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Human–Wildlife Interactions: From Conflict to Coexistence
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... Mesopredators are known to often prey on eggs from bird and turtle nests (Conover and Conover 2022). ...
... Shooting for control and hunting tend to have a positive effect as well, but with more variability in the results. Controlling at the population level through lethal practices is very labor-intensive and must be maintained over the long-term (Conover and Conover 2022). On the other hand, individual-based (selective) lethal methods can be more challenging but might be more readily socially accepted (Swan et al. 2017). ...
... A study on larger carnivores indicated that supplementary feeding even led to an increase in damage (Khorozyan and Waltert 2019). Over longer periods of time, supplemental feeding may have a counterproductive effect by increasing local population size (Conover and Conover 2022). There is also a risk of spreading disease by concentrating individuals at a feeding site (Castillo et al. 2011, Møller et al. 2014. ...
Conflicts between humans and mesopredators are frequent and widespread. Over the last decades, conflicts have led to the development and application of different mitigation methods to diminish the costs and damage caused by such conflicts. We conducted a systematic literature search and meta‐analysis to assess the influence of different mitigation methods on 3 common nuisance species: raccoons ( Procyon lotor ), red foxes ( Vulpes vulpes ), and striped skunks ( Mephitis mephitis ). A majority of the studies, from 1963‒2022, were conducted in North America, followed by Australia and Europe. The predation of wildlife species of conservation concern by nuisance species is the main reported source of conflict in the published literature. Lethal control is the most commonly tested method and is generally effective at reducing conflicts based on the calculated effect size. Barriers have mixed effects, with electric fences and nest exclosures both being effective, whereas conventional fences seem to be less effective. Repellents mimicking predators (e.g., guard animal, predator smell) are also effective. Conditioned taste aversion is a promising approach, but no precise product or chemical has proven to be effective. Many interventions suffered from a lack of validation through experimental approach. Research on human–mesopredator conflict mitigation would benefit from repeated studies using the same methods in similar contexts, thus reducing heterogeneity in the results, and by testing new and innovative methods.
... Wild carnivores are frequently involved in human-wildlife conflict (Treves andKaranth 2003, Expósito-Granados et al. 2019), with some species, such as coyotes in North America often perceived as particularly threatening (Timm and Baker 2007, White and Gehrt 2009, Poessel et al. 2013. The frequency of human-wildlife conflict is likely increasing due to expanding human populations usurping spaces previously occupied by wildlife (Madden 2004, Bateman and Fleming 2012, Conover and Conover 2022, or when wildlife is attracted to anthropogenic resources (Gehrt et al. 2010). As adaptable omnivores, coyotes adjust their diet to their environment, routinely switching to accommodate seasonal and spatial variation in resource availability (Gilbert-Norton et al. 2009). ...
Coyotes Canis latrans in urban landscapes provide important food web functions and ecological services but can also trigger human-wildlife conflict when their diet includes anthropogenic resources or domestic pets. As adaptable omnivores, coyotes adjust their diet to their environment, routinely switching among food items to accommodate spatial and seasonal differences in availability. To evaluate the coyote’s potential impacts within the food web of urban Long Beach, California where human-wildlife conflict involving coyotes may occur, we analyzed 115 scat samples collected once every two weeks from four open space fragments inside the urban matrix. We hypothesized that differences in scat composition would correlate with seasonal and site differences, with greater use of anthropogenic resources during the dry season supplementing lower prey availability, and with greater consumption of wild mammal prey during the wet season when fruiting plants are less abundant. We found coyote diet was predominately composed of natural prey and vegetation year-round, with seasonal variation. Mammals made up more of coyote diet in the wet season than the dry, while invertebrates and vegetation were more prevalent in dry season scats. Coyotes relied on rabbits as their main prey year-round across all sites. Domestic cats Felis catus were the third most common individual prey species found in coyote scats, occurring in 14% of scat samples in both seasons. Coyotes also supplemented seasonally available natural food sources with anthropogenic resources, which occurred in 13% of coyote scats overall with no significant seasonal variation. While rabbits appeared in scat from all sites, the occurrence of invertebrates, small mammals, and vegetation in scats varied between sites. While there is a potential for human-wildlife conflict in coyote’s consumption of feral or domestic cats, coyotes may also be providing an ecological service by reducing cats in natural habitat fragments.
