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1.
X-rays of wild caught barnacle geese from the Russian/Baltic population were taken in Denmark in the springs of 2009 and 2011 to determine the incidence of embedded shotgun pellets and to estimate the annual hunting kill. On average, 13 % of adult geese (n?=?212) and 6 % of first year geese (n?=?35) examined contained pellets in their tissue. Assuming that these birds represented a random sample, extrapolation to the entire population of c. 770,000 individuals indicates that 96,000 barnacle geese carry embedded pellets. Based on the assumption that the ratio between the number of birds with embedded shot and the total number of birds harvested per season is similar to that found in pink-footed geese Anser brachyrhynchus (recorded as 3.6:1 during 1990–1996 and 1.7:1 during 2009–2011), the annual kill of barnacle geese was estimated at 26,300–58,300 birds. The Russian/Baltic barnacle geese are protected from hunting on their winter quarters (The Netherlands, Germany and Denmark), but are quarry in Russia and are shot under license to protect agricultural crops in Estonia, Germany, Sweden and Denmark (amounting to a total of c. 1,800–3,000 geese shots per year). Barnacle geese are known to be shot illegally (accidentally and deliberately) along the migration route, but in the absence of Russian bag statistics, the contribution of illegal hunting to the overall harvest cannot be substantiated. Although the population is currently increasing at an annual rate of 8 %, the indirectly estimated hunting pressure (3–7 %) is not insubstantial and should be taken into account in future population management models.  相似文献   

2.
Illegal killings of protected species may significantly affect their population status or lower recovery rates after protection. Poaching is difficult to monitor directly, hence indirect methods are required to document poaching incidences and levels. The use of shotguns inevitably results in wounding some animals that are not killed. Inefficient hunting methods may result in high annual infliction rates in game species. To reduce wounding of game species, an action plan was implemented in Denmark. Using X-ray analysis, we monitor trends in prevalence of embedded shotgun pellets in the legally hunted red fox (Vulpes vulpes) after the implementation of the action plan, and assess poaching levels of two protected species, the otter (Lutra lutra) and the badger (Meles meles) in Denmark. Overall, 13.8% of the red foxes and 6.9% of the otters carried embedded shotgun pellets, while none were recorded in badgers. The prevalence of embedded shotgun pellets in red foxes declined from 24.9% to 8.5% from the late 1990s to the late 2000s, while no change was recorded in otters. Prevalence of embedded shotgun pellets was similar in otters and red foxes collected in the late 2000s. The decline in wounded red foxes suggests that the hunting methods have changed after the action plan was implemented in Denmark. The high proportion of otters carrying embedded shotgun pellets shows that there is a significant poaching of this protected species in Denmark, possibly by hunters and fish farmers that cannot distinguish between otter and non-native American mink (Neovison vison).  相似文献   

3.
Lead remnants from spent ammunition introduce health risks to humans and wildlife that consume game harvested with firearms. Most current research has focused on effects of high-velocity rifle bullets, whereas low-velocity lead ammunition has received little attention. We examined whether fragmentation characteristics differed between 3 common low-velocity ammunition types when shot into the thoracic cavity or shoulder of white-tailed deer (Odocoileus virginianus) culled in Indiana, USA, from May–September of 2009. We shot and subsequently radiographed 43 deer to determine the number of fragments, fragment size, and distance traveled by individual fragments. We also radiographed deer post-evisceration to determine the proportion of fragments available to humans and wildlife scavengers for consumption in muscle and visceral tissue, respectively. All radiographed deer had evidence of fragmentation, with a geometric mean of 13.1 (95% CI = 10.3, 16.8) fragments/deer. Most fragments (89%) were <5 mm from wound channels, and no fragment traveled beyond 205 mm from a wound channel. Fragments were often retained within the muscle tissue of deer with a geometric mean rate of 0.55 (95% CI = 0.48, 0.65). Muzzleloader bullet fragments were larger than those generated by rifled and sabot slugs, and sabot slug fragments had the shortest dispersal from wound channels. Shoulder-shot placement and bone contact for all ammunition resulted in a greater number of fragments (P < 0.01). Shoulder-shots also generated more small fragments and higher fragment retention in muscle tissue. The overall mean number of lead fragments detected across our ammunition treatments was less than previous studies. Our results indicate ammunition type and shot placement may be considerations for hunters wishing to limit their potential exposure to lead from harvested big game. Additionally, when compared to high-velocity rifle bullets, significantly fewer lead fragments are made available to humans and wildlife that consume game harvested with low-velocity ammunition types, such as those tested here. Complete elimination of lead ingestion by humans and wildlife, however, is only possible by using non-toxic ammunition alternatives. © 2020 The Wildlife Society.  相似文献   

