Effects of Coyote Population Reduction on Swift Fox Demographics in Southeastern Colorado

ABSTRACT The distribution and abundance of swift foxes (Vulpes velox) has declined from historic levels. Causes for the decline include habitat loss and fragmentation, incidental poisoning, changing land use practices, trapping, and predation by other carnivores. Coyotes (Canis latrans) overlap the geographical distribution of swift foxes, compete for similar resources, and are a significant source of mortality amongst many swift fox populations. Current swift fox conservation and management plans to bolster declining or recovering fox populations may include coyote population reduction to decrease predation. However, the role of coyote predation in swift fox population dynamics is not well-understood. To better understand the interactions of swift foxes and coyotes, we compared swift fox population demographics (survival rates, dispersal rates, reproduction, density) between areas with and without coyote population reduction. On the Piñon Canyon Maneuver Site, Colorado, USA, we monitored 141 swift foxes for 65,226 radio-days from 15 December 1998 to 14 December 2000 with 18,035 total telemetry locations collected. Juvenile swift fox survival rate was increased and survival was temporarily prolonged in the coyote removal area. Adult fox survival patterns were also altered by coyote removal, but only following late-summer coyote removals and, again, only temporarily. Coyote predation remained the main cause of juvenile and adult fox mortality in both areas. The increase in juvenile fox survival in the coyote removal area resulted in a compensatory increase in the juvenile dispersal rate and an earlier pulse in dispersal movements. Adult fox dispersal rate was more consistent throughout the year in the coyote removal area. Coyote removal did not influence the reproductive parameters of the swift foxes. Even though juvenile survival increased, swift fox density remained similar between the areas due to the compensatory dispersal rate among juvenile foxes. We concluded that the swift fox population in the area was saturated. Although coyote predation appeared additive in the juvenile cohort, it was compensatory with dispersal.     

Fox Squirrel Survival in Urban and Rural Environments

Abstract A number of studies on mammalian species that have adapted to urban areas suggest survival may be higher for urban populations than rural populations. We examined differences in fatalities between an urban and rural population of fox squirrels (Sciurus niger). We radiocollared (n = 50 rural, n = 78 urban) fox squirrels during approximately 2 years. We found monthly survival of rural fox squirrels (Ŝ = 0.936) was lower than urban fox squirrels (Ŝ = 0.976) over the same 12-month period. Nonetheless, when comparing a 24-month period of survival data on urban squirrels with an 18-month period on the rural squirrels (periods overlapped for 12 months), survival rates were more similar between urban (Ŝ = 0.938) and rural squirrels (Ŝ = 0.945). Our data suggest that sex and season may influence survival of urban squirrels and not rural squirrels. We also found that cause of fatalities differed between the urban and rural squirrels, with >60% of fatalities on the rural site caused by predation. In contrast, <5% of the fatalities on the urban site were caused by predation and >60% of urban fox squirrel fatalities were caused by motor vehicle collisions. This study illustrates the need to advance our ability to understand, predict, and mitigate effects of urbanization on wildlife resources.     

Survival and Cause-Specific Mortality of Corsac and Red Foxes in Mongolia

ABSTRACT The corsac fox (Vulpes corsac) and red fox (Vulpes vulpes) range widely across northern and central Asia and may be declining in many regions due to overhunting and other causes. However, details of the fundamental causes of survival and mortality of both species remain largely unquantified, but may be crucial for understanding interspecific relationships and developing effective conservation actions. We studied a radiomarked population of sympatric corsac and red foxes in central Mongolia to quantify survival and cause-specific mortality rates from April 2005 to April 2007. Survival probability was 0.34 for corsacs (n = 18) and 0.46 for red foxes (n = 17) and did not vary by year within or between each species. Among both foxes, mortality occurred mainly from hunting by humans, but also from predation by larger canids and unknown causes. Our results suggest that illegal human hunting represents the principal source of mortality for both species and that a recently initiated ranger patrol program in the study area did not affect fox survival. As such, more stringent protective measures will likely be necessary to halt declines of both foxes. Our results also suggest that interference competition occurs between species as red foxes killed but did not consume corsacs. Our results will be useful for developing science-based management strategies to protect foxes in Mongolia, and in understanding the competitive relationships between them.     

