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Dagny KRAUZE-GRYZ
1
* and Jakub GRYZ
2
1
Department of Forest Zoology and Game Management, Warsaw University of Life Sciences
WULS-SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland,
*e-mail: dagny.krauze@wl.sggw.waw.pl (corresponding author)
2
Department of Forest Ecology, Forest Research Institute, Sękocin Stary,
Braci Leśnej 3, 05-090 Raszyn, Poland
FREERANGING DOMESTIC DOGS CANIS FAMILIARIS
IN CENTRAL POLAND: DENSITY, PENETRATION RANGE
AND DIET COMPOSITION
ABSTRACT: The aim of this study was to
assess the density and diet composition of free-
ranging dogs in Poland. The study was conducted
in a field and forest mosaic in the central part of
the country in the years 2005–2011. The density
of the free-ranging dogs was assessed during night
counts along repeated transect routes. The num-
ber of dogs seen and the feasible observation area
were recorded to calculate density index for each
control. The day and night counts captured data
on group composition and penetration range. Di-
ets were studied through scat analyses. The dog
density ranged from 2.2–3.1 ind. km
–2
depending
on the area. Most dogs were observed alone, and
40% formed groups of 2 to 5 dogs. Most groups
were recorded close to buildings, but the group
organisation changed (especially during the day-
time) with increasing distance from the buildings:
35% of dogs in the village were in groups, but 55%
of dogs formed groups at a distance of more than
100 m from the buildings. The night proportion of
dogs in groups was approximately 50%, regardless
of the distance. Their scats contained mostly cere-
al given by farmers. The prey remains were game
species: roe deer (1.3% of occurrences in summer
and 12% in winter), brown hare (3–4%), small
mammals (5–9.5%) and birds (approx. 1.5%). The
study demonstrated that the abundance of dogs in
the rural areas of central Poland may play an im-
portant role in the ecosystem.
KEY WORDS: rural areas, distances from
buildings, group composition, predation, habitat
exploration
1. INTRODUCTION
The anthropogenic predators: domestic
dogs (Canis familiaris) and cats (Felis catus)
are among the most common carnivores in
the world (Liberg et al. 2000, Vanak and
Gompper 2009). A number of studies have
investigated cat predation, activity patterns,
interactions with other carnivores or hy-
bridization problems in Europe, including
in Poland (e.g., Pielowski 1976, review in:
Fitzgerald and Turner 2000, review in: Li-
berg et al. 2000, review in: Wayne and Brown
2001, Daniels et al. 2001, Woods et al.
2003, Pierpaoli et al. 2003, Bíro et al. 2005,
Goszczyński et al. 2009, Krauze-Gryz
et al. 2012a, b). However, only a few studies
have considered non-urban dog interactions
with wildlife in Europe (Pielowski 1976,
Boitani 1983, Romanowski 1985, Boi-
tani and Ciucci 1995, Boitani et al. 1995,
Okarma et al. 1995, Krauze-Gryz et al.
2012b). Free-ranging dogs can act as preda-
tors, prey, competitors, disease reservoirs and
vectors (Vanak and Gompper 2009). Hy-
Polish Journal of Ecology
Pol. J. Ecol. (2014) 62: 183–193
Regular research paper
Dagny Krauze-Gryz, Jakub Gryz
bridisation with dogs may pose an important
threat to wild canids (Wayne and Brown
2001). Dogs are also perceived dangerous
to humans, i.e., in Italian survey, personal
safety from dogs was stated as the most com-
mon fear (Slater et al. 2008). Dog attacks on
livestock can create financial problems, but
damages caused by dogs may be attributed
to wolves (Kossak 1998). We expect numer-
ous direct and indirect effects on wildlife in
central Poland due to the highly fragmented
environment and free-ranging dogs. This
situation results in an influx of domestic dogs
in the remaining natural areas. An increased
dog presence on the edges of natural reserves
can be perceived as an edge effect (Lacerda
et al. 2009). Dogs as a dominant species are
known to interact with other carnivores, i.e.,
Indian foxes (Vulpes bengalensis) (Vanak and
Gompper 2010), maned wolves (Chrysocyon
brachyurus) (Lacerda et al. 2009) and chilla
foxes (Lycalopex griseus) (Silva-Rodríguez
et al. 2010). Dogs in rural areas of central Po-
land influenced red fox (Vulpes vulpes) space
utilization (Krauze-Gryz et al. 2012b).
They were reported to kill red foxes, raccoon
dogs (Nyctereutes procyonoides), badgers (Me-
les meles) and polecats (Mustela putorius)
(Goszczyński and Skoczyńska 1996,
Goszczyński 2004, Gryz et al. 2011). Free-
ranging and feral dogs may compete with
wolves for food and range in Italy (Boitani
1983) but dogs can be killed by wild preda-
tors, e.g., leopards (Panthera pardus), lions
(Panthera leo), hyenas (Crocuta crocuta), coy-
otes (Canis latrans) or wolves (Vanak and
Gompper 2009). Such contact between dogs
and wild predators creates circumstances ad-
vantageous for disease transmission (Butler
et al. 2004). Most dog populations are free-
ranging and unvaccinated, and rabies and ca-
nine distemper have resulted in severe popula-
tion declines in several endangered carnivores
near high-density dog populations (Vanak
and Gompper 2009). In Poland, dogs make
regular contact with foxes (Goszczyński
et al. 2008) because the foxes come close to
buildings (Krauze-Gryz et al. 2012a). Dogs
additionally make contact with other scaveng-
ing species while sharing the same carcasses
(Selva et al. 2005).