4.
Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15–409) and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80%) of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 µg/dL (maximum 3.8 µg/dL) 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 µg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low-income beneficiaries of venison donations.  相似文献   

5.
ABSTRACT The scientific evidence that California condors (Gymnogyps californianus) are frequently sickened and killed by lead poisoning from spent ammunition supports the conclusion that current levels of lead exposure are too high to allow reintroduced condors to develop self-sustaining populations in the wild in Arizona and, by inference, in California. The evidence for lead poisoning and its source comes from the following sorts of data: 1) 18 clinical necropsies revealing high levels of lead in body tissues and (or) presence of lead shotgun pellets and bullet fragments in digestive tracts; 2) moribund condors showing crop paralysis and impending starvation with toxic levels of lead in their blood; 3) widespread lead exposure among free-flying condors, many with clinically exposed or acute levels; 4) temporal and spatial correlations between big game hunting seasons and elevated lead levels in condors; and 5) lead isotope ratios from exposed condors showing close similarity to isotope ratios of ammunition lead but isotope ratios in less exposed condors being similar to environmental background sources, which are different from ammunition lead. Simple population models reveal harmful demographic impacts of unnatural mortality from lead on population trajectories of reintroduced condors. Recent innovations in the manufacture of nonlead shotgun pellets and bullets with superior ballistics now provide for a simple solution to the problem of lead ingestion by condors, many other species of wildlife, and human beings: substitute nontoxic forms of ammunition for traditional lead-based ammunition. The substitution of nontoxic ammunition would be highly efficacious for hunting, economically feasible, and the right thing to do.  相似文献   

6.
The use of lead shot for wildfowling is a severe threat to waterbirds through ingestion of toxic lead pellets. Consequently, lead shot has been banned in many countries since the late 1990s and on Tour du Valat estate since 1994 (Camargue, France). An experimental study was undertaken to check if hunters would habituate to this new type of cartridge and consequently improve their effectiveness (average number of shots per bagged animal), assess the factors influencing effectiveness, and assess the trend of contamination in shot waterbirds and the estate sediment. From 1995 to 2005, we monitored hunting bags, spent cartridges, and the gizzards of shot ducks. Using generalized mixed effect models, we assessed the factors influencing hunter effectiveness. Instances of non-toxic pellets in duck gizzards increased, probably as a result of rapid accumulation in the sediments. We estimated that between 1995 and 2005, the lead shot ban spared 456 kg of lead from entering 403 ha of temporary marshes and avoided the contamination of 8 % of the ducks foraging on Tour du Valat. After 11 years of hunting with non-toxic shot, there was unexpectedly no clear pattern in trends of individual effectiveness among hunters. Hunter effectiveness was instead positively influenced by game abundance and hunter assiduity and negatively influenced by wind and number of shots, suggesting a lassitude effect. Our results suggest crippling loss can be reduced through regular practice, self-limitation of shooting intensity to below 20 shots to avoid lassitude effects, and self-limitation of shooting distance under strong wind conditions.  相似文献   

