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Movement ecology and minimum density estimates of red foxes in wet grassland habitats used by breeding wading birds

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The red fox (Vulpes vulpes) is a widely distributed generalist meso-predator implicated in declines of wading bird populations. In the wet grassland habitats where waders breed, wildlife managers work to mitigate fox predation risk to waders during the nesting period through lethal and non-lethal control methods. However, limited knowledge on fox movement ecology in these habitats makes it difficult to design effective management strategies. We used GPS telemetry to understand fox home range size, daily activity and movement patterns, and how these metrics may vary among wet grassland sites with different management. We caught and GPS-tagged 35 foxes in the March–June wader nesting period on two wet grassland sites in central southern England; Britford during 2016/17 and Somerley during 2018/19. We estimated home range areas from location data using local convex hulls, and from these estimates we derived the minimum fox density at each site and year. Daily activity patterns and movement behaviour of each fox were obtained using both telemetry and trail camera data. Mean fox home range area at Britford (0.21 km², SE = 0.025) was significantly smaller than at Somerley (0.68 km², SE = 0.067), and estimated minimum densities were around four times higher (Britford = 10.6 foxes/km², Somerley = 2.4 foxes/km²). Foxes were more active and moved faster during twilight and night hours, but both telemetry and camera data indicate they were also active for one-third of daylight hours. Distances moved per day were variable between foxes but generally smaller at Britford. We also found evidence for dispersal during spring, with movements of up to 19 km per day. Home ranges at both wet grassland sites were smaller than comparable sites elsewhere. These indicated foxes were living at exceptionally high densities at Britford, where there is no fox control, increased food availability and where waders no longer breed. Spatio-temporal movement patterns were closely related to home range metrics, with higher levels of fox activity at Somerley, where home ranges were larger. The movements of itinerant and dispersing foxes during the nesting period suggests that lethal control would need to be very intensive to be effective. The likely anthropogenic food subsidy of fox density at Britford suggests that controlling access to similar food resources would help reduce predation pressure on breeding waders.
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European Journal of Wildlife Research (2024) 70:8
https://doi.org/10.1007/s10344-023-01759-y
RESEARCH
Movement ecology andminimum density estimates ofred foxes
inwet grassland habitats used bybreeding wading birds
TomA.Porteus1 · MikeJ.Short1· AndrewN.Hoodless1· JonathanC.Reynolds1
Received: 13 July 2023 / Revised: 21 November 2023 / Accepted: 6 December 2023 / Published online: 28 December 2023
© The Author(s) 2023
Abstract
The red fox (Vulpes vulpes) is a widely distributed generalist meso-predator implicated in declines of wading bird popula-
tions. In the wet grassland habitats where waders breed, wildlife managers work to mitigate fox predation risk to waders
during the nesting period through lethal and non-lethal control methods. However, limited knowledge on fox movement
ecology in these habitats makes it difficult to design effective management strategies. We used GPS telemetry to understand
fox home range size, daily activity and movement patterns, and how these metrics may vary among wet grassland sites with
different management. We caught and GPS-tagged 35 foxes in the March–June wader nesting period on two wet grassland
sites in central southern England; Britford during 2016/17 and Somerley during 2018/19. We estimated home range areas
from location data using local convex hulls, and from these estimates we derived the minimum fox density at each site
and year. Daily activity patterns and movement behaviour of each fox were obtained using both telemetry and trail camera
data. Mean fox home range area at Britford (0.21 km2, SE = 0.025) was significantly smaller than at Somerley (0.68 km2,
SE = 0.067), and estimated minimum densities were around four times higher (Britford = 10.6 foxes/km2, Somerley = 2.4
foxes/km2). Foxes were more active and moved faster during twilight and night hours, but both telemetry and camera data
indicate they were also active for one-third of daylight hours. Distances moved per day were variable between foxes but
generally smaller at Britford. We also found evidence for dispersal during spring, with movements of up to 19 km per day.
Home ranges at both wet grassland sites were smaller than comparable sites elsewhere. These indicated foxes were living at
exceptionally high densities at Britford, where there is no fox control, increased food availability and where waders no longer
breed. Spatio-temporal movement patterns were closely related to home range metrics, with higher levels of fox activity at
Somerley, where home ranges were larger. The movements of itinerant and dispersing foxes during the nesting period suggests
that lethal control would need to be very intensive to be effective. The likely anthropogenic food subsidy of fox density at
Britford suggests that controlling access to similar food resources would help reduce predation pressure on breeding waders.
Keywords Vulpes vulpes· GPS telemetry· Home range· Activity patterns· Movement behaviour· Breeding waders·
Wader predation· Nesting period· Avon Valley
Background
The long-term population decline of some wading bird
species in Europe, e.g. northern lapwing (Vanellus vanel-
lus) and redshank (Tringa totanus), has been relatively well
documented, but is still poorly understood. In common
with other ground-nesting bird species, population growth
appears to be prevented by high levels of nest and chick
predation (Macdonald and Bolton 2008; Roos etal. 2018;
McMahon etal. 2020). Breeding density, and sometimes
productivity in terms of chicks fledged, of lapwing and red-
shank are greatest in wet grassland habitats (Wilson etal.
2005; Merricks 2010; Silva-Monteiro etal. 2021), but it
is not clear whether this is because of food availability for
chicks, partial protection from predators afforded by the high
water table or some other effect. High predation rates have
been recorded in most studies in these habitats, and although
a wide spectrum of predator species is involved, the red fox
(Vulpes vulpes) figures prominently in almost every study
(Teunissen etal. 2008; Mason etal. 2018; Kaasiku etal.
2022). While waders make up only a small component of fox
* Tom A. Porteus
taporteus@outlook.com
1 Game & Wildlife Conservation Trust,
FordingbridgeSP61EF, UK
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European Journal of Wildlife Research (2024) 70:8
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diet and do not appear to be specifically targeted by foraging
foxes (Meisner etal. 2014), incidental predation from foxes
is evidently an important factor in wader population declines
(Mason etal. 2018; Roos etal. 2018; Zielonka etal. 2019).
The fox is an adaptable and opportunistic generalist
meso-predator (Voigt and Macdonald 1984; Cavallini
1996; Macdonald and Reynolds 2004; Devenish-Nelson
etal. 2013) distributed across the northern hemisphere in
habitats as diverse as tundra, desert, forest and agricultural
land, as well as in urban areas (Macdonald and Reynolds
2004). Territory-holding fox groups are typically dominant
breeding pairs, often with non-breeding females (Macdonald
1979; von Schantz 1981; Reynolds and Tapper 1995), but
both the number of non-breeding females and territory size
vary with food availability (Voigt and Macdonald 1984;
Iossa etal. 2009). This plasticity means that fox density can
vary considerably among different parts of a given landscape
(Heydon etal. 2000; Webbon etal. 2004; Sidorovich etal.
2006; Scott etal. 2014), with implications for the amount of
dispersal between different areas. Fox movement behaviour
has been widely studied (Macdonald and Reynolds 2004),
but understanding of fox group structure, density and home
range use in and around wet grassland habitats remains
poor. It has been studied in the coastal regions of Denmark,
Germany and the Netherlands (Mulder 1985; Meisner etal.
2014; Schwemmer etal. 2021), but not elsewhere in Europe.
This knowledge gap limits the development ofmanagement
aimed at the conservation of waders.
Historically, efforts to recover wader populations have
focused on increasing the availability and quality of breeding
habitats on farmland, particularly through agri-environment
measures across western Europe (Smart et al. 2014;
McMahon etal. 2020). However, given continued declines
(Smart etal. 2013; Franks etal. 2018; Heldbjerg etal. 2018),
it has become clear that wader breeding productivity remains
poor without parallel predation management (Smart etal.
2014; McMahon etal. 2020; Laidlaw etal. 2021). Predation
risk may be reduced to varying extents, either directly
through lethal control of predators (Tapper etal. 1996;
Fletcher etal. 2010; Smith etal. 2010; Baines etal. 2023),
exclusion fencing (Rickenbach etal. 2011; Smith etal.
2011; Malpas etal. 2013), nest exclosures (Isaksson etal.
2007) or other non-lethal methods (Selonen etal. 2022); or
indirectly through habitat management (Laidlaw etal. 2019).
Lethal control of both foxes and corvids can substantially
benefit ground-nesting bird productivity (Tapper etal. 1996;
Fletcher etal. 2010), but may not always be so effective.
The impact of culling on fox density varies considerably
due to both site and operator effects (Porteus etal. 2019).
Removal of foxes can lead to compensatory nest and chick
predation by avian or smaller mammalian predators that
are harder to control, e.g. stoat (Mustela erminea), with no
reduction in overall predation rate (Holy and Belting 2019).
Lethal control is also controversial on ethical grounds (Fall
and Jackson 2002). Non-lethal methods such as exclusion
fencing around preferred nesting sites can reduce direct
predation pressure from foxes during the nesting season
but require regular maintenance and do not protect against
avian predators (Laidlaw etal. 2021). A better understanding
of fox ecology—density, home range size, habitat use and
dispersal—in the vicinity of key wet grassland habitats
would help to design effective management strategies.
We studied fox ecology during the wader nesting season
at two contrasting wet grassland sites within a river valley
in central southern England. The two sites were thought to
differ in the availability of food resources for foxes other
than waders and in the intensity of fox culling. Although
the extent of the floodplain differed, both sites had short
swards in March–April with shallow wet channels and small
pools and patches of sedge and rush, i.e. good-quality nest-
ing and chick-rearing habitat for lapwing and redshank, but
at one site waders no longer bred successfully. We sought
(1) to quantify fox home range sizes; (2) to describe typical
fox movement behaviour, home range overlap, daily activity
patterns during the wader breeding season and the extent of
extraordinary movements outside normal home ranges; and
(3) to estimate minimum fox population density.
