Individual Birds Research Articles

Plastic Behaviour Buffers Climate Variability in the Wandering Albatross.

Climate change has marked effects on global weather patterns and oceanic systems, impacting animal behaviour and fitness in potentially profound ways. Despite this, we lack detailed information about species' responses to climatic variation. Using an 11-year tracking dataset of over 300 individual birds, we explore the consequences of variation in the southern annular mode (SAM) and southern oscillation index (SOI) for individual behaviour and fitness in wandering albatrosses Diomedea exulans breeding in the Southern Indian Ocean. Our results reveal distinct responses between males and females to climatic variation that align with the impacts of each climatic index on the distinct foraging ranges of each sex. In positive SAM phases, linked to poorer foraging conditions in female ranges and better conditions in male ranges, females exhibited behaviour consistent with reduced foraging success: that is, fewer prey capture attempts and more movement between feeding patches. Males, on the other hand, showed no behavioural change. During positive SOI phases, associated with good foraging conditions in both male and female foraging ranges, both sexes showed evidence of more successful foraging, with birds engaging in more search behaviour, and taking shorter trips with fewer prey capture attempts, together indicating increased food intake per unit time. We found limited evidence for a role of individual variation, as measured through differences in personality, suggesting that plastic responses to climate are sufficiently important so as to obscure inter-individual variation. Supporting this was the finding that individual breeding success was unaffected by climatic variation, suggesting that plastic foraging behaviour allows albatrosses to mitigate climate impacts and maintain reproductive output.

Impact of Seasonal Changes on Avifauna Diversity in Nguru Wetland, Yobe State, Nigeria

The research on impact of seasonal changes on avifauna diversity in Nguru Lake of Hadejia-Nguru Wetland was carried out in two different seasons for the period of six 6 months, from April to June (dry season) and July to September (wet season). The aim was to evaluate the impact of seasonal changes on avifauna diversity and the species richness in the study area. A reconnaissance survey was carried out to select study sites and sampling points. Five (5) different points were selected which comprises of Madauka, Kayayyashi, Farin Ruwa, Badum and Guzan respectively and Point count census techniques were adopted. In each counting station, bird observation was carried out twice daily; morning between 6:00 am and 10:00 am and evening between 4:00 pm and 6:00 pm. Data compilation was done using Microsoft Excel and were analysed using statistical software Past 326b. Bird diversity was calculated using Shanon-Weiner diversity index. The findings of this research showed that the majority of birds identified were Resident species (12,225 individual birds), Migratory species (8,186 individual birds) and Palearctic Migrants (10,876 individual) species in the study area. Dominant bird species in Nguru lake were Philomachus pugnax, Actophilornis africanus and Phalacrocorax africanus. A total of 5,538 individual birds’ was identified (Dry Season) in Nguru lake ‘’ belonging to 21 families in which Ardeidae family had the highest (7) species of bird. Shannon Diversity Index’ has 2.55 in dry season, while in Wet Season’ has 3.40. This indicated that there was relatively equal and high diversity of bird species in Wet Season in the study area and has the total species richness of 6,711. Overgrazing and other anthropogenic activities which affect the population diversity of avifauna species serve as major threats to the continued existence of Wetlands. Typha grass also remained pressing problem which create microhabitats reducing critical habitat for feeding, nesting and roosting habitat for birds, as well as hampers the smooth flow of water used by many water bird species. In view of the findings of this study, effective monitoring and strategies for conservation to restore the population of bird species, provide public enlightenment of the people around the wetland and management of Hadejia-Nguru Wetland promptly advice the significant importance of the wetland in serving as home for resident and migratory birdspecies.