7.
Lead poisoning affects numerous threatened raptors and is a major cause of death in white-tailed eagles (Haliaeetus albicilla). A major reason for intoxication is assumed to be lead fragments ingested while feeding on game animals killed by lead-based projectiles. However, empirical evidence on the relevance of carrion in raptor diets remains scarce. We therefore investigated the link between raptor feeding ecology and lead poisoning, with white-tailed eagles as a model species for scavenging birds. We collected data on seasonal diet composition and food availability of 7 territorial white-tailed eagle pairs in northeastern Germany. We also analyzed stomach contents (SCs) of 126 eagles found dead from 1996 to 2008 throughout Germany. Multiple regression models revealed that fish were the primary prey for eagles, and waterfowl and carcasses of game mammals comprised a large portion of alternative diet components. Eagles used individual foraging tactics, adjusted to local food supply, to maximize profitability. They showed a type II functional response to fish availability. When fish availability sharply declined, eagles switched to waterfowl and carrion. The consumption of game mammal carrion increased over autumn and winter and was positively correlated with a concomitant seasonal increase in the incidence of lead poisoning in eagles throughout Germany. The stomachs of lead-poisoned eagles predominantly contained game ungulate remains. These results indicate that carcasses of game mammals were the major sources of lead fragments. The link between raptor feeding ecology and lead poisoning is the specific functional response of raptors to changing food availability or poor habitat quality, leading to scavenging on lead-contaminated carrion. This shows that carrion constitutes a considerable threat to white-tailed eagles and other birds with similar feeding habits as long as it contains lead bullet fragments. Conservation management of scavenging birds would be substantially improved if carrion was free of lead bullet fragments. One method to achieve this is the widespread introduction of lead-free ammunition. © 2012 The Wildlife Society.  相似文献   

8.
Two collection methods for screening the mallard (Anas platyrhynchos) population in the Netherlands for the ingestion of spent lead shot were compared. One method consisted of examination of gizzards from mallards shot by hunters (n = 2,859) and the other method consisted of examination of gizzards from mallards caught in duck traps (n = 865). The 95% confidence interval of lead shot ingestion in the mallard population estimated by the first method was 1.7 to 2.9% and by the second method 1.1 to 3.1%. These values were not significantly different. From the numbers of lead pellets embedded in the gizzard wall in hunter-killed and trapped mallards it was estimated that at least 22 to 68% of the trapped ducks had been hit by lead shot previously, but survived. Furthermore, this study shows that it is reasonable to assume that a substantial part of the pellets which are identified (in this study and other studies) as ingested, may well have been shot into the gizzard lumen at some time before the birds were actually killed. To avoid lead poisoning in mallards and in raptors depredating waterfowl hit by lead shot, a change to steel shot is advocated.  相似文献   

9.
Although metal legbands have been an important scientific tool, their use for estimation of harvest and survival relies on samples of dead birds harvested by hunters using shotguns. We hypothesized that the force of steel pellets discharged from a shotgun, within the range of conditions normally experienced by goose hunters, was sufficient to reduce probability of band retention. We conducted 8 experimental trials to estimate retention per round fired at aluminum bands normally applied to arctic-nesting geese in relation to effects of 1) target range (20 m vs. 40 m), 2) steel pellet size (4.57 mm [BB] vs. 3.81 mm [number 2]), 3) cartridge size (76.2 mm [3 in.] vs. 69.9 mm [2.75 in.]), and 4) number of rounds fired (up to 25). There was nearly complete band retention (0.999/round) at 40 m regardless of shot size or shell size used. Retention per round fired at 20 m declined to between 0.984 and 0.987 for number 2 shot and between 0.968 and 0.974 for BB shot. Our conclusions apply to unworn bands, so we recommend further simulations to assess how retention may change with age of bands as they erode or corrode on free-ranging geese. Bias in estimates associated with loss of older bands from shotgun discharge could be adjusted if bias is estimated as done in this article. © 2011 The Wildlife Society.  相似文献   

