Red Fox Use of Landscapes with Nesting Shorebirds

Predation of nests and young is one of the limiting factors in the conservation of birds; understanding environmental covariates of predator distribution can assist with decisions regarding the best management strategies to reduce predation risk. The habitat of beach-nesting birds is often reshaped by storms in ways that may affect nest predation, such as by flattening vegetated dunes where mammals hunt, but human management of beaches tries to prevent the effects of storms on the landscape with unknown implications for predator distributions. Moreover, human development may affect predator distributions by subsidizing food and shelter. To determine the relationship between predator occupancy and landscape features in beach-nesting bird habitat, we repeated mammalian predator track surveys 8 times/year at 90 plots in southern New Jersey, USA, from 2015–2017. We used dynamic occupancy models to estimate the probability of use by red foxes (Vulpes vulpes) and to document changes in habitat use as related to landcover types over the avian breeding season within years. We had 373 red fox detections with years pooled. Detection probability for red foxes varied by year, and probability of use decreased as the distance to the nearest primary dune increased. We found no evidence that red fox habitat use depended on distance to human development. Our results suggest that conserving nesting habitat that includes open areas (i.e., storm overwash [whereby vegetation is scoured by tidal flooding]) may reduce predation risk because beach-nesting birds would not be forced into nesting close to dunes, which are typically used for hunting by red foxes. © 2020 The Wildlife Society.     

Traditional and New Cable Restraint Systems to Capture Fox in Central Spain

ABSTRACT Capturing animals is an essential tool of wildlife management, but the use of capture devices is being affected by public pressures on an international scale. In Europe, and particularly Spain, foxes (Vulpes vulpes) are often captured using traditional methods such as nonlocking Spanish Snares (SS) set in an ad hoc fence line known as an alar, but these traditional European methods are rarely compared to modernly described restraints such as the Wisconsin Cable Restraint (WR). We evaluated rates of efficiency, selectivity, injury, and impacts to foxes and nontarget species when using SS (as traditionally set in an alar) or WR within alars or on trails in Castilla-La Mancha, Spain. During 40,372 trap-nights from summer to winter of 2007, we captured 64 foxes, and 8 of 23 potential nontarget species. Our results indicated that WR set in trails were more efficient (0.28 capture rate) for capturing red foxes than SS set in an alar (0.11 capture rate). Relative to injury, foxes captured with the WR in the alar (95.4%), and WR in trails (90.5%), and the SS (90.9%) showed no indicators of poor welfare, and injury score analysis indicated that injuries were of similar magnitude for all capture devices. Overall, the WR set in trails may have performed the best, but all 3 methods are likely sufficient for capturing foxes with minimal injury, acceptable efficiency, and acceptable impact to foxes and sympatric nontarget species. Thus, wildlife managers in Spain and elsewhere can apply our findings to optimize capture and management of foxes.     

Evaluation of Cage-Traps and Cable Restraint Devices to Capture Red Foxes in Spain

Abstract: A growing international concern for the welfare of animals, combined with the need to capture and handle specific species for conservation, management, or recreational purposes, is increasing the need for scientific evaluation of capture methods. We evaluated the efficiency, selectivity, and injury of cable restraint devices and cage-traps for capture of red foxes (Vulpes vulpes) in 4 sites of Castilla y León (Spain) during spring of 2006. All traps performed similarly at all sites, with no apparent site and trap interactions. Fox capture rates and mechanical efficiencies of the Belisle® (Edouard Belisle, Saint Veronique, PQ, Canada) and Collarum® (Wildlife Control Supplies, East Granby, CT; mention of product names does not infer endorsement) were similar, but both had higher capture rates than the cage-trap. Similar to previous studies, the Collarum was 100% selective for canids and had a selectivity of 94.4 overall, which was higher than that for the Belisle (63.4); both Collarum and Belisle were much more selective than the cage-trap (21.4). Fox injuries were statistically indistinguishable using injury scores, but the Collarum and the Belisle surpassed international standards for humane trapping; an insufficient number of animals were captured in cage-traps to allow evaluation. Both the Collarum and the Belisle may be useful for the capture of foxes in Spain, but training and experience with each may be necessary to ensure the highest efficiency while preventing injuries, especially to nontarget species. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):830–836; 2008)     

Natal Dispersal and Philopatry of Red Foxes in Urban and Agricultural Areas of Illinois