... The economic and environmental impacts of wildlife include damage to crops and forestry, disease transmission, vehicle collisions, impact on biodiversity, livestock predation and attacks on people. Many of these impacts are due to local populations of wildlife exceeding the so-called "social carrying capacity": in these instances, wildlife is referred to as "overabundant" [2][3][4][5]. ...
Trends of human population growth and landscape development in Europe show that wildlife impacts are escalating. Lethal methods, traditionally employed to mitigate these impacts, are often ineffective, environmentally hazardous and face increasing public opposition. Fertility control is advocated as a humane tool to mitigate these impacts. This review describes mammalian and avian wildlife contraceptives’ effect on reproduction of individuals and populations, delivery methods, potential costs and feasibility of using fertility control in European contexts. These contexts include small, isolated wildlife populations and situations in which lethal control is either illegal or socially unacceptable, such as urban settings, national parks and areas where rewilding occurs. The review highlights knowledge gaps, such as impact of fertility control on recruitment, social and spatial behaviour and on target and non-target species, provides a decision framework to assist decisions about the potential use of wildlife fertility control, and suggests eight reasons for Europe to invest in this area. Although developing and registering contraceptives in Europe will have substantial costs, these are relatively small when compared to wildlife’s economic and environmental impact. Developing safe and effective contraceptives will be essential if European countries want to meet public demand for methods to promote human–wildlife coexistence.
... The economic and environmental impacts of wildlife include damage to crops and forestry, disease transmission, vehicle collisions, impact on biodiversity, livestock predation and attacks on people. Many of these impacts are due to local populations of wildlife exceeding the so-called "social carrying capacity": in these instances, wildlife is referred to as "overabundant" [2][3][4][5]. ...
Attacks on humans by wild pigs (Sus scrofa) have been documented since ancient times. However, studies characterizing these incidents are lacking. In an effort to better understand this phenomenon , information was collected from 412 wild pig attacks on humans. Similar to studies of large predator attacks on humans, data came from a variety of sources. The various attacks compiled occurred in seven zoogeographic realms. Most attacks occurred within the species native range, and specifically in rural areas. The occurrence was highest during the winter months and daylight hours. Most happened under non-hunting circumstances and appeared to be unprovoked. Wounded animals were the chief cause of these attacks in hunting situations. The animals involved were typically solitary, male and large in size. The fate of the wild pigs involved in these attacks varied depending upon the circumstances, however , most escaped uninjured. Most human victims were adult males traveling on foot and alone. The most frequent outcome for these victims was physical contact/mauling. The severity of resulting injuries ranged from minor to fatal. Most of the mauled victims had injuries to only one part of their bodies, with legs/feet being the most frequent body part injured. Injuries were primarily in the form of lacerations and punctures. Fatalities were typically due to blood loss. In some cases, serious infections or toxemia resulted from the injuries. Other species (i.e., pets and livestock) were also accompanying some of the humans during these attacks. The fates of these animals varied from escaping uninjured to being killed. Frequency data on both non-hunting and hunting incidents of wild pig attacks on humans at the Savannah River Site, South Carolina, showed quantitatively that such incidents are rare.
Ungulate herbivory poses global challenges to forest regeneration. Deer, in combination with other biotic and abiotic factors, threaten to shift forest composition away from palatable hardwoods, such as oaks (Quercus spp.), and cause regeneration failure in some cases. Many studies have assessed methods to reduce or manage browse, but comprehensive analyses of the relative effectiveness of these techniques among published experiments are lacking. We synthesized the literature describing the results of methods to reduce deer browsing impacts, and assessed the effectiveness of deer browse management methods in controlling damage to hardwood forest regeneration. Specifically, we systematically analyzed results from 99 studies that used repellents, physical barriers, lethal population control, timber harvests, facilitation by neighboring plants, or fertilizer to affect browse, survival, or height growth of hardwood seedlings. Across studies, browse was reduced (mean effect size and confidence intervals) with the following: Fencing −3.17 (CI: −4.00–−1.31), shelters −1.28 (CI: −2.02–−0.67), cages −1.48 (CI: −3.14–−0.62), facilitation from neighboring plants −0.58 (CI: −1.11–−0.13), repellents −0.45 (CI: −0.56–−0.21), and hunting −0.99 (CI: −1.51–−0.26). These methods each had positive effects on seedling height growth (except for repellents), and cages, timber harvests, fences, and mesh sleeves had positive effects on survival. Logging slash had no effect on browse incidence (−0.05, CI: −0.97–0.19). Fertilizer applied during seedling establishment increased browse (0.13, CI: 0.11–0.21), and did not affect height growth. We conclude that fences or other physical barriers best control for the effects of deer, but facilitation by surrounding vegetation, hunting, habitat management through timber harvest, and certain repellents may also be moderately effective. Discrepancies between browse effectiveness and relative costs suggest that economic analyses should be developed to help to guide prescriptions for management.