10.
Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites.  相似文献   

11.
Twenty mallards (Anas platyrhynchos) of both sexes were dosed by oral gavage with Heavi-Shot (H-S; Environ-Metal, Inc., Sweet Home, Oregon, USA) pellets, 20 with steel shot, and 10 with lead (Pb) pellets, all of equal size. All pellets were fired from a shotgun into an absorbent material, retrieved, and weighed prior to introduction into the ducks. Birds were fed whole kernel corn and grit and observed for signs of toxicity for 30 days following dosing. Hevi-Shot pellets lost an average of 6.2% of their mass and steel shot pellets lost 57% of their mass in the birds' gizzards. Almost all (90%) of the Pb shot dosed birds died before the end of the study, while no mortality was observed in the steel or H-S dosed groups. Even though total food consumption differed between the H-S and steel shot groups, mean bird weight change was not different. There were no significant morphologic or histopathologic abnormalities of the liver and kidney in the H-S and steel shot groups. Results indicated that mallards dosed orally with eight No. 4 H-S pellets were not adversely affected over a 30-day period, and that H-S provides another environmentally safe nontoxic shot for use in waterfowl hunting.  相似文献   

12.

Background

Lead is highly toxic to animals. Humans eating game killed using lead ammunition generally avoid swallowing shot or bullets and dietary lead exposure from this source has been considered low. Recent evidence illustrates that lead bullets fragment on impact, leaving small lead particles widely distributed in game tissues. Our paper asks whether lead gunshot pellets also fragment upon impact, and whether lead derived from spent gunshot and bullets in the tissues of game animals could pose a threat to human health.

Methodology/Principal Findings

Wild-shot gamebirds (6 species) obtained in the UK were X-rayed to determine the number of shot and shot fragments present, and cooked using typical methods. Shot were then removed to simulate realistic practice before consumption, and lead concentrations determined. Data from the Veterinary Medicines Directorate Statutory Surveillance Programme documenting lead levels in raw tissues of wild gamebirds and deer, without shot being removed, are also presented. Gamebirds containing ≥5 shot had high tissue lead concentrations, but some with fewer or no shot also had high lead concentrations, confirming X-ray results indicating that small lead fragments remain in the flesh of birds even when the shot exits the body. A high proportion of samples from both surveys had lead concentrations exceeding the European Union Maximum Level of 100 ppb w.w. (0.1 mg kg−1 w.w.) for meat from bovine animals, sheep, pigs and poultry (no level is set for game meat), some by several orders of magnitude. High, but feasible, levels of consumption of some species could result in the current FAO/WHO Provisional Weekly Tolerable Intake of lead being exceeded.

Conclusions/Significance

The potential health hazard from lead ingested in the meat of game animals may be larger than previous risk assessments indicated, especially for vulnerable groups, such as children, and those consuming large amounts of game.  相似文献   

13.
Lead poisoning threatens many species of raptors, including golden eagles (Aquila chrysaetos). Much of this lead likely comes from bullet fragments that remain in the carcasses of animals killed by hunters. The likelihood of lead exposure may peak during fall hunting seasons and early winter until carcasses from hunting become scarce. From 2011 to 2018 in western Montana, USA, we captured 91 golden eagles in winter, tested their blood lead levels (BLL), and outfitted a subset of birds (n = 29) with global positioning system [GPS] transmitters. Nearly all golden eagles (94.5%) had elevated BLL (≥10 μg/dL), and 8 of them had BLL above clinical exposure (>60 μg/dL), where they may lose coordination and experience a host of other neurological and physiological disorders. Golden eagles caught late in winter tended to have lower BLL than those caught earlier. At least 69% of the golden eagles equipped with GPS transmitters migrated northward, spending the summer throughout Alaska, USA, and northwestern Canada. Blood lead levels did not differ between migratory and nonmigratory golden eagles. Overall, elevated BLL are widespread among golden eagles throughout winter in western Montana. Promoting nonlead hunting ammunition in areas with high densities of golden eagles will reduce the birds' lead exposure. © 2020 The Wildlife Society.  相似文献   