Abstract: Dispersal and philopatry may be influenced by habitat, intraspecific and interspecific interactions, and resource quality. Dispersal may vary substantially between urban and rural wildlife populations due to differences in urban-rural habitat and trophic relationships. We examined effects of environmental, body condition, and social influences on dispersal and philopatry of urban and rural red foxes (Vulpes vulpes) in east-central Illinois and western Indiana, USA. We recorded 96 dispersal events and 66 cases of philopatry in juvenile foxes. We used Akaike's Information Criterion to evaluate regression models of dispersal probability, initiation date, distance, and days spent dispersing. Habitat (i.e., urban-rural), sex, row-crop percentage in natal home ranges, family home-range overlap, and social interactions with family members all influenced dispersal probability. Juvenile foxes with fewer row crops in their home ranges, individuals with high intra-familial overlap of summer range, females, and urban foxes were associated with philopatry. Dispersals began mid-September and ended in March. Rural juveniles dispersed 23 days earlier than did urban conspecifics. Heavier foxes (capture wt) and those with heavily row-cropped home ranges dispersed earlier. Littermates dispersed at similar times, although in different directions. Dispersal distances averaged 44.8 km for all foxes (range = 1–478 km). Male and urban foxes dispersed farther than female and rural foxes, respectively. Time between dispersal and settlement averaged 41.2 days (range = 2–114 days), with urban foxes dispersing over longer time periods. Dispersal direction between the sexes had different directional distributions, though mean vectors for both were oriented north. Dispersing foxes selected cropland in proportion to availability, whereas grassland was selected preferentially. We demonstrate influences of habitat, resource availability, familial social interactions, and interspecific interactions on dispersal and philopatry of juvenile red foxes in an intensively row-cropped region of the Midwest. Our findings demonstrate red fox dispersal ecology differences in urban and rural environments. In intensively row-cropped regions of the Midwest where landscape crop harvest alters dispersal timing, minimizing seasonal habitat changes with permanent vegetative structure (e.g., crop food plots, native grass fields) would likely delay dispersal activity, and increase survival.     

Factors influencing the nesting success of Lapwings Vanellus vanellus and behaviour of Red Fox Vulpes vulpes in Lapwing nesting sites

Capsule Lapwing nest predation was negatively correlated to nest density, while Lapwing alarm duration in response to foxes was positively correlated with the number of Lapwing broods present.

Aims To identify factors affecting Lapwing nest predation and Red Fox search effort.

Methods Lapwing nest success was monitored at four sites in 1996, seven sites in 1997 and six sites in 1998. In 1997 we mapped the position of all Lapwing nests in order to determine distances between nests, and the proximity of linear features and potential avian predator perches to each nest. From April to June 1998 we carried out 199 hours of nocturnal observations at six Lapwing nesting sites using night vision equipment.

Results The risk of nest predation was significantly higher for more isolated nests. Nocturnal observations showed that of all the nocturnal predators, foxes were the most active at Lapwing nesting sites. However, fox search effort in Lapwing colonies was relatively low, averaging 57 s/ha per visit. Foxes spent significantly longer foraging near breeding Lapwings (measured as duration of alarm calls) when more broods were present. Fox search effort (s/ha per hour of observation) tended to be greater in areas of high waterbird density.

Conclusion The lack of positive density-dependent nest predation, the relatively low search effort of foxes near Lapwing nesting sites and the high nest success sometimes achieved in areas with foxes all suggest that Lapwing nest predation by foxes is ‘incidental’. Lapwing chicks are probably more vulnerable to predation by foxes than clutches.     

Survival and Cause-Specific Mortality of Red Foxes in Agricultural and Urban Areas of Illinois

Abstract: Range expansion and population increase by coyotes (Canis latrans), reduced hunting and trapping, and intensified agricultural practices in the Midwest have altered red fox (Vulpes vulpes) mortality, although relative impacts of these factors are unknown. We examined mortality causes and survival of red foxes in urban and rural agricultural areas of Illinois, using radio telemetry data from 335 foxes (Nov 1996 to May 2002). We used Akaike's Information Criterion to evaluate six survival models for foxes reflecting 1) environmental effects, 2) intrinsic effects, 3) temporal effects, 4) behavioral effects, 5) social effects, and 6) a global model. Environmental and intrinsic models of survival were optimal for adult foxes. Adult foxes with low (0-20%) and high (80-100%) percentages of row crops in their home ranges had higher survival than adults with moderate percentages (40-70%). Heavier adults at capture also survived better. A global model (all covariates) was optimal for juvenile foxes. Higher juvenile survival associated with larger litters, lower body fat, and reduced dispersal time. Yearly survival ranged from 0.18 for rural male juveniles to 0.44 for rural female adults. Adult survival rates (0.35) were 11% higher than juvenile survival rates (0.24). Yearly survival varied for urban foxes due to cyclic outbreaks of sarcoptic mange (Sarcoptes scabei). Thus, summer survival (May-Sep) of urban juveniles ranged from 0.10 (mange present) to 0.83 (no mange recorded). Mange was the most common (45% of all fatalities) source of mortality for urban foxes, followed by road kill (31%). We recorded only 4 mange fatalities (2%) for rural foxes. Rural foxes experienced low hunting mortality (7%) and equivalent road kill and coyote predation fatalities (40% each). Sources of mortality for midwestern foxes have dramatically changed since the 1970s when hunting was the major cause of mortality. Coyote predation has effectively replaced hunting mortality, and cyclic patterns of mange outbreaks in urban fox populations might indicate a dynamic source or sink relationship to surrounding rural fox populations. Absent mange, urban areas might provide refugia for red foxes where coyote populations persist at high densities in rural areas. Managers of sympatric urban and rural wildlife populations must understand survival dynamics influencing the population at the landscape level.     