Methods
Study areas
This study took place between 2015 and 2019 on two rep-
resentative wet grassland sites in the River Avon Valley in
central Southern England (Fig.1). The Avon Valley is both
a Special Area of Conservation designated under the EU
Habitats Directive and a Special Protection Area under the
EU Birds Directive. It covers ~ 26 km2 of floodplain grass-
land and the most numerous breeding waders are lapwing
and redshank, but five other species breed in low numbers
and four frequent the valley to feed prior to breeding
elsewhere. In 1982, the valley supported the fourth highest
density of breeding waders of all lowland wet grassland sites
in England, but by 2002 was the site which had suffered the
greatest percentage decline (Wilson etal. 2005).
Britford
In 2016–2017, foxes were caught on a small privately
owned farm (c. 100 ha) bounded by the village of Britford
to the west and the River Avon to the east. The landscape
is predominantly wet grassland (floodplain grazing marsh
and lowland meadow) and pasture interspersed with semi-
natural woodland. Fields are generally small and enclosed
by hedgerows, ditches and barbed wire fences. Typical of
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the upper valley, there is a system of relict water meadows
(Cook and Williamson 2007) comprising ridges and fur-
rows, water carriers and drains, which on the neighbouring
farm downstream are traditionally managed, with the grass-
land periodically flooded using a system of hatches and
sluice gates, to encourage grass growth. The wet grasslands
here are c. 0.6 km at their widest point. Across the site,
grassland fields are rotationally and seasonally grazed by
cattle, some are left as hay crops each spring and some are
sheep paddocks. The site includes a commercial fish farm,
of which there are three throughout the Avon Valley. Habitat
management measures to help breeding waders, including
autumn mowing and grazing to improve grass growth, ditch
maintenance and willow pollarding, have been implemented
through agri-environment schemes. Historically, lapwing,
redshank and common snipe (Gallinago gallinago) have
all bredat Britford, withthree to four breeding pairs in
1990–1996, but none recorded on surveys since 2010
(GWCT, unpublished data). There was no concerted fox
control effort since 2000.
Somerley
In 2018–2019, foxes were caught at Somerley, a large (c.
3000 ha) privately owned country estate which supports sev-
eral tenanted farms around the Hampshire village of Har-
bridge, adjacent to and west of the New Forest. The estate
includes three contiguous wet grassland systems (Huckles-
brook, Ibsley and Ellingham) which run north–south along
the River Avon ~ 24 km downriver from Britford. The wet
grasslands are wider (up to 0.75 km) and wetter than Brit-
ford, and prone to late-winter flooding. The Hucklesbrook
wet grasslands are managed as flood-marsh and provide
low-intensity grazing for horses and cattle. The Ibsley and
Ellingham wet grasslands are predominantly grazed by
cattle, with some fields left for hay crops. The river cor-
ridor has an open aspect with few trees. Fields are gener-
ally bound by wire fence lines and water courses. Above
the floodplain, the landscape includes pastoral farmland
and estate parkland interspersed with residential properties,
gravel extraction pits and mixed woodland where pheasants
(Phasianus colchicus) are annually released at low density
for recreational shooting. Although with relatively low effort
compared to other nearby estates, foxes are routinely culled
by night-shooting in autumn and winter to prevent conflict
with game and sheep management objectives, with up to 20
foxes removed annually. The estate ceased culling efforts
during spring while we caught and tracked foxes. The wet
grassland fields supported an estimated 15 pairs of lapwing
and 7 pairs of redshank during 1990–1996, with numbers
increasing slightly to averages of 19 and 9 pairs, respec-
tively, in the early 2010s (GWCT, unpublished data). As part
of a parent project to increase wader productivity (see Fund-
ing), chick-rearing habitats were improved in 2015–2017 and
temporary electric fencing was installed opportunistically to
protect specific nesting lapwing (GWCT 2020).
Fox capture andtagging
Our aim was to understand the movements of foxes during
the wader nesting season, which we defined to be 15 March
to 15 June based on systematic records of local egg-laying
and chick fledging dates (GWCT, unpublished data). We
began fox tagging effort at the start of March and continued
either until early May or all available tags were in use. Fox
capture and tagging were conducted under a UK Govern-
ment Home Office licence in accordance with the Animals
(Scientific Procedures) Act (1986). Fox capture was initially
attempted using live-capture cage traps (XL Heavy Duty
Fig. 1 Location of the study sites within the River Avon Valley in
central southern England. Britford (upper left zoomed inset) is in
the upper valley, close to the city of Salisbury (population: 42,000).
Somerley (lower left zoomed inset) is in the lower valley (composed
of Hucklesbrook, Ibsley and Ellingham wet grasslands), close to the
town of Ringwood (population: 14,000). Map shows conurbation
(pink with grey outline), woodland (green), water courses (blue) and
roads (brown); all other land classification shown as yellow
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European Journal of Wildlife Research (2024) 70:8
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Fox Trap; JDA Engineering Ltd, UK), but following zero
captures all foxes were subsequently caught using passive
neck snares (DB snare; Perdix Wildlife Supplies, UK). Con-
trary to widespread misconception, live-catch neck snares
(also known as Humane Cable Restraints) catch and restrain
foxes without serious injury provided they are well-designed
and carefully used (Defra 2012; Short etal. 2012), i.e. in
accordance with the Defra Code of Practice on fox snares
(Defra 2016). The DB snare includes designed-in techni-
cal components both to facilitate fox capture, and to allow
non-target species like roe deer (Capreolus capreolus) and
badger (Meles meles) to self-release (Short etal. 2012). We
used trail cameras (Ltl Acorn 5310) set along linear fea-
tures and at water crossing points, e.g. tracks, fence lines
and foot bridges, at a height of 1–2 m to detect foxes and
avoid non-targets, e.g. badger and otter (Lutra lutra). Up
to 20 cameras were set at any one time and were typically
moved between locations every couple of weeks. After tag-
ging effort was complete, cameras remained in key loca-
tions to record tagged and untagged fox activity. These data
and field observations, including searching for scats, tracks
and breeding earth (den) locations, were used to identify
locations where foxes were active and to minimise risk
of capture of non-target species, especially badger and
otter. Snares were set only in areas known to be visited by
untagged foxes, or to recapture specific foxes to replace a
collar, and were inspected early morning and late afternoon.
Snare use was influenced by fox and non-target activity,
presence of livestock and by water levels: snares can only
be set on fields where livestock are absent and when the
ground is dry enough for snares to be tethered to secure
ground-anchors.
Once captured, foxes were restrained by ‘scruffing’
them—holding securely by the loose skin at the back of
the neck—and examined for visible external injuries and to
assess general body condition. Any physical injuries (e.g.
skin abrasions or pre-existing bite wounds) were treated
in accordance with an agreed Home Office licence proto-
col. Professional veterinary advice was always available
by telephone if required. We recorded sex and reproduc-
tive condition, but to minimise handling stress, we did not
weigh foxes. All foxes caught were judged to be adults and
to weigh > 5 kg. For captured foxes not requiring veterinary
consultation (17/18 timed events), the average time to assess
physical condition, fit a collar and release the fox was 6 min
13 s. All foxes were released where caught.
We used Tellus Ultra-Light GPS collars (215 g; Followit,
Sweden) which have 22 GPS channels, activity sensors and
a remote drop-off device. We conducted tests of the GPS
location accuracy and confirmed that 90% of fixes were
within 10–15m for an active animal (Appendix 2). Collars
were programmed to attempt a location fix every 10 min,
but there were circumstances in which we switched them
remotely to a 60-min schedule to conserve battery life, for
instance, following dispersal events away from the wet grass-
land sites. For all resident foxes, the 60-min schedule was
adopted following initial data collection on a 10-min sched-
ule, either during daytime (0800–1800) or for 4-day periods
within each week; this allowed data recording during more
of the nesting period. We programmed collars to search for
available satellites for up to 90 s, after which time the col-
lar turned itself off until the next scheduled attempt. When
conditions allowed, collar data were uploaded automatically
to the Followit Tellus server on an hourly basis, and we
reviewed it daily. Besides monitoring tagged animals for any
abnormal behaviour, e.g. prolonged lack of movement or
dispersal events, this also allowed the remote drop-off to be
activated when battery voltage fell to a critical level. Collars
were retrieved using an integrated VHF antenna activated
upon drop-off, and data were downloaded from the internal
memory for analysis. In six cases where the remote drop-off
failed, attempts were made to recover collars by shooting the
fox from a high seat located in the area where the fox had
been active. For two collars which were not retrieved due
to drop-off failure, we used the data uploaded to the server.
It is unknown whether any foxes were tagged in successive
years as they were not permanently marked.
Data preparation
We filtered out inaccurate fixes by visual assessment of esti-
mated locations, also removing 2D fixes based on only three
satellites and those with negative or outlier altitude values.
There was no relationship between high horizontal degree
of precision (HDOP) values and obvious outlier locations,
so HDOP was not used to filter fixes. Fixes were converted
from latitude–longitude to British National Grid for analysis
in metres.
Home range size estimation
In a social and territorial species like the red fox, concepts
of individual or group home-range, territorial defence and
exclusivity are easily confounded. In this paper, we use the
term ‘home range’ to mean the subset of geographic space
where a particular individual is most likely to be found based
upon its observed movements (Hooten etal. 2017).
