Animal Populations Research Articles

A Look at Genomic Selection Techniques for Climate Change Adaptation and Production in Livestock

Livestock production profoundly intersects with global climate dynamics, contributing to greenhouse gas emissions and confronting vulnerability to climate impacts. In addressing these challenges, imperative adjustments are requisite to fortify the climate robustness of livestock systems. Notably, the prevalent reliance on commercial breeds with limited genetic diversity exposes production strategies to disruption, especially if these breeds are confined to environments that may lose economic viability under future climate scenarios. Consequently, understanding the adaptability of animal populations to forthcoming environmental conditions is paramount for sustaining livestock production. Assessing the genetic underpinnings of climate adaptation necessitates the exploration of tailored genomic selection techniques encompassing both production traits, presumed to have moderate heritability, and adaptation traits, presumed to have low heritability. Through a nuanced examination of genomic selection dynamics, insights into the genetic mechanisms fostering resilience in livestock populations amidst shifting environmental contexts are garnered. Employ genomic analysis to pinpoint genetic markers associated with traits like heat tolerance, disease resistance, and feed efficiency in livestock. Collaborate across disciplines to develop tailored breeding programs integrating these markers, and validate their effectiveness through rigorous field trials and ongoing monitoring to enhance livestock resilience and productivity in varied climatic conditions. Elucidating these mechanisms and their application in breeding programs offers a comprehensive understanding of how genetic advancements can enhance both production efficiency and climate resilience in livestock. This discourse aims to bridge the chasm between scientific inquiry and pragmatic implementation, thereby facilitating informed decision-making in livestock breeding strategies tailored to mitigate the ramifications of climate change.

SpAbundance: An R package for single‐species and multi‐species spatially explicit abundance models

Abstract Numerous modelling techniques exist to estimate abundance of plant and animal populations. The most accurate methods account for multiple complexities found in ecological data, such as observational biases, spatial autocorrelation, and species correlations. There is, however, a lack of user‐friendly and computationally efficient software to implement the various models, particularly for large data sets. We developed the spAbundance R package for fitting spatially explicit Bayesian single‐species and multi‐species hierarchical distance sampling models, N‐mixture models, and generalized linear mixed models. The models within the package can account for spatial autocorrelation using Nearest Neighbour Gaussian Processes and accommodate species correlations in multi‐species models using a latent factor approach, which enables model fitting for data sets with large numbers of sites and/or species. We provide three vignettes and three case studies that highlight spAbundance functionality. We used spatially explicit multi‐species distance sampling models to estimate density of 16 bird species in Florida, USA, an N‐mixture model to estimate black‐throated blue warbler (Setophaga caerulescens) abundance in New Hampshire, USA, and a spatial linear mixed model to estimate forest above‐ground biomass across the continental USA. spAbundance provides a user‐friendly, formula‐based interface to fit a variety of univariate and multivariate spatially explicit abundance models. The package serves as a useful tool for ecologists and conservation practitioners to generate improved inference and predictions on the spatial drivers of abundance in populations and communities.

Are there opportunities to strengthen animal welfare through improved management of feedlot chronic pens?

In feedlot cattle production systems, there is a population of sick cattle that fail to respond to treatment, are deemed chroni­cally ill, and typically placed in a “chronic pen”. This popula­tion of chronic cattle is understudied in the current literature, and the absence of evidence-based protocols and guidance re­sources may lead to specific cattle welfare risks associated with chronic pens. Anecdotally, management of this population of animals varies widely across feedlots with potential impacts on animal welfare and productivity. The purpose of this descrip­tive epidemiologic study was to identify and describe key demo­graphic patterns in chronic feedlot cattle populations.