三种犬科动物春季洞穴特征

2004年4月-2005年6月在内蒙古达赉湖国家级自然保护区对20个狼穴、27个赤狐洞穴、33个沙狐洞穴进行测量调查,结果如下：3种犬科动物洞穴的洞口朝向无显著差异,赤狐和沙狐洞穴在洞口倾角、洞口直径、第一洞道长度3个特征上无显著差异,洞口直径可作为判别狼穴与其它两者洞穴的依据。影响狼春季洞穴选择的前3位主要因子是隐蔽、人为干扰和水源。影响赤狐春季洞穴选择的前3位主要因子是地形、水源、和人为干扰。影响沙狐春季洞穴选择的前3位主要因子是微气候、人为干扰和食物。通过对3种犬科动物春季洞穴生境选择的比较发现：3种动物洞穴都有远离人为干扰,提高隐蔽性的趋势;不同的是赤狐和狼的洞址都靠近水源,沙狐洞址则远离水源;3种动物在地形及坡位选择上也存在差异,赤狐和狼的洞穴多位于平地。而沙狐洞穴多位于坡地的坡顶,且洞穴周围啮齿类数量显著大于赤狐洞穴和狼穴。柳灌丛、干旱苇塘、高草坡地分别是赤狐、狼、沙狐偏爱的生境类型。3种犬科动物中洞穴生态位宽度最大的是狼（0．5051）,其次为赤狐（0．4292）,最小为沙狐（0．2591）。其中狼与赤狐洞穴空间生态位重叠指数较高,达到了0．4692,沙狐与赤狐洞穴空间生态位重叠指数最低,只有0．2356。     

Genetic tagging reveals a significant impact of poison baiting on an invasive species

Globally, invasive predators are major pests of agriculture and biodiversity and are the focus of comprehensive control programs. Because these species are typically elusive, wary of traps, and occur at low densities, their fundamental population dynamics are difficult to determine and quantitative evaluations of control programs are rarely conducted. Noninvasive DNA analysis has the potential to resolve this long-standing limitation to pest management. We carried out a landscape-scale experiment to quantify reduction in the abundance of a red fox (Vulpes vulpes) population when baited with sodium fluoroacetate (1080) poison (the most widely used method of fox control in Australia). We collected fox hairs with hair snares during 4 4-day sessions over the course of 6 months at a site in semi-arid Western Australia. The first session took place in late summer just prior to when juvenile foxes typically disperse, and the final session followed aerial baiting with 1080 poison. We obtained consensus microsatellite genotypes from 196 samples, and used them to conduct both spatially explicit and open model capture–recapture analysis. Twenty-eight percent of trap nights yielded hair samples suitable for identification of individual foxes, which is more than an order of magnitude greater than trapping rates reported with conventional techniques. Fox density changed little during 3 pre-baiting sessions and averaged 0.73 foxes/km² (±0.33 SE), which is less than most previous trap-based estimates for Australian foxes. Density dropped significantly in response to baiting to 0.004 foxes/km². Prior to baiting, the apparent survival of foxes remained static (0.72 ± 0.14 SE), but in response to baiting it dropped precipitously and was effectively zero. This experiment provides the first quantitative assessment of the effectiveness of 1080 poison baiting for reducing fox density, and in this case demonstrates it to be a highly effective method for culling foxes from a region. Further, it demonstrates that noninvasive DNA analysis will provide significantly more data than conventional trapping methods. This method is likely to provide greater precision and accuracy than conventional methods and therefore result in more robust evaluations of management strategies for the fox in Australia, and for cryptic species elsewhere. © 2011 The Wildlife Society.     

