Reneco (United Arab Emirates)

The Asian Houbara Bustard (Chlamydotis macqueenii), a partially migratory bird from the western and Central Asian steppes, is listed as vulnerable on the IUCN Red List. This study reassesses the species' genetic structure using modern genomics to identify evolutionary significant units (ESUs). Following the generation of a de novo reference assembly and resequencing data (114 birds, 10 locations), we integrated genetic results, migratory behaviour, and geography to identify eight hierarchically structured ESUs: four near range edges (Yemen, Mongolia, Eastern Kazakhstan, Israel) and four within the central range (Central-Eastern, Central-Western, North Iran, South Iran). Low genetic diversity and recent inbreeding make ESUs on the range periphery (Israel, Mongolia, Yemen) the most genetically threatened, consistent with the central-marginal hypothesis. ESUs do not cluster according to their migrant/non-migrant status. Geographic distance significantly shaped genetic structure, with longitudinal separation (isolation-by-distance along an east-west axis) emerging as the strongest predictor of differentiation, particularly among high-latitude migrant populations. Our findings underscore the importance of integrating genomic, geographic and behavioural criteria to define intraspecific units that effectively address the conservation needs of widespread species with complex evolutionary dynamics.

AI tools are increasingly employed in wildlife conservation to monitor animal populations and detect anthropogenic threats. Although various wild animal image datasets exist for training deep learning algorithms in species recognition, few resources focus on bird classification, particularly for monitoring reproductive success at nests. To address this gap, we introduce a new dataset concentrating on the Houbara bustard, a bird of both ecological and cultural significance, comprising 10,394 images and 23,387 object instances (Houbara adults, chicks, and eggs), each manually annotated with bounding boxes. We assessed several state-of-the-art object detection techniques on this dataset, with YOLOv12 demonstrating superior performance across multiple evaluation metrics. This dataset provides a valuable resource for researchers and conservation practitioners, enhancing the capability for automated wildlife monitoring and conservation efforts. [GitHub: https://github.com/sadaf-ali/HBCE].

ABSTRACT Captive breeding of endangered species, such as the African Houbara bustard (Chlamydotis undulata) is an essential part of conservation programmes. However, several factors may negatively impact the health and reproductive performance of captive animals, including genital infections. Between 2010 and 2023, a total of 439 cases of salpingo-peritonitis were diagnosed in a flock of African Houbara breeders belonging to a Moroccan conservation project, relying exclusively on artificial insemination and artificial incubation of eggs (annual prevalence from 0.07% to 1.64%). To improve the overall knowledge of reproductive pathology in this avian species, a representative sample of 14 cases registered in 2022 were characterized, combining gross pathology, histopathology, microbiology and molecular biology. Overall, 4/14 bustards died spontaneously and exhibited septicaemic changes, while 10/14 euthanized birds presented signs consistent with chronic salpingo-peritonitis and oviductal impaction. The latter was further confirmed at histopathology and, in eight bustards, was associated with mucosal changes resembling cystic endometrial hyperplasia, a condition commonly reported in mammals and potentially predisposing to secondary bacterial infections. Escherichia coli was isolated from the reproductive tract of 12/14 birds. Molecular characterization of nine selected isolates revealed the presence of several virulence factors associated with avian pathogenic E. coli. The variety of virulence, as well as antimicrobial sensitivity profiles identified, combined with the pathological presentation, suggested the involvement of multiple bacterial strains. Overall, in addition to the presence of specific virulence genes, management and host-related factors should also be considered as important determinants of the pathogenic potential of E. coli in captive African Houbaras. RESEARCH HIGHLIGHTS First comprehensive description of salpingo-peritonitis in African Houbaras. First report of cystic oviductal hyperplasia in African Houbaras. Escherichia coli isolated from the reproductive tract of the majority of birds. Several virulence and antimicrobial sensitivity profiles identified.

Using a RAD sequencing approach to investigate the taxonomic classification of Tridacninae giant clams (genera: Hippopus and Tridacna) and address the phylogenetic discordance within the current literature. Population Size and Structure: Focusing in American Sāmoa, we conducted a comprehensive array of surveys on SCUBA, to assess current population stocks and identifying local hotspots for restoration purposes. Population Genetics: Using T. maxima samples, we are analyzing population genetics to identify source-sink populations and measure interisland connectivity.