The impact of sarcoptic mange Sarcoptes scabiei on the British fox Vulpes vulpes population

• 1 Disease epizootics can significantly influence host population dynamics and the structure and functioning of ecological communities. Sarcoptic mange Sarcoptes scabiei has dramatically reduced red fox populations Vulpes vulpes in several countries, including Britain, although impacts on demographic processes are poorly understood. We review the literature on the impact of mange on red fox populations, assess its current distribution in Britain through a questionnaire survey and present new data on resultant demographic changes in foxes in Bristol, UK.
• 2 A mange epizootic in Sweden spread across the entire country in < 10 years resulting in a decline in fox density of up to 95%; density remained lowered for 15–20 years. In Spain, mange has been enzootic for > 75 years and is widely distributed; mange presence was negatively correlated with habitat quality.
• 3 Localized outbreaks have occurred sporadically in Britain during the last 100 years. The most recent large‐scale outbreak arose in the 1990s, although mange has been present in south London and surrounding environs since the 1940s. The questionnaire survey indicated that mange was broadly distributed across Britain, but areas of perceived high prevalence (> 50% affected) were mainly in central and southern England. Habitat type did not significantly affect the presence/absence of mange or perceived prevalence rates. Subjective assessments suggested that populations take 15–20 years to recover.
• 4 Mange appeared in Bristol's foxes in 1994. During the epizootic phase (1994–95), mange spread through the city at a rate of 0.6–0.9 km/month, with a rise in infection in domestic dogs Canis familiaris c. 1–2 months later. Juvenile and adult fox mortality increased and the proportion of females that reproduced declined but litter size was unaffected. Population density declined by > 95%.
• 5 In the enzootic phase (1996–present), mange was the most significant mortality factor. Juvenile mortality was significantly higher than in the pre‐mange period, and the number of juveniles classified as dispersers declined. Mange infection reduced the reproductive potential of males and females: females with advanced mange did not breed; severely infected males failed to undergo spermatogenesis. In 2004, Bristol fox population density was only 15% of that in 1994.

     

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.     

Effects of Habitat on Competition Between Kit Foxes and Coyotes

Abstract: San Joaquin kit foxes (Vulpes macrotis mutica) are an endangered species with a narrow geographic range whose natural populations are limited by predation by coyotes (Canis latrans). In the warm, arid grassland and shrubland habitats where kit foxes occur, coyotes are more cover dependent than kit foxes, creating the possibility of habitat segregation. Effects of habitat variation on coyote and kit fox competition are unknown. We assessed exploitation and interference competition between coyotes and kit foxes in grassland and shrubland habitats to determine if such competition varies among habitats. With respect to exploitation competition, we evaluated habitat and spatial partitioning, diet, prey abundance, and survival for kit foxes and coyotes at the Lokern Natural Area in central California, USA, from January 2003 through June 2004. Kit foxes partitioned habitat, space, and diet with coyotes. Coyotes primarily used shrubland habitats whereas kit foxes selectively used burned grasslands. Kit foxes and coyotes had high dietary overlap with regards to items used, but proportional use of items differed between the 2 species. Kit foxes selected for Heermann's kangaroo rats (Dipodomys heermanni), which were closely tied to shrub habitats. With respect to interference competition, predation was the primary source of mortality for kit foxes, and survival of individual kit foxes was inversely related to proportion of shrub habitat within their home ranges. Our results suggest that a heterogeneous landscape may benefit kit foxes by providing habitat patches where predation risk may be lower.     

The city-fox phenomenon: genetic consequences of a recent colonization of urban habitat

The red fox (Vulpes vulpes) is one of the best-documented examples of a species that has successfully occupied cities and their suburbs during the last century. The city of Zurich (Switzerland) was colonized by red foxes 15 years ago and the number of recorded individuals has increased steadily since then. Here, we assessed the hypothesis that the fox population within the city of Zurich is isolated from adjacent rural fox populations against the alternative hypothesis that urban habitat acts as a constant sink for rural dispersers. We examined 11 microsatellite loci in 128 foxes from two urban areas, separated by the main river crossing the city, and three adjacent rural areas from the region of Zurich. Mean observed heterozygosity across individuals and the number of detected alleles were lower for foxes collected within the city as compared with their rural conspecifics. Genetic differentiation was significantly lower between rural than between rural and urban populations, and highest value of pairwise FST was recorded between the two urban areas. Our results indicate that the two urban areas were independently founded by a small number of individuals from adjacent rural areas resulting in genetic drift and genetic differentiation between rural and urban fox populations. Population admixture and immigration analysis revealed that urban-rural gene flow was higher than expected from FST statistics. In the five to seven generations since colonization, fox density has dramatically increased. Currently observed levels of migration between urban and rural populations will probably erode genetic differentiation over time.     

