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African Zoology
ISSN: (Print) (Online) Journal homepage: www.tandfonline.com/journals/tafz20
The underground cat: burrow use by female black-
footed cats (Felis nigripes)
Harold Brindley, M Justin O’Riain & Alexander Sliwa
To cite this article: Harold Brindley, M Justin O’Riain & Alexander Sliwa (18 Oct 2024): The
underground cat: burrow use by female black-footed cats (Felis nigripes), African Zoology, DOI:
10.1080/15627020.2024.2402249
To link to this article: https://doi.org/10.1080/15627020.2024.2402249
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African Zoology 2024: 1–12
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AFRICAN ZOOLOGY
ISSN 1562-7020 EISSN 2224-073X
https://doi.org/10.1080/15627020.2024.2402249
African Zoology is co-published by NISC (Pty) Ltd and Informa UK Limited (trading as Taylor & Francis Group)
This is the nal version of the article that is
published ahead of the print and online issue
The underground cat: burrow use by female black-footed cats (Felis nigripes)
Harold Brindley1* , M Justin O’Riain1 and Alexander Sliwa2
1 Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Cape Town,
South Africa
2 Cologne Zoo, Köln, Germany
* Correspondence: halbrindley4@gmail.com
The black-footed cat (Felis nigripes) is the smallest and one of the rarest cats in Africa. Endemic to the semi-arid
regions of South Africa, Namibia and Botswana, this nocturnal carnivore spends daytime in burrows, thus avoiding
high temperatures and diurnal predators. Despite the importance of burrows, den usage has never been studied
in detail for this species. Here we report on the frequency with which female black-footed cats use burrows of
different dimensions and compared with burrow availability. The entrances of 50 dens, used by five radio-collared
black-footed cats over four weeks, were scanned with LiDAR to measure tunnel width (mean = 15.2 ± 3.9 cm) and
height (mean = 13.9 ± 3.6 cm). Of these, 98% (n = 49) most closely matched the dimensions of springhare (Pedetes
capensis) burrows. Each cat used a mean of 11.6 den sites and spent a mean of 2.0 consecutive days in a den
before selecting a new one. When kittens reached an age of 44–50 days, mothers switched from using a den for a
mean of six days-per-den, to changing dens every day. Our results suggest that female black-footed cats are reliant
upon springhares to provide suitable daytime refugia and maternity dens in southern Namibia. Further studies
should be conducted to determine what den sites are selected in the absence of springhare, and whether localised
persecution of springhare impacts the survival of black-footed cats.
Keywords: 3D scan, den, carnivore, LiDAR, Namibia, springhare
Burrow occupation is a rare behaviour for cats, with only
four species observed using burrows for daily shelter.
These are the Arabian wildcat (Felis lybica lybica), Pallas’s
cat (Otocolobus manul), sand cat (Felis margarita) and
black-footed cat (Felis nigripes) (Phelan and Sliwa 2005;
Ross et al. 2010; Sliwa et al. 2016). However, only the
black-footed cat depends on the excavations of other
animals for year-round daytime shelter and maternity
dens (Sliwa 2004). Despite the importance of burrows to
black-footed cats, there is no detailed research on factors
influencing den selection or the spatial and temporal
patterns of den usage. For clarification, the word burrow
herein refers to a tunnel dug into soil by an animal, while
the word den refers to a semi-enclosed space used as
shelter by an animal, e.g. a cat may den inside a burrow.
The black-footed cat is the smallest and probably one
of the rarest cats in Africa (Sliwa, 2013). Females weigh
a mean 1.30 ± 0.07 kg and males 1.93 ± 0.15 kg (Sliwa,
2013). The population is estimated to be between 7 500
and 12 000 individuals, although systematic search efforts
have not been conducted throughout their distribution
(Wilson et al. 2016). It is southern Africa’s only endemic
cat and is restricted to semi-arid regions of South Africa,
Namibia and Botswana, possibly extending into Angola and
Zimbabwe (Wilson 2015). Black-footed cats are short-grass
specialists, capturing prey by either waiting at rodent holes,
slow stalking, or weaving between tufts and low shrubs at a
frenetic pace (Sliwa 1994).
Black-footed cats have large home ranges for their
diminutive size. At Benfontein Nature Reserve near
Kimberley, South Africa, (hereafter referred to as Benfontein)
five adult male cats had annual home ranges averaging 20.7
km2 using 100% Minimum Convex Polygon (MCP100) (Sliwa
2004). These were significantly larger than the mean annual
home ranges of seven adult female cats at 10 km2 (MCP100)
in the same area. Preliminary results from drier habitats in
southern Namibia show annual home ranges at least double
the size of those in Benfontein (Sliwa et al. 2022). Large home
ranges result, in part, from cats travelling substantial distances
each night. For example, cats in Benfontein travel an average
of 8.4 km per night (range 4–16 km) (Sliwa 1996a).
While no studies have focused on den usage, several
den-related observations have appeared in publications.
Cats remain in burrows throughout the day, emerging
around 30 minutes before or after sunset and actively
hunting throughout the night before returning to a den
or choosing a new one around and up to 40 minutes after
sunrise (Sliwa 1993). Captive cats have been observed
digging in their enclosures, which led to assumptions
that wild black-footed cats might dig their own burrows
(Sunquist and Sunquist 2002). However, black-footed cats
do not dig in the wild (Sliwa 1996b). Sliwa (1993) noted
that black-footed cats in Benfontein used abandoned
southern African springhare (Pedetes capensis) burrows
and occasionally hollowed out termite mounds as dens, and
suggested that they might also use Cape porcupine (Hystrix
Introduction
This article will be published in the upcoming Special Issue for the Zoological Society of South Africa
Published online 18 Oct 2024
Brindley, O’Riain and Sliwa
2
africaeaustralis), aardvark (Orycteropus afer) (Sliwa 1996a)
and Cape ground squirrel (Xerus inauris) burrows (Sliwa
et al. 2010).
Sliwa (1993) noted a female using the same den three
days in a row and then again when tracked a week later,
but also using three different burrows over three consecutive
days. Overall, two thirds of 28 recorded dens were only
observed to be used once (Sliwa 1996a). Mothers were
noted to change dens frequently after the first week following
the birth of kittens (Olbricht and Sliwa 1997).