We limited our home range analysis to resident tagged
foxes, defined as those that remained on the wet grassland
sites for the duration each was tagged within the wader nest-
ing season and showed a stationary spatial distribution. We
did not analyse data from foxes that were (1) tagged for < 14
days (n = 2); (2) itinerant, defined as those that moved away
from the wet grassland sites within a day of capture and
spent most of their time away from them, suggesting they
were caught on exploratory movements from elsewhere
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(n = 3); and (3) dispersers, defined as those that were ini-
tially present on the wet grassland sites but moved away
within weeks of capture and subsequently resided elsewhere
(n = 3). One male fox moved from Ibsley on the day of cap-
ture but subsequently remained exclusively on the Ellingham
wet grasslands within the Somerley site. We assumed he was
a resident given the early capture date (1 March) and size
of his resident home range; it is likely that when caught, he
was a territorial male making an excursion at the end of the
mating season (Macdonald 1987).
We derived home ranges using the local convex hull
(LoCoH) method (Getz etal. 2007). LoCoH has been used
elsewhere for deriving fox home ranges as they perform
better than the Minimum Convex Polygon (MCP) method
where there are distinct boundaries that may limit move-
ment, e.g. geographic or physiographic features, so are more
suitable for animals with territory boundaries that follow
hard-edged features such as roads and rivers (Walton etal.
2017). The k-LoCoH method subsets the data by selecting
the k − 1 nearest neighbours of each reference location, then
constructs the local convex polygon (i.e. local hull) around
each to produce a set of non-parametric kernels whose union
is the utilisation distribution (UD) (Getz etal. 2007). We
took initial estimates of k for each fox as the square root
of the number of locations, then evaluated by examining
diagnostic plots of area covered by the UD against the value
of k (Getz etal. 2007; Lyons etal. 2013). We examined
sensitivity of area to selection of the k-value and found lit-
tle difference for values ± 5 of the initial estimate. LoCoH
home ranges were derived using the adehabitatHR package
v0.4.19 (Calenge 2006) in R v.4.0.4 (R Core Team 2021).
We obtained both the 95% and 100% isopleths and examined
correlations between the home range areas and perimeters
for each.
To calculate minimum fox density of resident and total
(i.e. resident plus itinerant and disperser foxes), we first cal-
culated combined area of all resident fox home range areas
in each year. We then determined the resident and total
fox numbers tagged in each year and divided each of these
numbers by the combined home range area to estimate the
minimum density of the resident and total fox population,
respectively, during the tagging periods. We used two-way
ANOVA with Type-III sums of squares to examine the effect
of site and sex on 95% LoCoH home range areas of resi-
dent foxes. To determine the extent of social relationships
between the resident tagged foxes in each year, we con-
structed an intersection matrix of the percentage overlap of
each fox with the individual home ranges of all other foxes.
Movement behaviour
We determined the movement trajectory of each fox using
the adehabitatLT package (Calenge 2006) in R v4.3.1, based
on 10-min fixes. For periods when individual collars had
been switched to a 60-min fix schedule to conserve battery
life, regular interval trajectories were created by interpolat-
ing missing values at the intervening 10-min intervals when
fixes were not collected. We considered only active fixes
so that phantom movements due to GPS fix inaccuracies
while foxes were resting did not enter the calculation, e.g.
while underground at earths. For each fox, we summarised
the mean and maximum distance moved in 10 min, and for
whole days where fixes were on a 10-min schedule, the mean
and maximum distance moved in a day. Using the distance
moved per 10-min fix event, we then calculated the speed of
movement between successive fixes and related this to hour
of day. We used two-way ANOVA to examine the effect of
site and sex on mean daily movement distance. We exam-
ined the mean distances moved by each fox in relation to
home range area and perimeter to determine whether foxes
that have larger home ranges move further to patrol them.
In addition, we examined fix locations in each successive
day post-release in relation to the estimated home range to
determine whether capture influenced movement behaviour.
Activity patterns
Each collar recorded activity as the time it was moving
in either the x- or y-plane during each scheduled 90-s fix
attempt. We set the activity sensor at the most sensitive set-
ting to ensure movements were not missed. Based upon tests
with static collars, a collar was ‘active’ during a fix event
(i.e. the fox was not resting) if there was a total 2 s of
activity in each plane during the event. Choice of this thresh-
old was supported by the presence of long periods (> 4 h)
within each 24 h where ‘activity’ as judged by this criterion
was zero, indicating periods of rest. Activity was recorded
regardless of fix success, giving a continuous sample for
each fox during its tagged period. Active hours were defined
as the hours in each day in which there was ≥ 1 active fix.
We used generalised linear mixed models (GLMMs) to
examine activity patterns in relation to time of day, month
of year, sex and study site. The response variable was the
activity status of each fox (active or inactive) at each fix
attempt, modelled assuming binomial errors with a logit link
function. Fox ID was included as a random effect, to allow
for individual variation in behaviour and collar fit. All other
variables were converted to factors and included as fixed
effects. We examined for interactions between time of day
and month as foxes may increase daily activity during the
spring to resource cubs.
A time-of-day factor was included as either (1) the hour
or (2) diel period in which each fix attempt was made. As
there was a change from GMT to BST during the study
period, we analysed fox activity against both GMT and local
time to determine whether fox activity aligned more closely
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with astronomical time or human activity. We divided time
into discrete non-overlapping diel periods: day, night and
twilight. Day was defined as the time between sunrise and
sunset, occurring when the sun is level with the horizon. We
divided twilight into two periods likely to reflect ways in
which human activity might influence fox behaviour. During
Civil Twilight (sun < 6° below the horizon), humans can
carry out outdoor activities without artificial light (USNO
2020). During Nautical Twilight (sun 6 to 12° below the
horizon), terrestrial objects are still distinguishable by
humans, but artificial light is required for outdoor activity.
Initial examination of fox activity data by hour indicated that
the start of activity around sunset was more synchronous
than the cessation of activity around sunrise, so we also
distinguished AM and PM twilight periods. Night was
defined as the diel period between evening Nautical Twilight
and morning Nautical Twilight. This resulted in a six-level
diel period factor (morning Nautical Twilight, morning Civil
Twilight, Day, evening Civil Twilight, evening Nautical
Twilight, Night).
We fitted GLMMs using the lme4 package v1.1–26
(Bates etal. 2015) in R v4.0.4. We compared models using
Akaike’s Information Criterion (AIC). Animals do not ran-
domly switch between activity and rest; however, GLMMs
including temporal autocorrelation failed to converge, so we
were unable to test the assumption of independence in activ-
ity status between fixes.
We supplemented GPS data on activity patterns using
trail camera images of foxes. Cameras were primarily used
to guide fox tagging effort and were frequently moved
between locations within the sites before and during the
nesting period to monitor mammalian predators, but none-
theless at each site provided information on the timing of
fox activity during this period. For each fox detection, we
recorded age (adult or juvenile), sex (if obvious) and whether
it was tagged or not. Detections of foxes < 5 min apart were
considered as a single visit to the location (Kämmerle etal.
2019; Fiderer etal. 2019). Only images showing adult foxes
were used to avoid bias from high levels of juvenile activity
around breeding earth locations. Each detection event was
categorised into the diel periods described above. For each
site, a fox detection rate was calculated based on the number
of hours cameras were operating within each diel period.
Results
Tagging effort
In total, 3454 snare-days resulted in 47 fox captures (includ-
ing 10 recaptures) and 5 non-target captures, excluding ani-
mals that self-released. During the typical local wader nest-
ing period (15 March–15 June), we recorded location data
for 19 foxes (8F, 11M) at Britford (2016–17, TableA1 in
Appendix 1) and 16 foxes (8F, 8M) at Somerley (2018–19,
TableA2 in Appendix 1). One Britford fox was tagged
for < 24 h as the collar became detached on a livestock
fence during a movement event away from the study site,
so we only used data from the 34 foxes tagged for > 1 week
for analysis. Overall mean data period for foxes was 45.0
days (range: 8.9–80.6 days); during the nesting period only
it was slightly shorter at 41.1 days (range: 8.9–66.3 days).
The number of fixes recorded by collars before battery life
expired was variable, with some recording > 6000 fixes. Col-
lars on which the battery failed before reaching 3000 fixes
were typically attached to female foxes who spent a lot of
time underground at breeding earths: we assume their bat-
teries depleted attempting to contact satellites. While most
fixes were obtained on a 10-min schedule, a mean of 8.6%
of fixes (range: 0.6–29.8%) for 28 foxes were from a 60-min
schedule. Filtering removed 19,061 fixes (12.6%) from the
total number of 151,822 fix attempts. Also, 47.3% of suc-
cessful fixes were active fixes.
Collars were recovered from 33 foxes, with the fate of two
foxes unknown after remote drop-off failures. We recorded
an unidentified tagged fox on a trail camera at Britford on 18
July 2019; this indicated no obvious adverse effect on con-
dition > 2 years post-release. Ten foxes died while tagged:
three from natural causes (according to veterinary pathol-
ogy reports: two from sepsis; one from thoracic injuries fol-
lowing a suspected attack by a nesting mute swan Cygnus
olor); three were shot on the study areas to recover collars
after remote drop-off failures; and four were shot by wildlife
managers outside the study areas following dispersal events.
