Free-ranging Wild Animals Research Articles

Restless roosts: Light pollution affects behavior, sleep, and physiology in a free-living songbird.

The natural nighttime environment is increasingly polluted by artificial light. Several studies have linked artificial light at night to negative impacts on human health. In free-living animals, light pollution is associated with changes in circadian, reproductive, and social behavior, but whether these animals also suffer from physiologic costs remains unknown. To fill this gap, we made use of a unique network of field sites which are either completely unlit (control), or are artificially illuminated with white, green, or red light. We monitored nighttime activity of adult great tits, Parus major, and related this activity to within-individual changes in physiologic indices. Because altered nighttime activity as a result of light pollution may affect health and well-being, we measured oxalic acid concentrations as a biomarker for sleep restriction, acute phase protein concentrations and malaria infection as indices of immune function, and telomere lengths as an overall measure of metabolic costs. Compared to other treatments, individuals roosting in the white light were much more active at night. In these individuals, oxalic acid decreased over the course of the study. We also found that individuals roosting in the white light treatment had a higher probability of malaria infection. Our results indicate that white light at night increases nighttime activity levels and sleep debt and affects disease dynamics in a free-living songbird. Our study offers the first evidence of detrimental effects of light pollution on the health of free-ranging wild animals.

The Ecology of Prions.

Chronic wasting disease (CWD) affects cervids and is the only known prion disease readily transmitted among free-ranging wild animal populations in nature. The increasing spread and prevalence of CWD among cervid populations threaten the survival of deer and elk herds in North America, and potentially beyond. This review focuses on prion ecology, specifically that of CWD, and the current understanding of the role that the environment may play in disease propagation. We recount the discovery of CWD, discuss the role of the environment in indirect CWD transmission, and consider potentially relevant environmental reservoirs and vectors. We conclude by discussing how understanding the environmental persistence of CWD lends insight into transmission dynamics and potential management and mitigation strategies.

Six Years in the Life of a Mother Bear - The Longest Continuous Heart Rate Recordings from a Free-Ranging Mammal

Physiological monitoring of free-ranging wild animals is providing new insights into their adaptations to a changing environment. American black bears (Ursus americanus) are highly adaptable mammals, spending up to half the year hibernating, and the remainder of the year attempting to gain weight on a landscape with foods that vary seasonally and year to year. We recorded heart rate (HR) and corresponding activity of an adult female black bear over the course of six years, using an implanted monitor. Despite yearly differences in food, and an every-other year reproductive cycle, this bear exhibited remarkable consistency in HR and activity. HR increased for 12 weeks in spring, from minimal hibernation levels (mean 20–25 beats/minute [bpm]; min 10 bpm) to summer active levels (July daytime: mean 95 bpm). Timing was delayed following one cold winter. In August the bear switched from primarily diurnal to nocturnal, coincident with the availability of baits set by legal hunters. Activity in autumn was higher when the bear was with cubs. Birthing of cubs in January was identified by a transient increase in HR and activity. Long-term physiological and behavioral monitoring is valuable for understanding adaptations of free-ranging animals to climate change, food availability, and human-related stressors.

Diel activity, frequency and visit duration of pollinators in focal plants: in situ automatic camera monitoring and data processing

Summary Data collection on interactions between organisms and their environment has traditionally been conducted by on‐site human observations, a time‐consuming enterprise that could explain the shortage of around‐the‐clock observations of free‐ranging wild animals. In this paper, I outline a time‐efficient procedure to collect data on flower‐visiting animals. The objectives were, first, to model diel activity rhythms by using cosine‐based mixed‐effects regression models (cosinor method) on data from an established automatic video monitoring system and, secondly, to test the use of a cheap off‐the‐shelf digital camera modified for automated monitoring of flower visitors. Two different model systems were studied: foraging bumblebees visiting focal white clovers, monitored around‐the‐clock (193 h) to model diel activity; and honeybees visiting thistles, monitored over a shorter period (5 h) to test the applicability and reliability of a new method for monitoring pollinators. The data were automatically entered and processed using R‐scripts after manual filtering of the images, obviating the need for manual data entry prior to analysis. For diel activity in bumblebees, the model that gave the best fit included the 24‐h fundamental period and one harmonic, a 12‐h period to modulate the signal, together with temperature. The bumblebees were exclusive diurnal, with activity starting about 5 h after sunrise, peaking sharply in the afternoon and ending about 1 h before sunset. In addition to time of day, activity also increased with temperature. The off‐the‐shelf digital camera, Canon PowerShot®, with motion detection script, was triggered by every flower‐visiting honeybee. In addition to recorded visitor frequency and visitor duration, it enabled high‐resolution images, which could be important for species identification. Automatic camera recording is advantageous for close‐up monitoring, compared with continuous video recording, because the latter demands more time and effort in reviewing the material. It could be used to study a range of different species such as pollinators, on‐plant behaviour of herbivorous animals, cavity dwellers or cavity breeders. Moreover, the procedures for automatic data entry, data processing and statistical analysis for modelling diel activity rhythms could have great relevance for researchers using other types of camera monitoring systems operating 24 h per day.