These early studies rarely recorded den locations of an
individual for more than four consecutive days, making
temporal den usage patterns challenging to quantify. The
aim of our study was to explore which burrows female
black-footed cats use as den sites, attempt to identify the
mammalian species that created the burrow, and to evaluate
how this critical and limiting resource may affect black-footed
cats’ distribution and conservation. The first objective of our
study was to compile a reference table of burrow entrance
dimensions for species whose distribution overlapped with
that of the black-footed cat in the study area. The second
objective was to determine the size range of dens selected
by female black-footed cats, specifically the width and height
of the tunnel entrance, then compare those dimensions to
our reference list to determine which species’ burrows the
cats were selecting. Our final objective was to describe the
attributes of selected dens and document temporal and spatial
den usage patterns for breeding female black-footed cats in
the study area.
Methods
Study area
The study area in southern Namibia consists of 70 000
hectares of private farmland, with the northeast corner 2 km
from the small village of Grünau (Figure 1). It is a dry region
with annual rainfall of 80 to 120 mm (Sliwa et al. 2022). The
Nama Karoo vegetation is dominated by grassland with
intermittent dwarf shrub savanna. The ephemeral Gamkab
River runs through the study area and is characterised by
a narrow band of camel thorn trees (Vachellia erioloba) and
dense shrubs in an otherwise nearly treeless landscape. The
farms are stocked with sheep (Ovis aries) at low densities.
The primary burrow-making species in the study area
include a diversity of small rodents (mainly mice and gerbils),
Cape ground squirrel, springhare and aardvark. Burrow
modifiers (that may or may not dig their own burrows but often
or always adapt and enlarge burrows dug by other species)
include Cape fox (Vulpes chama), bat-eared fox (Otocyon
megalotis), aardwolf (Proteles cristata) and Cape porcupine.
No above-ground structures of the snouted harvester termite
(Trinervitermes trinervoides) occur within the study site.
Creation of a reference table of burrow entrance sizes
for local burrowing species
We consulted available literature to create a burrow
entrance size reference table for the burrowing species at
the study site. To determine the size range of springhare
burrow entrances, we selected the minimum and maximum
values for width and height from three burrow systems
excavated by Butynski and Mattingly (1979) and from
45 springhare tunnel entrances measured by Anderson
and Richardson (2005). For aardvark, we subtracted one
SD from the shortest site mean and added one SD to the
longest site mean from Whittington-Jones (2006) who
measured 60 burrows at each of three reserve sites. For
aardwolf, we used the shortest and longest measures of
width and height from two dens excavated by Anderson and
Richardson (2005).
Where no burrow dimensions were available in the
literature, we took measurements in the field when a species
was observed to enter a burrow, or we made inferences
based on published details of a species’ mass and denning
behaviour. We measured 11 burrow entrances that we
observed Cape ground squirrels entering (seven at the
study site, four at Benfontein) and used the shortest and
longest measures for width and height, at a depth of 10
cm inside the tunnel entrance. We measured the entrance
of a single burrow that a pair of bat-eared foxes were
excavating and found it to have a width and height nearly
identical to the mean width and height of aardwolf burrows
measured by Anderson and Richardson (2005). We thus
inferred that bat-eared fox burrow entrances have the same
size range as aardwolf. Though smaller than aardvark,
porcupine often widen aardvark burrows to suit their own
requirements (Happold 2013), so we inferred porcupine
burrow width to encompass the largest third (a rough
guess) of aardvark burrow width, plus a third beyond that
range and inferred height range to be the same as aardvark.
Cape fox commonly modify springhare burrows (Nel and
Maas 2013); but have a smaller mass than bat-eared fox
and aardwolf (Anderson 2013; Nel and Maas 2013) and a
mass about twice that of springhare (Butynski 1973). We,
thus, inferred a width range encompassing the top 25% of
springhare width range, extending to the shortest width of
aardwolf burrows, and a height range encompassing the top
40% of springhare height range (again these were merely
approximations). Various small rodents were assumed to
have created burrows with a width or height from 5 to 10 cm.
Black-backed jackals (Lupulella mesomelas) were omitted
from the reference table because we never observed them in
the study area, likely due to predator control.
While these size ranges are useful as a general guide
for determining which species created or most recently
modified a burrow, it is important to point out that
burrow dimensions may differ by substrate and location
(Whittington-Jones 2006) and are ever-changing due
to continual modification or disturbance by a variety of
animals and plants, as well as the impacts of wind and
water which lead to erosion, in-fill and eventual collapse
(Bragg et al. 2005).
Study animals
The Black-footed Cat Working Group (BFCWG) captured
and radio-collared four female black-footed cats in February
2020 (Prima, Kara, Auas and Lace) and an additional two
females in June 2021 (Nama and Zola). Auas was found
dead on the first day of the study, so the remaining five cats
were tracked. Capture, sedation and radio-collaring methods
are detailed in BFCWG annual reports (Sliwa et al. 2021).
The BFCWG and site manager Martina Küsters of
the Black-footed Cat Research Project Namibia allowed
African Zoology 2024: 1–12 3
us to access the study site to conduct our research in
October 2022, under permit RCIV00032018BFCWG
from the National Commission on Research, Science
and Technology in Windhoek, Namibia. A field technician
assisted with night- and daytime tracking, camera
monitoring of the collared cats, and data collection. Most
cats had been well-habituated to vehicle tracking and to
being photographed by camera traps at den sites for periods
ranging from 1.4 to 2.7 years. We presumed that regular
camera trapping at the entrances of dens had habituated
the cats to humans approaching den sites on foot and that
using telemetry to pinpoint the cats’ locations in burrows
would not affect den usage or selection behaviour.
Data collection
The cats were tracked to their daytime resting location inside
a den daily for 29 days, from 7 October 2022 to 4 November
2022, excluding 14 and 24 October 2022 when the tracking
vehicle was being repaired. On the first day, only three cats
were tracked resulting in 133 total cat-den-days recorded.
To reduce the chance of disturbing a cat resting outside a
burrow, we tracked between a minimum of one and a half
hours after sunrise and a minimum of one hour before
sunset. To locate cats, we drove along sand tracks to
within 100 to 200 m of a tracked cat, then completed final
tracking to the den site by slowly approaching on foot. The
cats’ position was pinpointed below ground using telemetry,
marking this position on the surface with a stone, and
taking a GPS waypoint on both a Garmin GPSMAP 64sx
handheld unit and a Vivo mobile phone (model 1938) using
the application Avenza Maps by Avenza Systems. Cross
checking with 3D scans (referenced below) showed that
this method effectively corresponded with tunnel direction
and likely pinpointed a cat’s resting location to within a 50 cm
radius. If a cat was visible at the entrance to the den, or the
den was in unusually dense vegetation, no surface position
was taken. Approaching and retreating from dens was done
as quietly as possible to limit disturbance, although cats were
likely able to detect our approach through the dry grass.
