three parameters $(A,B,C)$. These constants are determined using suitable matching conditions and observational data for compact objects which include Her X-1, SAX J 1808.4-3658, PSR J038-0842, LMC X-4 and SMC X-1. The equation of state offered by the $\mathbb{MIT}$ bag model for quark–gluon plasma is used to investigate the inner structure and other characteristics of these compact objects. For a fixed bag constant, $\mathcal{B}=60{\mathrm{MeV}/\mathrm{fm}}^3$, and two sets of the Rastall and charge parameters, $\zeta =0.255,0.259$ and $\tilde{\mathcal{Q}}=0.2,0.7$, respectively, we analyze the consistency of the matter variables in the model and other physical parameters such as energy conditions, stellar mass, compactness, and surface redshift. In addition, we assess the stability of the constructed model through two different approaches. It is found that the obtained model is physically viable and stable. Full article

Conspicuousness increases the risk of predation. One strategy to reduce this risk is to increase vigilance. We investigated the frequency of head movements as a measure of vigilance at waterholes in two related songbird species that differed in their conspicuousness: the Gouldian finch and the long-tailed finch. While both species showed a high frequency of head movements (high vigilance) when sitting in an open tree, the more colourful Gouldian finch remained more vigilant than the less conspicuous long-tailed finch when sitting under cover. Moreover, juvenile Gouldian finches had similar vigilance levels than adults; whereas, juveniles of the long-tailed finch were less vigilant, possibly because of staying in the family group. Furthermore, both species showed a similar temporal course of vigilance with a fast decrease in vigilance after landing in the tree, which was affected by group size. Single individuals had much higher vigilance than groups of birds. Finally, vigilance was higher at small waterholes. The results show that conspicuousness, uncertainty when arriving at waterholes, and higher perceived risk at small waterholes increased vigilance. Full article

Background/Objectives: Transcriptome assembly and functional annotation are essential in understanding gene expression and biological function. Nevertheless, many existing pipelines lack the flexibility to integrate both short- and long-read sequencing data or fail to provide a complete, customizable workflow for transcriptome analysis, particularly for non-model organisms. Methods: We present TrAnnoScope, a transcriptome analysis pipeline designed to process Illumina short-read and PacBio long-read data. The pipeline provides a complete, customizable workflow to generate high-quality, full-length (FL) transcripts with broad functional annotation. Its modular design allows users to adapt specific analysis steps for other sequencing platforms or data types. The pipeline encompasses steps from quality control to functional annotation, employing tools and established databases such as SwissProt, Pfam, Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and Eukaryotic Orthologous Groups (KOG). As a case study, TrAnnoScope was applied to RNA-Seq and Iso-Seq data from zebra finch brain, ovary, and testis tissue. Results: The zebra finch transcriptome generated by TrAnnoScope from the brain, ovary, and testis tissue demonstrated strong alignment with the reference genome (99.63%), and it was found that 93.95% of the matched protein sequences in the zebra finch proteome were captured as nearly complete. Functional annotation provided matches to known protein databases and assigned relevant functional terms to the majority of the transcripts. Conclusions: TrAnnoScope successfully integrates short and long sequencing technologies to generate transcriptomes with minimal user input. Its modularity and ease of use make it a valuable tool for researchers analyzing complex datasets, particularly for non-model organisms. Full article