According to Polish Hunting Association
between 2004 and 2010 on average 38,924
feral and 97,290 free-ranging dogs were ob-
served in hunting grounds annually killing
on average 260 domestic animals (cattle,
sheep and goats), 264 red deer, 111 fallow
deer, 8903 roe deer, 1,178 wild boars, and
16,135 brown hares (Zarząd Główny PZŁ,
http://src.pzlow.pl). Although these statistics
were based on information from hunters not
a regular study, they show that free-ranging
dogs can be perceived as a threat to domestic
animals and game.
Legal status of free-ranging dogs in Po-
land has changed over years. Since 1959
they were treated as game pests and hunters
were obliged to eliminate dogs found in the
hunting ground (Dz.U. 1959 nr 36 poz. 226).
Next, between 1995 and 1997 it was forbid-
den to shot dogs (Dz.U. 2005 nr 127 poz.
1066). From 1997 dogs that went feral could
be killed if they were more than 200 m from
the nearest human settlements and if they
posed direct threat to wildlife (Dz.U. 1997 nr
111 poz. 724). Because this regulation were
imprecise (i.e. it was difficult to decide if
dogs were actually feral) in 2012 an amend-
ment to this act was introduced (Dz.U. 2011
nr 230 poz. 1373). Nowadays, it is allowed to
kill dogs if they pose direct threat to people or
animals. Nevertheless, various organizations
for animal welfare want killing free-ranging
dogs to be banned absolutely.
In the light of this, our aim was to assess
the density of free-ranging dogs in central Po-
land, analyse their diet, and discuss possible
influences on wildlife.
2. STUDY AREA
Our investigation included two survey
sites, Dobieszyn and Rogów, both located
in central Poland in a distance of approx. 80
km. The field work was concentrated around
Brzeźce village (51°40’07’’N; 21°00’15’’E)
in Dobieszyn and Marianów Rogowski
(51°49’10’’N; 19°53’53’’E) in Rogów (Fig. 1).
These rural areas in central Poland represent
a typical field-forest mosaic with a preva-
lence of open areas. Woods of a few hundred
hectares are surrounded by a fine mosaic of
patches of different crops, pastures, fallow
land and groups of trees. Villages (primar-
ily consisting of a row of settlements along
a road) and single farms are evenly distrib-
184
Free-ranging domestic dogs in Poland
uted in the area within a distance of no more
than a few kilometres from each other. The
Dobieszyn area includes numerous summer
houses grouped in three places close to and
within the village of Brzeźce. Farms in these
regions are typically small (i.e., less than
10% of farms are larger than 15 ha; most are
1–10 ha big; Central Statistical Office-GUS
data). The main tree species in the forest is
the Scots pine (Pinus sylvestris), with an ad-
mixture of oaks (Quercus spp.).
This region is affected by the mild oceanic
climate of Western Europe and the harsh and
dry continental climate of Eastern Europe and
Asia. The duration of the growing season is
approximately 210 days. The total precipita-
tion is as much as 600 mm per year, and the
mean ambient temperature ranges from –4°C
in January to +18°C in July. A door-to-door
survey of cats in the area (Krauze 2008) re-
corded data indicating that most farms have
dogs (D. Krauze-Gryz, J. Gryz, unpubl.). The
free-ranging dogs (Slater et al. 2008) in the
area have owners, but the dogs are either not
confined to their owners’ property or allowed
to leave settlements without supervision, es-
pecially at night. Inhabitants of nearby towns
and cities also abandon dogs in the villages.
No large carnivores are present in the study
areas; other carnivores include the red fox,
pine and stone martens (Martes martes, M.
foina), badger, polecat, stoat (Mustela er-
minea), least weasel (Mustela nivalis) and
domestic cat (Gr yz et al. 2011, Krauze-
Gryz et al. 2012b). Ungulates are primarily
represented by roe deer (Capreolus capreolus),
whose density in Rogów numbers among the
highest in Poland and Europe (17–67 ind. 100
ha
–1
, depending on the forest complex). The
density of the roe deer in Dobieszyn is a few
times lower, yet, no exact data are available
for the area. Other ungulates include the red
deer (Cervus elaphus, rare in both areas), fal-
low deer (Dama dama, introduced to both
areas) and, occasionally, moose (Alces alces)
(Gryz et al. 2011, Krauze-Gryz D., Gryz J.,
unpubl. data). Brown hare (Lepus europaeus)
is approximately four times more abundant in
Dobieszyn than Rogów (Gr yz and Krauze
2007).
3. METHODS
Day and night counts were conducted
on repeated census routes (Fig. 1) (Krauze
2008, Goszczyński et al. 2009). They were
established randomly and run along local,
field and forest roads through a mosaic of
different habitats (typical for the study ar-
eas) and villages. The transect route length
was approximately 30.7 km in Rogów and
19.9 km in Dobieszyn. The route passes by
the vicinity of 180 and 100 farms in Rogów
and Dobieszyn, respectively. The possibility
of counting the same individual twice during
the same night was slight owing to transects’
length and their distribution in the study
area. If, however, the same individual was
Fig. 1. Localisation of census routes in the study
areas.
