In Cambodia, farmers construct artificial household bat roosts to collect and sell guano as fertilizer. We investigated farming practices and attendant spillover risks using: 1) surveys on guano production; 2) estimating bat population size and species present using carcasses, visual identification, and audio recordings; 3) surveying guano-producing and neighbor households on water, sanitation, and hygiene practices; and 4) testing guano and household food, water and surfaces for coronaviruses by PCR. Bat roosts are constructed using dried palm leaves with coconut tree and/or steel/concrete supports. Roosting areas ranged from 42-327 m2, bat abundance varied from 0-11,187, guano production was 5-120 kg/week, guano yields were 0.15-0.4 kg/m2/week, and farmers earned ~100-200 USD/household/month. Higher guano production in peak (normally wet) season was associated with greater bat abundance (p=0.016). The lesser Asiatic yellow house bat (Scotophilus kuhlii) was the only bat species identified. Roosts were <20 m from guano-producing households. Neighbors and households’ hygiene risks included not having handwashing stations and not covering food in storage/while drying. Alphacoronaviruses or Infectious Bronchitis Virus were found in 14.6%, 17.3%, 2.9%, 1.4%, and 0.0% of guano, urine, surface, food, and water samples, respectively. While guano farming offers economic benefits, spillover risks exist. Safe guano collection and storage, handwashing, and food covering in guano-producing communities are necessary to mitigate spillover risks.
In Cambodia, farmers construct artificial household bat roosts to collect and sell guano as fertilizer. We investigated farming practices and attendant spillover risks using (1) surveys on guano production; (2) an estimation of bat population size and species present using carcasses, visual identification, and audio recordings; (3) surveys of guano-producing and neighboring households on water, sanitation, and hygiene practices; and (4) the testing of guano and household food, water, and surfaces for coronaviruses using RT-qPCR. Bat roosts are constructed using dried palm leaves with coconut tree and/or steel/concrete supports. Roosting areas ranged from 42 to 327 m2, bat abundance varied from 0 to 11,187, guano production was between 5 and 120 kg/week, guano yields were from 0.15 to 0.4 kg/m2/week, and farmers earned USD ~100-200/household/month. Higher guano production in the peak (normally wet) season was associated with greater bat abundance (p = 0.016). The lesser Asiatic yellow house bat (Scotophilus kuhlii) was the only bat species identified. Roosts were <20 m from guano-producing households. Neighbors and households' hygiene risks included not having handwashing stations and not covering food in storage/while drying. Coronaviruses (Alphacoronaviruses or Infectious Bronchitis Virus) were detected in 14.6%, 17.3%, 2.9%, 1.4%, and 0.0% of guano, urine, household surface, food, and water samples, respectively. While guano farming offers economic benefits, spillover risks exist. Safe guano collection and storage, handwashing, and food covering in guano-producing communities are necessary to mitigate spillover risks.
Objectives To generate and employ scenarios of sentinel human and animal outbreak cases in local contexts that integrate human and animal health interests and practices and facilitate outbreak risk management readiness. Methods We conducted a scoping review of past outbreaks and the strengths and weaknesses of response efforts in USAID STOP Spillover program countries. This information and iterative query-and-response with country teams and local stakeholders led to curated outbreak scenarios emphasizing One Health human:animal interfaces at sub-national levels. Results Two core scenarios were generated adapted to each of 4 countries’ pathogen priorities and workflows in Africa and Asia, anchoring on sub-national outbreak response triggered by either an animal or human health event. Country teams subsequently used these scenarios in a variety of local preparedness discussions and simulations. The process of creating outbreak scenarios encourages discussion and review of current country practices and procedures. Guideline documents and lessons learned do not necessarily reflect how workflows occur in outbreak response in countries at highest risk for spillover events. Conclusions Discussion-based engagement across One Health stakeholders can improve sub-national coordination, clarify guidelines and responsibilities, and provide a space for interagency cooperation through use of scenarios in tabletop and other exercises.