Individual dietary specialization in a generalist predator: A stable isotope analysis of urban and rural red foxes

Some carnivores are known to survive well in urban habitats, yet the underlying behavioral tactics are poorly understood. One likely explanation for the success in urban habitats might be that carnivores are generalist consumers. However, urban populations of carnivores could as well consist of specialist feeders. Here, we compared the isotopic specialization of red foxes in urban and rural environments, using both a population and an individual level perspective. We measured stable isotope ratios in increments of red fox whiskers and potential food sources. Our results reveal that red foxes have a broad isotopic dietary niche and a large variation in resource use. Despite this large variation, we found significant differences between the variance of the urban and rural population for δ¹³C as well as δ¹⁵N values, suggesting a habitat‐specific foraging behavior. Although urban regions are more heterogeneous regarding land cover (based on the Shannon index) than rural regions, the dietary range of urban foxes was smaller compared with that of rural conspecifics. Moreover, the higher δ¹³C values and lower δ¹⁵N values of urban foxes suggest a relatively high input of anthropogenic food sources. The diet of most individuals remained largely constant over a longer period. The low intraindividual variability of urban and rural red foxes suggests a relatively constant proportion of food items consumed by individuals. Urban and rural foxes utilized a small proportion of the potentially available isotopic dietary niche as indicated by the low within‐individual variation compared to the between‐individual variation. We conclude that generalist fox populations consist of individual food specialists in urban and rural populations at least over those periods covered by our study.     

Effects of Sarcoptic Mange on Coyotes at Wind Cave National Park

Abstract: Home-range size and population abundance indices of coyotes (Canis latrans) have not been documented in Wind Cave National Park, South Dakota, USA. In 2003 and 2004, we captured a total of 26 coyotes and radiocollared 22 adults (12 F, 10 M). In 2003 and 2004, 2 of 17 (12%) and 5 of 9 (56%) coyotes, respectively, were infected with sarcoptic mange (Sarcoptes scabiei) at the time of capture. Thus, objectives were modified to document effects of the mange epizootic on the coyote population. In 2003, home-range (adaptive-kernel) sizes for male coyotes with mange and those considered healthy were 8.26 ± 1.63 (SE) km² and 9.67 ± 2.80 km², respectively. In 2004, home-range sizes for those male coyotes with and without mange were 22.69 ± 9.06 km² and 12.51 ± 2.73 km², respectively. Male home-range size did not differ between years (P = 0.14) or by status (with or without mange; P = 0.84). Survival of collared coyotes was 60% at the end of 2003. Results from fecal line transects, an index of relative abundance, indicated that the coyote population decreased by 48% from 2003 to 2004. Continued monitoring of sarcoptic mange epizootics will enable managers to assess the effects of mange on coyote populations.     

Predation by red foxes limits recruitment in populations of eastern grey kangaroos

We investigated the impact of red fox (Vulpes vulpes Linnaeus 1758) predation on juvenile eastern grey kangaroos (Macropus giganteus Shaw 1790) using a replicated predator removal experiment. In two sites in Namadgi National Park, south‐eastern Australia, a persistent 1080 poisoning campaign over 18 months reduced fox density by more than 85%, and to less than 10% of the fox density in two other sites with no fox baiting. Changes in the mother : young ratios and densities of kangaroo populations were monitored twice monthly along 2‐km transects in each site from July 1993 to February 1995. Compared to nonremoval sites, where foxes were controlled, 25–40% more females retained juveniles over the period when these young became emergent from the pouch. This higher survival of emergent pouch young resulted in a significantly higher proportion of juveniles in kangaroo populations at fox control sites, which resulted in a significantly higher annual growth rate. We conclude that predation upon juveniles is an important limiting factor for kangaroo populations in Namadgi NP.     