Potential of accelerometer tags for monitoring of Japanese quail (Coturnix japonica) reproductive behaviour

ABSTRACT 1. Monitoring behavioural dynamics in complex animal environments, such as poultry breeding facilities, poses a challenge. Utilising technological approaches, such as accelerometers, offers a solution to assess long-term changes in reproductive activity at an individual bird level. Specifically, these sensors measure acceleration associated with the position and movements of the body over time. However, it is important to assess the most suitable method for attaching accelerometer tags to ensure they do not negatively impact behaviour and yield high-quality data. 2. The potential of tri-axial accelerometer tags for assessing reproductive behaviour in Japanese quail was evaluated. Two attachment methods – a backpack (plastic platform with elastic bands near wing bases) and a patch (accelerometer on fabric glued to the synsacrum region) – were compared. Controls were handled similarly but without tags. Eighteen pairs of females were housed in pens and assessed immediately and 24 h after handling. After a week of habituation, a male from the same treatment group was introduced into each pen on d 8. The reproductive behaviour of the males was recorded using accelerometers and video recordings. 3. The results showed that birds with patches were able to remove their conspecific’s accelerometer and displayed an increased initial immobility response compared to the control and backpack groups. The presence of accelerometer tags did not impact male/female reproductive interactions nor fear responses to a novel object. From accelerometer recordings, male reproductive behaviour was easily identified as high amplitude fluctuations in the three axial components of the acceleration vectors, which was reflected as large values of dynamic body acceleration (VeDBA). 4. In conclusion, the use of backpacks with accelerometers is a useful strategy to address highly relevant and difficult to tackle behavioural topics such as the temporal dynamic of male reproductive behaviour within breeding groups.

Partial migration pays off in black-faced cormorants: insights from post-breeding GPS tracking

Seasonal variation in food availability or adverse weather patterns can create challenging conditions for year-round survival. Birds experiencing such fluctuations may migrate to locations with better food availability in the non-breeding period. While some species are obligate migrants, others are facultative migrants where various post-breeding strategies exist within populations. Several cormorant and shag species are facultative migrants with a range of post-breeding movement strategies within populations. Currently, most of the information available on cormorant post-breeding strategies originates from banding studies and little is known about their movements, time budget or habitat use during the non-breeding period. In the present study, Australian endemic black-faced cormorants (Phalacrocorax fuscescens), breeding on Notch Island, Victoria, were tracked with GPS data loggers during the non-breeding period. Different post-breeding strategies were observed. Individuals were either resident (N = 36, 69%), remaining within a short distance of the colony (16.7 ± 2.2 km) or migratory (N = 16, 31%), travelling greater distances (250.7 ± 24.4 km) to establish a new central place foraging location. Data from individuals which covered the entire non-breeding period indicated that, across strategies, individual birds had one area of residency during the non-breeding period. Migratory individuals were found to have lower daily activity levels, spending less time flying and foraging, than resident individuals during the early non-breeding period, possibly indicating that they had access to greater prey resources. Regardless of the post-breeding strategy, individuals utilised foraging locations that were of similar seabed depths year-round suggesting individual specialisation in prey resources or foraging habitats.

Mercury concentrations in blood and back feathers are repeatable, heritable and correlated in a long-lived seabird

Mercury pollution is increasing both in the environment and in various organisms, especially top-predators. If variation in individual mercury concentrations is underpinned by genetic among-individual differences in traits related to mercury uptake, storage or excretion, and results in variation in fitness, populations may have the potential to evolve in response to this development. Few studies, however, have been able to collect sufficient information to investigate the genetic basis of pollution levels. We ran Bayesian quantitative genetic analyses, combining pedigree information obtained from a marine top-predator, the common tern (Sterna hirundo), with total mercury concentrations (THg) measured in 1364 blood and 1560 back feather samples obtained from >600 individual birds across seven years. Blood and back feather THg concentrations differed in repeatability (19 vs. 64 %, respectively), but showed similar levels of heritability (c. 9 %) and evolvability (c. 2 %). Blood and back feather THg concentrations were positively correlated at the phenotypic, but not genetic, level. Although further work is needed to elucidate the uptake, storage or excretion pathways underlying these patterns, our study provides pioneering insights into the architecture of THg concentrations, and suggests that adaptation to environmental pollution may to some extent be possible.