185
Dagny Krauze-Gryz, Jakub Gryz
registered twice during one control it was not
included into analyses. The daytime counts
were primarily conducted on foot (by one
or two observers at the same time) and thus,
the entire route in each site was divided into
three parts (of 5.8 to 9.5 km) that were easily
covered at one time. The counts were con-
ducted for five to six days per month at each
study site during different times throughout
the day. The night counts were accomplished
with a spotlight from a car (always two ob-
servers were engaged at the same time) driv-
ing at an average speed of less than 20 km
hour
–1
(Krauze 2008). The maximum beam
range was estimated at 100 m, but the actual
range changed with vegetation development,
necessitating empirical adjustment during
each census (see below). The night counts
were conducted once monthly in each study
site. Each count covered the entire transect
route in the study site. We attempted to choose
days with clear weather because rain, snow or
fog diminished visibility (Goszczyński et
al. 2009). The counts were conducted from
ca. 9 p.m. until midnight, and one count took
ca. two hours.
The strip of land surveyed was a maxi-
mum of 100 m wide. This distance let us dis-
tinguish dogs from other medium mammals
present in the area. The observation condi-
tions and animal detection within the obser-
vation strip differed markedly depending on
the weather (e.g., the presence or absence of
snow), vegetation cover and the dates of the
onset of field work, such as ploughing, har-
vesting and haymaking. To account for this
variation, we conducted detailed monthly
assessments of the actual area feasibility. We
assessed the routes alongside and across the
width of the observation strip (adjusted to the
actual visibility and possibility of noticing a
dog) within various habitats (i.e., arable lands,
meadows, fallow lands). We only included
the areas where the vegetation cover made
dog sighting possible. The area with feasible
observations considerably varied throughout
each year; the area was smallest in summer
(June–July) and largest in winter and early
spring (December–March) (Goszczyński
et al. 2009). Dog density was assessed on the
basis of night counts, when many dogs are un-
leashed and are allowed to run free. The num-
ber of dogs seen and the feasible observation
area were recorded during each observation
so a density index could be calculated from
each control (Goszczyński et al. 2009).
When a dog was noticed, we noted
whether it was in a village or, if not an ap-
proximate distance from the nearest settle-
ments was measured. We recorded the dog
size and whether it was alone or in group. We
sorted dogs into three size categories: small
(i.e., dachshund), medium (i.e., cocker span-
iel) and large (i.e., German shepherd); how-
ever, most of the dogs were mongrels. If a
person (and potential dog owner) was nearby,
we did not take the dog observation into ac-
count. However, dog walkers were only ob-
served sporadically in a part of the Dobieszyn
area, close to Brzeźce village. Only dogs out-
side properties were counted.
In Dobieszyn, day counts were conduct-
ed from December 2005 to April 2007 and
night counts from January 2005 to December
2007 and November and December 2010. In
Rogów, day counts were conducted between
January 2006 and November 2007 and May
2011 and night counts from January 2005 and
December 2007 and December 2008, Novem-
ber 2009 and October 2010.
Data on the number of dogs shot by hunt-
ers and the red fox hunting bags in Rogów
were taken from the Forest Experimental Sta-
tion in Rogów (such data was not available for
Dobieszyn).
Data on feral dogs that breed in the wild
were obtained from random observations in
Rogów from 2001–2008. The data are from
previous systematic forest penetration during
other research (Goszczyński et al. 2005,
Gryz et. al. 2011). Additionally, a study fo-
cused on red foxes that included a den search
was conducted in Rogów from 1999–2006
(Goszczyński et al. 2008).
Scats were collected along the same cen-
sus routes during daytime transects from No-
vember 2005 to March 2008. Only samples
found outside villages were included. We did
not collect samples in the area where dog
walkers were observed. In the laboratory, the
scats were sieved under water, and the main
components were identified. We record-
ed items belonging to different categories,
summed the total occurrences, and calcu-
lated the percentage share for each category
(Romanowski 1985, Litvaitis 2000).
186
Free-ranging domestic dogs in Poland
We also recorded cases of dogs chasing
or killing animals during fieldwork for this or
other studies in the study areas.
4. RESULTS
We conducted 40 controls on the standard
routes at night and 98 during the day in Rogów,
while the respective numbers for Dobieszyn
were 37 and 115. In Rogów, 67 dogs were regis-
tered at night in a total area of 3,328 ha, with an
average night density of 2.2 ind.km
–2
(SE=0.4).
In Dobieszyn, we observed 71 dogs in 2,316 ha,
with an average density of 3.1 ind.km
–2
(SE=0.4).
In both study sites, the highest densities were
obtained in the spring (3 ind. km
–2
, SE=1.0 in
Rogów and 4.4 ind. km
–2
, SE=1.2 in Dobieszyn),
the lowest densities in Rogów were recorded in
the winter (1.3 ind. km
–2
, SE=0.4) and in the
autumn in Dobieszyn (2.1 ind. km
–2
, SE=0.6)
(Fig. 2) but no significant difference was found
between seasons (one-way ANOVA, P> 0.05).