Private Keeping of Dangerous Wild Animals in Great Britain

We analysed the licences issued by British local government authorities under the Dangerous Wild Animals Act 1976, which regulates the private keeping of wild animals categorised as “dangerous”, to assess the scope and scale of private keeping of dangerous wild animals in Great Britain. Results are compared with historical data from England and Wales, showing that there has been an overall decrease both in the total population of dangerous wild animals privately kept under licence and the number of licences, resulting primarily from a decrease in the farming of wild boar and ostrich, and from certain other species no longer requiring a licence to be kept. Nonetheless, the private keeping of dangerous wild animals remains prevalent, with a total population of 3950 animals kept under licence, and at least one-third of local authorities in Britain licensing keepers of one or more such animals. The population of non-farmed dangerous taxa has increased by 59% in 20 years, with notable increases in crocodilians (198%), venomous snakes (94%), and wild cats (57%). We present evidence that the average cost of a licence to keep dangerous wild animals has fallen over time, and that there is a negative association between cost and licensing. The current schedule of species categorised as dangerous is compared to a formally recognised list of species kept in zoos assessed by risk to the public. Problems with the legislation, enforcement of the licensing system, and animal welfare for privately kept dangerous wild animals are identified and discussed.

Synchronizing Drosophila larvae with the salivary gland reporter Sgs3-GFP for discovery of phenotypes in the late third instar stage.

The larval stage of the Drosophila melanogaster life cycle is characterized by rapid growth and nutrient storage that occur over three instar stages separated by molts. In the third instar, the steroid hormone ecdysone drives key developmental processes and behaviors that occur in a temporally-controlled sequence and prepare the animal to undergo metamorphosis. Accurately staging Drosophila larvae within the final third instar is critical due to the rapid developmental progress at this stage, but it is challenging because the rate of development varies widely across a population of animals even if eggs are laid within a short period of time. Moreover, many methods to stage third instar larvae are cumbersome, and inherent variability in the rate of development confounds some of these approaches. Here we demonstrate the usefulness of the Sgs3-GFP transgene, a fusion of the Salivary gland secretion 3 (Sgs3) and GFP proteins, for staging third instar larvae. Sgs3-GFP is expressed in the salivary glands in an ecdysone-dependent manner from the midpoint of the third instar, and its expression pattern changes reproducibly as larvae progress through the third instar. We show that Sgs3-GFP can easily be incorporated into experiments, that it allows collection of developmentally-equivalent individuals from a mixed population of larvae, and that its use enables precise assessment of changing levels of hormones, metabolites, and gene expression during the second half of the third instar.

225 Genomic diversity of Katahdin sheep and impacts on genomic prediction

Abstract In the late 1950s, Katahdin hair sheep were developed as a composite breed of medium size and moderate prolificacy, with potential to express resistance to gastrointestinal nematodes. With its increasing popularity and the recent adoption of genomic prediction in the Katahdin breeding program, evaluating the genetic diversity in this breed is necessary. Prediction accuracies rely on the strength of genetic relationships. That strength often increases with selection using genomically-enhanced estimated breeding values; however, it carries the risk of decreasing diversity. We aim to characterize the genetic diversity present in the breed and the subsequent impact on the accuracies of genomic predictions. Genotypes on Katahdin sheep from member flocks in the National Sheep Improvement Program were used. Data from two medium density 50k bead chips and one high density 600k bead chip were merged and limited to shared autosomal single nucleotide polymorphisms (SNP). After quality control, there were 9,705 animals and 31,984 SNP remaining. Only for analyses of inbreeding and heterozygosity, linkage disequilibrium (LD) pruning was performed; variants with an LD score exceeding 0.8 were removed with 29,904 SNP remaining. To determine the extent of population structure, principal component (PC) analysis was conducted with PC one and PC two explaining 4.9% and 3.8% of the variation in the population, respectively. When examining subpopulations, a single ancestral population explained 99.9% of the genetic variation among animals. When clustered by identity-by-state, all animals were placed in a single cluster. Inbreeding coefficients were estimated with four methods: method of moments, variance-standardized relationship minus one, excess homozygosity, and correlation between uniting gametes. Across methods, average inbreeding coefficients ranged from 1.14% to 1.20% with Pearson and Spearman correlations ranging from -0.51 to 0.91 (Table 1). Historical effective population sizes (Ne) were estimated for earlier generations, and a linear regression fit to predict more recent Ne. At the founding of the breed, historical Ne was estimated to be 310, and the current Ne was estimated to be 150. Effects of Ne on the accuracy of genomic predictions were examined for reference population sizes ranging from 1k to 25k for traits of low (0.1), moderate (0.3), and high (0.5) heritabilities. The corresponding number of effective chromosomal segments were 2NeL, where L was the length of the genome in morgans (26M). Accuracies of genomic predictions increased as the reference population size grew, with only marginal gains once the population exceeded 15k. Overall, there were no detectable genetic subpopulations in the Katahdin breed. Current levels of inbreeding were low. With a small Ne the breed can achieve high accuracy for genomic predictions by aiming for a reference population of 15k animals. Negative impacts on genetic diversity due to genomic selection are not of immediate concern.