14.
Abstract: Although lead shot has been banned for waterfowl hunting in North America, some predators continue to exhibit elevated lead burdens, which has been attributed to ingesting metallic lead from other projectiles. Few studies have investigated residual lead fragments in hunted upland animals. Therefore, specific portals for lead entering wildlife food chains remain largely unknown. Prairie dogs (Cynomys spp.) are shot for recreation with minimal regulation in western North America. Because recreational shooters mostly use expanding bullets and rarely remove or bury carcasses, shot prairie dogs could make lead accessible to predators and scavengers. To determine whether and to what degree shot prairie dogs carry lead fragments, we analyzed carcasses shot by recreational shooters with 2 bullet types. Bullet type influenced the probability of bullet fragments being retained in carcasses; 87% of prairie dogs shot with expanding bullets contained bullet fragments, whereas 7% of carcasses shot with non-expanding bullets did. The amount of bullet fragments per carcass also differed between bullet types; carcasses shot with expanding bullets contained a mean of 228.4 mg of the lead-containing bullet core and 74.4 mg of the copper-alloy jacket, whereas carcasses shot with non-expanding bullets averaged only 19.8 mg of the core and 23.2 mg of the jacket. Lead fragments in carcasses shot with expanding bullets were small in size; 73% of all lead mass in each carcass was from fragments that weighed <25 mg each, small enough to be easily ingested and absorbed by secondary consumers. The amount of lead in a single prairie dog carcass shot with an expanding bullet is potentially sufficient to acutely poison scavengers or predators. Therefore, shot prairie dogs may provide an important portal for lead entering wildlife food chains and may pose risks to raptors and carnivores. Managers should consider measures, such as using non-expanding or lead-free ammunition, to reduce the likelihood of lead consumption and poisoning in upland wildlife.  相似文献   

15.
Top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. Lead accumulation can induce severe disorders and alter survival both in mammals (including humans) and in birds. A potential source of lead poisoning in wild animals, and especially in scavengers, results from the consumption of ammunition residues in the tissues of big game killed by hunters. For two consecutive years we quantified the level lead exposure in individuals of a sentinel scavenger species, the common raven (Corvus corax), captured during the moose (Alces alces) hunting season in eastern Quebec, Canada. The source of the lead contamination was also determined using stable isotope analyses. Finally, we identified the different scavenger species that could potentially be exposed to lead by installing automatic cameras targeting moose gut piles. Blood lead concentration in ravens increased over time, indicating lead accumulation over the moose-hunting season. Using a contamination threshold of 100 µg.L−1, more than 50% of individuals were lead-contaminated during the moose hunting period. Lead concentration was twice as high in one year compared to the other, matching the number of rifle-shot moose in the area. Non-contaminated birds exhibited no ammunition isotope signatures. The isotope signature of the lead detected in contaminated ravens tended towards the signature from lead ammunition. We also found that black bears (Ursus americanus), golden eagles and bald eagles (Aquila chrysaetos and Haliaeetus leucocephalus, two species of conservation concern) scavenged heavily on moose viscera left by hunters. Our unequivocal results agree with other studies and further motivate the use of non-toxic ammunition for big game hunting.  相似文献   

16.
ABSTRACT Wildlife managers are becoming more concerned about the exposure of birds, in addition to waterfowl, to spent lead shot. Knowledge of hunter attitudes and their acceptance of nontoxic-shot regulations will be important in establishing new regulations. Our objective was to assess the attitudes of small game hunters in Missouri, USA, toward a nontoxic-shot regulation for small game hunting, specifically for mourning doves (Zenaida macroura). Most hunters (71.7–84.8%) opposed additional nontoxic-shot regulations. Hunters from rural areas, hunters with a rural background, hunters who hunt doves, hunters who currently hunt waterfowl, hunters who primarily use private lands, and current upland game hunters were more likely to oppose new regulations. For mourning dove hunting, most small game hunters (81.1%) opposed further restrictions; however, many non-dove hunters (57.1%) expressed no opinion. Because our results demonstrate that most small game hunters and dove hunters in Missouri are decidedly against further nontoxic-shot regulations, any informational and educational programs developed to accompany future policy changes must address their concerns.  相似文献   