Novel Insights into the Map Stage of True Navigation in Nonmigratory Wild Birds (Stone Curlews, Burhinus oedicnemus).

In the map-and-compass model of true navigation, animals at unfamiliar sites determine their position relative to a destination site (the map stage) before progressing toward it (the compass stage). A major challenge in animal navigation research is to understand the still cryptic map stage in general and the map stage for free-ranging wild animals in particular. To address this challenge, we experimentally translocated wild, nonmigratory birds (stone curlews [Burhinus oedicnemus]) far from their nests and GPS-tracked their subsequent movements at high resolution and for long durations. Homing success was high and cannot be explained by random chance or landmark navigation, implying true navigation. Although highly motivated to return home, the homing trajectories of translocated birds exhibited a distinct, two-phase pattern resembling the map and compass stages: a long, tortuous wandering phase without consistent approach home, followed by a short and direct return phase. Birds retranslocated to the same site initially repeated the original wandering path but switched to the return phase earlier and after covering a smaller area; they returned home via a different path but with similar movement properties. We thus propose the map learning hypothesis, asserting that birds resolve the map by acquiring, potentially through learning, the relevant navigation cues during the wandering phase.

Determining position, velocity and acceleration of free-ranging animals with a low-cost unmanned aerial system.

Unmanned aerial systems (UASs), frequently referred to as 'drones', have become more common and affordable and are a promising tool for collecting data on free-ranging wild animals. We used a Phantom-2 UAS equipped with a gimbal-mounted camera to estimate position, velocity and acceleration of a subject on the ground moving through a grid of GPS surveyed ground control points (area ∼1200 m(2)). We validated the accuracy of the system against a dual frequency survey grade GPS system attached to the subject. When compared with GPS survey data, the estimations of position, velocity and acceleration had a root mean square error of 0.13 m, 0.11 m s(-1) and 2.31 m s(-2), respectively. The system can be used to collect locomotion and localisation data on multiple free-ranging animals simultaneously. It does not require specialist skills to operate, is easily transported to field locations, and is rapidly and easily deployed. It is therefore a useful addition to the range of methods available for field data collection on free-ranging animal locomotion.

Isolation of Escherichia coli and Salmonella spp. from free-ranging wild animals.

Increasing interactions between humans, domestic animals and wildlife may result in inter-species transmission of infectious agents. To evaluate the presence of pathogenic E. coli and Salmonella spp. and to test the antimicrobial susceptibility of isolates, rectal swabs from 36 different free-ranging wild mammals were taken from two distinct natural sites in Brazil: Cantareira State Park (CSP, state of São Paulo) and Santa Isabel do Rio Negro Region (SIRNR, state of Amazonas). The swabs were randomly collected and processed for bacterial isolation, identification, characterization and antimicrobial resistance. Eighteen E. coli strains from CSP and 20 from SIRNR were recovered from 14 and 22 individuals, respectively. Strains from animals captured in CSP, the site with the greatest anthropization, exhibited a higher range and percentage of virulence genes, including an eae+/bfpA+ strain. Antimicrobial resistance was verified in strains originating from both sites; however, in strains from SIRNR, aminopenicillins were almost the exclusive antimicrobial class to which strains exhibited resistance, whereas in CSP there were strains resistant to cephalosporins, sulfonamide, aminoglycoside, tetracycline and fluoroquinolone, in addition to strains exhibiting multidrug resistance. Two strains of Salmonella enterica that are known to be associated with reptiles, serotypes Belem and 60:r:e,n,z15, were recovered only from Amazonian animals and showed susceptibility to all classes of antimicrobials that were tested. Although the potential impact of these pathogens on wildlife remains unknown, bacteria isolated from free-ranging wild animals may provide relevant information about environmental health and should therefore be more deeply studied.