226 Oral and rumen microbiome characterization to predict host phenotypes

Abstract Studies have utilized rumen microbiome composition and function to predict animal phenotypes. Yet, sample collection for rumen microbial community analysis can be difficult and invasive and hinders the possibility of sampling large animal populations. In this study, we investigated the development of the bovine rumen microbiome over time, to identify the potential of the oral microbiome as a proxy for the rumen microbiome, and to test the applicability of using the oral microbiome for predicting phenotypes in beef cattle. We employed 16S rRNA amplicon sequencing to characterize the rumen and oral bacterial community structure over time and collected both birth and weaning weights in a population of 220 animals. Our findings show that both the oral and rumen microbiomes are established early, and a significant portion of the taxa persists even after weaning. We identified a group of core successional species shared between the oral and rumen bacterial communities, which are established early and persist over time. The oral bacterial community was dominated by phyla Proteobacteria, Firmicutes, Bacteroidota, and Actinobacteria, while the rumen bacterial community was dominated by phyla Bacteroidota, Firmicutes, Verrucomicrobia, Fibrobacteria, and Spirochaetota. Furthermore, we observed that 38% of Amplicon Sequence Variants (ASVs) were shared between the oral and rumen microbiomes at 50 to 120 d of age. At 170 to 240 d of age, 37% of ASVs were shared, and at 295 to 365 d, 33% of ASVs were shared. Finally, at 400 to 468 d, 21% of ASVs were shared. Based on weighted Unifrac analysis, notable differences and distinct clustering was observed between oral and rumen microbiome communities at different sampling ages (P = 0.001; R2 = 0.50969, 50 to 120; P = 0.001; R2 = 0.66247, 170 to 240; P = 0.001; R2 = 0.62036, 295 to 365; and P = 0.001, R2 = 0.66559, 400 to 468). Microbiability estimates varied across different stages and microbial environments. For the oral bacterial community at 50 to 120, the estimates were 0.029%, 0.032%, 0.029%, and 0.028% for birth weight, weaning weight, intramuscular fat (IMF), and ribeye area (REA), respectively. In contrast, the rumen microbiome exhibited microbiability values of 0.034%, 0.058, 0.059, and 0.069% for birth weight, weaning weight, IMF, and REA respectively during the same period. As the animal aged the microbiability increased. At 170 to 240, oral microbiomes showed microbiability estimates of 0.051%, 0.060%, 0.069%, and 0.21% for birth weight, weaning weight, IMF, and REA respectively. In comparison, the rumen microbiome displayed greater microbiability estimates of 0.12%, 0.124%, 0.20%, and 0.26% for birth weight, weaning weight, IMF, and REA respectively. In conclusion, the oral microbiome is not a good proxy for the rumen microbiome composition; however, there is potential to use the oral microbiome for phenotype prediction.

Microbial dynamics and climatic interactions in pig sheds: Insights into airborne microbes and particulate matter concentrations.

Emissions of airborne pollutants from livestock buildings affect indoor air quality, the health and well-being of farmers, animals and the environment. This study aimed to evaluate the microbial count within pig sheds and its relationship with meteorological variables (temperature, relative humidity and air velocity) and particulate matter (PM10 and PM2.5) and microbial diversity. Sampling was conducted both inside and outside of two pig sheds over three seasons (summer, rainy and winter), with regular monitoring at fortnightly intervals. Results showed that the bacterial and fungal counts ranged from 0.07 to 3.98 x 103 cfu/m3 inside the sheds and 0.01 to 1.82 x 103 cfu/m3 outside. Seasonal variations were observed, with higher concentrations of particulate matter detected during the winter season, followed by summer. Climatic variables such as temperature, air velocity and relative humidity demonstrated significant impacts on the abundance of Enterobacteriaceae and fungi, while air velocity specifically influenced the presence of mesophilic bacteria and staphylococci. Importantly, no significant disparities were found between microbial counts and particulate matter levels. Staphylococcaceae emerged as the predominant bacterial family, while Aspergillus and Cladosporium spp. were the dominant fungal species within the pig sheds. The average levels of airborne bacteria and fungi in pig sheds were found to be within the recommended range, which can be attributed to the loose housing design and lower animal population on the farms.