17.
Scavengers are subsidized by the remains of hunting worldwide. Although most studies focus on carcasses of large mammals, small mammals that have been shot likely provide a significant food subsidy as well, particularly in parts of the western United States. Millions of small mammals are estimated to be shot each year for damage control and recreation, many being left in the field. Despite this prevalence of carrion, and the potential for scavengers to ingest residual lead from bullet fragments, the fate of these carcasses is largely unknown. We deployed remote cameras to observe which scavengers consumed shot ground squirrels (Urocitellus spp.) and black-tailed prairie dogs (Cynomys ludovicianus) in 8 locations across Montana, USA. At least 5 species of mammals and 9 species of birds scavenged, including burrowing owls (Athene cunicularia). Scavengers fully consumed 66% of carcasses and partially consumed 9%. Carcasses lasted an average of 24.5 hours before the first scavenger arrived. Of carcasses that were scavenged, mammals ate 16% and birds ate 84%, with corvids and raptors consuming an equal number of carcasses. Common ravens (Corvus corax) and black-billed magpies (Pica hudsonia) visited the most carcasses and often arrived first. Scavengers consumed only 9% of the carcasses that were partially concealed by being inside a burrow. Overall, our results indicate that a diverse scavenger community consumes shot ground squirrels and black-tailed prairie dogs, and consequently, may be exposed to lead from bullet fragments. © 2019 The Wildlife Society.  相似文献   

18.
ABSTRACT

Capsule: Diet analysis revealed high lead exposure for Greater Spotted Eagles Clanga clanga wintering in southeast Spain.

Aims: To describe the diet composition of the endangered Greater Spotted Eagle in a wintering area located in southeast Spain, and determine lead ammunition exposure through analysis of regurgitated pellets and prey remains.

Methods: Between 2008 and 2018, a total of 26 pellets, 29 prey remains and 10 direct predation observations were collected in El Hondo Natural Park, Spain. All the pellets and 10 prey remains were analysed with X-ray in order to detect metal from ammunition.

Results: Greater Spotted Eagles fed mainly on birds, with 18 different species accounting for 73.1% of prey items and 66.1% of biomass consumed. The most frequent species identified were Common Moorhen Gallinula chloropus (23.1%), rats Rattus spp. (15.4%) and Common Teal Anas crecca (8.9%). Ammunition was detected in 42.3% of regurgitated pellets and in 40.0% of prey remains analysed. Of those containing ammunition, lead shot was found in 63.9% of pellets and 25.0% of prey remains.

Conclusion: High lead shot presence in pellets and prey remains of wintering Greater Spotted Eagles in southeast Spain warns of a high risk of lead poisoning. Factors such as feeding behaviour, the large space–time overlap between the raptor presence and the waterbird hunting season and non-compliance with the ban on the use of lead ammunition are likely contributing to high lead exposure.  相似文献   

19.
Many populations of wildlife, including large- and medium-sized predators are increasing in Europe. Trapping can be one way to reduce negative impacts of predators on human interests, such as game species and threatened species, but there is little knowledge of trap usage and motivation behind it. We used a mail survey in Sweden (n?=?3,886 respondents) to compare predator trappers with hunters who used other methods to kill predators, and with other hunters who did not kill predators, in regard to sociodemographics, beliefs, behaviors, and constraints. During 12 months prior to the survey 19 % of respondents had trapped any small- or medium-sized predator, while 15 % of respondents had trapped and 55 % had hunted (without using traps) red fox (Vulpes vulpes), European badger (Meles meles), or corvid birds. Reducing predator numbers was an important reason for hunting predators with traps. Of predator trappers, 97 % had hunted species that were potentially prey of the targeted predators (e.g., roe deer [Capreolus capreolus], hare [Lepus spp.], and grouse), 94 % believed that there were too many red foxes, badgers, or corvids on their main hunting ground, and 64 % believed it to be very important to reduce predator numbers to benefit other game species. We conclude that the use of traps is widespread among Swedish hunters, and that increasing wildlife populations, increased presence of wildlife in urban areas, and management of invasive species calls for effective management actions, of which trapping can be one.  相似文献   

20.
Studies suggest hunter discarded viscera of big game animals (i.e., offal) is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005–2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL) during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009–2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles.  相似文献   

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