Growing Significance of Mycobacterium bovis in Human Health

Tuberculosis is one of the most wide spread highly infectious bacterial zoonotic diseases, and is responsible for high morbidity and mortality in the world particularly in the developing nations. Mycobacterium bovis and closely associated acid fast bacilli cause disease in humans and animals. Humans can be infected with M. bovis where cattle act as the principal reservoir. Air borne infections continue to occur among the persons working in the meat industry, slaughterhouses, and in persons living in close physical contact with infected animals.M. bovis infection is recognized as an occupational hazard to abattoir workers, livestock handlers and veterinarians. The main cause of concern related to M. bovis in industrialized counties are epizootics nature of the disease in domesticated and wild animals. In addition, latent infection in immigrants particularly in HIV infected patients are also a big issue in developed world, since those people could be the potential source of TB for other people. The reemergence of M. bovis infection in captive and free-ranging wild animals, with subsequent transmission to domestic animals, is of concern to livestock producers and regulatory officials. As wild animals represent major reservoir of tuberculosis bacilli, it is imperative to investigate the role of wild animals in transmission dynamics of M. bovis infection. Further studies on the molecular epidemiology and development of safe, cheap and potent drugs to mitigate tuberculosis in highly susceptible population particularly in HIV/AIDS patients is emphasized. In addition, multidisciplinary approaches such as ‘One Health’ that comprise professionals from medical science, veterinary medicine and wildlife etc. are essential to take measures to control this devastating bacterial zoonosis. DOI: http://dx.doi.org/10.3329/mh.v3i1.19779 Microbes and Health, June 2014. 3(1): 29-34

First parasitological survey of Endangered Bornean elephants Elephas maximus borneensis

Relatively few studies have been carried out on the parasites of free-ranging wild animal species, which has led to a lack of baseline parasitological data. This is a concern because endoparasites can have an important influence on fitness and survival, particularly in small populations of endangered species. This field study is the first parasitological survey of Endangered Bornean elephants Elephas maximus borneensis. Using a special modification of the McMaster method, trematode, cestode and nematode ova were identified in the faeces of wild Bornean elephants in 2 key range areas in Sabah, Malaysian Borneo: the Tabin Wildlife Reserve and the Lower Kinabatangan Wildlife Sanctuary. Preliminary comparisons between the sites suggest that prevalence, load and diversity vary between the two, leading to hypotheses on host, parasite and environmental factors which may affect endoparasite infection dynamics in wild Bornean elephants. This study provides an initial catalogue of parasite types in the Bornean elephant and reports on endoparasite prevalence and load, valuable baseline data for future research.

Mixed strategies of griffon vultures' (Gyps fulvus) response to food deprivation lead to a hump-shaped movement pattern.