Of the 407 dogs observed during both
the day and night, most were observed alone
(238 individuals), but 169 individuals formed
groups that contained 2 to 5 individuals
(Table 1). Because most of the dogs were
mongrels, we did not classify their pedigree
and only assigned them to one of three body
size classifications (small, medium or large);
small dogs were most frequent in the rural
areas of our study sites (Table 1).
We registered most of the dogs during the
day and night (χ
2
=2.6, df=2, P> 0.05) in the
villages or close to human properties (Table 1).
However, the organisation of the dogs changed
with increasing distance to buildings. In the
village, most of them were observed individu-
ally (35% formed groups). When the distance
increased to 100 m from the nearest human
settlements, the number of dogs in groups in-
creased (46%). When the distance was great-
er than 100 m, 55% of dogs were grouped
(χ
2
=11.27, df=2, P <0.005). This pattern was
more obvious during the day (χ
2
=12.29, df=2,
P <0.005), while the proportion of dogs in
groups at night was approximately 50%, re-
gardless of distance (χ
2
=1.01, df=2, P> 0.05)
(Fig. 3). The disproportion between day and
night was more visible in the vicinity of the
buildings. More than 50% of dogs were ob-
served in groups at distance of 100 m or more
during both the day and night (Fig. 3).
Four cases of breeding in the wild were reg-
istered in the area of Rogów (distances from the
nearest human settlements are given in brackets):
Table 1. Dog population characteristics (group composition, body size, and distance to buildings) in
central Poland in the years 2005–2011.
Group size
(n of ind.)
N
of groups
% of groups
2 57 77.03
3 14 18.9
4 2 2.7
5 1 1.3
Total 74 100.0
Body size category
N of dogs % of dogs
small 165 47.7
medium 99 28.6
large 82 23.7
Total 346 100.0
Distance to buildings
Observed dogs
Day Night
N % N %
in the village 160 58.0 79 60.3
≤100 m 54 19.6 31 23.7
>100 m 62 22.5 21 16.0
Total 276 100.0 131 100.0
187
Dagny Krauze-Gryz, Jakub Gryz
• in 2003, a female with three juveniles
was observed in a self-dug den in a
forest (780 m),
• in 2005, three big, adult dogs that
lived in an old badger sett in a forest
were killed by hunters; all the dogs
were in very good condition, and the
tracks of pups were recorded at the
den a few months earlier (530 m),
• in 2006, a female bred three or four
juveniles in the cereal crops (250 m),
• in 2011, we found an old badger sett
that was occupied by a group of dogs,
although breeding was not confirmed
in this case (520 m).
In Dobieszyn, two litters were bred in
2009 (4 juveniles) and 2010 (5 juv.) in a den
located in a dense group of spruces on an
abandoned property.
Each year from 2003–2006, hunters shot
27 to 66 dogs in the Rogów hunting district
(in total 130.6 km
2
).
Diet analyses were based on 417 scats
(Table 2). We most frequently recorded re-
mains of different plant origins in both areas
(43 and 46% of total occurrences for winter
and summer, respectively). These remains
primarily included cereal (oats and less often
maize), seeds (sunflower, pea and acorns) or
fruit (apples or pears). All total cereal occur-
rences constituted an average of 23% in sum-
mer compared to 30% in winter. Among ani-
mals, small mammals (rodents and less often
soricomorphs) were represented by ca. 5%
of all items in winter and ca. 9% in summer.
Birds were recorded infrequently (ca. 1%),
and insects were only present in scats from
the summer (more often in Dobieszyn – 13%,
than in Rogów – 2%). Game remains includ-
ed roe deer, recorded mostly in winter (12%
of occurrences), and brown hare, which ac-
counted for ca. 3 to 4% of all remains in both
winter and summer. The rest were organic
and inorganic parts (e.g., coal, wood, plastic,
strings and pieces of fabric) and other mate-
rial that were not identified.
Throughout the study period (primar-
ily in winter 2005/2006), we found 26 car-
casses of roe deer with signs of dog pres-
ence in Rogów and three in Dobieszyn. We
identified dog tracks indicating that at least
8 (7 in Rogów, 1 in Dobieszyn) of those in-
dividuals were killed by dogs; dogs in groups
killed their prey by chasing them into fences
or railway embankments. Also, in Rogów, we
witnessed an organised group of dogs during
a successful hunting. The group chased a hare
onto a road embankment and killed it.
5. DISCUSSION
Density assessments were based on night
counts because dogs are most active at this
time (Scott and Causey 1973, Daniels
and Bekoff 1989, Boitani and Ciucci
1995, Krauze-Gryz et al. 2012b). Dogs in
the study area are often released and allowed
to roam freely at night. The data showed that
on average, dogs were less numerous than do-
mestic cats (densities from 3.9–6.1 ind.km
–2
,
Krauze 2008) but more abundant than red
foxes (0.9–1.2 ind. km
–2
, Krauze-Gryz D.,
Fig. 2. Indices of dogs’ density (±SE) on the basis
of nightime counts on repeated census routes in
central Poland in the years 2005–2010 (one-way
ANOVA, P> 0.05).
Fig. 3. Percentage of dogs that formed groups
during day (χ
2
=12.29, df=2, P <0.005), and night
(χ
2
=1.01, df=2, P> 0.05, chi-square test) with an
increasing distance to buildings in central Poland
in the years 2005–2011.