Abstract Animal–vehicle collisions cause many millions of animal deaths each year worldwide and present a substantial safety risk to people. In the United States and Canada, deer (Odocoileus spp.) are involved in most animal–vehicle collisions associated with human injuries. We evaluated a vehicle‐based collision mitigation method designed to decrease the likelihood of deer–vehicle collisions during low‐light conditions, when most collisions occur. Specifically, we investigated whether the use of a rear‐facing light, providing more complete frontal vehicle illumination than standard headlights alone, enhanced vehicle avoidance behaviors of white‐tailed deer (O. virginianus). We quantified flight initiation distance (FID), the likelihood of a dangerous deer–vehicle interaction (FID ≤ 50 m), and road‐crossing behavior of deer in response to an oncoming vehicle using only standard high‐beam headlights and the same vehicle using headlights plus an LED light bar illuminating the frontal surface of the vehicle. We predicted that frontal vehicle illumination would enhance perceived risk of deer approached by the vehicle and lead to more effective avoidance responses. We conducted 62 vehicle approaches (31 per lighting treatment) toward free‐ranging deer over ~14 months. Although FID did not differ across treatments, the likelihood of a dangerous deer–vehicle interaction decreased from 35% of vehicle approaches using only headlights to 10% of vehicle approaches using the light bar. The reduction in dangerous interactions appeared to be driven by fewer instances of immobility (freezing) behavior by deer in response to the illuminated vehicle (n = 1) compared with approaches using only headlights (n = 10). Because more deer moved in response to the illuminated vehicle, road‐crossing behavior likewise increased when the light bar was on, although these road crossings primarily occurred at FIDs > 50 m and thus did not increase collision risk. Road‐crossing behavior was influenced heavily by proximity to concealing cover; deer only crossed when the nearest cover was located on the opposite side of the road. We contend that frontal vehicle illumination via rear‐facing lighting has potential to greatly reduce vehicle collisions with deer and other species. Future work should explore fine‐tuning the method with regard to the visual capabilities of target species.
Population change, survival, and the relative importance of mortality factors were estimated for white-tailed deer (Odocoileus virginianus) in the 839-km2 Bearville Study Area in north-central Minnesota during January 1981-December 1986; 143 deer 26 months old were radio collared and monitored. Annual aerial surveys incorporating reobservation rates of marked deer to estimate observability bias indicated deer density likely declined from about 10 deer/km2 in midwinter 1981-82 to 4 deer/km2 in 1985-86 (mean annual finite rate of change [A] = 0.79). Mean annual survival of marked deer '1.0 year old was 0.46 for males and 0.69 for females. Mortality during the hunting season was 2-4 times higher for deer residing <0.2 km from a road than for those 20.8 km from a road. Survival of marked fawns during December-May was 0.89 when winter snow depth averaged 13-16 cm, but 0.60 when snow depth was 36-44 cm. Demographic calculations incorporating survival rates from telemetry, estimates of fawn production (1.30 fawns/all females), sex ratio of deer -1.0 year old (28M:72F) on 1 June, and observed fawn occurrence (28% of population) on 15 January suggested fawn survival was 0.38 in summer, 0.82 during the November hunting season, and 0.22 annually. Estimated finite rate of change derived from these calculations (A = 0.84) also indicated a population decline.
Most deaths of marked deer 21.0 year old were caused by legal hunting (33 and 15% of 1 Jun population for males and females, respectively). Other mortality was due to poaching (weighted x = 5% of 1 Jun population); wounding during the hunting season (3%); predation by wolves (Canis lupus) (4%), domestic dogs (1%), or other predators (2%); and other causes (2So). Most fawns probably died during summer (62% of 1 Jun population) and the hunting season (6%). During winter, radio-marked fawns died of predation by wolves (4%), domestic dogs (25G), and other predators (1.5%) and as the result of harsh winter weather (1.5%). Independent estimates of deer mortality due to hunters and wolves corroborated estimates based on telemetry data.