Shadow-boxing: Major gaps to knock out in bird–window interaction research

ABSTRACT Bird–window collisions are a leading source of bird mortality worldwide, estimated to kill as many as 1 billion birds annually in the U.S. alone. Though researchers have examined the factors contributing to general bird–window collisions, shadow-boxing, a nonfatal but potentially ecologically significant bird–window interaction, has primarily been excluded from the conversation. Shadow-boxing occurs when birds attack their reflection in human-made surfaces believing the reflection to be another individual intruding on their territory. Current bird–window interaction research often does not consider the unique drivers, impacts, and mitigation strategies associated with shadow-boxing. In this paper, we identify 5 major knowledge gaps: (1) building and environmental characteristics that lead to shadow-boxing; (2) the impacts on individual birds, (3) populations, and (4) people; and (5) the effectiveness of existing mitigation strategies for shadow-boxing. For each knowledge gap, we list research questions that will further our understanding of the scale and significance of shadow-boxing.

Seasonal Dynamics and Avian Diversity along the Adyar Riverbank: Insights from a Year-Long Survey

The avian survey conducted along the Adyar Riverbank (Manapakkam) from January 2023 to December 2023 documented a total of 3120 individual birds across 75 species from 16 avian orders, highlighting the significant biodiversity within this urban ecosystem. This study aimed to assess seasonal variations in bird diversity and abundance, emphasizing the river’s role as an important habitat. The highest diversity was observed during winter, specifically in February 2023, with a diversity index of 296.80 and a Simpson’s index of 0.22. A total of 36 species and 636 individuals were recorded. In contrast, the lowest diversity was observed in summer, particularly in July 2023, with a diversity index of 29.29 and a Simpson’s index of 0.05, corresponding to 18 species and 114 individuals. The monsoon and post-monsoon periods exhibited a prominent increase in diversity due to the arrival of migratory species and improved habitat conditions. Important species recorded throughout the year included the Paddy Field Pipit, House Crow, and Rufous Treepie, while conservation-significant species such as the Black-headed Ibis and Spot-billed Pelican were also observed. Thus, the present study underscores the Adyar River’s ecological importance and highlights the need for continuous monitoring and targeted conservation efforts to maintain avian biodiversity in urban river ecosystems.

Per- and poly-fluoroalkyl substances (PFAS) do not accumulate with age or affect population survival in ruddy turnstone (Arenaria interpres)

Per- and poly-fluoroalkyl substances (PFAS) may threaten wildlife due to their high environmental persistence, toxicity potential and potential to bioaccumulate. Bioaccumulation may be particularly profound in long-lived animals inhabiting higher trophic niches. To date, there is a paucity of data on PFAS bioaccumulation potential in individual wild birds over their lifetime. In this study, we analysed within-individual PFAS contamination in a declining long-distance migratory shorebird, the ruddy turnstone (Arenaria interpres), and the variation in PFAS contamination with age by repeatedly sampling 19 individuals throughout their lives between 2007 and 2022. We found blood-sampled turnstones on their non-breeding grounds in King Island, Tasmania, exhibited no variation of PFAS contamination with age, with low overall circulating PFAS concentrations (<0.015–25 ng/g, median: 0.78 ng/g). Moreover, irrespective of the increased PFAS usage along the East Asian Australasian Flyway over the past two decades, ruddy turnstone survival remained consistent throughout the 15-year sampling period, with no temporal trend in percentage of juveniles in the population. From a conservation perspective, low concentrations of PFAS found in this study are good news as they suggest PFAS alone do not seem to threaten turnstone survival. However, the unknown effects of exposure to mixtures of pollutants may yet threaten turnstones.

The decline of ground nesting birds in Europe: Do we need to manage predation in addition to habitat?