Home range size anddensity estimates
The estimates of resident fox home range showed vari-
able differences between 95 and 100% LoCoH isopleths
(Table1). For some foxes, 100% LoCoH isopleths included
areas with no fix locations that were never used (Figs. A1
and A2 in Appendix 1). 95% LoCoH isopleths followed
hard-edged features and included fewer unused areas com-
pared to 100% isopleths, such as static water bodies and
specific fields in which there were no locations (Figs.2 and
3). However, for some foxes the 95% LoCoH isopleths con-
sisted of multiple polygons, had convoluted shapes or had
holes indicating unused areas in the middle of the polygon.
This complicated both estimation and interpretation of 95%
LoCoH home range perimeters. The correlation between
home range perimeter and home range area for LoCoH
100% isopleths was stronger (r = 0.88) than for 95% isop-
leths (r = 0.59). We therefore present both 95% and 100%
LoCoH home range area estimates but only 100% LoCoH
perimeter estimates (Table1).
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European Journal of Wildlife Research (2024) 70:8
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Home ranges at Somerley were larger than those at Brit-
ford (mean and range 0.68 km2, 0.23–1.24 km2, and0.21 km2,
0.12–0.38 km2 respectively; ANOVA F1,22 = 12.03,
P = 0.002). Although male home ranges were mostly larger
across both sites, sex was not significant. However, the
interaction between site and sex approached significance
(F1,22 = 3.87, P = 0.062) due to female home ranges being
larger than male home ranges at Britford, but males hav-
ing larger home ranges at Somerley. The combined home
range areas differed between years at each site due to the
number and sex composition of foxes tagged, which resulted
in variable minimum resident and total density estimates
(Table2). Nonetheless, minimum densities were over three
times higher at Britford compared to Somerley. Averaged
across both years, the minimum resident density at Britford
was 7.0 foxes/km2 compared to 2.1 foxes/km2 at Britford.
Including the itinerant and disperser foxes tagged at each
site, the minimum total density at Britford was 10.6 foxes/
km2 compared to 2.4 foxes/km2. The home range overlap
matrix between resident foxes (Fig.A3 in Appendix 1)
showed that high percentage overlaps (> 80%) were most
frequent for male–female combinations. It was also com-
mon for females to share some home range area with other
females, indicating presence of social groups. Males gen-
erally had low percentage overlaps with other male home
ranges, but there were two high-percentage male–male com-
binations, also indicating social group structure.
Movement behaviour
Across all 34 foxes, the mean distance moved per day was
4.65 km (SE = 0.33). The maximum distance moved in a
day was 19.46 km, during a dispersal movement away from
Somerley. Daily movement distance of foxes at Britford was
lower (mean = 3.4 km/day, SE = 0.34) compared to Somerley
(mean = 6.1 km/day, SE = 0.35). Across both sites and years,
female foxes moved further per day (mean = 5.1 km/day,
SE = 0.41) than males (mean = 4.3 km/day, SE = 0.50). There
was a significant interaction between the effects of site and
sex on daily distance moved (ANOVA F1,30 = 4.36, P = 0.045)
as females moved further each day than males at Britford,
but males moved further than females at Somerley. The
mean distance moved in an active 10-min interval was 105 m
(SE = 6.2). Mean movement distance per 10-min interval for
resident foxes was positively related to both home range area
and perimeter from 100% LoCoH isopleths (Fig.4). Move-
ment speeds were highest during night and twilight hours,
Table 1 Home range estimates determined as the 95% and 100% isop-
leths of the utilisation distribution given by local convex hulls (LoCoH)
The number of nearest neighbour polygons (k) used in LoCoH esti-
mation is shown. Only foxes determined to have a stationary distri-
bution, i.e. resident, are included. Each fox was assigned a unique
code using site (B = Britford, S = Somerley), year, sex (F = female,
M = male) and number, e.g. B16F01 identifies female fox number 1
tagged at Britford in 2016
Fox kArea 95% (km2) Area 100%
(km2)
Perimeter
100% (m)
B16F01 29 0.23 0.35 2677
B16F02 49 0.23 0.38 2718
B16F03 46 0.38 0.67 3956
B16M02 53 0.33 0.79 4856
B16M05 44 0.13 0.21 2124
B16M06 45 0.13 0.22 2221
B17F01 25 0.15 0.19 2349
B17F03 51 0.29 0.40 3509
B17F04 48 0.23 0.35 3596
B17F05 44 0.21 0.47 3448
B17M01 31 0.14 0.23 2212
B17M05 42 0.12 0.37 3711
S18F01 37 0.59 1.15 4612
S18F02 49 0.81 1.28 5270
S18M02 39 0.66 0.86 5134
S18M03 51 1.24 1.61 6759
S18M04 46 0.80 1.19 4936
S19F01 58 0.64 0.90 4419
S19F03 26 0.51 0.66 5338
S19F04 47 0.23 0.78 3828
S19F05 44 0.82 1.29 4910
S19F06 39 0.47 0.72 3424
S19M01 45 1.01 1.45 4990
S19M02 61 0.62 0.87 3797
S19M03 58 0.45 1.20 5455
S19M04 41 0.72 1.15 4566
Table 2 Combined home range
area of resident foxes tagged in
each year, estimated using the
95% isopleths obtained from
local convex hulls
These areas were used to estimate the minimum resident density and minimum total (resident + itiner-
ant + disperser) density given numbers of tagged adult foxes
Site Year N resident foxes Resident home
range (km2)
Minimum resident
density (foxes/km2)
Minimum total
density
(foxes/km2)
Britford 2016 6 (3F, 3M) 1.03 5.83 8.74
2017 6 (4F, 2M) 0.73 8.23 12.35
Somerley 2018 5 (2F, 3M) 3.26 1.53 1.84
2019 9 (5F, 4M) 3.45 2.61 2.90
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European Journal of Wildlife Research (2024) 70:8
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with females moving at faster speeds than males, particularly
during daylight (Fig.5). The maximum distance moved in a
10-min interval was 1.14 km, implying an average speed of
6.8 km/h during that 10 min.
Movement behaviour of resident foxes in the first week
post-release was similar to their later behaviour (Figs. A4
and A5 in Appendix 1). While some appeared to spend part
of the initial day following capture outside of their home
range (i.e. B17F03, B17M05, S18F01, S19M03), this may
reflect the tendency to catch foxes at or near their home
range boundary because similar excursions occurred at other
times. The exception was S18M02, who was resident > 2 km
from the capture location and never revisited it.
We recognised two aberrant patterns of behaviour, which
we interpreted as ‘itinerancy’ and ‘dispersal’. ‘Itinerants’
moved away from the capture locations in wet grasslands
within 1 day. A male from each site moved immediately
upon release to locations 1–3 km away and resided within
small wooded areas (< 0.15 km2), from where over several
weeks they made repeated movements direct to the wet
grasslands and close to their capture sites. For the Britford
male, this included visits to the Britford fish farm where
dead fish were available to scavenge. The frequency of
return visits dropped during the period each itinerant fox
was tagged. A Somerley female moved 20 km to a new loca-
tion in the first night post-capture, spent 2 weeks exploring
rural and urban areas around this location then moved 22
km back to a wet grassland area important for breeding
waders just south of Somerley, where she was shot by the
site wildlife manager about a week later. ‘Dispersers’, all
Britford males, resided on the wet grasslands for up to a
month after being tagged, before dispersing to new loca-
tions away from them. One fox made weekly visits back to
the fish farm, despite residing for over a month in an area
(< 5 ha) of woodland 4 km from Britford. All dispersers
were subsequently shot by wildlife managers on the new
areas within 2–8 weeks of arrival.
Activity patterns
The number of hours per day in which there were active fixes
was greater for female foxes (mean = 18.6 h/day, SE = 0.55)
than male foxes (mean = 16.7 h/day, SE = 0.42). One female
fox was recorded active in every hour, for a mean of 23.2
in each 24-h period (SE = 0.17). Foxes were more active at
Somerley (mean = 18.6 h/day, SE = 0.51) compared to Brit-
ford (mean = 16.6 h/day, SE = 0.43). The percentage of total
fixes that were active was also higher at Somerley (Fig.6).
Although foxes were more active during twilight and night
hours, they remained active on one-third of fixes during day-
light hours, with total levels of activity increasing during the
spring and into summer months (Fig.6). The model which
best explained the activity data included diel period, month,
site and an interaction between diel period and month
(Table3). The effect of site indicated that the probability of
a fox being active during a location fix at Somerley was 34%
higher (β = 0.29, SE = 0.09, P < 0.01) than at Britford. The
significant (P < 0.05) interaction effect between diel period
and month, for all levels except one, indicates that activity
in each diel period is different in each month; from March
through June, the activity during twilight and night increased
(Fig. A6 in Appendix 1).
Cameras were operated at Britford in 14 locations in 2016
(363 camera days) and 20 locations in 2017 (589 camera
days), and at Somerley in 22 locations in 2018 (812 camera
days) and 43 locations in 2019 (1048 camera days, Table4).
Across both sites, fox detection rate per hour was highest
during evening twilight periods and lowest during daylight
(Fig.7). Daylight detection rate was 23% of detection rate
during evening civil twilight hours and 38% of detection
rate at night. Cameras located at earths increased detection
rates at both sites. With those detections excluded, the pat-
tern of activity among diel periods was the same at both
sites (Fig.7). Fox detection rates were higher in all periods
at Britford compared with Somerley, if detections at earths
were excluded; with earth detections included, detection
rate was highest in morning nautical and civil twilight at
Somerley (Fig.7).