188
Free-ranging domestic dogs in Poland
Gryz J., unpubl.), the most numerous wild
carnivores in central Poland (Gryz et al.
2011). A similar pattern was found when we
considered the number of visits to tracking
stations (Krauze-Gryz et al. 2012b). The
density obtained in this study was lower com-
pared to that in communal land in Zimbabwe
(Butler et al. 2004) or in some rural areas in
Chile (Acosta-Jamett et al. 2010). Howev-
er, those assessments utilized a survey instead
of actually recording dogs outside of proper-
ties. Our assessments should be treated as the
minimum number of dogs because the data
only included individuals who were outside
of properties.
More than half of the dogs were observed
alone, and groups were as large as 2–5 indi-
viduals. Research found similar sizes of feral
dog groups in Alabama (Scott and Causey
1973), of free-ranging dog groups in Zimba-
bwe (Butler et al. 2004), and of suburban dog
groups in California (Berman and Dunbar
1983). In Israel, some groups reached 8 dogs,
but most of the groups were smaller (3–4,
Manor and Saltz 2004). Dogs form groups
when such behaviour is advantageous. In ar-
eas when food is plentiful and cooperative
hunting is not necessary, dogs primarily re-
main solitary (Daniels and Bekoff 1989,
Boitani and Cucci 1995). In our study area,
the dogs primarily remained solitary when
close to buildings and during the daytime.
The dogs were usually observed in groups
while outside the village and at night. There
were no garbage dumps around villages in
the study areas. When dogs left these areas,
they either searched for carrion or attempted
to hunt, and thus, group organisation was po-
tentially beneficial.
Cereal was the most recorded item in
scats. Farmers traditionally feed dogs cooked
oats and grains with animal fat and/or some
leftovers (so-called nawara). Similarly, dogs
were fed with sadza (maize/sorghum/millet
porridge) in Zimbabwe (Butler and du Toit
2002). Domestic food (42.2%) was most im-
portant for dogs in Chile (Silva-Rodrigues
et al. 2012). In a suburban zone of Warsaw, do-
mestic food constituted as much as 94% of all
food occurrences (Romanowski 1985), and
homemade food in the rural areas of western
Poland was the most common food category
Table 2. Occurrence percentage of food items in dog scats from two study sites in the years 2005–2008.
Food item
Winter Summer
Rogów Dobieszyn Total Rogów Dobieszyn Total
N % N % N % N % N % N %
Cereal 78 30.0 52 36.4 130 32.3 25 30.1 12 16.0 37 23.4
Other seeds 4 1.5 2 1.4 6 1.5 2 2.4 3 4.0 5 3.2
Fruit 4 1.5 3 2.1 7 1.7 6 7.2 7 9.3 13 8.2
Other plant
remains
21 8.1 11 7.7 32 7.9 7 8.4 11 14.7 18 11.4
Roe deer 40 15.4 8 5.6 48 11.9 2 2.4 0 0.0 2 1.3
Brown hare 5 1.9 8 5.6 13 3.2 2 2.4 4 5.3 6 3.8
Small mam-
mals
12 4.6 8 5.6 20 5.0 8 9.6 7 9.3 15 9.5
Bird 6 2.3 0 0.0 6 1.5 1 1.2 1 1.3 2 1.3
Insect 0 0.0 0 0.0 0 0.0 2 2.4 10 13.3 12 7.6
Organic
indet.
81 31.2 48 33.6 129 32.0 23 27.7 18 24.0 41 25.9
Inorganic
indet.
9 3.5 3 2.1 12 3.0 5 6.0 2 2.7 7 4.4
Total n of
occurrences
260 100 143 100 403 100 83 100 75 100 158 100
N of scats 207 114 321 53 43 96
189
Dagny Krauze-Gryz, Jakub Gryz
present in 79% of analysed stomach contents
(Pielowski 1976). Other food categories
in our study were plant remains of different
origins (e.g., fruit and seeds) and vertebrate
and invertebrate prey. Radio-tracked dogs in
Alabama similarly preyed primarily on small
mammals, garbage and vegetable material
(Scott and Causey 1973). Game (roe deer
and brown hare) was recorded in scats, and
the game frequency in the two study areas re-
flected differences in the abundance of these
two species. The roe deer was more frequently
observed in Rogów, while the brown hare was
more common in Dobieszyn. Both species
were found in stomach contents from west-
ern Poland, and most of the roe deer mate-
rial was found during especially severe winter
(Pielowski 1976). In our case, roe deer was
also primarily recorded in scats during the
winter, and most records of carrion with signs
of being killed by dogs were found from a se-
vere winter of 2005/2006. In the Białowieża
forest, the majority of carcasses of animals
killed by stray dogs was found during the
winter or cold months (Okarma et al. 1995).
Similar to our area, in Białowieża primeval
forest dogs were present in most of the vil-
lages distributed along the edge of the forest
and searched for wild food to supplement the
food given by their owners. Groups of mon-
grels were sometimes observed to hunt coop-
eratively for wild ungulates (Jędrzejewska
and Jędrzejewski 2001).