Bird populations are declining globally with losses recorded in many European breeding birds. Habitat management measures have not resulted in widespread reversal of these declines. We analysed national bird population trends from ten European countries (France, Hungary, Ireland, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the UK) for which data on individual bird species was freely available online in relation to the species’ nesting strategy (‘ground-nesting’ or ‘other’), Annex I designation (‘designated’ or ‘not designated’) and association with agricultural habitats for breeding (‘associated’ or ‘not associated’). For each country in our dataset, we also broadly categorised the following factors: farming intensity; predator community complexity; and predator control effort. Our results showed additive effects of nesting strategy, designation, and breeding habitats on the likelihood of population decline. Ground-nesting birds were 86 % more likely to decline than birds with other nesting strategies. Annex I designated species of the Birds Directive were 50 % less likely to decline than non-designated birds. Birds breeding primarily in agricultural habitat were more likely to decline than birds breeding in other habitats, interactively with farming intensity. Homogenous trends across Europe (i.e. trends in two or more countries that were either not declining in all countries or declining in all countries), indicate that the probability of population decline was related to nesting strategy and breeding habitat. Ground-nesting birds were 15.6 times more likely than other birds to have a declining trend across Europe, and birds nesting in agricultural habitats were 17.8 times more likely to decline than birds nesting in other habitats. Our results highlight a widespread challenge, therefore widespread instruments (e.g. legislation, economic policies, agri-environment schemes) will be required to reverse these declines. Ground-nesting species requirements can be complex and multiple strategies will be needed to restore populations including the development of predation management tools.

Effective range of auditory frightening devices based on hearing capabilities and antipredator responses of nuisance blackbirds

AbstractA variety of acoustic strategies have been implemented to disperse wildlife from areas of human‐wildlife conflict. Propane cannons are a popular tool; however, their efficacy based on avian behavior has yet to be fully explored. We collected sound attenuation data for a propane cannon, compared to a rifle and shotgun, with reference to hearing capabilities in birds. We evaluated the behavioral responses of red‐winged blackbirds (Agelaius phoeniceus, RWBL) and brown‐headed cowbirds (Molothrus ater, BHCO) to detonations of a cannon. We placed birds in individual enclosures, void of visual stimuli, at 15–495 m from a cannon and evaluated responses (i.e., relaxed, vigilant, startled) to cannon blasts using 2 approaches: 1) incremental, where individual birds were exposed to a series of detonations at decreasing distances and 2) random assignment, where individual birds were randomly assigned distances and exposed to 2 series of 4 cannon blasts. We found behavioral responses of birds significantly decreased at greater distances (χ2(1) = 127, P &lt; 0.001), regardless of species (χ2(1) = 0.74, P = 0.389), when incrementally approached. The probability of startling (i.e., flinch, wing flap, feather compression, or flight) was greater than vigilance (i.e., increased head turning, sudden head‐up, or neck extension) within 64 m for BHCO and 136 m for RWBL. We found a significant effect of distance (χ2(1) = 97.8, P &lt; 0.001), between species (χ2(1) = 19.6, P &lt; 0.001), and blast number (χ2(3) = 17.6, P &lt; 0.001) when birds were randomly assigned a distance from the cannon. With the first cannon blast, the probability of startling was greater than vigilance or relaxed within 334 m for BHCO and 153 m for RWBL. With subsequent blasts the probability of startling was greater than vigilance and relaxed within 204–221 m of the cannon for BHCO, but startling was never greater than vigilance for RWBL. We note that the estimated range of the cannon is conservative given birds are contained with limited flight ability. Nevertheless, information on effective range and avian responses to repeated blasts informs managers on the potential interstimulus timing and distribution of propane cannons to protect resources from birds.

Development and validation of machine-learning models for monitoring individual behaviors in group-housed broiler chickens