Discussion
Our study determined fox home range size and movement
patterns in wet grassland habitats important to breeding
wading birds. Our estimates of mean home range size in
the Avon Valley were 0.21 km2 at Britford and 0.68 km2
at Somerley. Previous estimates of home range size in the
UK show wide variation among rural habitats (Voigt and
Macdonald 1984; Hewson 1986; Reynolds and Tapper 1995;
Baker and Harris 2008). Among previous studies, the most
local to the Avon Valley is the estimate of 2.7 km2 from a
drier farmland site with mixed agriculture about 16 km away
(90% harmonic mean contour; Reynolds and Tapper 1995).
This compares to wet grassland habitat estimates of 1.05–2.0
km2 from the coastal dunes of the Netherlands (estimator not
reported; Mulder 1985), 2.5 km2 from the coastal polders of
southwest Denmark (95% MCP; Meisner etal. 2014) and 4.4
km2 from a wetland area of central Germany (95% MCP;
Fiderer etal. 2019). To make meaningful comparisons, the
model and isopleth used to estimate home range area should
be the same, and unfortunately there is no consensus for
choice of home range estimation method (Laver and Kelly
2008; Fieberg and Börger 2012; Seidel etal. 2018). Never-
theless, some fox home range areas in the Avon Valley were
less than one-tenth the size of comparable estimates else-
where. Indeed, our estimates were more similar to previous
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European Journal of Wildlife Research (2024) 70:8
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UK urban fox home range estimates (e.g. Doncaster and
Macdonald 1991; White etal. 1996; Scott etal. 2018).
LoCoH home range boundaries followed features that
could be expected to be important to territory-holding foxes
but were not in themselves barriers to movement. These
included river channels, carriers, ditches, roads, tracks and
field boundaries. Even the main channel of the river Avon
at Ellingham was frequently crossed by tagged foxes, indi-
cating no physical barrier to their movement. Nevertheless,
there was minimal overlap of activity by social groups with
home ranges on opposite sides of these linear features so
they can be interpreted as territory boundaries. As expected,
we found male–female and female–female overlaps within
shared territories. However, we also found multiple male
foxes living within the same home ranges at both wet grass-
land sites, something that has previously been noted only in
urban habitats (Harris and Smith 1987).
Although LoCoH estimates typically represent the areas
utilised by each fox closely, some 100% LoCoH isopleths
included unavailable areas, e.g. S19M03 home range
included a small lake that was excluded from the 95%
LoCoH isopleth. Also, 95% LoCoH home range areas at
Somerley were three times the size of those at Britford, but
the estimated minimum fox densities were less than a quarter
of those at Britford. Trail camera detection rates away from
earths also support higher densities at Britford. True density
is likely to be higher than these minimum estimates due to
the known presence of untagged foxes. A more complete
estimate of density incorporating DNA evidence from the
same study will be attempted in the future. Previous esti-
mates of spring fox density in rural UK landscapes range
from 0.16 to 2.23 foxes/km2 (Heydon etal. 2000; Webbon
etal. 2004). While Britford densities were very high, esti-
mated minimum densities at Somerley were within the con-
fidence intervals of fox densities estimated both locally and
in similar pastural habitats (Webbon etal. 2004; Porteus
etal. 2019).
The smaller home ranges and thus higher densities at
Britford may be explained by two main factors: culling pres-
sure and food availability. At Somerley, foxes were removed
by culling each autumn and winter, which must have lowered
spring fox density. Even with replacement through immi-
gration (Lieury etal. 2015; Porteus etal. 2018), all of the
22 fox culling operations studied by Porteus etal. (2019)
resulted in suppression of spring density, with density on
average 47% (range 20–90%) of estimated carrying capac-
ity. The absence of fox control at Britford means the fox
population was probably closer to carrying capacity. Food
availability, and thus carrying capacity, may also be higher
at Britford than Somerley. The wet grassland management in
the upper Avon valley coupled with multiple drainage chan-
nels on water meadows leads to vegetation growth expected
to benefit vole populations (Microtus spp. and Arvicola
amphibius) which tend to cycle. Vole densities may have
been especially high at Britford during the study period
because a subsidiary study found they were the principal
prey items identifiable in fox faeces by macroscopic analy-
sis (Sadoff 2017). Dead fish from the fish farm provided
an abundant anthropogenic food resource that was regularly
replenished during the nesting season, and numerous foxes
(tagged and untagged) were photographed utilising it in 45
separate images. Utilisation of this fish resource by breeding
vixens feeding cubs could explain why female home ranges
were larger than male home ranges at Britford, though we
caution that apparent differences in home range size between
sexes will also reflect the social status of the foxes caught.
Camera data also hint at higher food availability at Britford
as the difference in detection rates between evening twilight
and night periods, and morning twilight periods, was much
greater than at Somerley, suggesting that food requirements
were met within a shorter activity period each night at Brit-
ford. This interpretation is in line with the global finding
that increased food availability from anthropogenic sources
results in smaller fox home ranges (Main etal. 2020). A fur-
ther factor that could explain differences in fox home range
on wet grassland sites is the availability of suitable breeding
earth locations. At Britford, the river valley is narrower and
there are more dry locations suitable for earths on adjacent
farmland (Fig.2). At Somerley, further downstream, the wet
grasslands are wider and therefore dry earth locations above
the river terrace are necessarily further away (Fig.3). Breed-
ing adults at Somerley that regularly used the wet grass-
lands had further to travel between them and earth locations,
resulting in larger home ranges.
Repeated movements to the fish farm location within and
between home ranges highlight its importance to the Britford
fox population. Such recursive use of resource locations
has been shown to shape fox home ranges (McKeown etal.
2020); our results provided evidence of foxes remembering
and revisiting such a resource in the weeks after dispersal to
new areas several kilometres away. Return movements were
not limited to Britford dispersers, as non-resident Somerley
foxes also regularly returned to the wet grassland sites.
Although the age of dispersing foxes was not determined,
they were most likely young adults from the previous year
who were pushed out of territories when new cubs were
born. All dispersers were noticeably subordinate and
docile when handled for tagging, compared to the resident
foxes, with the most aggressive fox (B16M02) having a
much larger home range than other resident male foxes at
Britford. The new areas settled by dispersers were typically
very small, and the male fox (S18M01) which secured the
largest area post-dispersal made the least frequent returns
to the wet grassland sites. The frequencies of return visits
by each dispersing fox decreased over time, presumably as
they developed a cognitive map of predictable food resource
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European Journal of Wildlife Research (2024) 70:8
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8 Page 10 of 18
locations in their new home ranges. Due to collar battery
lifespan and because most dispersing foxes were killed
within weeks, we do not know for how long these return
movements persisted, but similar dispersal patterns have
been described elsewhere (Mulder 1985).
Autumn and winter are the main dispersal period for
foxes (Macdonald and Reynolds 2004), but we observed
several dispersal events during the spring nesting season.
Three of these events were at Britford in 2017, when fox
density was high, but we cannot say whether these unusual
events were density related as we did not have all foxes
tagged at each site in each year. All dispersers were male
foxes, consistent with female philopatry and male-biased
dispersal (Macdonald and Reynolds 2004; Walton etal.
2021). However, location fixes of captured and tagged
foxes showed that itinerant foxes of both sexes were also
present on wet grassland sites during this spring period.
Movements of non-resident foxes across the landscape,
even where there is no culling to perturb territory struc-
ture (Macdonald and Bacon 1982; Carter etal. 2007), are
Fig. 2 Britford fox fix locations and estimated home ranges in a 2016
and b 2017. Fixes (left panels) are shown using transparent colours so
denser colour indicates areas with greater use. Known or suspected
breeding earth (den) locations are shown by solid white circles. Home
ranges (right panels) determined as the 95% isopleth of the utilisation
distribution given by local convex hulls. Wet grassland habitats are
shown in transparent white. Capture locations for each fox are shown
by matching coloured circles with a white outline. The fish farm is
shown by a salmon-coloured triangle with a white outline. Contains
Bing imagery (©Microsoft Corporation 2022)
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European Journal of Wildlife Research (2024) 70:8
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likely to increase predation pressure on nesting waders at
a critical time of year.
At Somerley, larger home ranges meant on average those
resident foxes moved almost twice as far and were active
for an additional 2 h each day compared to foxes at Britford.
Increased area means lengthier home range perimeters,
and—if home ranges can be equated with territories—imply
additional time must be spent patrolling and defending
their boundaries. Together with smaller social group sizes,
territory defence could explain why male foxes at Somerley
moved greater daily distances. Female foxes were active
for more hours each day and also moved at faster speeds
than males. During the wader nesting season, vixens have
increased food requirements due to rearing of cubs. In the
UK, cubs are born between mid-March and mid-April
(Lloyd 1980). The additional female food required per cub
during lactation is around 25% of female food requirement
(Sargeant 1978), meaning a typical litter of four cubs
(Reynolds and Tapper 1995) will require each breeding
female to double the amount of prey captured. Once cubs
Fig. 3 Somerley fox fix locations and estimated home ranges in
a 2018 and b 2019. Fixes (left panels) are shown using transparent
colours so denser colour indicates areas with greater use. Known or
suspected breeding earth (den) locations are shown by solid white
circles. Home ranges (right panels) determined as the 95% isopleth
of the utilisation distribution given by local convex hulls. Wet grass-
land habitats are shown in transparent white. Capture locations for
each fox are shown by matching coloured circles with a white outline.
Contains Bing imagery (©Microsoft Corporation 2022)
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European Journal of Wildlife Research (2024) 70:8
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8 Page 12 of 18
are weaned, they then require an increasing amount of prey
to be provisioned during the remainder of the nesting season
(Sargeant 1978). An extreme example from our data was
S19F03, who was active in almost all hours of the day and
night. Although this level of activity seems unsustainable,
our active hours metric means that a fox recorded as active in
two consecutive hours could be resting for much of that time.