Evolution of Cooperation in Spatio-Temporal Evolutionary Games with Public Goods Feedback.

In biology, evolutionary game-theoretical models often arise in which players' strategies impact the state of the environment, driving feedback between strategy and the surroundings. In this case, cooperative interactions can be applied to studying ecological systems, animal or microorganism populations, and cells producing or actively extracting a growth resource from their environment. We consider the framework of eco-evolutionary game theory with replicator dynamics and growth-limiting public goods extracted by population members from some external source. It is known that the two sub-populations of cooperators and defectors can develop spatio-temporal patterns that enable long-term coexistence in the shared environment. To investigate this phenomenon and unveil the mechanisms that sustain cooperation, we analyze two eco-evolutionary models: a well-mixed environment and a heterogeneous model with spatial diffusion. In the latter, we integrate spatial diffusion into replicator dynamics. Our findings reveal rich strategy dynamics, including bistability and bifurcations, in the temporal system and spatial stability, as well as Turing instability, Turing-Hopf bifurcations, and chaos in the diffusion system. The results indicate that effective mechanisms to promote cooperation include increasing the player density, decreasing the relative timescale, controlling the density of initial cooperators, improving the diffusion rate of the public goods, lowering the diffusion rate of the cooperators, and enhancing the payoffs to the cooperators. We provide the conditions for the existence, stability, and occurrence of bifurcations in both systems. Our analysis can be applied to dynamic phenomena in fields as diverse as human decision-making, microorganism growth factors secretion, and group hunting.

Male elephant management in AZA institutions: Current status and priorities for the future.

Asian elephant (Elephas maximus) and African savanna elephant (Loxodonta africana) populations collectively managed by ex-situ facilities accredited by the Association of Zoos and Aquariums (AZA)face sustainability challenges. Among the priorities to strengthen animal wellbeing and population sustainability is male elephant management. We conducted a survey of AZA facilities currently housing male elephants to assess the status, challenges, and priorities in three areas of male elephant management: musth, socialization, and semen collection. Surveys were administered to elephant care teams at AZA-accredited institutions between November 2022 and February 2023, and we received responses from 34 institutions (91.9% of AZA-accredited facilities holding adult male elephants), housing 32 adult male Asians and 26 adult male Africans. Most facilities prioritized breeding and male socialization over musth management and semen collection (although most facilities acknowledged that all these efforts are important), citing leadership support and staffing as most important to achieve male management goals. Behaviors most commonly accompanying musth included reduced appetite, difficulty training or shifting, human-directed aggression, and interest in females. Musth timing was variable between males and facilities. Most males were well-socialized with females and/or other males, though elephant compatibility and facility design were limiting factors in managing socialization. Although 60.6% of facilities collected semen or were training for semen collection, very few male elephants could reliably provide viable semen samples, challenging assisted reproductive efforts that could bolster population sustainability in both species. Together, our results provide a better understanding of the state of male elephant management, offering specific areas deserving of research and development to enhance wellbeing and sustainability.

Evidence of SARS-CoV-2 Antibody in Mississippi White-Tailed Deer.