We named dens with the first letter of the cat’s name
followed by two digits representing the sequence of den
sites recorded. On two occasions a den was used within
3 m of another den, so the dens were given the same
name appended ‘a’ and ‘b’. A den location was acquired
for every cat on every tracking day. On one occasion, when
considered too close to sunset to approach the den without
potentially disturbing the cat, the location was estimated
by direction and signal strength (labelled P07est). When a
cat was observed to have selected a different den to the
previous day, the previous den was revisited to collect the
following data.
A LiDAR scan of the burrow entrance was taken using
a 12.9-inch Apple iPad Pro 2020 with the factory built-in
LiDAR sensor and the application 3D Scanner by Laan
Labs. The sensor was placed at the mouth of the entrance
and manoeuvred to obtain all line-of-sight distances within
the burrow, including a scan of the aboveground surface
from the burrow entrance to the previously marked point
where the cat was determined to be positioned below
ground. The application allowed digital measurement of
straight-line distances in the 3D model which were later
used to measure burrow dimensions. Tunnel width and
height were digitally measured to the nearest millimetre,
10 cm inside the entrance. The distance from the floor of
the tunnel to the surface of the soil directly above it was
also digitally measured to the nearest centimetre at the
maximum depth of the scan. To estimate the angle of
descent in relation to the horizontal a protractor was laid
over the 3D model on the iPad screen. The distance from
the top lip of the tunnel entrance to the stone marking the
estimated position the cat had been resting to the nearest
centimetre was manually measured using a tape measure.
Thirty-one transect plots were completed to estimate
size and frequency of available burrows in the study
area. Sixteen were conducted with a black-footed cat
den at the centre (Figure 2) and 15 were conducted at
randomised locations within the known home range of cats
as determined from the previous year’s tracking (Sliwa
et al. 2022). Random plots were selected as follows:
we started by driving down a sand track, then selected a
random number between 0 and 20 using the application
Random UX on a mobile phone and drove that number
Figure 1: Location of study area near Grünau in Namibia
Gamkab River
STUDY AREA
0 5 10 km
AFRICA
Namibia
Namibia
Botswana
South Africa
See
larger
map
Grünau
C12
B1
C10
C10
Brindley, O’Riain and Sliwa
4
of 100-m lengths, resulting in a driving distance from 0 to
2.0 km. A random compass bearing between 0 and 359°
was then selected and, following that bearing, a random
distance between 0 and 300 m was walked. The final point
was marked as the centre of the plot. A square with 100-m
sides from the den location or random centre point was
then projected, using Avenza Maps on a mobile phone, with
corners to the NW, NE, SW and SE. These corners were
marked with stakes and used to facilitate visual navigation.
A transect line completing six north-to-south transects, each
separated by 20 m, was then used to survey 2.5 m to the
left and to the right of each transect line. At every burrow
detected, a tape measure was used to measure the width
and height of the tunnel to the nearest centimetre at a depth
of 10 cm inside the tunnel entrance, with GPS waypoints
recorded at each burrow entrance. The 20-m space
between transect lines was intended to eliminate overlap
due to the researcher weaving off course. It also excluded
the selected den and the burrow complex surrounding it
unless the complex was wider than 15 m. These data were
recorded in the application Avenza Maps. The skull width of
adult black-footed cats exceeds 5 cm and therefore burrows
with a width less than 5 cm were considered too small to
be used as a den and were not recorded. Furthermore,
any diggings less than about 40 cm deep (determined with
a high-powered flashlight) were not recorded as they were
considered to have limited utility as dens.
Determining reproductive status
During the study, custom-made infrared camera traps
(SECACAM, Browning and Bushnell models) were set
at various den sites as part of ongoing research, and
information from these cameras was used to identify the
presence of kittens. Cameras were mounted on low tripods
(10–20 cm high) and placed on the ground pointing directly
into the mouth of the den from 1–2 m away. In addition,
direct observation during the study, or by BFCWG staff
during collar replacement procedures 10 days after the end
of this study, provided further evidence of kitten presence.
Kitten ages were estimated by A. Sliwa and M. Küsters
based on personal experience and information outlined in
Olbricht and Sliwa (1995).
Analyses
A ‘single diameter’ reported for burrow size is the mean
of the measured width and height, as burrow entrances
in the study area were found to be roughly circular or
elliptical in shape. Values following a mean represent ±
one standard deviation. To simplify temporal analyses,
we assumed that on the two missed tracking days,
cats selected the same den as the previous day. When
analysing the number of consecutive days per den, the
first and last recorded dates that a cat used the same
den were included. To analyse den range (the area
encompassing all dens used by an individual) 100%
Minimum Convex Polygon (MCP100) was calculated using
the tool Minimum Bounding Geometry (set to Convex Hull)
in the software ArcGIS Pro (Esri Inc. 2022).
To compare the distribution of entrance diameters of
selected burrows to available burrows, width and height
were used to create a single diameter for each burrow,
with chi-square goodness of fit tests using the R base
package in R Statistical Software (v4.2.2; R Core Team
2022). Due to the heavily skewed distribution of available
burrow sizes, it was not possible to test whether the
distribution of selected burrow sizes varied significantly
from the distribution of available burrow sizes, and still
be able to meet the requirements of a reliable chi-square
goodness-of-fit test. It was, however, possible to compare
the distribution of the sizes of selected burrows to the
distribution of sizes of available burrows within the range
of selection by black-footed cats. To meet the requirements
for a reliable chi-square test in this size range, we grouped
burrow diameters into 2 cm bins in the region of high selection
(10–17.99 cm) and the remainder (18–26.99 cm) were
grouped into a single bin.
Results
Burrow entrance size reference table
A reference table of burrow entrance sizes for seven
prominent burrowing species in the study area reveals a
potentially continuous range of available burrow sizes with
widths ranging from 5 to 57 cm and heights from 5 to 50 cm
(Table 1).