BackgroundThe need to obtain food is a critical proximate driver of an organism’s movement that shapes the foraging and survival of individual animals. Consequently, the relationship between hunger and foraging has received considerable attention, leading to the common conception that hunger primarily enhances a “food-intake maximization” (FIMax) strategy and intensive search. A complementary explanation, however, suggests a trade-off with precautions taken to reduce the risk of physiological collapse from starvation, under a strategy we denote as “energy-expenditure minimization” (EEMin). The FImax-EEmin trade-off may interact with the forager’s hunger level to shape a complex (non-monotonic) response pattern to increasing hunger. Yet, this important trade-off has rarely been investigated, particularly in free-ranging wild animals.We explored how hunger affects the movements of adult griffon vultures (Gyps fulvus) in southern Israel. Transmitters combining GPS and accelerometers provided high-resolution data on vultures’ movements and behavior, enabling the identification of feeding events and the estimation of food deprivation periods (FDPs, measured in days), which is used as a proxy for hunger.ResultsData from 47 vultures, tracked for 339 ± 36 days, reveal high variability in FDPs. While flight speed, flight straightness and the proportion of active flights were invariant in relation to food deprivation, a clear hump-shaped response was found for daily flight distances, maximal displacements and flight elevation. These movement characteristics increased during the first five days of the FDP sequence and decreased during the following five days. These characteristics also differed between short FDPs of up to four days, and the first four days of longer FDP sequences.These results suggest a switch from FIMax to EEMin strategies along the FDP sequence. They also indicate that vultures’ response to hunger affected the eventual duration of the FDP. During winter (the vultures’ incubation period characterized by unfavorable soaring meteorological conditions), the vultures’ FIMax response was less intensive and resulted in longer starvation periods, while, in summer, more intensive FIMax response to hunger resulted in shorter FDPs.ConclusionsOur results show a flexible, non-monotonic response of free-ranging wild animals to increasing hunger levels, reflecting a trade-off between increasing motivation to find food and the risk of starvation. The proposed trade-off offers a unifying perspective to apparently contradictory or case-specific empirical findings.Electronic supplementary materialThe online version of this article (doi:10.1186/2051-3933-1-5) contains supplementary material, which is available to authorized users.

Faecal steroid metabolites assay as a non-invasive monitoring of reproductive status in animals

Measurement of faecal steroids as a non-invasive technique is widely used to monitor reproductive hormones in captive and free-ranging wild animals. This method offers a great advantage over invasive techniques like blood collection and deserves to be used in domestic animals. Repeated blood sampling is stressful, having animal welfare issues, difficult to obtain in field condition. In the faeces of cow, estradiol 17-α predominated, whereas in mares and sows, estradiol 17-β and estrone are main estrogens. Steroids are metabolized in liver, excreted in faeces and extraction is done by using a variety of methods such as ethanol, methanol etc. Faecal estrogen and progesterone metabolites evaluations are wel1 established approaches for monitoring of reproductive functions in a variety of mammalian species. So in future this method may be the most suitable for monitoring of reproductive status in farm animals particularly under field conditions.

Observing the unwatchable through acceleration logging of animal behavior

Behavior is an important mechanism of evolution and it is paid for through energy expenditure. Nevertheless, field biologists can rarely observe animals for more than a fraction of their daily activities and attempts to quantify behavior for modeling ecological processes often exclude cryptic yet important behavioral events. Over the past few years, an explosion of research on remote monitoring of animal behavior using acceleration sensors has smashed the decades-old limits of observational studies. Animal-attached accelerometers measure the change in velocity of the body over time and can quantify fine-scale movements and body postures unlimited by visibility, observer bias, or the scale of space use. Pioneered more than a decade ago, application of accelerometers as a remote monitoring tool has recently surged thanks to the development of more accessible hardware and software. It has been applied to more than 120 species of animals to date. Accelerometer measurements are typically collected in three dimensions of movement at very high resolution (>10 Hz), and have so far been applied towards two main objectives. First, the patterns of accelerometer waveforms can be used to deduce specific behaviors through animal movement and body posture. Second, the variation in accelerometer waveform measurements has been shown to correlate with energy expenditure, opening up a suite of scientific questions in species notoriously difficult to observe in the wild. To date, studies of wild aquatic species outnumber wild terrestrial species and analyses of social behaviors are particularly few in number. Researchers of domestic and captive species also tend to report methodology more thoroughly than those studying species in the wild. There are substantial challenges to getting the most out of accelerometers, including validation, calibration, and the management and analysis of large quantities of data. In this review, we illustrate how accelerometers work, provide an overview of the ecological questions that have employed accelerometry, and highlight the emerging best practices for data acquisition and analysis. This tool offers a level of detail in behavioral studies of free-ranging wild animals that has previously been impossible to achieve and, across scientific disciplines, it improves understanding of the role of behavioral mechanisms in ecological and evolutionary processes.