Background: Early detection and monitoring of SARS-CoV-2 infections in animal populations living in close proximity to humans is crucial for preventing reverse zoonosis of new viral strains. Evidence accumulated has revealed widespread SARS-CoV-2 infection among white-tailed deer (WTD), (Odocoileus virginianus) populations in the United States except in the southeast region. Therefore, the objective was to conduct surveillance for evidence of SARS-CoV-2 infection among WTD in Mississippi. Materials and Methods: Blood, kidney tissues, and nasal swab samples were collected in 17 counties from hunter-harvested deer during 2021-2022 and 2022-2023.Samples of kidney tissue were collected to evaluate for detecting antibody as a possible alternative to blood that is not always available from dead WTD. Nasal swab samples were tested for SARS-CoV-2 viral RNA by a RT-PCR assay. Sera and kidney tissue samples were tested for SARS-CoV-2 antibody by an enzyme-linked immunoassay (ELISA) and sera by a plaque reduction neutralization test (PRNT80). Results: The results of testing sera and kidney homogenate samples provided the first evidence of SARS-CoV-2 infection among WTD in Mississippi. The infection rate during 2021-2022 was 67% (10/15) based on the detection of neutralizing antibody by the PRNT80 and 26%(16/62) based on the testing of kidney tissue homogenates by an ELISA, and viral RNA was detected in 25% (3/12) of nasal swab samples. In 2022 to 2023, neutralizing antibody was detected in 62% (28/45) of WTD serum samples. In contrast, antibodies were not detected in 220 kidney homogenates by an ELISA nor was viral RNA detected in 220 nasal swab samples. Evidence of WTD activity was common in urban areas during the survey. Conclusion: Overall, the findings documented the first SARS-CoV-2 infection among WTD in Mississippi and showed that WTD commonly inhabited urban areas as a possible source of acquiring infection from humans infected with this virus.

Dispersal and connectivity in increasingly extreme climatic conditions.

While climate change has been shown to impact several life-history traits of wild-living animal populations, little is known about its effects on dispersal and connectivity. Here, we capitalize on the highly variable flooding regime of the Okavango Delta to investigate the impacts of changing environmental conditions on the dispersal and connectivity of the endangered African wild dog (Lycaon pictus). Based on remote sensed flood extents observed over 20 years, we derive two extreme flood scenarios: a minimum and a maximum flood extent, representative of very dry and very wet environmental periods. These conditions are akin to those anticipated under increased climatic variability, as it is expected under climate change. Using a movement model parameterized with GPS data from dispersing individuals, we simulate 12,000 individual dispersal trajectories across the ecosystem under both scenarios and investigate patterns of connectivity. Across the entire ecosystem, surface water coverage during maximum flood extent reduces dispersal success (i.e., the propensity of individuals to disperse between adjacent subpopulations) by 12% and increases dispersal durations by 17%. Locally, however, dispersal success diminishes by as much as 78%. Depending on the flood extent, alternative dispersal corridors emerge, some of which in the immediate vicinity of human-dominated landscapes. Notably, under maximum flood extent, the number of dispersing trajectories moving into human-dominated landscapes decreases by 41% at the Okavango Delta's inflow, but increases by 126% at the Delta's distal end. This may drive the amplification of human-wildlife conflict. While predicting the impacts of climate change on environmental conditions on the ground remains challenging, our results highlight that environmental change may have significant consequences for dispersal patterns and connectivity, and ultimately, population viability. Acknowledging and anticipating such impacts will be key to effective conservation strategies and to preserve vital dispersal corridors in light of climate change and other human-related landscape alterations.

Quantifying cost of disease in livestock: a new metric for the Global Burden of Animal Diseases

Increasing awareness of the environmental and public health impacts of expanding and intensifying animal-based food and farming systems creates discord, with the reliance of much of the world's population on animals for livelihoods and essential nutrition. Increasing the efficiency of food production through improved animal health has been identified as a step towards minimising these negative effects without compromising global food security. The Global Burden of Animal Diseases (GBADs) programme aims to provide data and analytical methods to support positive change in animal health across all livestock and aquaculture animal populations. In this study, we present a metric that begins the process of disease burden estimation by converting the physical consequences of disease on animal performance to farm-level costs of disease, and calculates a metric termed the Animal Health Loss Envelope (AHLE) via comparison between the status quo and a disease-free ideal. An example calculation of the AHLE metric for meat production from broiler chickens is provided. The AHLE presents the direct financial costs of disease at farm-level for all causes by estimating losses and expenditure in a given farming system. The general specification of the model measures productivity change at farm-level and provides an upper bound on productivity change in the absence of disease. On its own, it gives an indication of the scale of total disease cost at farm-level. The AHLE is an essential stepping stone within the GBADs programme because it connects the physical performance of animals in farming systems under different environmental and management conditions and different health states to farm economics. Moving forward, AHLE results will be an important step in calculating the wider monetary consequences of changes in animal health as part of the GBADs programme. Bill & Melinda Gates Foundation, the UK Foreign, Commonwealth and Development Office, EU Horizon 2020 Research and Innovation Programme.