Identifying and Controlling for Variation in Canid Harvest Data

An accurate understanding of harvest trends is required for effective wildlife management. Trapper harvest data represent valuable long-term data for evaluating patterns and trends for wildlife species at broad spatiotemporal scales. Inferring accurate trends from harvest data, however, first requires identifying and controlling for confounding factors that vary independent of abundance. We investigated trends in 43 years of trapper harvest data (1976–2018) from Illinois, USA, for red fox (Vulpes vulpes), gray fox (Urocyon cinereoargenteus), and coyote (Canis latrans) while controlling for factors that may affect trapper effort, including number of effective (i.e., successful) trappers, pelt price, gasoline price, winter unemployment, and winter weather conditions. Annual trapper harvest for red and gray foxes declined and was affected by gasoline price and winter unemployment, whereas annual trapper harvest for coyotes increased and was not strongly affected by other covariates. After adjusting for pelt price, harvest of red foxes was relatively stable, but harvest of gray foxes declined and harvest of coyotes increased. Effects of covariates on harvest per successful trapper varied by species; nevertheless, we detected an increasing trend for coyotes and decreasing trends for gray foxes and red foxes. Concordance across indices for gray foxes and coyotes was consistent with hypothesized declines for gray foxes and increases for coyotes in the midwestern United States. Trends for red foxes varied depending on how we accounted for potential confounding factors and it is unclear if these trends suggest population declines or distribution shifts to urban areas with reduced trapping susceptibility. Our results highlight the importance of understanding sources of variation in harvest data and that their effects can vary across species. © 2020 The Wildlife Society.     

Clinical Picture and Antibody Response to Experimental Sarcoptes scabiei var. vulpes Infection in Red Foxes (Vulpes vulpes)

Three red foxes (Vulpes vulpes) were experimentally infected with Sarcoptes scabiei isolated from a naturally infected wild red fox. A fourth red fox served as a control. The first signs of sarcoptic mange became evident on the 31st day post infection (dpi). The signs gradually increased thereafter and between dpi 49 and 77 characteristic lesions of hyperkeratosis developed. Two of the infected foxes developed severe sarcoptic mange, and one of these animals died on dpi 121. The third fox developed a chronic hyperkeratotic lesion on its back, at the site where the mites had been applied. On dpi 127 the surviving foxes were treated systemically with ivermectin, and within 4 weeks the skin lesions had healed except on the pinnae of one animal. Antibodies to S. scabiei var. vulpes were demonstrated in the infected foxes by an ELISA with which seroconversion was seen around 4 weeks post infection (wpi). Western blot analysis of sequential sera of the infected animals demonstrated antibody activity consistently after the 2nd wpi. The fourth, non-infected, fox did not show any skin lesions throughout the experimental period nor any specific antibodies to S. scabiei var. vulpes. kw|Keywords|k]sarcoptic mange; k]red fox; k]serodiagnosis; k]ELISA     

Influence of revegetation on predation rates by introduced red foxes (Vulpes vulpes) in south‐eastern Australian farmland

Interactions between wild carnivore abundance and landscape composition in agricultural landscapes are poorly understood despite their importance to both production and conservation. In Australia, introduced red foxes (Vulpes vulpes) prey on both native species and lambs in the temperate agricultural regions. Historically these areas were extensively cleared of native vegetation. Recently revegetation programmes have been implemented, but there is concern that this may benefit foxes and hence increase their impacts. We used an artificial prey placed in eight revegetated (6–12% cover) and 10 cleared (0–1.5% cover) landscapes of ～700 ha to assess how these landscapes influenced fox predation rates. In June and August 2006 (winter) when we expect fox populations to be relatively stable following juvenile dispersal, predation rates were 1.5–2 times higher in revegetated landscapes than in cleared landscapes. We found no evidence of microhabitat effects on predation rates suggesting these landscape‐level differences were probably due to differences in fox population density. In April 2007 (autumn) the results were more variable, possibly indicating more transient populations including dispersing juveniles at this time. Our results suggest that the impact of foxes on highly vulnerable prey could increase with revegetation. However, the benefits of revegetation to prey may offset negative impacts of foxes and future work is required to assess the likely net effects.     