Scat analyses do not allow for differentia-
tion between prey that was actually killed and
carrion and dogs are known to use carcass-
es. Butler and du Toit (2002) studied the
mammal carrion of both domestic and wild
species and concluded that carrion constitut-
ed half of all observed meals. Moreover, dogs
found more carcasses and consumed more
available biomass compared to other scaven-
gers. Carrion was additionally consumed in
Chile (Silva-Rodrigues et al. 2010), Ala-
bama (Cause and Cude 1980), and Poland
(Selva et al. 2005). We suggest that the game
found in dog scats was likely from carrion,
but our observations (primarily during the
winter) confirmed that dogs were able kill roe
deer or brown hare, usually by chasing them
onto some barriers like fences. In the Rogów
area, 2 of 22 radiotracked adult roe deer were
successfully killed by dogs (Wasilewski
2001), some brown hares that were released
as a part of restocking program in another
area of central Poland were also killed by dogs
(Misiorowska and Wasilewski 2012).
Many investigations researched the im-
portance of dogs as a source of mortality for
ungulate neonates (white-tailed deer Odoico-
leus virginianus) (Huegel et al. 1985, Nel-
son and Mech 1986, Nelson and Woolf
1987, Long et al. 1998, Ballard et al. 1999).
Packs of feral dogs in Alabama regularly
chased deer (Causey and Cude 1980) but
did not prey on the adults (Scott and Cau-
sey 1973). A study by Manor and Saltz
(2004) showed that dog chases can have a
negative effect on the ungulate gazella Gazella
gazella) female/kid ratio by indirectly affect-
ing reproductive success due to the energetic
costs involved in dog avoidance. On the other
hand, Pielowski (1976) suggested that the
real negative impact of dogs in the hunting
ground is their noisy area penetration and
frequent chasing rather than actual preda-
tion. Indeed, the presence of dogs on walking
trails in the protected areas of Colorado cor-
related with altered patterns of habitat utilisa-
tion for some of the mammals indicating that
dogs can elicit behavioural reactions from
a potential prey even without giving chase
(Lenth et al. 2008).
According to our observations domestic
dogs in the study areas often received im-
proper care and inadequate food. They left
settlements unrestricted and often success-
fully preyed on wildlife. Some of individuals
were recorded to breed in the wild. Overall,
this research showed that dogs in rural areas
of central Poland are abundant predators and
because of this they may play an important
role in an ecosystem mostly by chasing and
sometimes successfully hunting game and
other wildlife, competing with medium-sized
carnivores (i.e., changing spatiotemporal
space or den utilisation) or transmitting dis-
ease.
ACKNOWLEDGEMENTS: We would like
to thank forest service of Forest Experimental Sta-
tion in Rogów and Dobieszyn Forest District for
their help in this study. Special thanks to Dariusz
Dałkowski who allowed us to use data on hunting
bags in Rogów.
190
Free-ranging domestic dogs in Poland
6. REFERENCES
Acosta-Jamett G., Cleaveland S., Cun-
ningham A.A., de C Bronsvoort B.M.
2010 – Demography of domestic dogs in rural
and urban areas of the Coquimbo region of
Chile ad implications for disease transmission
– Prev. Vet. Med. 94: 272–281.
Ballard W.R., Whitlaw H.A., Young S.J.,
Jenkins R.A., Forbes G.J. 1999 – Preda-
tion and survival of white-tailed deer fawns in
north central New Brunswick – J. Wildl. Man-
age. 63: 574–579.
Bíro Z., Lanszki J., Szemethy L., Heltai
M., Randi E. 2005 – Feeding habits of fe-
ral cats Felis catus, wild cats Felis silvestris and
their hybrids: trophic niche overlap among cat
groups in Hungary – J. Zool. 266: 187–196.
Boitani L. 1983 – Wolf and dog competition in
Italy – Acta Zool. Fenn. 174: 259–264.
Boitani L., Ciucci P. 1995 – Comparative so-
cial ecology of feral dogs and wolves – Ethol.
Ecol. Evol. 7: 49–72.
Butler J.R.A., du Toit J.T. 2002 – Diet of
free-ranging dogs (Canis familiaris) in rural
Zimbabwe: implications for wild scavengers
on the periphery of wildlife reserves – Anim.
Conserv. 5: 29–37.
Butler J.R.A., du Toit J.T., Bingham J.
2004 – Free-ranging domestic dogs (Canis fa-
miliaris) as predators and prey in rural Zim-
babwe: threats of competition and disease to
large wild carnivores – Biol. Conserv. 115:
369–378.
Causey M., Cude C.A. 1980 – Feral dogs and
white-tailed deer interactions in Alabama – J.
Wildl. Manage. 44: 481–484.
Daniels T.J., Bekoff M. 1989 – Spatial and
temporal resource use by feral and abandoned
dogs – Ethology, 81: 300–312.
Daniels M.J., Beaumont M.A., Johnson
P.J., Balharry D., MacDonald D.W.,
Barratt E. 2001 – Ecology and genetics of
wild-living cats in the north-east Scotland and
the implications for the conservation of the
wild cat – J. Appl. Ecol. 38: 146–161.
Dz. U. 1959 nr 36 poz. 226. Ustawa z dnia 17
czerwca 1959 r. o hodowli, ochronie zwierząt
łownych i prawie łowieckim [Dz.U. 1959, vol.
36, item 226. Act of June 17, 1959 on Manage-
ment and protection of game and hunting law]
(in Polish).