Mongolia represents the eastern most global distribution range of Asian houbara and the Uvs Lake Basin in western Mongolia supports most northwestern distribution of the species in the country. Standardized Circular Observation (SCO) surveys for three sites around the Uvs Lake were conducted for bustard surveys during the breeding period of the species, between 12-30 May 2024 and four houbara males were observed displaying on two locations in the east of the lake. In the north of the lake, one nesting female houbara was observed during non-SCO surveys while driving on 13 May and the camera trap was installed 3m near the nest from 15 May until 26 May for 11 days brought insights on the challenges faced by nesting houbara female in the region. The camera data reveal important livestock disturbances at the nest causing nest damaged and probably leading to its detection by several predator species (kite, fox, wolf), attracted by the scents left by previous visitors or damaged eggs. 

Understanding the behaviours and time budgets of translocated animals post‐release has the potential to improve rearing and release protocols, and therefore survival rate. Otididae (bustards) inhabit open landscapes across the Middle East and Asia, are highly mobile on the ground and have similar lifestyles and body plans. The Asian houbara Chlamydotis macqueenii is a bustard of conservation concern inhabiting the Middle East to Central Asia and is frequently reared in captivity for population management. We deployed tri‐axial accelerometers on 20 captive Asian houbaras in two seasons to catalogue basic behaviours, provide a template applicable to other bustard species and examine seasonal differences in behaviour. We created Boolean algorithms to define the following behaviours using raw acceleration data and derived metrics: stationary, eating/drinking and locomotion. We used video recordings to cross‐validate the algorithms, yielding recalls from 95 to 97%, and precisions between 97 and 98%. Houbaras spent significantly more time ‘stationary' and less time on ‘locomotion' in summer (June) compared to spring (March). Simple Boolean algorithms proved useful in identifying several behaviours and have the potential to be applicable to other bustard species, in captivity and in the wild post‐release. Keywords: accelerometer, animal behaviour, Asian houbara bustard, captive breeding, conservation translocation

Birds have a sex chromosome system in which females are heterogametic (ZW) and males are homogametic (ZZ). The differentiation of avian sex chromosomes from ancestral autosomes entailed the loss of most genes from the W chromosome during evolution. However, to what extent mechanisms evolved that counterbalance the consequences of this extensive gene dosage reduction in female birds has remained unclear. Here we report functional in vivo and evolutionary analyses of a Z-chromosome-linked microRNA (miR-2954) with strongly male-biased expression that was previously proposed to play a key role in sex chromosome dosage compensation1. We knocked out miR-2954 in chicken, which resulted in early embryonic lethality of homozygous knockout males, likely due to the highly specific upregulation of dosage-sensitive Z-linked target genes of miR-2954. Our evolutionary gene expression analyses further revealed that these dosage-sensitive target genes have become upregulated on the single Z in female birds during evolution. Altogether, our work unveils a scenario where evolutionary pressures on females following W gene loss led to the evolution of transcriptional upregulation of dosage-sensitive genes on the Z not only in female but also in male birds. The resulting overabundance of transcripts in males resulting from the combined activity of two dosage-sensitive Z gene copies was in turn offset by the emergence of a highly targeted miR-2954-mediated transcript degradation mechanism during avian evolution. Our findings demonstrate that birds have evolved a unique sex chromosome dosage compensation system in which a microRNA has become essential for male survival.

Abstract Geographic speciation models assume that time in allopatry should result in greater reproductive isolation between populations. Here we test the prediction that greater time in allopatry results in greater reproductive isolation using comparative ultraconserved element (UCE) data from ten bird lineages in secondary contact in Panama, measuring both genome-wide divergence and the geographic extent of hybridization. The best-fit models for the proportion of fixed Z-linked and autosomal loci to our data includes a combination of both time (as measured by mtDNA divergence) and hand-wing index, emphasizing that the role of time is tempered by dispersal capability. Furthermore, time does not predict the extent of genome-wide introgression as measured by the median width of diagnostic loci clines or the degree of variation in cline centers or widths. These metrics of the outcome of secondary contact were best predicted by ecological and genomic factors, including diet, hand-wing index, and genome-wideFSTrespectively, that are understood to serve as proxies for dispersal, the variability of population size, and overall genomic divergence. We find a primary role for ecological factors instead of isolation time in determining secondary contact outcomes for a lineage, highlighting how ecology shapes the development of reproductive isolation.