Predation processes: behavioural interactions between red fox and roe deer during the fawning season

Predation by red fox (Vulpes vulpes) is the most important mortality cause for neonatal roe deer (Capreolus capreolus) in Scandinavia. With the objective of investigating how the fox finds fawns and how antipredatory behaviour of roe deer females influences choice of hunting method, I analysed observations of interactions between red fox and roe deer females. The observations were collected over 14 years in a mixed forest/agricultural landscape in Sweden. Of 49 fox–doe encounters, the doe attacked the fox in 59%. In 90% of these attacks the fox was successfully deterred. In two observations a doe saved a fawn attacked by a fox. Two hunting methods used by the fox were discerned. In 28 cases foxes searched the ground, and in 18 cases they surveyed open areas, often from a forest edge. The latter behaviour seemed more directed at fawns and was seen leading to a capture attempt. Searching seemed less efficient and also difficult to conduct due to the aggressiveness of does. A surveying sit-and-wait type of hunting method thus appeared as the most successful. The possibility to use this method could explain why roe deer fawns are more vulnerable to fox predation in open habitats.     

Release method evaluation for swift fox reintroduction at Bad River Ranches in South Dakota

Reintroductions have increasingly become effective at restoring populations of imperiled native wildlife. How animals are reintroduced into unfamiliar environments may have pronounced impacts on behavior, survival, and reproduction. We evaluated the influence of four release methods on survival rates of translocated swift foxes at Bad River Ranches (BRR) in western South Dakota: (1) hard‐release, (2) short‐soft‐release, (3) long‐soft‐release, and (4) captive born. A total of 179 foxes captured in Wyoming during 2002–2007 and in Colorado during 2006–2007 were released into BRR and the surrounding area. In addition, 43 pups born to foxes in the long‐soft‐release category were also released. All release methods incorporated a 14‐ to 21‐day quarantine period. Hard‐release foxes were released directly from a transport kennel, whereas short‐soft‐release foxes were released from soft‐release pens by opening the door and allowing the foxes to leave voluntarily. Long‐soft‐release foxes were held for more than 250 days on‐site in soft‐release pens through the winter and released in the following year in early summer. During 2002–2007, survival of reintroduced foxes differed significantly (p < 0.05) by age (adult vs. juvenile), release year, and release method. The short‐soft‐release method had the highest 60‐day post‐release survival probability compared with the other release methods. We did not detect any differences in mortality hazards between wild‐born and short‐soft‐release foxes. Reintroduction programs based on short‐soft‐releases are useful for restoring or augmenting populations to advance the conservation of the swift fox.     

Morbidity and mortality of red foxes (Vulpes vulpes) and gray foxes (Urocyon cinereoargenteus) admitted to the Wildlife Center of Virginia, 1993-2001

The medical records of 48 red foxes (Vulpes vulpes) and 35 gray foxes (Urocyon cinereoargenteus) examined at the Wildlife Center of Virginia (Waynesboro, Virginia, USA) from 1993 to 2001 were reviewed. The most common diagnosis in red foxes was orphaned (33%), followed by trauma (27%), undetermined diagnosis (23%), and sarcoptic mange (17%). Trauma (46%) was the most frequent cause of morbidity and mortality in gray foxes followed by orphaned (23%), undetermined (20%), toxoplasmosis (6%), presumptive canine distemper (3%), and rabies (3%). One gray fox had concurrent toxoplasmosis and presumptive canine distemper (3%). Similar diseases were detected in previous studies at a diagnostic laboratory; however in this study, trauma and orphaned animals were more common than infectious diseases. The lack of diagnostic information on some cases limited the usefulness of this study, and more emphasis should be placed on performing postmortem examinations of wildlife presented to wildlife rehabilitation centers.     