Reproductive status of cats
Only one of the five cats (Zola) did not show any signs of
reproductive activity during the study. Lace gave birth
24–30 days before the study and Nama gave birth 21–27
days before the study, each to two kittens. Kara gave birth
Figure 2: Transect plot method for surveying availability of burrows
around black-footed cat dens and around randomly selected centre
points
Den location
Walking path
Survey area
5 m 20 m
100 m
100 m
African Zoology 2024: 1–12 5
sometime around 23 October (17 days into the study) to at
least one kitten, and Prima was pregnant for the duration
of the study, giving birth to two kittens about four days after
study completion. Kara was the only cat we observed scent
marking while hunting at night, doing so on both 14 October
and 22 October, just before the presumed birth, but she
was no longer scent marking when next observed on
2 November.
Attributes of black-footed cat dens
Of 58 den sites recorded, 50 could be revisited and 3D
scanned when no cat was present. These 50 dens had a
mean tunnel width of 15.2 ± 3.9 cm (range 9.1–31.9 cm)
and mean height of 13.9 ± 3.6 cm (range 8.5–28.5 cm),
resulting in a mean tunnel diameter of 14.5 cm (average of
width and height), with little variation in the mean diameter
selected by each cat (Prima: 16.5 ± 3.3 cm, Lace: 15.0 ±
3.7 cm, Zola 14.2 ± 1.8 cm, Nama: 14.1 ± 3.0 cm, Kara:
13.3 ± 2.0 cm). Prima may have been preferentially
selecting the largest burrows due to her visibly enlarged
mid-section during pregnancy. The largest den (L04,
32 cm wide × 21cm high) was used by Lace with her two
six-to-seven-week-old kittens for six consecutive days
before she started changing dens daily. Three dens could
not be effectively scanned beyond the entrance due to an
abrupt turn or dense vegetation. The remaining 47 dens
showed two distinct angles of descent. Six (13%) had a
nearly vertical entrance (mean = 68°, range 40–90°) and
the remaining 41 (87%) had a shallow angle of descent
(mean = 23°, range 14–31°). These two types of entrances
may correspond to springhare ‘clean’ holes and ‘mound’
holes referred to by Butynski and Mattingly (1979). The
LiDAR scanner scanned a mean distance of 75 ± 23.8 cm
beyond the burrow entrance. At the deepest point of these
47 scans, the mean depth of the floor of the tunnel below
the soil surface directly above was 51.0 ± 9.8 cm (range
33–74 cm). About 80% of scans showed a levelling off
toward the horizontal after the initial slope, so that this
range of depth (33–74 cm) likely represents a typical
resting depth for a black-footed cat, with about 37 cm of soil
above their heads assuming a 14 cm tunnel height.
We determined the cat’s resting position below ground
at 47 of the 58 den sites and found that black-footed cats
rested a mean distance of 119 ± 41.7 cm from the entrance
of the burrow (range 72–290 cm). When cats used the
same burrow on multiple occasions, the underground
resting location was found to be at the same point within
the burrow, except for two dens where the cat appeared
to have two distinct internal resting positions about
1.0 m apart within the same burrow. While it is unclear if
the detected resting position of each cat represents daily
sleeping locations or a point the cat would move to when
movement was detected outside, these positions were
consistent across multiple days in the same burrow. Based
on these values, Figure 3 represents a typical female
black-footed cat den in the study area.
Table 1: Burrow entrance size range (to the nearest cm) for burrowing species in the study area
Species Burrow entrance size range (cm)
Common name Scientific name Width Height
Small rodents assorted 5–10 5–10
Cape ground squirrel Xerus inauris 9–15 7–12
Springhare Pedetes capensis 10–23 8–25
Cape fox* Vulpes chama 20–29 18–25
Bat-eared fox* Otocyon megalotis 30–40 19–24
Aardwolf Proteles cristata 30–40 19–24
Aardvark Orycteropus afer 32–52 27–52
Cape porcupine* Hystrix africaeaustralis 45–57 30–50
*Indicates size ranges based primarily on inference.
Figure 3: A typical den selected by female black-footed cats in southern Namibia, based on mean values for cat resting position, tunnel
width and height 10 cm inside the entrance, and the depth of the tunnel floor at the deepest point of 3D scans
Cat resting position: 119 cm from entrance
Soil above
cat: 37 cm
Depth of tunnel
floor: 51 cm
62 cm of 23° slope
Tunnel width: 15 cm
Tunnel height: 14 cm
Brindley, O’Riain and Sliwa
6
Size of burrow entrances selected by black-footed cats
versus available burrows
The 438 available burrows measured within 31 transect
plots ranged from 5 cm in width and height up to 55 cm
width and 45 cm height, but the distribution along this
range was discontinuous with a near absence of burrows
in the 22 to 31 cm width range (n = 3) and in the 25 to
31 cm height range (n = 4). The distribution of available
burrow sizes showed a similar pattern in both the
randomly selected transect plots (n = 15) and in the
transect plots centred on black-footed cat dens (n = 16).
Plotting the width and height of all available burrow sizes,
along with the widths and heights of the 50 measured
burrows selected by the cats, and overlaying these with
the reference burrow size ranges by species, showed that
49 of the 50 selected dens fell within or adjacent to the
size range of springhare burrows (Figure 4). One burrow
was within the size range of aardwolf and bat-eared fox.
Looking at each burrow as a single diameter (the mean
of the width and height of the entrance) and comparing
the relative frequency of each burrow diameter in 1 cm
bins, shows that the cats in this study never selected
burrows in the 5 to 10 cm range even though they had
the highest availability in the cat’s home ranges (Figure
5). The cats in this study also never selected dens larger
than 27 cm in diameter, even though there was some
availability. A chi-square goodness of fit test for available
burrows and selected dens from 10 to 27 cm diameter
showed that the proportions of selected den diameters
did not differ significantly from the proportions of available
burrow diameters χ2(4, n = 50) = 5.24, p = 0.264,
suggesting that den selection in this size range followed
availability.
Temporal den usage patterns in relation to
reproductive status
Each of the five female cats used a burrow as a daytime
resting den site on all 27 observed days of the study. No
cat was ever found denning in vegetation. Zola, the only
cat which showed no signs of reproduction, was also the
only cat to be found outside of a den nearly two hours
after sunrise, but on each of these two occasions she was
located inside a burrow later the same day.
The cats used a mean of 11.6 ± 2.2 den sites each over
27 observed days. Nama used eight den sites, Prima
used 10, Kara and Lace each used 13, and Zola used 14,
totalling 58 den sites (Table 2). The cats spent a mean of
2.0 ± 2.0 consecutive days in the same den (range 1–13
days) averaging a den change on 47% of days (65 of 138).
Nama, who had the youngest kittens during the study,
changed dens least frequently (26% of days, 7 of 27).