Animals' individual behavior is commonly monitored by live or video observation by a person. This can be labor intensive and inconsistent. An alternative is the use of machine learning-based computer vision systems. The objectives of this study were to 1) develop and optimize machine learning model frameworks for detecting, tracking and classifying individual behaviors of group-housed broiler chickens in continuous video recordings; and 2) use an independent dataset to evaluate the performance of the developed machine leaning model framework for individual poultry behaviors differentiation. Forty-two video recordings from 4 different pens (total video duration = 1,620 min) were used to develop and train multiple models for detecting and tracking individual birds and classifying 4 behaviors: feeding, drinking, active, and inactive. The optimal model framework was used to continuously analyze an external set of 11 videos (duration = 326 min), and the second-by-second behavior of each individual broiler was extracted for the comparison of human observation. After comparison of model performance, the YOLOv5l, out of 5 detection models, was selected for detecting individual broilers in a pen; the osnet_x0_25_msmt17, out of 4 tracking algorithms, was selected to track each detected bird in continuous frames; and the Gradient Boosting Classifier, out of 12 machine learning classifiers, was selected to classify the 4 behaviors. Most of the models were able to keep previously assigned individual identifications of the chickens in limited amounts of time, but lost the identities throughout an examination period (≥4 min). The final framework was able to accurately predict feeding (accuracy = 0.895) and drinking time (accuracy = 0.9) but subpar for active (accuracy = 0.545) and inactive time (accuracy = 0.505). The algorithms employed by the machine learning models were able to accurately detect feeding and drinking behavior but still need to be improved for maintaining individual identities of the chickens and identifying active and inactive behaviors.

Comparison of hunting site strategies of the common buzzard Buteo buteo in open landscapes and along expressways.

The expansion of human activities in their many forms increases the frequency, diversity, and scale of human-wildlife interactions. One such negative form is the expansion of road infrastructure, causing road kill and traffic-related noise as well as habitat loss and fragmentation. Even so, habitats around road infrastructure are attractive foraging areas that attract certain bird species. We assessed the impact of road infrastructure on the foraging strategies of the common buzzard Buteo buteo. Birds were observed during two winter seasons in two land-use types, along an expressway and an open agricultural landscape. Individual birds were tracked for a 10-min sequence as a separate sample was analysed. The material, covering 1,220 min along the expressway, and 1,100 min in the agricultural landscape, was collected. Time spent by buzzards on medium-height sites was higher along the expressway than in farmland. Buzzards changed their hunting sites following the mean wind speed. Also, they more often changed their sites along the expressway than in farmland. The land-use types, snow cover, and the mean wind speed mediated the number of attacks on prey. These results illustrate the high plasticity of the buzzards' behaviour, which can adapt their hunting strategies to both foraging locations (expressway and farmland) and weather conditions. Roadsides along expressways are attractive foraging areas for this diurnal raptor, so reducing the risk of vehicle collisions with this and other birds of prey may require targeted planning efforts.

Zero-shot image segmentation for monitoring thermal conditions of individual cage-free laying hens

Body temperature is a critical indicator of the health and productivity of egg-laying chickens and other domesticated animals. Recent advancements in thermography allow for precise surface temperature measurement without physical contact with animals, reducing animal stress from human handling. Gold standard temperature analysis via thermography requires manual selection of limited points for an object of interest, which could be time-consuming and inadequate for representing the comprehensive thermal profile of a chicken’s body. The objective of this study was to leverage and optimize a zero-shot artificial intelligence technology for the automatic segmentation of individual cage-free laying hens within thermal images, providing insights into their overall thermal conditions. A zero-shot image segmentation model (Segment Anything, “SAM”) was modified by replacing manual selections of target points with automatic selection of the initial point using pre-processing techniques (e.g., thresholding) in each thermal image. The model was also incorporated with post-processing techniques integrated with a machine learning classifier to improve segmentation accuracy. Three versions of modified SAM models (i.e., SAM, FastSAM, and MobileSAM), two common instance segmentation algorithms (i.e., YOLOv8 and Mask R-CNN), and two foundation segmentation models (i.e., U2-Net and ISNet) were comparatively evaluated to determine the optimal one for bird segmentation from thermal images. A total of 1,917 thermal images were collected from cage-free laying hens (Hy-Line W-36) at 77–80 weeks of age. The image dataset exhibited considerable variations such as feathers, bird movement, body gestures, and the specific conditions of cage-free facilities. The experimental results demonstrate that the modified SAM did not only surpass the six zero-shot models—YOLOv8, Mask R-CNN, FastSAM, MobileSAM, U2Net, and ISNet—but also outperformed other modified SAM-based models (Modified FastSAM and Modified MobileSAM) in terms of hen detection performance, achieving a success rate of 84.4 %, and in segmentation performance, with an intersection over union of 85.5 %, recall of 91.0 %, and an F1 score of 92.3 %. The optimal model, modified SAM, was pipelined to extract statistics including the averages (°C) of mean (27.03, 27.04, 28.53, 26.68), median (26.27, 26.84, 28.28, 26.78), 25th percentile (25.33, 25.61, 27.26, 25.53), and 75th percentile (28.04, 27.95, 29.22, 27.55) of surface body temperature of individual laying hens in thermal images for each week. More statistics of hen body surface temperature can be extracted based on the segmentation results. The developed pipeline is a useful tool for automatically evaluating the thermal conditions of individual birds.