As that collar was only used on S19F03, we also cannot
rule out that it was oversensitive to activity compared to
other collars. Trail cameras at that earth confirmed she was
tending a litter of two cubs, but other than a tagged male
(S19M03) no other foxes were detected, implying that there
was no help with food provisioning from non-breeding foxes.
Increased activity may also relate to earths being further
from the wet grasslands, where we hypothesise that food
availability was greater than around the natal earth locations.
We observed S19F01 relocating cubs to the Hucklesbrook
wet grasslands once they were weaned and active above
ground. Although foxes in smaller home ranges did not
travel so far each day, the higher density of foxes implies a
greater predation risk for wader species, as suggested by the
lack of recent wader breeding events at Britford.
Fox activity increased overall during the wader nest-
ing season, and activity during twilight and night hours
increased month by month, presumably related mainly to
the need to provision growing cubs. Previous studies have
reported that nocturnal activity patterns of foxes are related
to human presence during daylight (Díaz-Ruiz etal. 2016;
Kämmerle etal. 2020). Human activity can be assumed to
be linked more to clock time than to sunrise–sunset, so our
finding that fox activity was better predicted by GMT than
daylight-adjusted time suggests that human activity pat-
terns were not such an important influence on fox activity
on these wet grassland sites. Foxes were two to three times
more likely to be active and moved faster during twilight
and night hours compared with day, with highest activity
in evening nautical twilight, supporting the understanding
that fox foraging behaviour is chiefly crepuscular and noc-
turnal (Reynolds and Tapper 1995; Díaz-Ruiz etal. 2016;
Kämmerle etal. 2020). Nevertheless, in contrast to those
studies and similar to findings from a study in coastal polder
regions (Schwemmer etal. 2021), foxes at wet grassland
sites were active on about 30% of daylight fixes. Camera
detection rates also showed a day–night difference (daylight
rate was 23–38% of other periods), and daylight detections
accounted for almost 40% of total detections. Average move-
ment speeds during daylight hours were slower than dur-
ing other periods, but routes and speeds > 1 km/h suggest
some daylight foraging as well as smaller movements around
den sites. This level of daylight activity highlights that it is
unsafe to assume that daylight predation events are due to
other predator species as foxes represent a threat to breeding
waders during daylight hours as well as during twilight and
night periods (Mason etal. 2018).
Fig. 4 Relationship between mean distance moved in each 10-min interval and a home range area and b home range perimeter as determined by
the LoCoH 100% isopleths for each fox. Symbols and colours represent different sexes and sites, respectively
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European Journal of Wildlife Research (2024) 70:8
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Capture locations were mostly at or near what later
appeared to be the home range boundary, which supports
that they are more vulnerable to capture in snares on
unfamiliar ground (Reynolds and Tapper 1995). In con-
trast to other studies that have used them successfully in
other habitats (e.g. Walton etal. 2017), cage traps were
ineffective at capturing foxes in wet grassland habitats
as we had no fox captures in them, and no evidence of
baits in cages being taken by foxes. This suggests that
snares can be a uniquely successful capture device in
this environment. Our experience in this and previous
studies (Reynolds and Tapper 1995) suggests rapid recov-
ery of red fox from capture in cable restraints, given the
methodological safeguards practised here. This is sup-
ported by evidence from other canids, as Gese etal.
(2019) found that wolves (Canis lupus) recover normal
movement behaviour more quickly after capture in cable
restraints compared to foothold traps.
Fig. 5 Movement speed of foxes between successive 10-min fixes in relation to the hour of day, grouped by site and year. Data are jittered on
each hour and male fox data (green) are shown overlaid on female fox data (orange)
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European Journal of Wildlife Research (2024) 70:8
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8 Page 14 of 18
Fig. 6 Activity levels of tagged foxes 2016–2019 in relation to time of day, month, diel period (day, night, nautical twilight, civil twilight), sex
and site
Table 3 Activity pattern model
comparisons using AIC
Variables in parentheses were included as random effects. ‘:’ indicates an interaction and ‘/’ indicates nested
terms. All other variables were included as fixed effects
a Diel6 = 6-level factor (night, nautical twilight AM, civil twilight AM, day, civil twilight PM, nautical twilight PM)
b HourGMT = GMT time, Hour = daylight-adjusted time
Model Variables included AIC ΔAIC n parameters
1 Diel6a + Month + Site + Diel6:Month (+ FoxID) 168,570.4 0.0 26
2Diel6 + Month + Site (+ FoxID) 169,301.5 731.1 11
3Diel6 + Month + Site + Sex (+ FoxID) 169,301.5 731.1 12
4Diel6 + Month (+ FoxID) 169,307.3 736.8 10
5Diel6 + Site (+ FoxID) 169,705.4 1134.9 8
6Diel6 (+ Site/FoxID) 169,711.0 1140.6 8
7Diel6 + Sex (+ FoxID) 169,713.3 1142.8 8
8Diel6 (+ FoxID) 169,713.9 1143.4 7
9 HourGMTb + Month + Site (+ FoxID) 170,522.9 1952.4 29
10 HourGMTb (+ FoxID) 170,605.6 2035.2 25
11 Hourb + Month + Site (+ FoxID) 170,978.6 2408.1 29
12 Hourb (+ FoxID) 171,061.6 2491.2 25
13 Month (+ FoxID) 208,073.7 39,503.3 5
14 Site (+ FoxID) 208,108.6 39,538.1 3
15 Sex (+ FoxID) 208,119.2 39,548.7 3
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
European Journal of Wildlife Research (2024) 70:8
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Page 15 of 18 8
Conclusions
We found very different fox home range size on two wet
grassland sites within the same river catchment. Based solely
on the subset of foxes captured and tagged, minimum fox
density at both sites was greater than expected from other
studies in rural areas, and at one site (Britford) was compa-
rable only with urban UK fox densities. This was plausibly
explained by the absence of lethal fox control and subsidy
by a significant anthropogenic food resource. The presence
of multiple males in some territories and the spring dispersal
of some of these fits this interpretation. In turn, high fox
density may explain the near absence of waders at this site
and their failure to breed there despite suitable habitat.
Spatio-temporal movement patterns of resident foxes
were closely related to home range metrics, in that larger
home-ranges involved more daily travel. Larger home-
ranges at Somerley may have reflected lower resource avail-
ability and lower population density than at Britford, but
landscape structure, i.e. a wider floodplain at Somerley,
may also have played a part in obliging foxes to den further
from wetland food resources. The need to provision cubs
led to increased fox activity in all diel periods, including
daylight hours. At both sites, some foxes made regular use
of villages and conurbations, presumably exploiting anthro-
pogenic food resources.
Several findings of this study will be helpful in focusing
fox management for waders. First, the use of anthropogenic
Table 4 Summary of camera
trapping effort during the
mid-March to mid-June nesting
period
The numbers of fox detections reflect adult foxes (not cubs at cameras located near earths) detected > 5 min apart
Site Year Number of camera
locations (with fox
detections)
Days operational Number of fox
detections
Mean fox detections
camera−1 day−1
Mean (range) Tagged Untagged Tagged Untagged
Britford 2016 14 (13) 25.9
(2.4–69.7)
29 342 0.08 0.94
2017 20 (17) 29.5
(8.1–86.6)
60 302 0.10 0.51
Somerley 2018 22 (21) 36.9
(9.2–79.2)
16 303 0.02 0.37
2019 43 (33) 24.4
(6.0–89.2)
126 441 0.12 0.42
Fig. 7 Adult fox detection rates of both tagged and untagged foxes
during each of the six diel periods (nautical twilight am, civil twi-
light am, day, civil twilight pm, nautical twilight pm, night) on trail
cameras located at Britford (2016–2017) and Somerley (2018–2019),
for all camera locations at each site (‘all’, solid colours) and for those
that were not situated at breeding earths (‘-earth’, hatched)
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European Journal of Wildlife Research (2024) 70:8
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8 Page 16 of 18
food resources by foxes suggests the desirability of reducing
their availability, where obvious sources of food are identi-
fied and are amenable to control. Reducing the availabil-
ity of food from anthropogenic sources has been shown to
increase fox home range sizes, driven by reduced survival
rates lowering fox density (Bino etal. 2010). Second, it was
apparent that wet grassland was an attractive habitat for
foxes at both sites, and certain individuals resided largely
or entirely within this habitat. Discussion with landowners
and game managers suggested that lethal control efforts were
focused within neighbouring habitats where access and vis-
ibility were more favourable. Our findings suggest that this
would be likely to target the wrong foxes, leading to poor
success and loss of faith in the approach, even though in
upland habitat, effective lethal control of key predators has
been shown to make the difference between wader popula-
tion decline and population increase (Fletcher etal. 2010).
However, wet grassland is not an easy habitat for either
lethal or non-lethal management. Lethal methods are lim-
ited by the flat topography and poor vehicular access, which
constrain safe shooting opportunities. Rough vegetation and
flooding in wet grasslands also limit the effectiveness of
electric fencing to protect nests and chicks against foxes. At
best, temporary electric fences are a deterrent (White and
Hirons 2019; Laidlaw etal. 2021; Verhoeven etal. 2022;
Jellesmark etal. 2023), and the willingness of foxes to
breach them may be related to the significance of the habi-
tat and its food resources in their daily lives. The successful
use of cable restraints, combined with trail cameras, to catch
foxes for tagging in this study shows that these tools can be
uniquely effective in wet grassland habitat if lethal control
is considered.