Before Nama’s kittens reached an estimated age of 44–50
Figure 4: Entrance widths and heights of available burrows measured to nearest centimetre in transect plots (white circles) and
burrows selected as dens by black-footed cats measured to nearest millimetre (black diamonds). Dotted lines represent reference
burrow entrance size range for species present in the study area. *Indicates size ranges based primarily on inference. Ground squirrel
burrow reference size range was omitted as none were encountered within the cats’ home ranges
10 20 30 40 50 60
10
20
30
40
50
BURROW HEIGHT (cm)
BURROW WIDTH (cm)
Burrow size range
for species
Selected by
black-footed cat
Available burrows
aardvark Cape
porcupine*
(enlarged
bat-eared fox*
and aardwolf
(enlaged
springhare)
Cape fox*
(enlarged
springhare)
small rodents
springhare
aardvark)
African Zoology 2024: 1–12 7
days, she spent a mean of 7.3 consecutive days in each
den (4, 5 and 13 days) equating to a den change on only
10% of days (2 of 21). After Nama’s kittens reached an
estimated age of 44–50 days, Nama changed dens nearly
every day (five of the six remaining days of the study).
Lace, who had slightly older kittens throughout the study,
had the second lowest rate of den change (46% of days,
13 of 28). Lace showed a similar pattern to Nama. Before
Lace’s kittens reached an estimated age of 44–50 days,
she spent a mean of 5.0 consecutive days per den (2, 9,
3 and 6 days) equating to a den change on only 16% of
days (3 of 19). After Lace’s kittens reached an estimated
age of 44–50 days, Lace changed dens every day for
nine consecutive days. Kara, who was presumed to have
given birth about halfway through the study, had the third
lowest rate of den change at 52% (14 of 27 days). She
changed dens on seven consecutive days leading up to
the estimated date of birth, whereupon she spent four
consecutive days in the same den and then changed
dens on 50% of the remaining 10 days (days 2, 4, 5 and
7). Both Prima (who was pregnant throughout the study)
and Zola (who showed no evidence of being pregnant or
having kittens) changed dens at the same high rate (57%
of days, 16 of 28) throughout the study, although Zola
used more den sites (n = 14) than Prima (n = 10).
Both the number of consecutive days per den and the
rate of use of previous dens (returning to a previously
used burrow on a non-consecutive day) appeared to be
linked to reproductive status. The two cats who had kittens
throughout the study (Lace and Nama) used the same
dens for the most consecutive days, but they were never
observed to select a burrow that they had previously used
during the study period. Assuming she used the same den
on the day she wasn’t tracked, Nama used den N03 for
Figure 5: Relative frequencies of entrance diameters of available burrows in the study area and of dens selected by black-footed cats,
overlayed with the reference entrance size ranges for the burrowing species present
Table 2: Den sites used by five female black-footed cats over 27
days. X represents days not tracked
Date Kara Lace Nama Prima Zola
7-Oct X L01 X P01 Z01
8-Oct K01 L01 N01 P01 Z02
9-Oct K02 L02 N01 P01 Z02
10-Oct K02 L02 N01 P01 Z03
11-Oct K02 L02 N01 P02 Z04
12-Oct K02 L02 N02 P03 Z05
13-Oct K03 L02 N02 P03 Z04
14-Oct X X X X X
15-Oct K03 L02 N02 P04 Z06
16-Oct K04 L02 N02 P01 Z06
17-Oct K05 L02 N03 P04 Z07
18-Oct K04b L03 N03 P05 Z06
19-Oct K06 L03 N03 P05 Z08
20-Oct K07 L03 N03 P04 Z06
21-Oct K04b L04 N03 P04 Z06
22-Oct K08 L04 N03 P05 Z09
23-Oct K08 L04 N03 P05 Z09b
24-Oct X X X X X
25-Oct K08 L04 N03 P05 Z09b
26-Oct K09 L04* N03 P06 Z09b
27-Oct K09 L05 N03 P07est Z09b
28-Oct K10 L06 N03 P06 Z10
29-Oct K10 L07 N03* P05 Z11
30-Oct K11 L08 N04 P08 Z12
31-Oct K09 L09 N05 P06 Z12
1-Nov K09 L10 N06 P06 Z13
2-Nov K12 L11 N07 P06 Z13
3-Nov K12 L12 N07 P09 Z13
4-Nov K12 L13 N08 P10 Z13
Unique dens 13 13 8 10 14
* Represents the day when kittens reached an estimated age of
44–50 days and den change pattern shifted
BURROW DIAMETER (cm)
NUMBER OF BURROWS
Burrows selected by black-footed cat
Available burrows
murids
ground squirrel
springhare
Cape fox
bat-eared fox/aardwolf
aardvark
Cape porcupine
120
100
80
60
40
20
12
8
4
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
Brindley, O’Riain and Sliwa
8
13 consecutive days. Assuming the same for Lace, she
used den L02 for nine consecutive days. The other three
cats exhibited the reverse pattern: occasionally re-using
previously selected dens but spending no more than
four consecutive days in the same den. Prima, who was
pregnant throughout the study, returned to four previously
used den sites on seven occasions (spending a total of 12
days in them) with a maximum of four consecutive days
in the same den. Zola, who showed no signs of having
kittens or being pregnant, returned to two previously
used dens on two occasions (total three days) with a
maximum of five consecutive days in the same den (Z09b)
if she used that den on a day not tracked. Kara, who was
presumed to have given birth more than halfway into the
study, also selected two previously used dens (once with
her kitten) on four occasions, but never used the same
den for more than four consecutive days. When cats
without kittens changed dens, they selected previously
used dens on average about 27% of days (11 of 41 den
changes: Kara 11%, 1 of 9; Zola 19%, 3 of 16; Prima 44%,
7 of 16) while the cats with kittens almost never did (4% of
days: 1 of 24 den changes).
Spatial den usage patterns in relation to reproductive
status
The den range (the area containing all the dens used by
an individual during the study period of 29 days) varied
between individuals (Figure 6) and had a mean of 0.650 ±
0.360 km2 (MCP100). Nama, who had kittens throughout
the study, had the smallest den range at 0.096 km2. Yet
Lace, who also had kittens throughout, had the second
largest den range which was more than ten times the size
of Nama’s at 1.016 km2. Kara, who gave birth halfway
through the study, had the largest den range at 1.116 km2.
Prima, who was pregnant throughout, had the third largest
at 0.828 km2. Zola, who showed no signs of pregnancy
or presence of kittens, had a very small den range only
slightly larger than Nama’s at 0.191 km2.
Even though some den range overlap was recorded,
none of the cats used a burrow that had been used by
another individual during the four weeks of observation.