Background/Objectives: The USAID STOP Spillover project in Cambodia aimed to reduce the risk of zoonotic virus spillover from bats to humans in bat guano farming communities. Methods: Using participatory tools, such as Outcome Mapping and Trials of Improved Practices, a team of local experts and community members collaboratively designed, tested, and refined biosafety and hygiene practices that are acceptable and sustainable to mitigate the risk of bat-borne disease spillover. We tracked progress and rolled out interventions to promote the adoption of safe behaviors that strengthen the understanding of zoonotic disease and reinforce the adoption of safety practices among bat guano producers and their neighbors. The intervention’s effectiveness was evaluated after three-month trials. Results: An improvement in knowledge, attitudes, and risk reduction practices was observed among participants. The primary motivators for adopting these measures were fear of disease, families’ well-being, cost savings, and experience of the COVID-19 pandemic. Conclusions: The community-driven approach fostered a sense of ownership, enabling participants to find the best solutions for their circumstance for long-term sustainability of the intervention. The findings recommended continued community engagement, improved access to biosafety and hygiene resources, and reinforced routine zoonotic disease surveillance. This model can be applied to mitigate emerging infectious disease spillover risks in similar contexts.
AIMS:Q fever is a globally distributed, neglected zoonotic disease of conservation and public health importance, caused by the bacterium Coxiella burnetii. Coxiella burnetii normally causes subclinical infections in livestock, but may also cause reproductive pathology and spontaneous abortions in artiodactyl species. One such artiodactyl, the dromedary camel (Camelus dromedarius), is an increasingly important livestock species in semi-arid landscapes. Ticks are naturally infected with C. burnetii worldwide and are frequently found on camels in Kenya. In this study, we assessed the relationship between dromedary camels' C. burnetii serostatus and whether the camels were carrying C. burnetii PCR-positive ticks in Kenya. We hypothesized that there would be a positive association between camel seropositivity and carrying C. burnetii PCR-positive ticks. METHODS AND RESULTS:Blood was collected from camels (N = 233) from three herds, and serum was analysed using commercial ELISA antibody test kits. Ticks were collected (N = 4354), divided into pools of the same species from the same camel (N = 397) and tested for C. burnetii and Coxiella-like endosymbionts. Descriptive statistics were used to summarize seroprevalence by camel demographic and clinical variables. Univariate logistic regression analyses were used to assess relationships between serostatus (outcome) and tick PCR status, camel demographic variables, and camel clinical variables (predictors). Camel C. burnetii seroprevalence was 52%. Across tick pools, the prevalence of C. burnetii was 15% and Coxiella-like endosymbionts was 27%. Camel seropositivity was significantly associated with the presence of a C. burnetii PCR-positive tick pool (OR: 2.58; 95% CI: 1.4-5.1; p = 0.0045), increasing age class, and increasing total solids. CONCLUSIONS:The role of ticks and camels in the epidemiology of Q fever warrants further research to better understand this zoonotic disease that has potential to cause illness and reproductive losses in humans, livestock, and wildlife.
Background: The geographic expansion and evolution of A/Goose/Guangdong/1/1996(H5N1) (Gs/GD) lineage H5Nx highly pathogenic avian influenza (HPAI) viruses since 1996 have raised awareness of enzootic circulation among migratory birds and the potential for intercontinental transport and spread. Recent Pacific- and Atlantic-route introductions of HPAI to North America were facilitated by avian migration through subarctic zones, specifically Alaska and Iceland. This study aimed to identify recent historical patterns of exposure to HPAI viruses among birds within and migrating through both regions and evaluate how geographic, demographic, and taxonomic differences contribute to exposure risk at two intercontinental staging locations. Methods: During 2010-2019, blood samples were obtained from captured wild migratory seabirds and waterfowl in Alaska and Iceland. All live birds were released following completion of sampling. Sampling date, species, sampling location, and age class was documented for each bird, and sex was documented when possible. Lentiviral pseudoviruses that express the influenza hemagglutinin surface glycoprotein for H5Nx HPAI and H5 low-pathogenicity avian influenza (LPAI) were constructed for use in serological assays to screen for and quantify titers of antibodies against the latter viruses. Data were analyzed to compare (a) categorical baseline ecological traits between Iceland and Alaska, and (b) ecological traits between birds identified to be seropositive and suggestive/seronegative/fully cross-reactive birds to H5Nx HPAI in Iceland and Alaska. Factors associated with seroreactivity to H5Nx HPAI and H5 LPAI were assessed. Results:The seroprevalence of HPAI among birds in both locations was 7.3% (112/1526). Findings reveal variability in seroprevalence by year, higher rates of exposure to H5 LPAI than H5Nx HPAI overall, and significantly more seropositive and suggestive exposure of birds to H5Nx HPAI in Alaska as compared to Iceland. Geographic, demographic, and taxonomic differences contribute to exposure risk between Alaska and Iceland. Most tested birds were immuno-naïve to HPAI in both locations, which indicates many migratory birds in the subarctic are susceptible to HPAI infection, demonstrating substantial risk for intercontinental transmission between Asia, Europe, and North America. Conclusions: Our findings provide further justification for increased viral and serosurveillance in Alaska and Iceland to monitor subarctic movements of migratory birds and intercontinental transmission dynamics of currently circulating and new strains of HPAI globally.