Dz. U. 1997 nr 111 poz. 724. Ustawa z dnia 21
sierpnia 1997 r. o o chronie zwierząt. [Dz.U.
1997, vol. 111, item 724. Act of August 21,
1997 on animal welfare] (in Polish).
Dz. U. 2005 nr 127 poz. 1066. Obwieszczenie
Marszałka Sejmu Rzeczypospolitej Polskiej
z dnia 1 lipca 2005 r. w sprawie ogłoszenia
jednolitego tekstu ustawy – Prawo łowieckie
[Dz.U. 2005, vol. 127, item 1066. Promulgation
of the Marshall of the Sejm of the Republic of
Poland of July 1, 2005 on an announcement of
an consolidated text of the hunting law act] (in
Polish).
Dz.U. 2011 nr 230 poz. 1373. Ustawa z dnia 16
września 2011 r. o zmianie ustawy o ochronie
zwierząt oraz ustawy o utrzymaniu czystości
i porządku w gminach. [Dz.U. 2011, vol. 230,
item 1373. Act of September 16, 2011 on the
change of the act on animal welfare and main-
tenance of an order in communes] (in Polish).
Fitzgerald B.M., Turner C.T. 2000 – Hunt-
ing behaviour of domestic cats and their im-
pact on prey populations (In: The domestic
cat. The biology of its behavior, Eds: D.C.
Turner, P. Bateson) – Cambridge University
Press, Cambridge, pp. 151–176.
Goszczyński J. 2004 – Density of selected car-
nivorous mammals and their perspective of
coexistence with man – Prace Komisji Nauk
Rolniczych, 5: 9–27.
Goszczyński J., Gryz J., Krauze D. 2005 –
Fluctuations of a Common Buzzard Buteo bu-
teo population in Central Poland – Acta Orn.
40: 75–78.
Goszczyński J., Krauze D., Gryz J. 2009 –
Activity and exploration range of house cats in
rural areas of central Poland – Folia Zool. 58:
363–371.
Goszczyński J., Skoczyńska J. 1996 – Den-
sity estimation, family group size and recruit-
ment in a badger population near Rogów
(Central Poland) – Miscellània Zoològica, 19:
27–33 (in Polish).
Goszczyński J., Misiorowska M., Juszko
S. 2008 – Changes in the density and spatial
distribution of red fox dens and cub numbers
in central Poland following rabies vaccination
– Acta Theriol. 53: 121–127.
Gryz J., Krauze D. 2007 – Long-term decrease
of brown hare population in central Poland
(In: Book of Abstracts of the International
Union of Game Biologists XXVIII Congress,
11–18 August 2007, Uppsala, Sweden, Eds. K.
Sjberg, T. Rooket) – Swedish University of Ag-
ricultural Sciences, Uppsala, Sweden, pp. 209.
Gryz J., Krauze-Gryz D., Lesiński G.
2011 – Mammals in the vicinity of Rogów –
Fragm. Faun. 54: 183–197.
Huegel C.N., Dahlgren R.B., Gladfelter
K. 1985 – Mortality of white-tailed deer fawns
in south-central Iowa – J. Wildl. Manage. 49:
377–380.
Jędrzejewska B., Jędrzejewski W. 2001
– Ekologia zwierząt drapieżnych Puszczy
191
Dagny Krauze-Gryz, Jakub Gryz
Białowieskiej [Ecology of predators of the
Białowieża Primeval Forest] – PWN, Warsaw,
pp. 307–309.
Kossak S. 1998 – Wilk – zabójca zwierząt gosp-
odarskich? Poradnik do rozpoznawania przyc-
zyn śmierci zwierząt wypasanych bez nadzoru
– Agencja Reklamowo-Wydawnicza A. Grze-
gorczyk, Warszawa. [Wolf – predator of do-
mestic animals? Guide to recognizing causes
of death of animals pasturing without supervi-
sion] – Advertising and Publishing Agency A.
Gregorczyk, Warsaw (in Polish).
Krauze D. 2008 – Biocenotical role of domes-
tic cat Felis silvestris catus in different types of
field and forest mosaic – Ph.D. dissertation,
Department of Forest Zoology and Game
Management, Warsaw University of Life Sci-
ences WULS-SGGW, Warsaw, Poland.
Krauze D., Goszczyński J., Gryz J. 2008
– Drapieżnictwo psów i kotów na zwierzynie
drobnej [Predation of dogs and cats on small
game] (In: Mat konf. II Konferencja z cyklu
Nauka łowiectwu pt. „Drapieżnictwo na zwi-
erzynie drobnej” [Conference Materials of 2
nd
Conference Science for Hunting “Predation on
small game”]) – Warszawa, pp. 54–55 (in Polish).
Krauze-Gryz D., Gryz J., Goszczyński J.
2012a – Predation by domestic cats in rural ar-
eas of central Poland: an assessment based on
two methods – J. Zool. 288: 260–266.
Krauze-Gryz D., Gryz J.B., Goszczyński
J., Chylarecki P., Żmihorski M. 2012b
– The good, the bad, and the ugly: space use
and intraguild interactions among three op-
portunistic predators – cat (Felis catus), dog
(Canis lapus familiaris), and red fox (Vulpes
vulpes) – under human pressure – Can. J. Zool.
90: 1402–1413.