Nama and Kara denned 280 m apart for four consecutive
days in dens N01 and K02, while Zola and Lace denned
33 m apart in dens Z01 and L06, each for a single day,
though not on the same day. The closest that two cats
Figure 6: Den range (dashed lines) (MCP100) and den locations for five female black-footed cats over four weeks. Ranges are shown at the
same scale. Inset: location of den ranges within the study area
Study area
Nama
Kara Lace
Zola
Prima
Den site
Den range
Nama
Kara
Lace
Zola
Prima
Hwy B1
0 0.5 1 km
N08
N01
N02
N03
N04
N05
N06
N07
K01 K02
K03
K04
K05
K06
K07 K08
K09
K10
K11
K12
L01
L02
L03
L04
L05
L06
L07
L08
L09
L10
L11
L12
L13
Z01
Z02
Z03
Z04
Z05
Z06
Z07 Z08 Z09
Z10Z11
Z12
Z13
P01
P02
P03
P04 P05
P06
P07 (est) P08
P09
P10
African Zoology 2024: 1–12 9
denned on the same day was 138 m apart in dens Z09b
and L05 for a single day.
Discussion
Attributes of burrows selected as dens by female
black-footed cats
The five female black-footed cats monitored in this study
selected burrows with tunnel entrance diameters (mean
of width and height) between 10 and 27 cm (median =
14.5 cm). Though smaller burrows (5–10 cm) had by far
the highest availability in the study area, they were never
selected as dens. This likely indicates that burrows smaller
than 10 cm were too small for the adult female cats to fit
inside, or perhaps too small to turn around in or to nurse
kittens. Likewise, large burrows (31–47 cm) were available
but never used as dens, probably because they don’t
provide adequate protection from predators, especially for
unguarded kittens. Selection of burrows between 10 and
27 cm followed availability closely, suggesting that the cats
in this study were not preferentially selecting a particular
size within this range. The lack of burrows between 27
and 31 cm makes it impossible to determine if the cats
would have selected burrows in this range had they been
available. There is, of course, a chance that these selection
distributions could be different for other reproducing
females in the study and a larger sample size may give a
clearer picture.
Species that black-footed cats depend on for den sites
The results from our study site in southern Namibia showed
that adult female black-footed cats were entirely dependent
on southern African springhare burrows for den sites. Of
50 measured dens that the cats used during our study,
49 fell within the size range of springhare burrows. The
only den that didn’t was in the size range of aardwolf and
bat-eared fox burrows. Because aardwolves usually modify
springhare burrows (Anderson and Richardson 2005) and
bat-eared foxes often do the same (Nel and Maas 2013),
even this burrow was likely to have started as a springhare
burrow. Twenty-six of the 50 measured dens were used
by cats with kittens, showing the importance of springhare
burrows for maternity dens.
Springhares were by far the most abundant burrowing
species observed during spotlighting surveys on 12 nights
of cat tracking in the study area, even though the site
lies at least 90 km outside of springhare range as listed
in the IUCN assessment for the species (Child 2016).
To determine whether the cats truly do persist outside of
springhare range, accurate range estimations of both
species would be required. Overlaying the two current
IUCN range maps (Figure 7) shows three main regions
where black-footed cats may occur outside of springhare
range: (1) the central region of southern Namibia, where
we observed the presence of springhares, (2) a region
in South Africa surrounding the western boundary of
Eswatini extending north and south, and (3) a large region
in the southwest corner of South Africa. Like the southern
Namibia region (region 1), the region around the western
edge of Eswatini (region 2) could potentially be explained
by inaccurate estimates of either species’ range. However,
due to the larger area of discrepancy between springhare
and black-footed cat range in the southwest (region 3),
it seems more likely that black-footed cats are persisting
without springhares in this part of their range. This will be
an interesting region for future study to understand what
types of dens are used.
Alternative denning sites
Of the 50 black-footed cat dens we measured, 11 (22%)
also fell within the size range of ground squirrel burrows
(using a reference range of 9.3–15.1 cm for width and
7.4–12.0 cm for height, as measured in this study).
Ground squirrels are diurnal and easily observed, yet none
were observed within or near any of the cat’s denning
ranges during more than 100 hours of daytime field
work. Therefore, none of the black-footed cat dens were
considered to have been made by ground squirrels. Our
results suggest that adult female cats might select larger
ground squirrel burrows (i.e. be able to fit in them) but this
would need to be verified in future studies.
Yellow mongoose and meerkat tend to create burrows
smaller than 10 cm in diameter (Lynch 1980) which
appear to be too small for black-footed cat to occupy.
Bat-eared fox and aardwolf occupy burrows daily and
change dens regularly (Anderson and Richardson 2005;
Nel and Maas 2013) and are therefore likely to create
a larger supply of potential den sites than the sympatric
Cape fox which tend to only use dens for rearing pups
(Kamler and Macdonald 2014). While aardwolf generally
modify springhare or aardvark burrows, bat-eared fox may
excavate burrows from scratch and could potentially create
suitable black-footed cat dens where springhares have
been extirpated or are absent. While these larger burrows
may not be as useful for females, especially those with
unguarded kittens, larger male cats might prefer them.
Aardvark burrows were relatively abundant in the female
black-footed cats’ home ranges, but they were never
selected as dens. Aardvark and Cape porcupine burrows
provide little protection for unguarded kittens from predators
such as jackal, which often select aardvark burrows for their
own dens (Loveridge and Nel 2013). However, adult male
cats have a mass up to 50% more than adult females (Sliwa
2013) and are likely more able to defend themselves against
predators. They might therefore utilise aardvark burrows
when convenient or when smaller den sites are unavailable.
Aardvarks also play an important role in providing
potential dens when excavating termite mounds. Although
no above-ground termite structures occured within the
study area, the rounded mounds created by snouted
harvester termite were used occasionally by black-footed
cats in Benfontein (Sliwa 1993). Therefore, in the absence
of springhares, excavated termite mounds may provide a
source of dens for black-footed cats.
Number of dens used by black-footed cats
The five female black-footed cats in our study used a
mean of 11.6 den sites each over a four-week period. On
average, the cats selected a different den from the one they
used the previous day 47% of the time (65 den changes
of 138 observed days). When changing to a different den,
82% had never been used before (53 of 65 den changes).
Brindley, O’Riain and Sliwa
10
No two individuals ever used the same den, even though
two pairs had overlapping home ranges. If cats continued
to select new den sites at a rate of 11.2 every four weeks
throughout the year, it would suggest that each adult
female cat might use upwards of 145 different den sites in a
year in southern Namibia. However, with longer periods of
study this rate would likely decrease as dens re-used more
than a month apart became apparent. In addition, cats with
kittens almost never selected a previously used den, so this
rate of new den selection would likely change seasonally
based on levels of reproductive activity or with changes in
home range size.
