Summary 1.Quantifying animal density is a fundamental requirement for the successful management of canid species. Faecal transects along linear features represent a costeffective means of quantifying relative density. However, it is unclear whether such counts can be utilized to estimate absolute density. 2. In Britain, due to proposed legislative changes in permitted culling practices, and as part of a wider monitoring programme, the current and future density of red foxes Vulpes vulpes is of applied interest. In this study, we counted fox faeces in 444 1-km squares throughout mainland Britain to construct a baseline index of fox density against which future changes could be measured. By incorporating estimates of the defecation rate and the proportion of scats associated with linear features, we estimated absolute density in seven landscapes. These estimates were compared with existing data on fox density. 3. On average, captive foxes consumed 0·85 kg food day −1 . Defecation rate (8 scats fox −1 day −1 ) was not affected by the type of food consumed. 4. The proportion of scats associated with linear features was determined by feeding individual free-living foxes a known amount of food containing an indigestible marker. On average, 5·7% of scats were deposited along linear features. 5. Mean fox density in landscapes ranged from 0·21 to 2·23 foxes km −2 . These estimates agreed closely with the limited data available on fox density in Britain. The total rural fox population was estimated to be 225 000 foxes (95% confidence interval 179 000-271 000). Including foxes in urban areas, the total national population is estimated to be approximately 258 000 individuals. 6. Synthesis and applications. The results suggest that faecal density counts have the potential to be used to estimate fox density over large spatial scales, although further work on estimating the proportion of scats associated with linear features and the use of faeces in territorial marking by canids is required.
1. A national monitoring scheme for recording the abundance of foxes and badgers in Britain would have to utilize a technique or techniques that could detect a wide range of animal densities in structurally different habitats. Furthermore, the likely reliance on volunteers for data collection means that these techniques must be easily applied by people with different levles of field expertise. 2. Direct methods that rely on counts of the animals themselves (e.g. capture‐mark‐recapture, radio‐tracking, spotlight counts) are generally unsuitable because of cost, manpower and licensing requirements, are not readily applied to all habitats and cannot easily be used by volunteers. However, density estimates derived from capture‐mark‐recapture and radio‐tracking methods are likely to represent the benchmark against which other estimates of abundance are measured. 3. The number of foxes killed per unit area is currently collated by non‐governmental organisations for some patterns of land use, e.g. game estates. No such data are available for badgers, as this species is legally protected in Britain. However, the applicability of hunting statistics for monitoring fox abundance is limited by differences in culling effort, the non‐independence of different culling practices applied in the same region, possible future changes in the legal status of different culling methods and changes in the ratio of land where foxes are and are not culled. 4. Indirect methods that rely on counts of the signs of the animals (e.g. droppings, breeding refugia) are less expensive than direct methods, can be applied to the range of habitats found in Britain and can easily be used by volunteers. To date, indirect methods have been utilised to derive estimates of relative animal density or the density of social groups. However, the major factor currently limiting the use of indirect methods is that their relationship with absolute animal density has not been validated. The preliminary results of two projects quantifying the use of field signs as a measure of absolute fox and badger abundance suggest that indirect methods could be applicable for monitoring changes in fox and badger numbers at a national scale.
The diet of 789 stoats Mustela erminea and 458 weasels M. nivalis collected in Great Britain between 1995 and 1997 is described from analyses of their gut contents. As a percentage frequency of occurrence, stoat diet consisted of 65% lagomorphs, 16% small rodents and 17% birds and birds' eggs. Weasel diet consisted of 25% lagomorphs, 68% small rodents, mainly Microtus agrestis, and 5% birds and birds' eggs. Male stoats ate a greater proportion of lagomorphs than females, which ate more small rodents. No differences in diet between the sexes of the weasels were detected. The proportion of lagomorphs in the diet of both species was greatest in the spring. Both species ate more lagomorphs in the 1990s than in the 1960s as a result of increasing rabbit populations following recovery from myxomatosis. The importance of small rodents had decreased for stoats and increased for weasels. Both species had a dietary niche that was more specialized than in the 1960s. The implications of these ®ndings for stoat and weasel conservation are discussed.
1. The winter diet of foxes Vulpes vulpes was quantified in seven landscape types in Britain, using faecal samples from 87 sites. 2. Medium-sized mammals (0.1-5.0 kg) were consistently the most important prey group in arable and pastural landscapes, occurring in 44-72% of scats and comprising 50-75% of the mass of prey ingested. Birds and small mammals ( < 0.1 kg) were important secondary prey groups. 3. Small mammals were the most frequently recorded prey group in marginal upland (42% of scats) and upland landscapes (75%), followed by large mammals (33% and 23%, respectively). In terms of mass ingested, small mammals (38%) and large mammals (52%) were the most important prey groups in these landscapes. 4. In all landscapes, field voles Microtus agrestis , lagomorphs, sheep/deer and passerines/ galliforms dominated their respective prey groupings.
Pressure to ban the hunting of foxes with hounds in Britain has fuelled debate about its contribution to the control of fox populations. We took advantage of a nationwide one-year ban on fox-hunting during the outbreak of foot-and-mouth disease (FMD) in 2001 to examine this issue and found that the ban had no measurable impact on fox numbers in randomly selected areas. Our results argue against suggestions that fox populations would increase markedly in the event of a permanent ban on hunting.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.