Using tri-axial acceleration data to identify behavioral modes of free-ranging animals: general concepts and tools illustrated for griffon vultures

Integrating biomechanics, behavior and ecology requires a mechanistic understanding of the processes producing the movement of animals. This calls for contemporaneous biomechanical, behavioral and environmental data along movement pathways. A recently formulated unifying movement ecology paradigm facilitates the integration of existing biomechanics, optimality, cognitive and random paradigms for studying movement. We focus on the use of tri-axial acceleration (ACC) data to identify behavioral modes of GPS-tracked free-ranging wild animals and demonstrate its application to study the movements of griffon vultures (Gyps fulvus, Hablizl 1783). In particular, we explore a selection of nonlinear and decision tree methods that include support vector machines, classification and regression trees, random forest methods and artificial neural networks and compare them with linear discriminant analysis (LDA) as a baseline for classifying behavioral modes. Using a dataset of 1035 ground-truthed ACC segments, we found that all methods can accurately classify behavior (80-90%) and, as expected, all nonlinear methods outperformed LDA. We also illustrate how ACC-identified behavioral modes provide the means to examine how vulture flight is affected by environmental factors, hence facilitating the integration of behavioral, biomechanical and ecological data. Our analysis of just over three-quarters of a million GPS and ACC measurements obtained from 43 free-ranging vultures across 9783 vulture-days suggests that their annual breeding schedule might be selected primarily in response to seasonal conditions favoring rising-air columns (thermals) and that rare long-range forays of up to 1750 km from the home range are performed despite potentially heavy energetic costs and a low rate of food intake, presumably to explore new breeding, social and long-term resource location opportunities.

Effect of tannins on the in vitro growth of Clostridium perfringens

Vegetable tannins are water-soluble polyphenolic compounds of varying molecular weights that occur abundantly in nature. The diet of many free-ranging wild animals contains significant amounts of tannins. Also, commercial tannins are used in animal industry as food additives to improve animal performance. In order to further determine the capacity of tannins to inhibit the development of intestinal diseases produced by Clostridium pefringens, we evaluated here the effect of tannins from quebracho, chestnut or combinations of both on C. perfringens and their toxins. The C. perfringens (types A, B, C, D and E) growth obtained from the intestine of healthy and diseased animals was reduced in a dose-dependent manner in the presence of quebracho tannins, chestnut tannins, combinations of both or a commercial formula based in these tannins. Although the minimal inhibitory concentration of both tannins varied between isolates, no statistically significant differences were observed between isolates from healthy or sick animals. Comparative analysis showed that the concentrations of quebracho tannin inhibiting the growth of C. perfringens were higher than chestnut tannin. In fact, antibacterial effect of quebracho tannin was increased up to 20 times with the addition of 25% of chestnut tannin and 85 times with 75% of chestnut tannin. Antibacterial activity of the commercial product was up to ∼50 times higher than quebracho tannin alone. Quebracho tannin showed partial bactericidal activity, whereas chestnut tannin activity was stronger. Both tannins were able to reduce the alpha toxin lecithinase activity and epsilon toxin cytotoxicity in MDCK cells. These results suggest that tannin-supplemented diet could be useful to prevent some clostridial diseases.

Comparison of infection by Brucella spp. in free-ranging and captive wild animals from São Paulo State, Brazil

The aim of the current study was to evaluate the infection rate by Brucella spp. in wild and in captive animals. Serum samples from 121 animals (94 free-ranging and 27 captive) of different mammal species were evaluated. Sera were submitted to rose Bengal test (RBT) for screening and serum agglutination tests (SAT) and 2-mercaptoethanol test (2-ME) for confirmatory results. Nine animals (five free-ranging and four captive) tested positive in RBT, but negative in the confirmatory tests. Several domestic animal diseases that have control programs are not focused on wild reservoirs, such as brucellosis in Brazil. The study of new reservoirs in wildlife is essential to prevent emerging diseases.

Clinical and research searching on the wild side: exploring the veterinary literature.

Zoological medicine furthers the health and well-being of captive and free-ranging wild animals. Effective information retrieval of the zoological medicine literature demands searching multiple databases, conference proceedings, and organization websites using a wide variety of keywords and controlled vocabulary. Veterinarians, residents, students, and the librarians who serve them must have patience for multiple search iterations to capture the majority of the available knowledge. The complexities of thorough literature searches are more difficult for nondomestic animal clinical cases and research reviews as demonstrated by three search requests involving poisonous snakes, a gorilla, and spiders. Expanding and better disseminating the knowledgebase of zoological medicine will make veterinary searching easier.