H5Nx highly pathogenic avian influenza (HPAI) viruses of clade 2.3.4.4 have caused outbreaks in Europe among wild and domestic birds since 2016 and were introduced to North America via wild migratory birds in December 2021. We examined the spatiotemporal extent of HPAI viruses across continents and characterized ecological and environmental predictors of virus spread between geographic regions by constructing a Bayesian phylodynamic generalized linear model (phylodynamic-GLM). The findings demonstrate localized epidemics of H5Nx throughout Europe in the first several years of the epizootic, followed by a singular branching point where H5N1 viruses were introduced to North America, likely via stopover locations throughout the North Atlantic. Once in the United States (US), H5Nx viruses spread at a greater rate between US-based regions as compared to prior spread in Europe. We established that geographic proximity is a predictor of virus spread between regions, implying that intercontinental transport across the Atlantic Ocean is relatively rare. An increase in mean ambient temperature over time was predictive of reduced H5Nx virus spread, which may reflect the effect of climate change on declines in host species abundance, decreased persistence of the virus in the environment, or changes in migratory patterns due to ecological alterations. Our data provide new knowledge about the spread and directionality of H5Nx virus dispersal in Europe and the US during an actively evolving intercontinental outbreak, including predictors of virus movement between regions, which will contribute to surveillance and mitigation strategies as the outbreak unfolds, and in future instances of uncontained avian spread of HPAI viruses.
This study was designed to identify abnormalities in the electroencephalograms (EEGs) recorded from stranded California sea lions (Zalophus californianus) with suspected domoic acid (DA) toxicosis. Recordings from animals presenting for non-neurological issues were also obtained to better understand the normal EEG (background activity and transient events) in this species, as, to date, studies have focused on examining natural sleep in pinnipeds. Most animals were sedated for electrode placement and EEG acquisition with some receiving antiepileptic medications or isoflurane during the procedure. A total of 103 recordings were read and scored from 0 (normal) to 3 (severely abnormal). Epileptiform discharges, consisting of spikes, sharp waves, slow waves, and/or spike waves, were present in all EEGs with scores of 1, 2, or 3. The distribution of these events over the scalp varied. While often generalized, others were lateralized over one hemisphere, bifrontal, bioccipital, and/or bitemporal, while some discharges were multifocal. Findings were different between sea lions and occasionally changed within the EEG on a given sea lion. No clinical seizures were observed during the recording but a few sea lions had findings consistent with electroencephalographic seizures. When available, supporting diagnostic results obtained from magnetic resonance imaging (MRI) and/or necropsy/histopathology were described, as well as the status of those sea lions that recovered and were released with satellite tags.
OBJECTIVE To determine (1) if chemokine (C-X-C motif) ligand 1 (CXCL1), matrix metalloproteinase 8 (MMP8), interleukin-10 (IL-10), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) can be detected in serum from Asian elephants, and (2) if their concentrations are significantly elevated in Mycobacterium tuberculosis (M.tb) culture-positive elephants compared to -negative elephants. CXCL1, MMP8, IL-10, IFN-γ, and TNF-α were recently identified as potential diagnostic biomarkers for pulmonary tuberculosis in experimental studies in animals and humans. Therefore, we hypothesized that they would be detectable and significantly elevated in M.tb culture-positive elephants compared to M.tb culture-negative elephants. SAMPLE 101 Asian elephant serum samples, including 91 samples from 6 M.tb-negative elephants and 10 samples from 5 M.tb-positive elephants (none of which exhibited clinical signs of disease). M.tb status was determined by trunk wash culture. PROCEDURES Commercially available ELISA kits were used to determine the concentrations of each biomarker in serum samples. RESULTS Biomarker concentrations were below the limit of detection for the assay in 100/101 (99%) samples for CXCL1, 98/101 (97%) samples for MMP8, 85/101 (84%) samples for IL-10, 75/101 (74%) samples for IFN-γ, and 45/101 (45%) samples for TNF-α. Multiple M.tb culture-positive elephants did not have detectable levels of any of the 5 biomarkers. CLINICAL RELEVANCE CXCL1, MMP8, IL-10, IFN-γ, and TNF-α were not elevated in M.tb culture-positive Asian elephants compared to M.tb culture-negative Asian elephants. This may be related to disease state (ie, clinically asymptomatic). More sensitive assays are needed to better understand the role of these biomarkers in M.tb infection in Asian elephants.