Social restructuring during harsh environmental conditions promotes cooperative behaviour in a songbird.

Cooperation may emerge from intrinsic factors such as social structure and extrinsic factors such as environmental conditions. Although these factors might reinforce or counteract each other, their interaction remains unexplored in animal populations. Studies on multilevel societies suggest a link between social structure, environmental conditions and individual investment in cooperative behaviours. These societies exhibit flexible social configurations, with stable groups that overlap and associate hierarchically. Structure can be seasonal, with upper-level units appearing only during specific seasons, and lower-level units persisting year-round. This offers an opportunity to investigate how cooperation relates to social structure and environmental conditions. Here, we study the seasonal multilevel society of superb fairy-wrens (Malurus cyaneus), observing individual responses to experimental playback of conspecific distress calls. Individuals engaged more in helping behaviour and less in aggressive/territorial song during the harsher non-breeding season compared to the breeding season. The increase in cooperation was greater for breeding group members than for members of the same community, the upper social unit, comprised of distinct breeding groups in association. Results suggest that the interaction between social structure and environmental conditions drives the seasonal switch in cooperation, supporting the hypothesis that multilevel societies can emerge to increase cooperation during harsh environmental conditions.

Widespread Circulation of Tick-Borne Viruses in Virginia—Evidence of Exposure to Heartland, Bourbon, and Powassan Viruses in Wildlife and Livestock

Emerging tick-borne viruses such as Powassan virus (POWV), Bourbon virus (BRBV), and Heartland virus (HRTV), whilst rare, can cause severe health problems in humans. While limited clinical cases have been reported thus far in Virginia, the presence of tick-borne viruses poses a serious health threat, and the extent of their prevalence in Virginia is unknown. Here, we sought evidence of POWV, BRBV, and HRTV exposure in Virginia via a serological assessment of wildlife and livestock. Wildlife in Virginia were found to be seropositive against POWV (18%), BRBV (8%), and HRTV (5%), with western and northern regions of the state having a higher prevalence. Multiple wildlife species were shown to have been exposed to each virus examined. To a lesser extent, cattle also showed exposure to tick-borne viruses, with seroprevalences of 1%, 1.2%, and 8% detected in cattle against POWV, BRBV, and HRTV, respectively. Cross-reactivity against other known circulating mosquito-borne flaviviruses was ruled out. In conclusion, there is widespread exposure to tick-borne viruses in western and northern Virginia, with exposure to a diverse range of both domestic and wild animal populations. Our study provides the first confirmation that HRTV is circulating in the Commonwealth. These findings strengthen the existing evidence of emerging tick-borne viruses in Virginia and highlight the need for public health vigilance to avoid tick bites.

Snow avalanches are a primary climate-linked driver of mountain ungulate populations

Snow is a major, climate-sensitive feature of the Earth’s surface and catalyst of fundamentally important ecosystem processes. Understanding how snow influences sentinel species in rapidly changing mountain ecosystems is particularly critical. Whereas effects of snow on food availability, energy expenditure, and predation are well documented, we report how avalanches exert major impacts on an ecologically significant mountain ungulate - the coastal Alaskan mountain goat (Oreamnos americanus). Using long-term GPS data and field observations across four populations (421 individuals over 17 years), we show that avalanches caused 23−65% of all mortality, depending on area. Deaths varied seasonally and were directly linked to spatial movement patterns and avalanche terrain use. Population-level avalanche mortality, 61% of which comprised reproductively important prime-aged individuals, averaged 8% annually and exceeded 22% when avalanche conditions were severe. Our findings reveal a widespread but previously undescribed pathway by which snow can elicit major population-level impacts and shape demographic characteristics of slow-growing populations of mountain-adapted animals.

Instances of Biowarfare in World War I (1914-1918).

