Monitoring vulnerable Houbara bustards, birds of both ecological and cultural significance, and detecting intruders that can pose a threat to their nests, is critical for effective conservation of these iconic species. Deep learning-based object detection offers an efficient solution for automating large-scale monitoring, yet its application to Houbara research has been hindered by the lack of comprehensive datasets. To address this gap, we present a new dataset of 24,318 camera-trap images, including 15,070 Houbara bustard images and 9,248 intruder images, all annotated with bounding boxes. Collected between 2011 and 2023 at various times of the day, and using 14 camera models, this dataset provides high diversity and complexity, enabling studies on Houbaras and other bustard species in similar habitats. We benchmarked 10 state-of-the-art object detection models, demonstrating that YOLOv10 outperforms others across evaluation metrics. This dataset represents a significant contribution to wildlife monitoring and conservation, supporting vulnerable Houbara bustard research while offering a foundation for broader applications by providing a valuable resource for wildlife researchers and practitioners.

The Houbara bustard, an avian species of conservation concern, poses significant challenges to researchers because of its elusive nature and sensitivity to human disturbances. Traditional research methods, often reliant on human observations, face some challenges and can inadvertently affect bird behavior. To overcome these limitations, we propose the HuBot, a biomimetic mobile robot designed to seamlessly integrate into the natural habitat of Houbara. By employing advanced real-time deep-learning algorithms, including YOLOv9 for detection, MobileSAM for segmentation, and vision transformer (ViT) for depth estimation, HuBot semi-autonomously tracks individual birds, providing unprecedented insights into their individual behavior, social interactions, and habitat use. HuBot can thus contribute to a deeper understanding of Houbara behavior and its ecology. The biomimetic design of the robot, including its life-like appearance and movement capabilities, minimizes disturbance, allowing for monitoring of Houbara birds while minimizing disruption to their behavior. Rigorous testing, including extensive laboratory experiments and field trials on challenging terrains, validated the performance of HuBot as a complementary tool for traditional observation methods.

Real-time animal detection and segmentation in natural environments are vital for wildlife conservation, enabling non-invasive monitoring through remote camera streams. However, these tasks remain challenging due to limited computational resources and the cryptic appearance of many species. We propose a mobile-optimized two-stage deep learning framework that integrates a Threading Detection Model (TDM) to parallelize YOLOv10-based detection and MobileSAM-based segmentation. Unlike prior YOLO+SAM pipelines, our approach improves real-time performance by reducing latency through threading. YOLOv10 handles detection while MobileSAM performs lightweight segmentation, both executed concurrently for efficient resource use. On the cryptic Houbara Bustard, a conservation-priority species, our model achieves mAP50 of 0.9627, mAP75 of 0.7731, mAP95 of 0.7178, and a MobileSAM mIoU of 0.7421. YOLOv10 operates at 43.7 ms per frame, confirming real-time readiness. We introduce a curated Houbara dataset of 40,000 annotated images to support model training and evaluation across diverse conditions. The code and dataset used in this study are publicly available on GitHub at https://github.com/LyesSaadSaoud/mobile-houbara-detseg. For interactive demos and additional resources, visit https://lyessaadsaoud.github.io/LyesSaadSaoud-Threaded-YOLO-SAM-Houbara.

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].

Birds have a sex chromosome system in which females are heterogametic (ZW) and males are homogametic (ZZ)1. The differentiation of avian sex chromosomes from ancestral autosomes entails the loss of most genes from the W chromosome during evolution1,2. However, the extent to which mechanisms evolved that counterbalance this substantial reduction in female gene dosage remains unclear. Here we report functional in vivo and evolutionary analyses of a Z-linked microRNA (miR-2954) with strong male-biased expression, previously proposed to mediate avian sex chromosome dosage compensation3. We knocked out miR-2954 in chicken, which resulted in early embryonic lethality in homozygous knockout males, probably driven by specific upregulation of dosage-sensitive Z-linked target genes. Evolutionary gene expression analyses further revealed that these dosage-sensitive target genes underwent both transcriptional and translational upregulation on the single Z in female birds. Altogether, this work unveils a scenario in which evolutionary pressures following W gene loss drove transcriptional and translational upregulation of dosage-sensitive Z-linked genes in females but also their transcriptional upregulation in males. The resulting excess of transcripts in males, resulting from the combined activity of two upregulated 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. This study uncovered a unique sex chromosome dosage compensation system in birds, in which a microRNA has become essential for male survival.