Reproductive characteristics of indigenous village chickens

BackgroundIndigenous village chickens (IVCs) show a wide variation in production performance and reproductive characteristics. This high variation is occurred due to genetic and environmental factors and gene-environment interactions.ResultsThis work reports the results of a cross-sectional study conducted using a face-to-face interview with 119 small-scale farmers regarding their insights on the production performance and reproductive characteristics of IVCs. It was reported that pullets were sexually mature on average at the age of 5.5 months and cockerels at 6 months. This comparatively early sexual maturity by the standards of IVCs might be associated with the impact of uncontrolled gene flow from production breeds. However, there is high variation in age at sexual maturity at an individual bird’s level. It was found that pullets mature earlier than cockerels (t = 3.250, df = 159, p = 0.001, 95% CI: -0.670, -0.166). According to the respondents, local hens laid on average 14 eggs per clutch. The average number of clutches per year was 4, which can culminate in the yearly production of 56 eggs. A significantly large proportion of the respondents reported that the dry season is appropriate for laying eggs (96.7%) and brooding chicks (94.1%). During the dry season, the scavenging feed resource is relatively abundant, the risk of infection is comparatively low, and the hot weather is suitable for laying eggs and brooding chicks. IVCs possess a long reproductive lifetime, that is, on average, 3 years in hens and 2 years in cocks, which makes them more productive than has been anticipated. For example, this study found that a hen, on average, can lay 174 eggs and hatch 58 chicks in its average reproductive lifetime of 3 years.ConclusionsThe high intrapopulation variation in the reproductive performance of IVCs is vital resource in genetic improvement programs.

EVALUATION OF BREED EFFECT ON GENE EXPRESSION OF ARYL HYDROCARBON RECEPTOR (AHR), CYTOCHROME P450 (CYP1A1) AND INTERLEUKINS (IL2) IN CHICKENS REARED IN A CRUDE OIL-POLLUTED ENVIRONMENT

Hydrocarbon toxicity resulting from the disruption of homeostasis caused by exposure to hydrocarbon pollutants is a significant obstacle that could impede the expression of the full genetic potentials of chicken breeds in the Niger Delta. Depending on the population, the mechanism and severity of toxicity may vary with the level of expression of certain genes modulated by xenobiotics. This study investigated breed effects on expression of aryl hydrocarbon receptor (AhR), cytochrome p450 (CYP1A1) and interleukins (IL2) in chickens. For the investigation, two breeds of chicken: (Nigerian native chickens and commercial line broiler chickens) raised under extensive system by rural smallholder farmers in Okrika and Nsukka Local government Areas, Rivers and Enugu States, Nigeria were utilized. Liver tissue was excised from individual bird (27 birds per breed) for RNA extraction and gene expression studies. Results revealed that there was significant breed effect in the response of chickens in Okrika where the expression of AhR, CYP1A1 and IL-2 genes was upregulated in the native chickens (p&lt;0.05). Such disparities were not observed in chickens reared in Nsukka. This could be an indication of increased metabolism and detoxification of hydrocarbon pollutants in the native chicken particularly in hydrocarbon polluted environment. We therefore propose studies on AhR, CYP1A1 and IL-2 as molecular markers for evaluating hydrocarbon toxicity in chickens and possible selection for genetic improvement.

Anti-coccidial efficacy of Enteromorpha prolifera polysaccharide in indigenous chickens of Northwest Ethiopia.