Arctic regions are ecologically significant for the environmental persistence and geographic dissemination of influenza A viruses (IAVs) by avian hosts and other wildlife species. Data describing the epidemiology and ecology of IAVs among wildlife in the arctic are less frequently published compared to southern temperate regions, where prevalence and subtype diversity are more routinely documented. Following PRISMA guidelines, this systematic review addresses this gap by describing the prevalence, spatiotemporal distribution, and ecological characteristics of IAVs detected among wildlife and the environment in this understudied region of the globe. The literature search was performed in PubMed and Google Scholar using a set of pre-defined search terms to identify publications reporting on IAVs in Arctic regions between 1978 and February 2022. A total of 2125 articles were initially screened, 267 were assessed for eligibility, and 71 articles met inclusion criteria. IAVs have been detected in multiple wildlife species in all Arctic regions, including seabirds, shorebirds, waterfowl, seals, sea lions, whales, and terrestrial mammals, and in the environment. Isolates from wild birds comprise the majority of documented viruses derived from wildlife; however, among all animals and environmental matrices, 26 unique low and highly pathogenic subtypes have been characterized in the scientific literature from Arctic regions. Pooled prevalence across studies indicates 4.23% for wild birds, 3.42% among tested environmental matrices, and seroprevalences of 9.29% and 1.69% among marine and terrestrial mammals, respectively. Surveillance data are geographically biased, with most data from the Alaskan Arctic and many fewer reports from the Russian, Canadian, North Atlantic, and Western European Arctic. We highlight multiple important aspects of wildlife host, pathogen, and environmental ecology of IAVs in Arctic regions, including the role of avian migration and breeding cycles for the global spread of IAVs, evidence of inter-species and inter-continental reassortment at high latitudes, and how climate change-driven ecosystem shifts, including changes in the seasonal availability and distribution of dietary resources, have the potential to alter host–pathogen–environment dynamics in Arctic regions. We conclude by identifying gaps in knowledge and propose priorities for future research.
Influenza A viruses (IAV) circulate endemically among many wild aquatic bird populations that seasonally migrate between wintering grounds in southern latitudes to breeding ranges along the perimeter of the circumpolar arctic. Arctic and subarctic zones are hypothesized to serve as ecologic drivers of the intercontinental movement and reassortment of IAVs due to high densities of disparate populations of long distance migratory and native bird species present during breeding seasons. Iceland is a staging ground that connects the East Atlantic and North Atlantic American flyways, providing a unique study system for characterizing viral flow between eastern and western hemispheres. Using Bayesian phylodynamic analyses, we sought to evaluate the viral connectivity of Iceland to proximal regions and how inter-species transmission and reassortment dynamics in this region influence the geographic spread of low and highly pathogenic IAVs. Findings demonstrate that IAV movement in the arctic and subarctic reflects wild bird migration around the perimeter of the circumpolar north, favouring short-distance flights between proximal regions rather than long distance flights over the polar interior. Iceland connects virus movement between mainland Europe and North America, consistent with the westward migration of wild birds from mainland Europe to Northeastern Canada and Greenland. Though virus diffusion rates were similar among avian taxonomic groups in Iceland, gulls play an outsized role as sinks of IAVs from other avian hosts prior to onward migration. These data identify patterns of virus movement in northern latitudes and inform future surveillance strategies related to seasonal and emergent IAVs with potential public health concern.
In light of the urgency raised by the COVID-19 pandemic, global investment in wildlife virology is likely to increase, and new surveillance programs will identify hundreds of novel viruses that might someday pose a threat to humans. Our capacity to identify which viruses are capable of zoonotic emergence depends on the existence of a technology—a machine learning model or other informatic system—that leverages available data on known zoonoses to identify which animal pathogens could someday pose a threat to global health. We synthesize the findings of an interdisciplinary workshop on zoonotic risk technologies to answer the following questions: What are the prerequisites, in terms of open data, equity, and interdisciplinary collaboration, to the development and application of those tools? What effect could the technology have on global health? Who would control that technology, who would have access to it, and who would benefit from it? Would it improve pandemic prevention? Could it create new challenges?