Lacerda A.C.R., Tomas W.M., Marinho-
Filho J. 2009 – Domestic dogs as an edge
effect in the Brasilia National Park, Brazil: in-
teractions with native mammas – Anim. Con-
serv. 12: 477–487.
Lenth B.E., Knight R.L., Brennan M.E.
2008 – The effect of dogs o wildlife communi-
ties – Nat. Area J. 28: 218–227.
Liberg O., Sandell M., Pontier D., Natoli
E. 2000 – Density, spatial organization and
reproductive tactics in the domestic cat and
other felids (In: The domestic cat. The Biology
of its behavior, Eds: D.C. Turner, P. Bateson)
– Cambridge University Press, Cambridge, pp.
119–147.
Litvaitis J.A. 2000 – Investigating food habits
of terrestrial vertebrates (In: Research tech-
niques in animal ecology, Eds: L. Boitani, T.K.
Fuller) – Columbia University Press, New
York, pp. 165–190.
Long R.A., O’Connell A.F. Jr, Harrison
D.J. 1998 – Mortality and survival of white
tailed deer Odocoileus virginianus fawns on a
north Atlantic coastal island – Wildl. Biol. 4:
237–247.
Manor R., Saltz D. 2004 – The impact of
free-roaming dogs on gazelle kid/female ra-
tio in a fragmented area – Biol. Conserv. 119:
231–236.
Misiorowska M., Wasilewski M. 2012 –
Survival and causes of death among released
brown hares (Lepus europaeus Pallas, 1778) in
Central Poland – Acta Theriol. 57: 305–312.
Nelson M.E., Mech L.D. 1986 – Mortality of
white-tailed deer in northeastern Minnesota –
J. Wildl. Manage. 50: 691–698.
Nelson T.A., Woolf A. 1987 – Mortality of
white-tailed deer fawns in southern Illinois –J.
Wild. Manage. 51: 26–329.
Okarma H., Jędrzejewska B., Jędrzejewski
W., Krasiński Z.A., Miłkowski L. 1995
– The roles of predation, snow cover, acorn
crop, and man-related factors on ungulate
mortality in Białowieża Primeval Forest, Po-
land – Acta Theriol. 40: 197–217.
Pielowski Z. 1976 – Cats and dogs in the Eu-
ropean hare hunting ground (In: Ecology and
management of European hare populations,
Eds: Z. Pielowski, Z. Pucek) – PWRiL, War-
saw, pp. 259–263.
Pierpaoli M., Bíro Z.S., Herrmann M.,
Hupe K., Fernandes M., Ragni B., Sze-
methy L., Randi E. 2003 – Genetic dis-
tinction of wildcat (Felis silvetris) populations
in Europe, and hybridization with domestic
cat in Hungary – Mol. Ecol. 12: 2585–2598.
Romanowski J. 1985 – The diet of stray dogs
in the suburbs of Warsaw – Rev. Ecol. 40: 203–
204.
Scott M.D., Causey K. 1973 – Ecology of
feral dogs in Alabama – J. Wildl. Manage. 37:
253–265.
Selva N., Jędrzejewska B., Jędrzejewski
W., Wajrak A. 2005 – Factors affecting
carcass use by a guild of scavengers in Euro-
pean temperate woodland – Can. J. Zool. 83:
1590–1601.
Silva-Rodríguez E.A., Ortega-Solís G.R.,
Jiménez J.E. 2010 – Conservation and eco-
logical implications of the use of space by
chilla foxes and free-ranging dogs in a human-
dominated landscape in southern Chile – Aus-
tral. Ecol. 35: 765–777.
Slater M.R., Di Nardo A., Pediconi O.,
Villa P.D., Candeloro L., Alessandrini
B., Del Papa S. 2008 – Free-roaming dogs
and cats in central Italy: Public perception of
the problem – Prev. Vet. Med. 84: 27–47.
192
Free-ranging domestic dogs in Poland
Vanak A.T., Gompper M.E. 2009 – Dogs
Canis familiaris as carnivores: their role and
function in intraguild competition – Mammal
Rev. 39: 265–283.
Wasilewski M. 2001 – Wpływ mozaiki polno-
leśnej na sposób użytkowania terenu przez
sarny (Capreolus capreolus Linnaeus, 1758)
[Influence of field-forest mosaic on a habitat
use by roe deer (Capreolus capreolus Linnaeus,
1758)] – Rozprawy Naukowe i Monografie,
Wydawnictwo SGGW, Warszawa (in Polish).
Wayne R.K., Brown D.M. 2001 – Hybrid-
ization and conservation of carnivores (In:
Carnivore Conservation, Eds: J.L. Gittleman,
S.M. Funk, D.M. Macdonald, R.K. Wayne) –
Cambridge University Press, Cambridge, pp.
145–162.
Woods M., McDonald R.A., Harris S.
2003 – Predation of wildlife by domestic cats
Felis catus in Great Britain – Mamm. Rev. 33:
174–188.
Zarząd Główny Polskiego Związku Łowieckiego.
Szkody wyrządzane przez psy i koty w pol-
skich łowiskach [Board of Polish Hunt-
ing Association. Damages caused by dogs
and cats in Polish hunting grounds] – PZŁ
(http://src.pzlow.pl/, access on 21.11.2013)
(in Polish).
Received after revision November 2013
193