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

Domestic chickens are less fearful, have a faster sexual development, grow bigger, and lay more eggs than their primary ancestor, the red junglefowl. Several candidate genetic variants selected during domestication have been identified, but only a few studies have directly linked them with distinct phenotypic traits. Notably, a variant of the thyroid stimulating hormone receptor (TSHR) gene has been under strong positive selection over the past millennium, but it's function and mechanisms of action are still largely unresolved. We therefore assessed the abundance of the domestic TSHR variant and possible genomic selection signatures in an extensive data set comprising multiple commercial and village chicken populations as well as wild-living extant members of the genus Gallus. Furthermore, by mean of extensive backcrossing we introgressed the wild-type TSHR variant from red junglefowl into domestic White Leghorn chickens and investigated gene expression, hormone levels, cold adaptation, and behavior in chickens possessing either the wild-type or domestic TSHR variant. While the domestic TSHR was the most common variant in all studied domestic populations and in one of two red junglefowl population, it was not detected in the other Gallus species. Functionally, the individuals with the domestic TSHR variant had a lower expression of the TSHR in the hypothalamus and marginally higher in the thyroid gland than wild-type TSHR individuals. Expression of TSHB and DIO2, two regulators of sexual maturity and reproduction in birds, was higher in the pituitary gland of the domestic-variant chickens. Furthermore, the domestic variant was associated with higher activity in the open field test. Our findings confirm that the spread of the domestic TSHR variant is limited to domesticated chickens, and to a lesser extent, their wild counterpart, the red junglefowl. Furthermore, we showed that effects of genetic variability in TSHR mirror key differences in gene expression and behavior previously described between the red junglefowl and domestic chicken.

Just as happy people see the proverbial glass as half-full, 'optimistic' or 'pessimistic' responses to ambiguity might also reflect affective states in animals. Judgement bias tests, designed to measure these responses, are an increasingly popular way of assessing animal affect and there is now a substantial, but heterogeneous, literature on their use across different species, affect manipulations, and study designs. By conducting a systematic review and meta-analysis of 459 effect sizes from 71 studies of non-pharmacological affect manipulations on 22 non-human species, we show that animals in relatively better conditions, assumed to generate more positive affect, show more 'optimistic' judgements of ambiguity than those in relatively worse conditions. Overall effects are small when considering responses to all cues, but become more pronounced when non-ambiguous training cues are excluded from analyses or when focusing only on the most divergent responses between treatment groups. Task type (go/no-go; go/go active choice), training cue reinforcement (reward-punishment; reward-null; reward-reward) and sex of animals emerge as potential moderators of effect sizes in judgement bias tests.

Climate change is associated with advancing phenology of seasonal traits in many taxa, but shifts by higher trophic levels are generally reduced compared with those of lower trophic levels. For example, the eclosion date of caterpillars and the lay date of insectivorous passerine birds have both advanced recently, but the former has done so more than the latter. While the ensuring phenological mismatch between predator and prey is well-documented, our understanding of the origins of this mismatch is more limited. Here we shed light on the interplay between ambient temperature, breeding phenology and reproductive success in a single population of blue tits (Cyanistes caeruleus) nesting over a 1,000 m (∼5°C) elevational gradient in the French Pyrenees. During the 6 years of this study, we found that average breeding phenology varied by 2–9 days among years, but was on average 11 days earlier at low versus high elevation. Despite the delay, breeding at high elevation was associated with lower and more variable temperatures during breeding. Early breeders within a given year generally had larger clutch sizes than late breeders, which led to more offspring fledged as typically found in other studies. However, in three of the 6 years, the probability of producing fledglings was actually lower among early layers. Additionally, birds breeding at high elevations who experience conditions typical of early breeders in other populations had reduced hatching success and were significantly less likely to fledge any young compared with those breeding at lower elevation. Reduced success at high elevation was not obviously driven by higher nest predation, which was exceptionally low, or reduced food availability because high elevation birds laid clutches of comparable size and fledged the same number of offspring of comparable mass as those breeding at low elevation. Our study reveals the capacity for substantial variation in breeding phenology within a population, but that the success of early breeders varies across years and temperature gradients. We suggest that the evolution of phenological advancements by small endotherms might be curtailed by increased probability of experiencing, and failure under, challenging meteorological conditions in late winter or very early spring.