Infectious zoonotic diseases are a threat to wildlife conservation and global health. They are especially a concern for wild apes, which are vulnerable to many human infectious diseases. As ecotourism, deforestation, and great ape field research increase, the threat of human-sourced infections to wild populations becomes more substantial and could result in devastating population declines. The endangered mountain gorillas (Gorilla beringei beringei) of the Virunga Massif in east-central Africa suffer periodic disease outbreaks and are exposed to infections from human-sourced pathogens. It is important to understand the possible risks of disease introduction and spread in this population and how human contact may facilitate disease transmission. Here we present and evaluate an individual-based, stochastic, discrete-time disease transmission model to predict epidemic outcomes and better understand health risks to the Virunga mountain gorilla population. To model disease transmission we have derived estimates for gorilla contact, interaction, and migration rates. The model shows that the social structure of gorilla populations plays a profound role in governing disease impacts with subdivided populations experiencing less than 25% of the outbreak levels of a single homogeneous population. It predicts that gorilla group dispersal and limited group interactions are strong factors in preventing widespread population-level outbreaks of infectious disease after such diseases have been introduced into the population. However, even a moderate amount of human contact increases disease spread and can lead to population-level outbreaks.
Orangutans are noteworthy among great apes in their predilection for chronic, insidious, and ultimately fatal respiratory disease. Termed Orangutan Respiratory Disease Syndrome (ORDS), this cystic fibrosis-like disease is characterized by comorbid conditions of sinusitis, mastoiditis, airsacculitis, bronchiectasis, and recurrent pneumonia. The aim of this retrospective study was to determine the sensitivity of clinical signs in the diagnosis of ORDS in Bornean orangutans (Pongo pygmaeus) compared with the gold standard for diagnosis via computed tomography (CT). We retrospectively compared observed clinical signs with CT imaging in a population of clinically affected animals at an orangutan rescue center in southeastern Borneo. From August 2017 to 2019, this center housed 21 ORDS-affected animals, all of which underwent CT imaging to delineate which areas of the respiratory tract were affected. We reviewed clinical signs recorded in medical records and keeper observation notes for each individual for the period of 2 years prior to the date of the CT scan. A chi-square test of association was used to assess whether the observed clinical signs could predict the results of CT imaging. Results show that clinical signs may not be sensitive indicators in predicting respiratory disease identified by CT imaging. Based on the results of this study, clinical signs appear to be very poor predictors of underlying respiratory pathology in orangutans, based on high P-values, low sensitivity, and low specificity. This result is observed even with clinical signs data gathered over a full 24-mo period prior to CT scan performance. The findings of this study suggest the need for advanced imaging to properly diagnose and manage the most common health issue of captive orangutans.
Welfare assessments have been largely successful in improving management and quality of life for animals in human care. This has prompted an increased interest in their use for free-ranging wild animals to assess health, environment, and human-induced impacts that influence policy decisions. The North Atlantic Right Whale (NARW, Eubalaena glacialis) is one of the most endangered whale species. NARWs constantly face serious injuries and mortalities due to human activities, which poses both a species conservation and an individual welfare concern. Establishing a standardized welfare assessment for the NARW is a holistic way to understand the cumulative effects of anthropogenic activities at both the individual and population levels. To investigate the potential use of welfare assessments in NARWs, we performed a brief literature review to explore the history and utility of animal welfare assessments. Following the review, we developed a welfare assessment tool specific to the NARW. The goal is for biologists to apply this tool to understand NARW welfare in conjunction with research in the field. Ultimately, the information gained from this review can aid in public dissemination of the results of human impacts on NARW welfare and may help influence future conservation policies.