Phylogeography of the North American red fox: vicariance in Pleistocene forest refugia

Fossil, archaeological, and morphometric data suggest that indigenous red foxes in North America were derived from vicariance in two disjunct refugia during the last glaciation: one in Beringia and one in the contiguous USA. To test this hypothesis, we conducted a phylogeographical analysis of the North American red fox within its presettlement range. We sequenced portions of the mitochondrial cytochrome b (354 bp) gene and D-loop (342 bp) from 220 historical red fox specimens. Phylogenetic analysis of the cytochrome b gene produced two clades that diverged c . 400 000 years before present ( bp ): a Holarctic and a Nearctic clade. D-loop analyses of the Nearctic clade indicated three distinct subclades (≥ 99% Bayesian posterior probability); two that were more recently derived (rho estimate c . 20 000 bp ) and were restricted to the southwestern mountains and the eastern portion of North America, and one that was older (rho estimate c . 45 000 bp ) and more widespread in North America. Populations that migrated north from the southern refugium following deglaciation were derived from the colonization of North America during or prior to the Illinoian glaciation (300 000–130 000 bp ), whereas populations that migrated south from the northern refugium represent a more recent colonization event during the Wisconsin glaciation (100 000–10 000 bp ). Our findings indicate that Nearctic clade red foxes are phylogenetically distinct from their Holarctic counterparts, and reflect long-term isolation in two disjunct forest refugia during the Pleistocene. The montane lineage, which includes endangered populations, may be ecologically and evolutionarily distinct.     

Total Counts Versus Line Transects for Estimating Abundance of Small Gopher Tortoise Populations

Abstract: Status and trends of gopher tortoise (Gopherus polyphemus) populations are a critical information need for natural resource managers, researchers, and policy makers. Many tortoise populations are small and isolated, which can present challenges for deriving population estimates. Our objective was to compare abundance and density estimates for a small tortoise population derived using a total burrow count versus estimates obtained with line transect distance sampling (LTDS) using repeated surveys. We also compared results of the 2 survey methods using standard burrow-to-tortoise correction factors versus assessing occupancy of all burrows with a camera scope. In addition, we compared LTDS data obtained using a compass and measuring tape to define transects to those obtained using a Global Positioning System (GPS) and Personal Data Assistant (PDA) field computer to navigate transects. Line transect distance sampling with repeated surveys (both with a measuring tape and compass and with a GPS—PDA) yielded sufficient observations of tortoises to calculate population estimates. From 18% to 31% of burrows were occupied by tortoises as determined with the burrow camera. We found 25 burrows during the LTDS survey that we did not find in the total count survey, which demonstrated that the assumption of 100% detection for the total count was not met; hence, density or abundance measurements derived with this method were underestimates. We recommend using GPS—PDA technology, scoping all burrows detected, and using LTDS with repeated surveys to estimate abundance and density for small gopher tortoise populations.     

Field Sedation of Coyotes,Red Foxes,and Raccoons With Medetomidine and Atipamezole

Abstract: We chemically restrained free-ranging coyotes (Canis latrans), red foxes (Vulpes vulpes), and raccoons (Procyon lotor) using medetomidine antagonized by atipamezole. All coyotes and 80% of red foxes were sedated with mean ± standard deviation doses of 0.12 ± 0.02 mg/kg and 0.14 ± 0.02 mg/kg medetomidine, respectively. Seventy-seven percent of raccoons were sedated with 0.21 ± 0.05 mg/kg medetomidine. In all species we observed occasional movement, muscle rigidity, and partial-arousal during sedation. Animals were alert within 4.3–8.6 ± 3.5–8.4 min following atipamezole at 0.4 mg/kg. Medetomidine and atipamezole provided safe handling in most animals and rapid recovery without use of a controlled substance. At these doses, biologists in the field should be prepared to administer a supplementary dose of medetomidine to some animals depending on ambient conditions and the objectives of the restraint event.     

The effect of habitat and human disturbance on the spatiotemporal activity of two urban carnivores: The results of an intensive camera trap study

With rising urbanization, the presence of urban wildlife is becoming more common, increasing the need for wildlife‐friendly spaces in urban planning. Despite this, understanding is limited to how wildlife exploits urban environments and interacts with human populations, and this is vital to our ability to manage and conserve wildlife in urban habitats. Here, we investigate how two urban mammal species, the red fox (Vulpes vulpes) and the European badger (Meles meles), exploit urban environments. Using intensive camera trap surveys, we assessed how habitat and human disturbance influenced the spatiotemporal activity of these species across south‐west London. Firstly, we found elevated activity levels of both species at boundaries and within built‐up areas, suggesting movement paths follow anthropogenic features. However, badgers were most active in woodland, indicating the importance of high cover habitats suitable for setts and foraging. Secondly, we found badger activity levels were negatively affected by human activity, whilst foxes were unaffected. Further investigation suggested foxes may adapt their activity patterns to avoid human disturbance, with badger activity patterns less plastic. Whilst the results of this study are useful for both the conservation and management of urban wildlife populations, these results also show potential factors which either facilitate or limit wildlife from fully exploiting urban environments.