Sensitivity analyses using plausible extremes of reproduction, summer fawn survival, winter survival, wolf mortality, and hunting pressure indicated that changes in harvest had the greatest impact on rates of population change. However, acceptable changes in hunting pressure alone likely would not cause the population to increase. Subsequent modeling incorporating successive years with mild winters and reduced harvest of antlerless deer resulted in a stable to increasing population. Biologists using accounting models with reasonable input data will be able to manage deer populations with greater understanding, but must realize the limitations of their predictive abilities.
The cumulative impact of human activities has driven many species into severe declines across the globe. However, the recent focus on conservation optimism has begun to highlight case studies that go against this trend. Reforestation, agricultural abandonment, reintroduction and legislative change have led to a situation where large mammals have recovered and are now widespread across the European continent. This study summarizes the knowledge about wild ungulate distribution in Europe and review the diversity of ways in which they interact with humans. Drawn from a wide range of sources, we built distribution maps of European wild ungulates. Results show that 90% of Europe is home to at least 1 species of wild native ungulate, with roe deer and wild boar occupying 74% and 64% of Europe respectively. In contrast, wild native mountain ungulates only occupy 5% of Europe, and are often associated with protected areas. The wide distribution of most European ungulates combined with the extensive human activity within Europe result in a wide range of interactions between ungulates and humans. These interactions can be classified as services or disservices depending on the value orientation and economic position of the various stakeholders perceiving this relationship. Overall, our survey highlights the success of wildlife management policies in Europe and the potential for continental scale conservation of large mammals in human-dominated landscapes. However, maintaining the success of wild ungulate conservation requires actions from national and European institutions to improve coordinated management across jurisdictional borders and sectorial coordination for the whole landscape.
Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat's home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 mg/kg brodifacoum bait was broadcast across Wake Atoll to eliminate rats, we collected whole-body fish samples from six near-shore sites and one intermittently landlocked pond to test for brodifacoum residues. Of the 69 samples tested using high-performance liquid chromatography with fluorescence detection, 20 were suspected of brodifacoum contamination and therefore subject to more selective liquid chromatography-mass spectrometry analysis. Of those 20 fish, brodifacoum was detected in two individuals of blacktail snapper (Lutjanus fulvus), although at levels too low to be accurately quantified. Both fish containing detectable brodifacoum residues were caught within an intermittently landlocked pond in an area of the island that received heavy brodifacoum baiting, and not truly in the "marine environment". Brodifacoum was not detected in any of the samples collected within the lagoon of the atoll or within near-shore waters outside the lagoon. These results demonstrate that under some circumstances very low levels of brodifacoum can occur in a low proportion of fish tissues for as long as three years after the application of the rodenticide to an environment. Such information is valuable in assessing the relative environmental risks associated with rodenticide use in rodent eradications for protection of threatened species and restoration of island ecosystems. The overall result is one of declining incidence and magnitude of residue concentrations over time and within limited environmental circumstances.
This book considers a number of problems posed by ungulates and their management in Europe. Through a synthesis of the underlying biology and a comparison of the management techniques adopted in different countries, the book explores which management approaches seem effective - and in which circumstances. Experts in a number of different areas of applied wildlife biology review various management problems and alternative solutions, including the impact of large ungulates on agriculture, forestry and conservation habitats, the impact of disease and predation on ungulate populations and the involvement of ungulates in road traffic accidents and possible measures for mitigation. This book is directed at practising wildlife managers, those involved in research to improve methods of wildlife management, and policy-makers in local, regional and national administrations.
Objectives
Errors and misreporting on death certificates are common, along with potential inaccuracies in cause-of-death coding. We characterized and compared fatalities by animal-encounter mentions reported as underlying cause of death (UCD) with animal-encounter mentions reported as multiple cause of death (MCD) to determine factors associated with misreporting UCD.
Methods
We analyzed fatality data from 1999-2016 from the Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research by UCD and MCD animal-encounter mentions ( International Classification of Diseases, 10th Revision codes W53-59, X20-27 and X29, T63.0-63.6, T63.8-63.9, and T78.2-78.4). We examined differences in reporting by age, sex, race, autopsy (yes, no, unknown), allergic reactions, and toxicities.