During World War I (WWI), also referred to as 'The Great War,' Germany implemented a pioneering biowarfare program as part of a broader military strategy to undermine Allied forces by targeting their logistical and supply capabilities. This initiative, unprecedented in its systematic and strategic application, utilized a variety of pathogens, primarily targeting animal populations, to disrupt support systems without contravening international laws, specifically the 1907 Hague Convention. The operations, shrouded in secrecy and largely led by the German General Staff, included sophisticated sabotage actions against both enemy and neutral states. The allegations and usage of bioweapons increased the interest of the Great Powers in further developing their own biowarfare program.

An agent architecture for expressive spatial knowledge and reasoning in land use modeling and simulations

This paper presents a new cognitive agent design approach integrating spatial knowledge representation and reasoning in agent-based modeling dedicated to land use simulations. A deep motivation for our agent-centric contribution is the ever-increasing development of spatially explicit agent simulation platforms. We build on this technological evolution and topology theory to endow the agent with human’s spatial representation and reasoning following a Belief–Desire–Intention architecture. A pilot implementation of the methodology with simulation experiments on a hunting model was carried out in GAMA platform to assess agent performances. Simulations display a consistent trend of animal population dynamics and also confirm a high model sensitivity to the integration of spatial knowledge and reasoning in agent-based models of human actor. These results demonstrate a successful implementation and the importance of spatial dimension in the expressive power and the validity of agent-based models. Future research efforts should therefore emphasize on designing human knowledge representation and incorporating learning abilities to improve models efficiency.

Coxiella burnetii and Reproductive Disorders in Cattle: A Systematic Review.

Coxiellosis or Q fever is an infectious zoonotic disease caused by the bacterium Coxiella burnetii. A systematic review using bibliographic research was carried out, and the focus was the relationship between C. burnetii infection and reproductive disorders in cattle [abortion/stillbirth/perinatal morality/weak calves (ASPW complex); retained foetal membranes (RFMs); metritis/endometritis; and infertility/sub-fertility]. The bibliographical search yielded 443 results from databases, but only 61 were deemed eligible. For each disorder, summary tables were prepared, and a scientific evidence score was calculated for each study based on four criteria to help assess the level of evidence for the impact of C. burnetii on the reproductive disorders assessed: type of publication (peer-reviewed or other); type of study (case-control/cohort or other); type of C. burnetii test (direct or indirect); and comparative statistical analysis (yes or no). In addition, summary tables also included information on the study population, country, authors and year of publication, key findings and an assessment of the evidence for an association. For the ASPW complex, RFMs, metritis/endometritis and infertility/sub-fertility, 43, 9, 8 and 19 studies provided data, respectively. On a scale of four, nearly 50% of all study citations had evidence scores of three or four. For ASPW, RFMs and infertility/sub-fertility, there is a significant body of evidence to support a deleterious role for Q fever. In contrast, for metritis/endometritis, the evidence is unclear. It is concluded that there is a substantial need for further research, particularly involving larger animal populations in more controlled settings. To provide more consistency, it is recommended that authors follow more precise definitions of reproductive parameters and more robust diagnostic methodologies.

The population trend of the largest breeding colony of the Indian Swiftlet Aerodramus unicolor: is it on the verge of extinction?

Fluctuations in animal populations are indicators of environmental change. Populations of the Indian Swiftlet Aerodramus unicolor on the Burnt and Old Lighthouse islands of Vengurla rocks, Sindhudurg district, Maharashtra were assessed using the logistic growth model. The study used secondary literature and primary surveys to estimate breeding population sizes on both islands. To understand population dynamics, we calculated the carrying capacity (K) using the Verhulst population growth model, and the percent rate of change in populations. Swiftlet populations on both islands are considered to be the maximum size their habitat can sustain, not exceeding 5,000 and 246 birds on Burnt and Old Lighthouse islands, respectively. These populations were observed to fluctuate between 2020 and 2023, with change rates of 5.5% on Burnt Island, and -53% on Old Lighthouse Island. The logistic growth model indicates that these Indian Swiftlet populations are fluctuating near the carrying capacities of their habitats, which could gradually lead to extinction. This highlights the urgent need for conservation and regular monitoring of these populations in Vengurla rocks.