A variety of bioactive compounds isolated from various botanical sources have been found to have therapeutic and immunotherapeutic effects on chicken coccidiosis. This study aimed to evaluate the anti-coccidial potential of Enteromorpha prolifera polysaccharide (EP) in indigenous chickens in Northwest Ethiopia. A total of 78 male indigenous chickens were used for this study. The study had two treatment groups: (1) the EP non-supplemented group (those fed on diets without EP and Eimeria oocyst inoculated) and (2) the EP group (those receiving diets supplemented with 400mgEP/kg diet and Eimeria oocyst inoculated). Each treatment group had five replications. Following fourteen days of EP supplementation, 1.5×104 oocysts of mixed Eimeria species were inoculated into individual birds. EP-supplemented chicken showed significantly lower (p<0.05) oocyst counts compared to non-supplemented ones on 9 and 11 days post-challenge. In addition, chickens in the EP-supplemented group showed less severe lesion scores, with an average score of 1.33. Chickens that received EP showed a maximum of 27.27% protection against lesions. In contrast, the non-supplemented chickens had a lower percentage of protection (19.83%). The maximum anti-coccidial index value (146.98) was obtained from EP-supplemented chickens. Chickens in the EP-supplemented group exhibited a significantly higher (p<0.05) weight gain. Overall, the inclusion of EP in chickens' diets shows promise as a potential anti-coccidial strategy. However, additional research is required to explore the mechanisms by which EP in chickens' diet could involve in increasing the protection ability of chickens against coccidiosis.

Individual timing consistency across long-distance songbird migrations.

Migration timing in long-distance migratory birds plays an essential role in individual survival and fitness and is thought to be driven by circannual routines cued by photoperiod with some plasticity to environmental conditions. We examined the individual order of migration timing in purple martins (Progne subis), a neotropical migratory songbird that travels between breeding sites throughout eastern North America and nonbreeding sites in Brazil. Migration timing data were collected for 295 different individual purple martins over 9 years using light-level geolocators deployed at breeding sites across the range. We used linear mixed-effect models to examine the influence of the rank order of individual departure dates in one season on the rank order of four subsequent migration events while controlling for the effects of breeding latitude, sex, and age. Overall, we found evidence for consistent individual timing that can extend across 8 months and 12,000-24,000 km of migration. Individual rank order of migration timing in purple martins was generally conserved across migrations with consistent timings between fall departure dates from, and spring arrival dates to the breeding site the following year (0.28 ± 0.03, 95% CI 0.22-0.34), as well as at a finer scale across fall migration (0.33 ± 0.05, 95% CI 0.23-0.43), over the stationary nonbreeding period (0.39 ± 0.04, 95% CI 0.31-0.47), and across spring migration (0.03 ± 0.001, 95% CI 0.028-0.032). These results demonstrate that purple martins exhibit consistency in individual migration timing throughout the annual cycle that is likely driven by inherent individual circannual schedules. We additionally found that migration distance played a significant role, as the consistency of individual timing lessened over longer distances. Understanding how individual birds time migrations and if individuals are consistent between events can provide insight into how birds respond to shifts in their environment with climate change.

Phylogenomic Analyses of Three Distinct Lineages Uniting Staphylococcus cohnii and Staphylococcus urealyticus from Diverse Hosts.

We sequenced and assembled genomes for 17 isolates of Staphylococcus cohnii isolated from osteomyelitis lesions in young broilers from two separate experiments where we induced lameness using a hybrid wire-litter flooring system. Whole genome comparisons using three different methods support a close relationship of genomes from both S. cohnii and Staphylococcus urealyticus. The data support three different lineages, which we designated as Lineage 1, Lineage 2, and Lineage 3, uniting these two species within an evolving complex. We present evidence for horizontal transfer between lineages of genomic regions from 50-440 kbp. The transfer of a 186 kbp region from Lineage 1 to Lineage 2 appears to have generated Lineage 3. Human-associated isolates appear to be limited to Lineages 2 and 3 but Lineage 2 appears to contain a higher number of human pathogenic isolates. The chicken isolates from our lameness trials included genomically diverse isolates from both Lineage 1 and 2, and isolates from both lineages were obtained from osteomyelitis lesions of individual birds. Our results expand the diversity of Staphylococci associated with osteomyelitis in poultry and suggest a high diversity in the microbiome of day-old chicks. Our data also support a reevaluation and unification of the taxonomic classifications of S. cohnii and S. urealyticus.