Demographic Parameters of Rural and Urban Adult Resident Canada Geese in Georgia

ABSTRACT In many urban metropolitan areas, resident Canada goose (Branta canadensis) populations have grown to nuisance levels in spite of increasing harvest opportunity. To document differences in demographic parameters between urban and rural geese, I estimated probabilities of survival, recapture, recovery, and fidelity for adult resident Canada geese between 2001 and 2006 using banding, live recapture, and dead recovery data from 2 distinct banding locations in Georgia, USA. Adult survival rates were higher for urban geese (0.958, SE = 0.020) than for rural geese (0.682, SE = 0.049). Using estimated recovery probabilities of 0.505 (SE = 0.107) for urban and 0.463 (SE = 0.045) for rural geese, along with current estimates of crippling loss and reporting rate, the estimated mean harvest rate for urban geese was 0.029 (SE = 0.006) and for rural geese was 0.202 (SE = 0.020). Fidelity rates were similar between urban (0.730, SE = 0.033) and rural geese (0.713, SE = 0.069). This information suggests that urban segments of the Canada goose population have substantially higher survival than rural geese and are harvested at a very low rate, and that liberalizing hunting regulations may have little impact on Georgia's urban goose population. Wildlife managers may need to consider options other than sport hunting to control nuisance goose populations in urban areas.     

The arctic fox Alopex lagopus in Fennoscandia: a victim of human-induced changes in interspecific competition and predation?

After a marked decline at the beginning of the 1900s, the arctic fox Alopex lagopus population in Fennoscandia has remained at a very low level. We suggest that the main cause for the population crash was winter starvation caused by (1) over-hunting of reindeer Rangifer tarandus populations, and thus reduced carcass availability in the mountains, and (2) increased interspecific competition for these carcasses because of increased invasion of red foxes Vulpes vulpes from lower altitudes. The failure of arctic fox populations to recover, despite increasing reindeer populations in the mid 1900s, can be explained by a concurrent strong increase in red fox numbers. Analyses of countywide hunting statistics from Norway 1891–1920 suggest that there actually was an increase in red fox numbers in the period of arctic fox decline, and that the increase in reindeer populations from the 1920s to the 1950s was accompanied by a new increase in red fox numbers. We conclude that restoring arctic fox populations most likely will require a substantial and lasting reduction of red fox populations.     

Habitat related differences in age structure and reproductive parameters of red foxes

We studied the age-structure and the reproductive parameters in two samples of red foxesVulpes vulpes (Linnaeus, 1758) from two contiguous areas in the Ebro valley (NE Spain) differing in the level of deliberate culling and in the habitat quality. Percent of juvenile foxes in the semiarid steppe (under higher persecution) was lower (53%) than in the irrigated highly productive “vegas” (67%). Conversely, foxes in the “vegas” (more favourable habitat) had a larger litter size (3.9 ± 0.23 cubs per female) and a higher amount of barren vixens (19.3%) than in the steppe (3.3 ± 0.12 cubs per female, and 1.7% of barren vixens). In this study, migration due to juvenile dispersal does not hide the effects of the habitat on fox population dynamics, despite the proximity between both areas. The results are discussed in relation to previous studies on red fox population dynamics.     

Lethal 1080 baiting continues to reduce European Red Fox (Vulpes vulpes) abundance after more than 25 years of continuous use in south‐west Western Australia

European Red Fox (Vulpes vulpes) baiting with 1080 poison (sodium fluoroacetate) is undertaken in many Australian sites to reduce fox abundance and to protect vulnerable native species from predation. The longest continuous use of fox baiting for fauna conservation commenced in south‐west Western Australia in the 1980s and includes baiting Dryandra Woodland and Tutanning Nature Reserve. The trap success of the Woylie (Bettongia penicillata) in these two reserves initially increased more than 20‐fold after the commencement of baiting and was maintained until 2000. Woylie captures then decreased rapidly, despite ongoing fox baiting, so the long‐term efficacy of 1080 baiting was questioned. Here, fox density and probabilities of detection, re‐detection and survival between replicated baited and unbaited sites were compared by modelling capture–recapture of individual foxes. These were identified from microsatellite DNA genotypes obtained non‐invasively from hair, scat and saliva samples. The frequency and duration of fox residencies were also quantified. Remote cameras were used to determine the fate of baits but uptake by foxes was low, whereas nontarget species' bait uptake was high. Nevertheless, foxes inhabiting baited reserves had significantly higher mortality, shorter residency times, and 80% lower density than foxes inhabiting unbaited reserves. Baiting continues to significantly reduce fox abundance after more than 25 years of continuous use. This has positive implications for fox control programmes throughout Australia but reduced fox abundance may facilitate increased predation by feral Cats (Felis catus).