FIRST ISOLATION OF MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS FROM WILD GUANACOS (LAMA GUANICOE) ON TIERRA DEL FUEGO ISLAND

The aim of this study was to search for Mycobacterium avium subsp. paratuberculosis (Map) infection in a free-ranging wild animal species in a region where Johnes's disease has yet to be reported and to classify Map isolates using a genomic typing method. Fecal samples were obtained from 501 wild guanacos (Lama guanicoe) from Tierra del Fuego Island, Chile, in August 2006. Samples were cultured using Herrold's egg yolk medium with and without mycobactin J. After 9 mo of incubation, suspected Map colonies showing mycobactin dependence were confirmed by real-time polymerase chain reaction (PCR) based on IS900 and F57. Isolates were further tested using IS1311 PCR with restriction endonuclease analysis in order to type the guanaco Map strains. Twenty-one of 501 (4.2%) animals were fecal culture-positive for Map; identity was confirmed by real-time PCR and isolates were classified as cattle-type. Most culture-positive animals were located in four contiguous geographic areas, and the infection was most commonly found among adult animals. Prevalence was higher in females (5.9%) than males (3.1%) but the difference was not statistically significant. This represents the first isolation of Map from a free-ranging wildlife species in Chile. It expands the geographic range of paratuberculosis and the diversity of wildlife species that can become infected with Map.

Vacunas para el control immnológico de la fertilidad en animales

Fertility control has gained considerable momentum as a management tool to regulate populations of captive and wild animals and to control aggressive behaviour or improve meat quality in livestock. Anti-fertility vaccination (immunocontraception and immunocastration) is a humane alternative to methods that rely on surgical or chemical sterilisation and lethal control. Two types of experimental immunocontraceptive vaccine have been registered for field use in animals. They contain either porcine zona pellucida (PZP) proteins extracted from pig ovaries or synthetic conjugated gonadotrophin releasing hormone (GnRH) peptides. These vaccines require repeated injections and are limited to captive or small populations of free-ranging wild animals. Alternative immunocontraceptive vaccines are actively being developed either to improve efficacy or enable large numbers of wild animals to be targeted. Some employ live genetically modified viruses to deliver immunocontraception and have proved successful under laboratory conditions. The relative merits, risks, social acceptability and regulations controlling the use of existing and novel animal immunocontraceptives are reviewed.

Future Directions in Training Zoological Medicine Veterinarians

The American College of Zoological Medicine (ACZM) is dedicated to excellence in furthering the health and well-being of both captive and free-ranging wild animals. Currently there are 14 ACZM-approved residency programs in zoological medicine. In addition, eight non-approved residencies and 15 internships in North America provide training opportunities in this field. This article outlines some of the training opportunities for both veterinary students and graduate veterinarians that would best position them for entry into a zoological medicine training program. Although there is a growing number of opportunities for individuals to serve in captive and free-ranging wildlife health positions, existing training programs are inadequate to meet these needs. It is also acknowledged that there is an increasing number of veterinary students entering veterinary schools with an interest in zoological medicine and that the job market is still limited. However, positions and opportunities in zoological medicine are available for those individuals with the drive, dedication, and passion to succeed.

Dietary analysis for mammals and birds: a review of field techniques and animal-management applications

Detailed information about the range and composition of the diets of free-ranging wild animals is extremely limited. The nutritional protocols of wildlife-conservation programmes or the maintenance of wild animals in captivity are based on a limited understanding of species’interactions and habitat strategies. More detailed information on diet can be obtained from direct observations of feeding, analysis of leftover food around feeding or nest/den sites, or identification of components in the digesta at various stages through the digestive tract, including faeces or pellets. In order to gather more specific data from animals it is essential that the food that has been consumed can be identified, even if it only appears as fragments within the digesta, faeces or pellets. The amounts eaten and how various foods respond to the rigours of digestion are also important; for example, soft prey items may be under-represented or non-existent at the end of the digestion process. This article describes various methods that can be used to identify the food items consumed by animals and suggests studies that can be carried out in both the wild and captivity to facilitate the development of a detailed and species-specific reference bank of food items.