La rehabilitación y liberación de primates no humanos después del decomiso, entrega o abandono durante el tráfico de vida silvestre tiene repercusiones para la conservación, el bienestar del animal y la salud pública. Riesgos asociados con la liberación de primates incluyen el daño al ecosistema, la incapacidad de los primates liberados de participar en comportamientos sociales y de alimentación normales, y la diseminación de patógenos. La Unión Internacional para la Conservación de la Naturaleza (UICN) tiene varios lineamientos para la rehabilitación y liberación de primates traficados con la intención de minimizar estos riesgos, aunque se sabe poco sobre el uso de estos lineamientos durante el decomiso, rehabilitación y liberación de primates o sobre los retos que enfrentan a los que intentan implementar dichos lineamientos en contextos específicos. Como una de las principales fuentes en el comercio de primates neotropicales en el mundo, el Perú tiene una población de primates particularmente vulnerable a las consecuencias negativas de la liberación de los primates traficados. Este estudio utilizó entrevistas semiestructuradas y encuestas estructuradas a 19 personas involucradas en el decomiso, rehabilitación y/o liberación de primates en Perú y descubrió que el conocimiento y la implementación de los lineamientos de la UICN son mínimos. Las oportunidades detectadas para mejorar la implementación de estos lineamientos en Perú incluyen: ampliar la participación y el apoyo del gobierno, adaptar los lineamientos a contextos y ubicaciones específicos, y establecer una plataforma para mayor comunicación, cooperación e investigación entre los que realizan este trabajo
In the light of the urgency raised by the COVID-19 pandemic, global investment in wildlife virology is likely to increase, and new surveillance programmes will identify hundreds of novel viruses that might someday pose a threat to humans. To support the extensive task of laboratory characterization, scientists may increasingly rely on data-driven rubrics or machine learning models that learn from known zoonoses to identify which animal pathogens could someday pose a threat to global health. We synthesize the findings of an interdisciplinary workshop on zoonotic risk technologies to answer the following questions. What are the prerequisites, in terms of open data, equity and interdisciplinary collaboration, to the development and application of those tools? What effect could the technology have on global health? Who would control that technology, who would have access to it and who would benefit from it? Would it improve pandemic prevention? Could it create new challenges? This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.
The rehabilitation and release of nonhuman primates after confiscation, surrender, or abandonment during illegal wildlife trafficking has implications for conservation, animal welfare, and public health. Risks associated with primate release include ecosystem disruption, inability of released primates to engage in normal foraging and social behaviors, and pathogen spillover. The International Union for the Conservation of Nature (IUCN) has several guidelines for the rehabilitation and release of trafficked primates intended to minimize such risks, though little is known about the use of these guidelines during primate confiscation, rehabilitation, and release or about the challenges faced by those who attempt to implement such guidelines in specific contexts. As one of the leading sources of Neotropical primate trade in the world, Peru has a primate population particularly vulnerable to the negative consequences of trafficked primate release. This study used semi-structured interviews and structured questionnaires of 19 people involved in primate confiscation, rehabilitation, and/or release in Peru and found that awareness and implementation of the IUCN guidelines are minimal. Opportunities to increase guideline implementation in Peru include expanding government involvement and support, adapting guidelines to specific contexts and locations, and establishing a platform for increased communication, cooperation, and research amongst those performing this work.
Objectives This study used computer simulation modeling to estimate and compare costs of different free-roaming cat (FRC) management options (lethal and non-lethal removal, trap–neuter–return, combinations of these options and no action) and their ability to reduce FRC population abundance in open demographic settings. The findings provide a resource for selecting management approaches that are well matched for specific communities, goals and timelines, and they represent use of best available science to address FRC issues. Methods Multiple FRC management approaches were simulated at varying intensities using a stochastic individual-based model in the software package Vortex. Itemized costs were obtained from published literature and expert feedback. Metrics generated to evaluate and compare management scenarios included final population size, total cost and a cost efficiency index, which was the ratio between total cost and population size reduction. Results Simulations suggested that cost-effective reduction of FRC numbers required sufficient management intensity, regardless of management approach, and greatly improved when cat abandonment was minimized. Removal yielded the fastest initial reduction in cat abundance, but trap–neuter–return was a viable and potentially more cost-effective approach if performed at higher intensities over a sufficient duration. Of five management scenarios that reduced the final population size by approximately 45%, the three scenarios that relied exclusively on removal were considerably more expensive than the two scenarios that relied exclusively or primarily on sterilization. Conclusions and relevance FRCs present a challenge in many municipalities, and stakeholders representing different perspectives may promote varying and sometimes incompatible population management policies and strategies. Although scientific research is often used to identify FRC impacts, its use to identify viable, cost-effective management solutions has been inadequate. The data provided by simulating different interventions, combined with community-specific goals, priorities and ethics, provide a framework for better-informed FRC policy and management outcomes.
Baseline health parameters are limited in the primary literature for gray seals (Halichoerus grypus) in the northwest Atlantic. Accurate normal physiologic reference ranges for both species and specific geographic populations are vital tools for assessing the health of individuals and understanding the health of the entire population. This study developed comprehensive reference intervals for biochemical and hematologic parameters of recently weaned gray seal pups on Cape Cod, Massachusetts from samples collected in 2013, 2016, and 2017. Reference ranges were developed using methodology outlined by the American Society of Clinical Veterinary Pathology. By establishing more comprehensive biochemical and hematologic reference ranges for this population based on a robust sample size, this study provides a new tool for clinicians, researchers, and rehabilitation organizations to improve individual patient care and population research.