Domestic animals are adapted to conditions vastly different from those of their wild ancestors, and this is particularly true for their diets. The most numerous of all domestic species, the chicken, originated from the Red Junglefowl (RJF), a native of subtropical forests in Southeast Asia. Surprisingly however, in domestic chicken breeds, a common haplotype of the β-carotene oxygenase 2 (BCO2) gene, which is involved in carotenoid metabolism, is introgressed from a related species, the Gray Junglefowl, and has been under strong selective pressure during domestication. This suggests that a hybridization event may have conferred a fitness advantage on chickens carrying the derived allele. To investigate the possible biological function of the introgressed BCO2 allele in chicken, we introgressed the ancestral BCO2 allele into domestic White Leghorn chickens. We measured gene expression as well as carotenoid accumulation in skin and eggs of chickens carrying either the ancestral or the derived BCO2 allele. The derived haplotype was associated with down-regulation of BCO2 in skin, muscle, and adipose tissue, but not in liver or duodenum, indicating that carotenoid accumulation occurred in the tissues with reduced gene expression. Most importantly, we found that hens with the derived BCO2 genotype were capable of allocating stored carotenoids to their eggs, suggesting a functional benefit through buffering any shortage in the diet during egg production. Nevertheless, it is of interest that loss of function mutations in BCO2 gene are prevalent in other domesticates including cows, rabbits, and sheep, and, given the importance of carotenoids in development, reproduction, and immunity, it is possible that derived BCO2 alleles may provide a general mechanism in multiple domestic species to deal with higher demand for carotenoids in an environment with carotenoid shortage in the diet.

Models on the evolution of bi-parental care typically assume that maternal investment in offspring production is fixed and predict subsequent contributions to offspring care by the pair are stabilized by partial compensation. While experimental tests of this prediction are supportive, exceptions are commonplace. Using wild blue tits ( Cyanistes caeruleus ), we provide, to our knowledge, the first investigation into the effects of increasing maternal investment in offspring production for subsequent contributions to nestling provisioning by mothers and male partners. Females that were induced to lay two extra eggs provisioned nestlings 43% more frequently than controls, despite clutch size being made comparable between treatment groups at the onset of incubation. Further, experimental males did not significantly reduce provisioning rates as expected by partial compensation, and if anything contributed slightly (9%) more than controls. Finally, nestlings were significantly heavier in experimental nests compared with controls, suggesting that the 22% average increase in provisioning rates by experimental pairs was beneficial. Our results have potential implications for our understanding of provisioning rules, the maintenance of bi-parental care and the timescale over which current–future life-history trade-offs operate. We recommend greater consideration of female investment at the egg stage to more fully understand the evolutionary dynamics of bi-parental care.

Accompanying data for Bründl et al. 2019 Proc Royal Soc B (DOI: 10.1098/rspb.2019.1013)

Models on the evolution of bi-parental care typically assume that maternal investment in offspring production is fixed and predict subsequent contributions to offspring care by the pair are stabilized by partial compensation. While experimental tests of this prediction are supportive, exceptions are commonplace. Using wild blue tits (Cyanistes caeruleus), we provide, to our knowledge, the first investigation into the effects of increasing maternal investment in offspring production for subsequent contributions to nestling provisioning by mothers and male partners. Females that were induced to lay two extra eggs provisioned nestlings 43% more frequently than controls, despite clutch size being made comparable between treatment groups at the onset of incubation. Further, experimental males did not significantly reduce provisioning rates as expected by partial compensation, and if anything contributed slightly (9%) more than controls. Finally, nestlings were significantly heavier in experimental nests compared with controls, suggesting that the 22% average increase in provisioning rates by experimental pairs was beneficial. Our results have potential implications for our understanding of provisioning rules, the maintenance of bi-parental care and the timescale over which current–future life-history trade-offs operate. We recommend greater consideration of female investment at the egg stage to more fully understand the evolutionary dynamics of bi-parental care.

Natural selection can act on between-individual variation in cognitive abilities, yet evolutionary responses depend on the presence of underlying genetic variation. It is, therefore, crucial to determine the relative extent of genetic versus environmental control of these among-individual differences in cognitive traits to understand their causes and evolutionary potential. We investigated heritability of associative learning performance and of a cognitive judgement bias (optimism), as well as their covariation, in a captive pedigree-bred population of red junglefowl (Gallus gallus, n > 300 chicks over 5 years). We analysed performance in discriminative and reversal learning (two facets of associative learning), and cognitive judgement bias, by conducting animal models to disentangle genetic from environmental contributions. We demonstrate moderate heritability for reversal learning, and weak to no heritability for optimism and discriminative learning, respectively. The two facets of associative learning were weakly negatively correlated, consistent with hypothesized trade-offs underpinning individual cognitive styles. Reversal, but not discriminative learning performance, was associated with judgement bias; less optimistic individuals reversed a previously learnt association faster. Together these results indicate that genetic and environmental contributions differ among traits. While modular models of cognitive abilities predict a lack of common genetic control for different cognitive traits, further investigation is required to fully ascertain the degree of covariation between a broader range of cognitive traits and the extent of any shared genetic control. This article is part of the theme issue ‘Causes and consequences of individual differences in cognitive abilities’.

Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.

Cognition is fundamental to animals' lives and an important source of phenotypic variation. Nevertheless, research on individual variation in animal cognition is still limited. Further, although individual cognitive abilities have been suggested to be linked to personality (i.e., consistent behavioral differences among individuals), few studies have linked performance across multiple cognitive tasks to personality traits. Thus, the interplays between cognition and personality are still unclear. We therefore investigated the relationships between an important aspect of cognition, learning, and personality, by exposing young and adult red junglefowl (Gallus gallus) to multiple learning tasks (discriminative, reversal, and spatial learning) and personality assays (novel arena, novel object, and tonic immobility). Learning speed was not correlated across learning tasks, and learning speed in discrimination and spatial learning tasks did not co-vary with personality. However, learning speed in reversal tasks was associated with individual variation in exploration, and in an age-dependent manner. More explorative chicks learned the reversal task faster than less explorative ones, while the opposite association was found for adult females (learning speed could not be assayed in adult males). In the same reversal tasks, we also observed a sex difference in learning speed of chicks, with females learning faster than males. Our results suggest that the relationship between cognition and personality is complex, as shown by its task- and age-dependence, and encourage further investigation of the causality and dynamics of this relationship.Significance statementIn the ancestor of today's chickens, the red junglefowl, we explored how personality and cognition relate by exposing both chicks and adults to several learning tasks and personality assays. Our birds differed in personality and learning speed, while fast learners in one task did not necessarily learn fast in another (i.e., there were no overall smarter birds). Exploration correlated with learning speed in the more complex task of reversal learning: faster exploring chicks, but slower exploring adult females, learned faster, compared to less explorative birds. Other aspects of cognition and personality did not correlate. Our results suggest that cognition and personality are related, and that the relationship can differ depending on task and age of the animal.

Extrinsic mortality has a strong impact on the evolution of life-histories, prey morphology and behavioural adaptations, but for many animals the causes of mortality are poorly understood. Predation is an important driver of extrinsic mortality and mobile animals form groups in response to increased predation risk. Furthermore, in many species juveniles suffer higher mortality than older individuals, which may reflect a lower phenotypic quality, lower competitiveness, or a lack of antipredator or foraging skills. Here we assessed the causes of mortality for 371 radio tagged Siberian jays. This sedentary bird species lives in family groups that contain a breeding pair as well as related and unrelated non-breeders. Ninety-five percent of death were due to predation (n = 59 out of 62 individuals) and most individuals were killed by Accipiter hawks. Multivariate Cox proportional hazards models showed that non-breeders had a lower survival than breeders, but only in territories in managed forest with little visual cover. Examining breeders, only sex influenced survival with males having a lower survival than females. For non-breeders, juveniles had lower survival than older non-breeders, and those on managed territories had lower survival than those on unmanaged territories. Additionally, a low feather quality reduced the survival probability of non-breeders only. Thus, living on managed territories and having a low feature quality affected only non-breeders, particularly juveniles. These findings add to previous research demonstrating that juvenile Siberian jays acquire critical antipredator skills from experienced group members. Thus, experience can buffer extrinsic mortality, highlighting that group living not only provides safety in numbers, but also provide social opportunities to learn critical life-skills.

Despite intense research efforts, biologists are still puzzled by the existence of animal personality. While recent studies support a link between cognition and personality, the directionality of this relationship still needs to be clarified. Early-life experiences can affect adult behaviour, and among these, cognitive stimulation has been suggested theoretically to influence personality. Yet, the influence of early cognitive stimulation has rarely been explored in empirical investigations of animal behaviour and personality. We investigated the effect of early cognitive stimulation on adult personality in the red junglefowl (Gallus gallus). To this end, we assessed adult behaviour across a number of personality assays and compared behaviour of individuals previously exposed to a series of learning tasks as chicks, with that of control individuals lacking this experience. We found that individuals exposed to early stimulation were, as adults, more vigilant and performed fewer escape attempts in personality assays. Other behaviours describing personality traits in the fowl were not affected. We conclude that our results support the hypothesis that early stimulation can affect aspects of adult behaviour and personality, suggesting a hitherto underappreciated causality link between cognition and personality. Future research should aim to confirm these findings and resolve their underlying dynamics and proximate mechanisms.