Attempts to control predator numbers through spatially restricted culling typically faces a compensation process via immigration from surrounding source populations. To extend control effort to avoid this issue is in most instances impractical, both logistically and financially. Evidence-based strategy is therefore required to improve management practices. In close collaboration with local managers and hunters, we manipulated culling effort on red fox (Vulpes vulpes) over 5-6 years in 5 areas measuring 246 AE 53 km 2 . We estimated fox density in late February each year by spotlight counts with distance sampling and estimated reproductive performance by post-mortem examination of culled foxes. We then used mixed modeling to assess how culling rate (defined as foxes killed/foxes available) affected fox population growth from year to year, accounting for compensatory feedbacks. We found a strong compensatory density feedback acting through immigration, allowing red fox populations to resist high culling rates. Culling appeared ineffective at reducing late winter densities to below 25-32% of the estimated carrying capacity. On average, an annual culling rate equivalent to about 45% of the pre-breeding population was required to maintain density at 1 fox/ km 2 , given a carrying capacity of 1.5 foxes/km 2 , although there was considerable variation among sites. The required culling rate dropped to 25% if the culling could be performed during winter, after the fox dispersal period. In contrast, culling during the pre-dispersal breeding period was totally compensated for through immigration by the following February. Concentrating culling during the winter could improve the ability of practitioners to control year-to-year trends in fox numbers, taking into account site-specific carrying capacity. A winter strategy would also reduce the number of animals killed and hence the ethical and logistical costs of fox control, given limited financial and human resources. Our study illustrates how collaboration between local practitioners and scientists can make large-scale replicated management experiments achievable, leading to mutually approved guidelines. Ó 2015 The Wildlife Society.

Summary 1.Monitoring red fox Vulpes vulpes abundance is necessary to assess the status and management of this species and to understand predator-prey relationships. Spotlight counts are most often used for this purpose. However, comparisons between regions or over years may be questionable when using encounter rates, i.e. the number of foxes seen per kilometre. We evaluated whether distance-sampling methods, which take account of variation in visibility, could be applied to spotlight counts of foxes along roads and trails. 2. Distance-sampling methods were used at 12 contrasting sites in France in a systematic design with equally spaced transects or points. Line and point transects were simultaneously applied at two sites to find the more precise and efficient method. 3. The number of foxes seen near the centreline was always low, although some foxes may have been missed. A peak of sightings at subsequent intervals from the centreline suggested evasive movements. 4. Despite the low sighting frequency near the centreline, which may reflect a violation of distance-sampling assumptions, a good model fit was obtained for eight out of 12 data sets using a regular 50-m grouping of the distance data. Increasing the first interval to account for evasive movement improved model fit in the four other data sets. Density estimates ranged from 0·39 to 3·54 foxes km − 2 (range of coefficient of variation 4·5 -24·6%). 5.Point and line transects resulted in similar density estimates, but point transects were more time consuming and resulted in larger coefficients of variation due to a smaller number of foxes seen by this method. Line transects may therefore produce better estimates of fox numbers. 6. There were few differences among the effective strip width estimates between the 12 sites (range 191-286 m), thus line transect estimates may have a limited advantage over encounter rates. 7. Synthesis and applications. The systematic scheme we applied in this study improved sampling design and variance estimations and should be useful for surveying terrestrial mammals with spotlight counts. However, the location of transects along roads and in open habitats probably induced biased results. Methodological improvements are necessary before spotlight distance sampling can become a routine monitoring tool for foxes.

Trapping records are often used to monitor long-term trends of small carnivore populations. However, many factors, not related to abundance, may affect capture rates. In this study, we examined whether trapper experience, trapping effort and trapping methods significantly affect capture rates of red fox Vulpes vulpes, stone marten Martes foina and pine marten M. martes. Data were col lected from 58 trappers (35,774 trap-nights) in a 660-km2 study area during one trapping season. The main trapping methods used for foxes and martens with different types of traps were identified by multiple correspondence analyses on 424 trap sites. Generalised linear modelling showed that trapping methods, the length of time traps were set in the same place, trapper experience and the presence of captures in neighbouring trap sites significantly affect capture rates of foxes and martens. Given the high variability of capture rates among differ ent combinations of these factors (0-3.4 captures/100 trap-nights for fox and 0.6-7.8 captures/100 trap-nights for martens), a separate trapping index should be calculated to detect trends in small carnivore populations.

We tested a staining method on uteri for counting placental scars on red fox. We estimated reproduction parameters on 358 females collected in three study areas in western France from 1st February 2002 to 31st January 2005. Placental scars (n=103) were described by macroscopic examinations using the following variables: (1) the width and (2) the aspect of placental scars, (3) the abundance of macrophages or the presence of blood, (4) the presence of swellings, (5) the presence and colour of a central band and (6) the presence and colour of lateral bands. A factorial correspondence analysis showed strong associations between the month when scars were examined and categories of variables. Staining on placental scars made macrophages more visible, facilitating identification of 'active' placental scars, i.e. related to the last pregnancy. However, distinction between placental scars due to earlier pregnancies and resorptions was not possible. The staining method used provides a standard that could be useful for obtaining comparable and repeatable results. The mean number of placental scars was 4.85±1.46 (n=103) per vixen. The mean number of embryos per vixen was 4.66± 1.35 (n=68) for yearlings and 5.53±1.50 (n=96) for older females. Including percentages of barren vixens, the total population productivity was significantly smaller for yearlings (3.62±1.86, n=158) than for older females (4.28± 1.75, n=186). We discuss these results in relation to fox densities, culling and food availability.