Understanding how mobile the fox population is during
the wader nesting season itself is also important. We already
knew that culled foxes can be replaced rapidly through
immigration (Porteus etal. 2019); these new results suggest
that potential replacement foxes can arrive overnight from
19 km away, greatly extending what we might consider to be
source populations. Although intensive culling efforts can
reduce the fox population locally during the wader nesting
season and provide short-term relief (Porteus etal. 2019),
it may be more appropriate to consider the cause of wader
decline and its longer-term solution at a much larger scale
(Roos etal. 2018).
Supplementary Information The online version contains supplemen-
tary material available at https:// doi. org/ 10. 1007/ s10344- 023- 01759-y.
Acknowledgements The authors thank the successive students who
helped in various capacities, notably Sophie Watts, Will Connock,
Emma Popham, Anna Jones, Peter Wood, Naomi Sadoff, Megan Bald-
issarra and Alex Shiskin-Smith; their GWCT colleagues Lizzie Gray-
shon, Ryan Burrell and Jodie Case; Mark Elliott for veterinary advice;
and the landowners who allowed access to the study sites.
Author contribution All authors designed the study; MJS collected
the data; TAP managed the data, performed the analysis and wrote the
initial draft of the manuscript; all authors contributed to the revisions
of the manuscript, read and approved the final manuscript.
Funding This work was undertaken as part of the ‘Waders for Real’
project funded by the EU LIFE + scheme (LIFE13 BIO/UK/000315).
Availability of data and materials The datasets generated and analysed
in the current study are available in the Movebank Data Repository,
https:// doi. org/ 10. 5441/ 001/1. 304.
Declarations
Conflict of interest The authors declare no competing interests.
Ethics approval Fox capture and tagging was conducted in compli-
ance with UK Home Office regulations under the Animals (Scientific
Procedures) Act 1986 (project licence PPL30/3273). All associated
field work was subject to review and approval by the GWCT’s Animal
Welfare and Ethical Review Body (AWERB).
Open Access This article is licensed under a Creative Commons Attri-
bution 4.0 International License, which permits use, sharing, adapta-
tion, distribution and reproduction in any medium or format, as long
as you give appropriate credit to the original author(s) and the source,
provide a link to the Creative Commons licence, and indicate if changes
were made. The images or other third party material in this article are
included in the article’s Creative Commons licence, unless indicated
otherwise in a credit line to the material. If material is not included in
the article’s Creative Commons licence and your intended use is not
permitted by statutory regulation or exceeds the permitted use, you will
need to obtain permission directly from the copyright holder. To view a
copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
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... We used binomial logistic regression to model the presence of each category according to the period in which the stomach was collected, and the distance to the nearest urban or suburban land parcel. For the latter, we extracted urban and suburban land parcels from the Centre for Ecology and Hydrology Land Cover Map 2020 vector layer different habitat categories (Webbon et al. 2004), and (ii) local-based estimates of fox density arising from a recent fox GPS-tagging study in the Avon Valley, immediately west of the New Forest; on a landholding at Britford -an area of pastoral farmland with a high fox population density and no predator management, and Somerley Estate -an area with a more moderate fox population density with some predator management (GWCT 2020; Porteus et al. 2024). At Somerley, some tagged-fox territories encompassed parts of the New Forest, immediately adjacent to important curlew breeding sites. ...
... Previous work has demonstrated that landscape-based metrics are not necessarily reliable predictors of fox density (Heydon and Reynolds 2000). Evidence of extreme population densities in Britford -among the highest ever recorded in mainland Britain outside of urban areas -maybe attributable to a fish farm operation providing a plentiful and easily accessible food resource coupled with a lack of population control (Porteus et al. 2024). Therefore, this almost certainly does not represent the general situation across the New Forest but might at the local scale where intentional feeding occurs. ...
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The red fox ( Vulpes vulpes ) is a generalist mesopredator found throughout the UK. It has been linked to national declines in native wildlife, especially ground-nesting birds such as waders. In the New Forest National Park, nest predation and poor chick survival is primarily responsible for low breeding success of Eurasian curlew ( Numenius arguata ), a species of high conservation concern. To reduce predation losses, foxes are lethally controlled by wildlife managers. Here, we identified the major food resources that are being exploited by foxes in the New Forest area and examined temporal and spatial patterns in the presence of specific food categories, with special reference to anthropogenic food. Stomachs from foxes culled in curlew breeding areas were collected from April 2021 - July 2022 and the contents of these stomachs were quantified. Foxes exhibited a highly varied diet with no single food category predominating. Anthropogenic food comprised 14% of the overall diet, with its presence predicted by proximity to human settlements and other infrastructure. We also estimated the total annual volume of anthropogenic food consumed by the fox population and by extension how many individual foxes this volume of food could support in isolation. According to these calculations, at present the number of foxes subsidised by anthropogenic food is approximately 64.8% (50.2–79.7%) of those removed by culling per year. Our findings highlight that better local food sanitation and education should become important parts of a more holistic management approach to reduce the burden of fox predation experienced by breeding waders.
... A situation in which all eggs disappeared from the nest before the date set for hatching or the nest was inundated was considered a loss. Nocturnal predation was attributed to be mammalian, while diurnal can be caused by both birds and mammals [52,53]. We did not take into account nests that were abandoned during the incubation (N = 2), as it was impossible to pinpoint what factors caused the abandonment, and the small sample size did not allow for us to analyze those cases as a separate group of nests. ...
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Predation is an important factor limiting bird populations and is usually the main factor influencing nest survival. In riverine habitats, flooding poses an additional significant challenge. Our study aimed to elucidate the influence of nest location and incubation timing on the survival of common sandpiper nests in a large, semi-natural, lowland river. The survey was carried out in central Poland on the Vistula River, in 2014–2015, 2021, and 2023, along two river sections 2 km and 10 km in length. The nest survival rate was 27%, which is twice as low as that reported on small upland rivers, with flooding being an additional factor causing losses on the Vistula River. Our research showed that mammalian and avian predation accounted for 51% of losses and flooding for 49% of losses. The negative impact of floods on nest survival decreased as the breeding season progressed between May and July, while the chances of being depredated increased during the same period. Nests placed under shrubs were less likely predated than nests located in grass. Moreover, locating the nest in proximity to water increased nesting survival and in fact, more nests found in our study were situated close to the water’s edge.
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Widespread changes in the European agricultural system have brought about drastic changes in food web interactions, including those between meadow birds and their (nest) predators. Mammals are considered the main nest predators, yet our current knowledge of predator communities in agricultural landscapes is limited. Using camera traps across 11 500 ha of dairy-farming land in Southwest Friesland, The Netherlands, during three spring seasons we monitored: (1) predator presence and (2) actual predation on black-tailed godwit (Limosa limosa limosa) nests. During 2021-2023 we detected 11 species of potential mammalian meadow bird predators. The top six, with a daily presence of ≥ 5%, were: domestic cat (Felis catus), brown rat (Rattus norvegicus), European badger (Meles meles), red fox (Vulpes vulpes), beech marten (Martes foina) and European polecat (Mustela putorius). There were marked, and for most species consistent, differences in spatial distribution, with positive co-occurrence of badgers and foxes. Across the three study years, red foxes were the most consistent predators of godwit nests, whereas domestic cats and brown rats predated very few nests despite their high presence. Patterns over the years indicated that as beech marten nest predation diminished, red fox nest predation increased. We suggest that (1) the presence of predator species alone is not an accurate reflection of their actual nest predation, and (2) the presence of single predator species, and their effects on, meadow birds should be assessed in context of the whole predator community.
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The UK supports a quarter of Eurasian curlew Numenius arquata, so a recent halving of numbers has impacted the global population. Low breeding success is a frequently cited cause of decline. We considered breeding success in relation to predator indices and habitat measures within 18 moorland-farmland blocks across several UK regions. Each block comprised one site where gamekeepers lethally controlled predators on moors managed for red grouse Lagopus lagopus scotica (grouse moor) and another on similar habitat where predators were not controlled (non-grouse moor). More wader species occurred on grouse moors, which supported twice the density of waders as non-grouse moors. Curlew productivity was fourfold higher on grouse moors (1.05 fledglings pair-¹) than non-grouse moors (0.27). Hatching and fledging success was negatively linked to a combined index of corvids and fox, which were three- to fourfold fewer on grouse moors but were unrelated to 11 habitats and two livestock grazing variables. Similar patterns were observed in three of four other wader species. These behaviour-based findings were validated by observations on actual nests and broods. Grouse moors appear to act as source populations, thereby slowing the current rapid decline. To halt declines and promote curlew recovery in the UK uplands, we recommend that predator control on grouse moors is maintained and longer term land use policies are developed to render landscapes less friendly to currently high levels of generalist predators.
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Complicated conservation problems may arise if predator numbers increase beyond their natural boundaries due to anthropogenic influence. For example, dramatic declines in ground-nesting birds are linked to increased nest predation by alien or human-subsidized mammals. While predator control can be temporarily effective, it is often laborious and carries ethical issues. Thus, we need alternative, non-lethal methods for reducing predator impact on their prey. We performed a landscape-scale experiment to study whether two non-lethal methods could protect ground-nesting waterfowl from nests predation. We spread either non-rewarding waterfowl odour (chemical camouflage) or eggs containing an aversive agent (conditioned food aversion) in the surroundings of study wetlands located in southern Finland. Predation of artificial waterfowl nests by red foxes decreased in sites with chemical camouflage, while there was no effect on predation by invasive raccoon dogs. Food aversion created less obvious effects than the chemical camouflage, but both methods indicated potential for reducing nest predation. Based on wildlife-camera data mesopredator observations did not, however, decrease near treatment wetlands. This suggests that treatments did not reduce predator activity, but affected foraging behaviour of predators and reduced their ability to find the nests. We conclude that managers considering non-lethal methods should carefully consider the effectiveness of different methods and potential species-specific responses. Nevertheless, our study support calls for wider use of non-lethal methods in reducing predator impacts on prey. These methods offer ethical and potentially effective approaches which keep native predator fauna intact, but create protection for vulnerable prey.