Results
The number of animal-encounter mentions by UCD was 3638 (202 average per year) and by MCD was 4280 (238 average per year), a difference of 18% (n = 642; 36 average per year) by MCD analysis. The number of nonvenomous animal-encounter mentions increased 20% (from 2138 UCD to 2567 MCD), and the number of venomous animal-encounter mentions increased 14% (from 1500 UCD to 1713 MCD). Decedents aged ≥65 had the highest additional number of animal-encounter mentions among all age groups, primarily encounters with other reptiles (n = 113), other mammals (n = 71), and dogs (n = 42). Of 642 MCD additional animal-encounter mentions, heart disease (n = 211, 33%) and infections (n = 146, 23%) represented more than half of the UCD. Of 553 dog-encounter fatalities, 165 (30%) were among children aged ≤4.
Conclusions
Animal-encounter fatalities, analyzed by UCD alone, may be underreported. An initiating animal injury, complicated by comorbidities and fatality, may obscure the causal chain, resulting in misreporting UCD. Ongoing training for medical certifiers is recommended, highlighting accurate identification of UCD and contributing causes in the causal chain of death.
West Nile virus (WNV) is an introduced pathogen, transmitted by mosquitos, that spread across North America following its arrival there in 1999. Birds host the virus, but consequences of the disease to bird species have been variable. A small number of avian species are especially susceptible to WNV, experience high mortality rates when infected, and have shown regional declines apparently because of the disease. Other species have seemingly been unaffected. Transmission of WNV is associated with climate, with higher incidence of transmission in dry areas with warm winters. The north-central United States is an area that exhibits clines in temperature and precipitation, and in this area changes in species abundance due to WNV have not been closely examined. We used Christmas Bird Count (CBC) data to investigate changes in winter abundance of selected species before and after the arrival of WNV in the Great Plains. After arrival of WNV, average estimated abundances of Black-billed Magpie (Pica hudsonia) were significantly lower than projected abundances across much of the Great Plains. Black-capped Chickadee (Poecile atricapillus) abundances reached their lowest counts in portions of the Great Plains immediately after the arrival of WNV and experienced overall negative annual declines from 1988 to 2017. Two other species that were examined did not experience changes in abundance across the study area. Abundances of Black-billed Magpies and Black-capped Chickadees have declined over the past 30 years in the Great Plains, and WNV has likely played a major role in recent declines of magpies throughout the study area.
Ungulate browsing limits forest regeneration on many reforestation and restoration sites. Silviculture can be used to mitigate the effects of ungulate damage by promoting rapid early growth of planted seedlings, but benefits may depend upon site characteristics and ungulate browse pressure. We studied the interactions among browsing by white-tailed deer (Odocoileus virginianus), use of genetically select seed sources, controlled-release fertilization (CRF) at planting, and site type (harvest openings and plantations) in a nine-year hardwood forest regeneration study. The experiment consisted of paired deer exclosure and control plots, with fertilization and seed source, established at two reforested clearcut sites and three afforested agricultural field sites in Indiana, USA. Our objectives were to examine treatment effects on growth (height and diameter), survival, and stem quality of four temperate deciduous hardwood species (northern red oak, white oak, black walnut, and black cherry). For all species, fencing had the greatest significant positive influence on survival (non-fenced: 50–72%, fenced: 71–75% by year 8) and growth (81–178% greater height and 90–167% greater diameter by year 8), as well as stem quality ratings. Fencing also increased (by 50–78%) the probability that black cherry and black walnut at afforested sites (as well as northern red oak at both site types) would reach free-to-grow status by year 5. We observed gains in height and diameter from CRF only during the first three years for fenced black cherry (11% greater height and 14% greater diameter in year 3), and for white oak regardless of fencing (13% greater height and 10% greater diameter in year 3). Genetically select seed sources had the greatest and most consistent growth benefit for black walnut (81% greater height and 50% greater diameter by year 8). Early growth was improved in genetically select P. serotina vs. non-select sources (11% greater height in year 3) but differences faded by the fifth growing season, while superior growth of genetically select Q. rubra began to manifest only after year 5 (16% greater height 21% greater diameter by year 8). In addition, select northern red oaks had an 8% greater probability of reaching free-to-grow status by year 5 and black walnuts at afforested sites had a 13% greater probability of reaching free-to-grow status. Without protection from herbivory, genetically improved sources did not realize their full potential for enhanced growth. Our results from this nine-year-long hardwood plantation experiment confirm that without browse protection, additional silvicultural treatments are unlikely to improve regeneration performance.