Effects of reproductive status on den use patterns
On average, each black-footed cat used the same den
site for two consecutive days before selecting another,
but the number of consecutive days-per-den shifted
for cats with kittens. Before Nama and Lace’s kittens
reached an age of 44–50 days, the cats spent a mean
of six consecutive days in each den (range 3–13 days).
After this age they changed dens every day. This may
represent the age at which kittens start travelling with
their mothers at night rather than staying alone in the
burrow − when kittens are following along, mothers are
free to select the nearest suitable burrow at the end of
each night’s hunting foray. When changing dens, mothers
with kittens almost never selected previously used dens
(1 of 24 den changes), unlike the other three cats which
did so on 27% of days (11 of 41 days). However, the rate
of den change for mothers with kittens might vary with
local predator abundance. In areas with a high density of
jackals, such as Benfontein, the number of days-per-den
might be substantially shorter than in areas with extensive
predator control like Grünau, but this theory would require
further study.
Though the sample size was too small to make
conclusive statements, it appeared that cats use
successively larger den ranges as they move through
reproductive stages: from not reproducing, to pregnant,
to nursing kittens. However, Nama, who had kittens
throughout, did not fit the pattern as she had the smallest
den range of all cats monitored. Nama showed above
average shyness of the research vehicle during night
tracking and was the only cat to consistently select dens
in mixed shrub habitat along a drainage rather than open
grassland. Her higher level of caution may have driven
her preference for denser vegetation around dens, which
in turn may have driven the smaller denning area which
was concentrated around a linear geographical feature.
However, if we consider Nama to be an exception, we
might infer that females with kittens move farther distances
between dens than those without kittens.
Figure 7: Distribution range of black-footed cat overlayed with the distribution range of springhares, revealing three potential regions where
black-footed cats persist outside the range of springhare. Range map data source IUCN Red List
1
2
3
Study
area
Springhare range
Black-footed cat range
Black-footed cat and
springhare overlap
0400 800 km
ANGOLA ZAMBIA
ZIMBABWE
MOZAMBIQUE
LESOTHO
ESWATINI
NAMIBIA
BOTSWANA
SOUTH AFRICA
African Zoology 2024: 1–12 11
Implications for black-footed cat conservation
Livestock and game farming regions with active control
of mesocarnivores such as jackal and caracal appear to
offer favourable grassland habitat for black-footed cats,
having lower rates of intraguild predation (Wilson 2015).
While black-footed cats can persist in areas with high
jackal densities (e.g. Benfontein, Kamler et al. 2013), they
likely experience lower mortality rates in the absence of
mesocarnivores. Therefore, working to increase tolerance
of black-footed cat amongst livestock farmers, game farmer,
and other private landowners who are already practicing
predator control may prove to be the most effective method
of conserving the black-footed cat. If springhares are the
primary burrow providers for female cats, and termite mounds
in combination with aardvarks (and possibly ground squirrels)
provide an additional or alternate supply of den sites, then
these burrow-creating species need to be tolerated on
farmland and other areas where black-footed cat occur.
Overgrazing by game and livestock may have both
negative and positive impacts on black-footed cats. Butynski
(1973) observed a notable increase in springhare densities
in overgrazed grasslands because they readily consumed
pioneer plants that emerged in place of depleted perennial
grasses. Though this relationship hasn’t been specifically
investigated, it may suggest that springhare numbers
are not necessarily negatively impacted by poor grazing
practices. However, high grazing intensity reduces small
mammal diversity and abundance (the black-footed cat’s
primary prey), while a low intensity, rotational grazing regime
supports a higher abundance of small mammals than areas
with no grazing (Hoffmann and Zeller, 2005). This suggests
that rotational grazing practices may promote a system that
provides both food (an abundance of small mammals) and
housing (springhare burrows) for black-footed cats.
Areas of further study
As far as we are aware, this is the first study to use LiDAR
to explore the dimensions of animal burrows. Using an
iPhone with LiDAR rather than an iPad, perhaps fastened
to a probe, may allow the scanner to be inserted deeper
into the entrance. However, this method could cause
some physical disturbance to the den walls (accidental
bumping), and leave a scent trail. We believe LiDAR pocket
technology will become an important tool for understanding
the characteristics of underground structures created and
used by animals.
Our results provide an insight into burrow selection and
use by female black-footed cats in southern Namibia.
However, male den use and selection, and regional and
seasonal variation in den selection by both sexes, requires
further research. In addition, if springhares are absent in
the southwest corner of the black-footed cat distributional
range, further study would be required to determine what
den sites are used in this region. These questions will
be important areas of future research for developing
interventions to conserve the black-footed cat.
Acknowledgements — We are most grateful to the Black-footed
Cat Working Group team for their capture and radio-collaring of the
study cats, making data collection possible using telemetry; and
to the Institute for Communities and Wildlife in Africa for providing
support for this research. We heartily thank Martina Küsters of the
Black-footed Cat Research Project Namibia for providing access to
the study site and for including this study on the research permit,
as well as for providing use of the tracking vehicle and telemetry
equipment. Finally, we are deeply grateful to Shipala Ndele for
many hours of field assistance, and to the landowners, the van der
Merwe family, for allowing us access to their property and for being
good custodians of black-footed cat habitat.
ORCIDs
Harold Brindley: https://orcid.org/0000-0002-4484-4980
M Justin O’Riain: https://orcid.org/0000-0001-5233-8327
Alexander Sliwa: https://orcid.org/0000-0002-9111-3371
References
Anderson MD. 2013. Proteles cristatus, aardwolf. In: Kingdon J,
Hoffman M (eds), Mammals of Africa, vol. V. London: Bloomsbury.
pp 282–292.
Anderson MD, Richardson PRK. 2005. The physical and thermal
characteristics of aardwolf dens. South African Journal of Wildlife
Research 35: 147–153.
Bragg CJ, Donaldson JD, Ryan PG. 2005. Density of Cape
porcupines in a semi-arid environment and their impact on soil
turnover and related ecosystem processes. Journal of Arid
Environments 61: 261–75. https://doi.org/10.1016/j.jaridenv.
2004.09.007.
Butynski TM. 1973. Life history and economic value of the springhare
(Pedetes capensis forster) in Botswana. Botswana Notes and
Records 5: 209–213.
Butynski TM, Mattingly R. 1979. Burrow structure and fossorial
ecology of the springhare Pedetes capensis in Botswana.
African Journal of Ecology 17: 205–215. https://doi.org/10.1111/j.
1365-2028.1979.tb00257.x.