Influence of perch provision during rearing on activity and musculoskeletal health of pullets.

Prior research suggests exercise during pullet rearing can mitigate lay-phase bone fractures by strengthening muscles, enhancing balance, and increasing bone mass. This study aimed to confirm that Hy-Line brown pullets with multi-tier perches show increased activity and improved musculoskeletal health. Pullets (n = 810) were randomly allocated to housing systems, either with multi-tier perches (P; n = 15 pens) or without (NP; n = 15 pens), spanning from 0-17 weeks of age. At 5, 11, and 17 weeks, individual birds were meticulously monitored for activity using accelerometers over three consecutive days (n = 90 randomly selected birds/week). At 11 and 17 weeks, 60 birds underwent euthanasia and computed tomography (CT) scans to ascertain tibiotarsal bone mineral density and cross-sectional area measurements. Post-CT scanning, birds were dissected for muscle size, tibiotarsal breaking strength, and tibiotarsal ash percentage measurements. Additionally, serum concentrations of bone-specific alkaline phosphatase and procollagen type 1 N-terminal propeptide were assessed as markers of bone formation (n = 90 birds/week). Pullet group P exhibited heightened vertical activity (P<0.05), with no discernible differences in overall activity (P>0.05) during weeks 5, 11, and 17 compared to group NP. Tibiotarsal bones of P pullets demonstrated superior total and cortical bone mineral density at week 11, alongside increased cortical bone cross-sectional areas and heightened total and cortical bone mineral densities at week 17 (P<0.05) compared to NP pullets. At week 11, P pullets displayed larger leg muscles, including triceps, pectoralis major and minor, and leg muscles at week 17 (P<0.05) compared to NP pullets. Notably, at both weeks, P pullets' tibiae exhibited greater breaking strengths, higher ash percentages, and elevated concentrations of bone-specific alkaline phosphatase and procollagen type 1 N-terminal propeptide compared to NP pullets (P<0.05). The study findings underscore the benefits of providing multi-tier perches for pullets, serving as a valuable tool for enhancing bird activity and musculoskeletal health preceding the lay phase.

A probabilistic time geographic approach to quantifying seabird‐vessel interactions

AbstractAccounting for uncertainty is essential for precautionary approaches to managing seabird bycatch in commercial fisheries. However, there is no existing mechanism to explicitly quantify the uncertainty of seabird‐vessel interactions (i.e. co‐occurrence in space and time). Here we develop a time geographic method to measure the probability of individual birds encountering (co‐occurring within 30 km) and attending (within 5 km) individual fishing vessels. The approach involves creating voxel‐based probabilistic space–time prisms (PSTPs) to model the movements of individual birds and vessels, with trajectory data from bird‐borne GPS devices and vessel Automatic Identification Systems (AIS). We intersected these PSTPs to quantify the probability of interaction between bird‐vessel pairs over time and space. We demonstrate the approach with a case study of interactions of Endangered Toroa (Antipodean Albatross; Diomedea antipodensis antipodensis) with pelagic longline vessels in part of the South Pacific high seas. We found 15 vessels within 150 km and 3 h of two birds, yet interaction occurred with only two of those vessels. We visualised the probability of encounter and attendance over time and space and determined that interactions lasted several hours each (up to 6.2–14.1 h attendance, 20.8–26.1 h encounter for one bird‐vessel pair). Our time geographic approach adds to existing tools to quantify seabird bycatch risk by providing an explicit measure of uncertainty of seabird‐vessel interactions. We provide a flexible methodological pathway and R scripts, the application of which would allow managers to estimate interaction probability for multiple marine species and fisheries, including those with lower‐resolution positional datasets.