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Abstract Breeding populations of many wading birds have declined globally, primarily caused by habitat degradation and loss. In the United Kingdom, population declines have been particularly notable on lowland wet grasslands. In response, some areas of lowland wet grassland have been restored and receive ongoing management to improve the breeding conditions of target species. Here, we assess the efficacy of management measures using a Bayesian framework and controlling for confounding factors. We focus on four wader species, Northern Lapwing (Vanellus vanellus), Eurasian Curlew (Numenius arquata), Common Snipe (Gallinago gallinago) and Common Redshank (Tringa totanus), that breed in numbers on wet grassland reserve sites in the UK. We collated annual site‐specific climate variables, management information (e.g. the creation of wet features and predator control measures) and bird counts between 1994‐2018. We found the effects of conservation actions varied between intervention types and species. For lapwing and redshank, excluding predators by predator‐exclusion fencing, especially in combination with fox control, were generally associated with higher breeding counts. For all study species, sites with longer histories of management were associated with higher breeding numbers, with the effect of site age being particularly notable for management on former arable land. Our findings support the effectiveness of targeted conservation actions to achieve high numbers of breeding waders on lowland wet grassland reserves, and also highlight the value of consistent and reliable monitoring data.
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Insufficient reproduction as a consequence of predation on eggs and chicks is a major determinant of population decline in ground‐nesting birds, including waders. For many populations, there is an urgent need to maintain breeding populations at key sites, and conservation practitioners need to find viable management solutions to reduce predation. One tool available to the practitioner is fences that exclude key predators from areas containing breeding birds. Temporary electric fencing is an increasingly popular predator exclusion intervention, but such fences have costs associated with purchase and the time needed to erect and maintain them. Their effectiveness and optimal application are also frequently questioned. We evaluate the use of temporary ditch‐side four‐strand electric fences in lowland grasslands in two countries, The Netherlands and England, in areas containing high densities of breeding waders. In both countries and in all years, godwit and lapwing nest survival was significantly higher within areas enclosed by ditch‐side electric fences. Brood survival, assessed for godwits in The Netherlands, was also higher within fenced areas in all years. This demonstrates that using temporary electric fences to enclose ground‐nesting birds can be an effective tool for improving breeding productivity. In our study, closely managed electric fences were effective at excluding red foxes Vulpes vulpes, but not avian and other mammalian predators. The positive effect that electric fencing had on nest and brood survival therefore likely results from a reduction in the total number of visits by mammalian predators, and especially visits by foxes. Although it requires a substantial time investment throughout the period of use, our temporary electric fence design provides flexibility compared to other fence designs when it comes to enclosing different areas within a season and between years, as the targets for protection change or as land and flood management dictate. This conservation intervention can help buy the time required to develop and implement longer term solutions for application at larger scales.
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Edge effects occur when the matrix has adverse impacts on the patches of remnant habitat. A widely explored example of this is the hypothesis of a higher predation pressure on bird nests closer to the habitat edge. In parallel with the recent loss of open habitats through afforestation as a climate change mitigation measure, an interest in the impact of forest on species dependent on open habitats has re‐emerged. We follow wader nest survival to study the issue of an edge effect in a system of wet grasslands fragmented by forests in a region where it has not been tested before, focussing mainly on northern lapwing (Vanellus vanellus), common ringed plover (Charadrius hiaticula), common redshank (Tringa totanus) and southern dunlin (Calidris alpina schinzii). To record nest survival, we monitored 753 nests of 10 wader species on coastal grasslands in Estonia for 3 consecutive years. A subset (n = 85) of these nests was equipped with camera traps to record nest predation events and predator association with forest edge. The distance to nearest trees and forest and a forest cover within a 1‐km buffer around each nest was measured. We recorded extremely low daily nest survival rates (0.903–0.922 for different species), with most nests lost to predation. We showed that nest survival is lower closer to the forest edge and negatively affected by the proportion of forest within a 1‐km buffer around each nest. Based on camera trap recordings, we suggest that the edge effect is caused by elevated nest predation rates by the most common predator, the red fox (Vulpes vulpes), closer to the forest edge. Future afforestation plans of open habitats need to acknowledge that the resulting fragmentation has a negative impact on nest survival of ground‐breeding birds. On the other hand, our results imply that restoration efforts aimed at removal of most damaging forest plantations could benefit breeding waders.
Article
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Wading birds can be found breeding in a myriad of habitats and ecosystems across Europe that vary widely in their land-use intensity. Over the past few decades, wader breeding populations have declined steeply in habitats ranging from natural undisturbed ecosystems to intensively managed farmland. Most conservation science has focused on factors determining local population size and trends which leave cross-continental patterns and the associated consequences for large-scale conservation strategies unexplored. Here, we review the key factors underlying population decline. We find land-use intensification in western Europe and mostly agricultural extensification and abandonment in northern, central and eastern Europe to be important drivers. Additionally, predation seems to have increased throughout the breeding range and across all habitats. Using collected breeding density data from published and grey literature, we explore habitat specificity of wader species and, of the most widely distributed species, how breeding densities change across a land-use intensity gradient. We found that two-thirds of all examined wader species have relatively narrow breeding habitat preferences, mostly in natural and undisturbed ecosystems, while the remaining species occurred in most or all habitats. The most widespread generalist species (black-tailed godwit, northern lapwing, common redshank, Eurasian oystercatcher, common snipe and ruff) demonstrated peak breeding densities at different positions along the land-use intensity gradient. To conserve both diverse wader communities and viable meta-populations of species, a diversity of habitats should be targeted ranging in land-use intensity from natural ecosystems to medium intensity farmland. Alongside, strategies should be designed to moderate predation of wader clutches and chicks.
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Wetlands such as the World Heritage Site in the Wadden Sea include important habitats for breeding waterbirds. Its saltmarshes and adjacent conservation polders are used by thousands of breeding birds. However, some alarming population declines have been recorded during recent decades and previous studies found indications that predation pressure from red foxes (Vulpes vulpes) and more recently from invasive racoon dogs (Nyctereutes procyonoides) played an important role. The current study aimed to assess habitat utilisation by foxes and racoon dogs along the coast of the Wadden Sea. We equipped 21 foxes and seven racoon dogs with GPS collars and recorded a total of 37,586 (mean: 2,088) GPS fixes during a total of 2,617 (mean: 145) equipment days for red foxes and 3,440 (mean: 573) GPS fixes during a total of 272 (mean: 45) equipment days for racoon dogs. Foxes showed high individual variability in Kernel 95% home range sizes, with a mean of 172.2 ha (range: 3 to 824 ha) and little overlap among territories. Males had significantly larger home ranges than females, and there were no differences in home range sizes between adults (n = 14) and young (n = 4). Racoon dogs had smaller home ranges than foxes (mean: 52.8 ha). The preferred habitat type of both predators during daytime was the conservation polders along the Wadden Sea, while foxes also selected saltmarshes during the night. In contrast, both species avoided farmland areas. Foxes showed 20% of their activity during daylight hours and spent this time largely in areas with dense vegetation cover. None of the tagged individuals entered areas with particularly high bird densities (i.e. Wadden Sea islands or Halligen). However, our data suggest that foxes and racoon dogs frequently make use of linear structures such as dykes and dams and patrol along the tide line for carcasses. This suggests that at least single individuals of both species are prone to enter islands that are connected by dams to the mainland.
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The genetic structure of a population can provide important insights into animal movements at varying geographical scales. Individual and social behaviors, such as philopatry and dispersal, affect patterns of relatedness, age and sex structure, shaping the local genetic structure of populations. However, these fine scale patterns may not be detected within broader population genetic structure. Using SNP genotyping for pairwise relatedness estimates, we investigated the spatial and genetic structuring of 141 red foxes within south-central Sweden at two scales. First, we looked at broad scale population structuring among red foxes at the regional level. We then estimated pairwise relatedness values to evaluate the spatial and genetic structure of male, female and mixed sex pairs for patterns of philopatry and dispersal at a more localized scale. We found limited genetic differentiation at the regional scale. However, local investigations revealed patterns of female philopatry and male biased dispersal. There were significant differences in pairwise geographic distances between highly related same sex pairs with the average distance between related males, 37.8 km, being six times farther than that of related females, averaging 6.3 km. In summary, the low levels of genetic differentiation found in this study illustrates the mobility and dispersal ability of red foxes across scales. However, relatedness plays a strong role in the spatial organization of red foxes locally, ultimately contributing to male biased dispersal patterns.
Article
Quelques aspects d’une population vulpine habitant les dunes néerlandaises de la Mer du Nord sont décrits. La plupart des renards adultes vivent en petits groupes, chaque groupe occupant un territoire stable de 105 à 200 ha. Plusieurs types caractéristiques de mouvements quotidiens ont été décrits concernant les renards territoriaux et les jeunes renards vivant sur de petits domaines situés parmi les territoires de groupe. Finalement cinq types de dispersion de jeunes renards pendant leur premier hiver et la période suivante sont décrits.