Child MF. 2016. Pedetes capensis. IUCN Red List of Threatened
Species 2016. https://doi.org/10.2305/IUCN.UK.2016-3.RLTS.
T16467A22240444.en [accessed 30 November 2023].
Esri Inc. 2022. ArcGIS Pro (2.8.0). Redlands, CA.
Happold DCD. 2013. Hystrix africaeaustralis, Cape crested
porcupine (Cape porcupine). In: Happold DCD (ed.), Mammals
of Africa, vol. III. London: Bloomsbury. pp 676–678.
Hoffmann A, Zeller U. 2005. Influence of variations in land use
intensity on species diversity and abundance of small mammals
in the Nama Karoo, Namibia. Belgian Journal of Zoology 135:
91–96.
Kamler JF, Macdonald DW. 2014. Social organization, survival
and dispersal of Cape foxes (Vulpes chama) in South Africa.
Mammalian Biology 79: 64–70. https://doi.org/10.1016/j.
mambio.2013.09.004.
Kamler JF, Stenkewitz U, Macdonald DW. 2013. Lethal and
sublethal effects of black-backed jackals on cape foxes and
bat-eared foxes. Journal of Mammalogy 94: 295−306. https://doi.
org/10.1644/12-MAMM-A-122.1.
Loveridge AJ, Nel JAJ. 2013. Canis mesomelas, black-backed
jackal (silver-backed jackal). In: Kingdon J, Hoffman M (eds),
Mammals of Africa, vol. V. London: Bloomsbury. pp 39–44.
Lynch CD. 1980. Ecology of the suricate, Suricata suricatta, and
yellow mongoose, Cynictis penicillata, with special reference to
their reproduction. Bloemfontein: Nasionale Museum.
Nel JAJ, Maas B. 2013. Otocyon megalotis, bat-eared fox. In:
Kingdon J, Hoffman M (eds), Mammals of Africa, vol. V. London:
Bloomsbury. pp 78–81.
Olbricht G, Sliwa A. 1995. Comparative development of juvenile
black-footed cats. Der Zoologische Garten 65: 8–20.
Brindley, O’Riain and Sliwa
12
Olbricht G, Sliwa A. 1997. In situ and ex situ observations and
management of black-footed cats Felis nigripes. International Zoo
Yearbook 35: 81–89. https://doi.org/10.1111/j.1748-1090.1997.
tb01194.x.
Phelan P, Sliwa A. 2005. Range size and den use of Gordon’s
wildcats Felis silvestris gordoni in the Emirate of Sharjah,
United Arab Emirates. Journal of Arid Environments 60: 15–25.
https://doi.org/10.1016/j.jaridenv.2004.03.010.
R Core Team. 2022. R statistical software (4.2.2 (2022-10-31)). R
Foundation for Statistical Computing, Austria, Vienna.
Ross S, Kamnitzer R, Munkhtsog B, Harris S. 2010. Den-site
selection is critical for Pallas’s cats (Otocolobus manul).
Canadian Journal of Zoology 88: 905–913. https://doi.
org/10.1139/Z10-056.
Sliwa A. 1993. A habitat description and first data on ecology
and behaviour of the black-footed cat (Felis nigripes) in the
Kimberley area, South Africa. International Studbook for the
Black-footed Cat 1993: 8–14. Wuppertal Zoo, Wuppertal.
Sliwa A. 1994. Diet and feeding behaviour of the black-footed cat
in the Kimberley region, South Africa. Der Zoologische Garten
64: 83–96.
Sliwa A. 1996a. Black-footed cat in situ, Benfontein Game Farm,
Kimberley, South Africa. Unpublished report. Wuppertal Zoo,
Wuppertal.
Sliwa A. 1996b. Pleasures and worries of a black-footed cat field
study in South Africa. Cat Times 23: 1–3.
Sliwa A. 2004. Home range size and social organisation of
black-footed cats. Mammalian Biology 69: 96–107. https://doi.
org/10.1078/1616-5047-00124.
Sliwa A. 2013. Felis nigripes, black-footed cat. In: Kingdon
J, Hoffman M (eds), Mammals of Africa, vol. V. London:
Bloomsbury. pp 203–206.
Sliwa A, Ghadirian T, Appel A, Banfield L, Shah S, Wacher
M. 2016. Felis margarita. The IUCN Red List of Threatened
Species 2016. https://doi.org/10.2305/IUCN.UK.2016-2.RLTS.
T8541A50651884.en [accessed 30 November 2023].
Sliwa A, Herbst M, Mills MGL. 2010. Black-footed cats (Felis
nigripes) and African wildcats (Felis silvestris): a comparison of
two small felids from South African arid lands. In: Macdonald
DW, Loveridge AJ (eds), Biology and Conservation of Wild
Felids. Oxford: Oxford University Press. pp 537–558.
Sliwa A, Wilson B, Küsters M, Hartmann A, Schroeder M, Ndele S,
Fölscher H, Hauptfleisch M. 2022. Report on surveying, catching
and monitoring black-footed cats (Felis nigripes) on Grünau
farms, Namibia and Benfontein Nature Reserve, South Africa in
2021. Black-footed Cat Working Group. https://doi.org/10.13140/
RG.2.2.16495.61608
Sliwa A, Wilson B, Küsters M, Herrick J, Lawrenz A, Lamberski
N, et al. 2021. Report on surveying, catching and monitoring
black-footed cats (Felis nigripes) on Benfontein Nature
Reserve, South Africa and on Grünau farms, Namibia in 2020.
Black-footed Cat Working Group. https://doi.org/10.13140/
RG.2.2.17733.78569
Sunquist M, Sunquist F. 2002. Wild cats of the world. Chicago:
University of Chicago Press.
Whittington-Jones GM. 2006. The role of aardvarks (Orycteropus
afer) as ecosystem engineers in arid and semi-arid landscapes
of South Africa. MSc thesis, Rhodes University, South Africa.
Wilson B. 2015. The black-footed cat Felis nigripes (Burchell,
1824): a review of the geographical distribution and conservation
status. MTech dissertation, Tshwane University of Technology,
South Africa.
Wilson B, Sliwa A, Drouilly M. 2016. A conservation assessment
of Felis nigripes. In: Roxburgh L, Vivier J, Power RJ, Child
MF, Hoffman M, Nowell K (eds.), The red list of mammals of
South Africa, Swaziland and Lesotho. South African National
Biodiversity Institute and Endangered Wildlife Trust.
Manuscript received: 1 December 2023, revised: 1 September 2024, accepted: 5 September 2024
Associate Editor: E Netherlands
