The European ground squirrel (''Spermophilus citellus''), also known as the European souslik, is a species from the
squirrel family,
Sciuridae
Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...
.
It is among the few European species in the genus ''
Spermophilus
''Spermophilus'' is a genus of ground squirrels in the squirrel family. As traditionally defined the genus was very species-rich, ranging through Europe, Asia and North America, but this arrangement was found to be paraphyletic to the certa ...
''. Like all squirrels, it is a member of the
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...
order. It is to be found in eastern Europe from southern
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inv ...
, to
Asia Minor
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
,
Austria
Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
, the
Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
,
Slovakia
Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the s ...
,
Serbia
Serbia (, ; Serbian: , , ), officially the Republic of Serbia (Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hungar ...
,
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders ...
,
Romania
Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, and ...
,
Bulgaria
Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
,
North Macedonia
North Macedonia, ; sq, Maqedonia e Veriut, (Macedonia before February 2019), officially the Republic of North Macedonia,, is a country in Southeast Europe. It gained independence in 1991 as one of the successor states of Yugoslavia. It ...
and north as far as
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...
but the range is divided in two parts by the
Carpathian Mountains.
The European ground squirrel grows to a length of approximately and a weight of approximately . It is a
diurnal animal
Diurnality is a form of plant and animal behavior characterized by activity during daytime, with a period of sleeping or other inactivity at night. The common adjective used for daytime activity is "diurnal". The timing of activity by an animal d ...
, living in
colonies
In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...
of individual burrows in pastures or grassy embankments. The squirrels emerge during the day to feed upon
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s, plant shoots and roots or flightless
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s. The colonies maintain sentinels who whistle at the sight of a predator, bringing the pack scurrying back to safety.
Breeding takes place in early summer when a single litter of five to eight young is borne. The European ground squirrel
hibernates between autumn and March, the length of time depending on the climate. In preparation they will build up reserves of
brown fat
Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). Brown adipose tissue is found in almost all mammals.
Classification of brown fat refers to two distinct cell populations with si ...
during the late summer.
Description
The European ground squirrel is about the size of a
brown rat
The brown rat (''Rattus norvegicus''), also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat, Norwegian rat and Parisian rat, is a widespread species of common rat. One of the largest muroids, it is a brown o ...
, with an adult measuring and a weight of . It has a slender build with a short bushy tail. The short dense fur is yellowish-grey, tinged with red, with a few indistinct pale and dark spots on the back. The underside is pale with a sandy-coloured abdomen. The large dark eyes are placed high on the head and the small, rounded ears are hidden in the fur. The dental formula is 1/1, 0/0, 2/1, 3/3. The legs are powerful with sharp claws well adapted for digging. Males are slightly larger than females otherwise they look alike.
The European ground squirrel has a shrill alarm call that will cause all other individuals in the vicinity to dive for cover. It also makes various soft chirruping and growling noises.
[
The European ground squirrel could be confused with the ]speckled ground squirrel
The speckled ground squirrel or spotted souslik (''Spermophilus suslicus'') is a species of rodent in the family Sciuridae from Eastern Europe. ''Spermophilus suslicus'' consists of three subspecies: ''S. s. boristhenicus'', ''S. s. guttatus'', a ...
which occurs in Poland (Lublin Voivodeship), Romania, Russia, Belarus and Ukraine, but that species has dark brown fur spotted with white and a thin tail and lives in areas with coarser vegetation.
Distribution and habitat
The European ground squirrel is native to central and southeastern Europe where its range is divided by the Carpathian Mountains. Its range includes land at altitudes of up to in southern Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inv ...
, Asia Minor
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
, Austria
Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
, the Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
, Slovakia
Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the s ...
, Hungary
Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the ...
, Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders ...
, Romania
Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, and ...
, Bulgaria
Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
, North Macedonia
North Macedonia, ; sq, Maqedonia e Veriut, (Macedonia before February 2019), officially the Republic of North Macedonia,, is a country in Southeast Europe. It gained independence in 1991 as one of the successor states of Yugoslavia. It ...
and north as far as Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...
. It has become locally extinct in Germany and Poland but was reintroduced successfully into the wild in Poland in 2005. Some of the animals were sourced from the Budapest Ferenc Liszt International Airport
Budapest Ferenc Liszt International Airport ( hu, Budapest Liszt Ferenc Nemzetközi Repülőtér) , formerly known as ''Budapest Ferihegy International Airport'' and still commonly called just ''Ferihegy'', is the international airport serving t ...
.
The European ground squirrel has very specific habitat requirements. It needs short turf in order to dig its tunnel system. It finds this on the steppes and in pasture, in dry banks, on sports fields, parks and lawns. These conditions are lost when changes in agricultural practice convert grassland into arable land and forest, or grazing ceases and the grass grows coarse and scrubland develops. Other places with short vegetation that sometimes provides suitable habitat are railway embankments and road cuttings and verges.[
]
Behaviour
The European ground squirrel is a colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 au ...
animal and is mainly diurnal. It excavates a branching system of tunnels up to deep with several entrances. At other places in the home range it digs unbranched bolt holes in which to hide if danger threatens. If alarmed it emits a piercing whistle and when it is out in the open it often sits upright and looks around for predators. These include the weasel
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slender b ...
, fox
Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush'').
Twelve sp ...
, domestic cat and some species of birds of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...
. It feeds on grasses, other plants, flowers, seeds, cultivated crops, insects and occasionally the eggs of ground nesting birds or their chicks.[ A study in Bulgaria found that the squirrel spent about eleven hours a day outside its burrow in mid-summer but by early autumn this has reduced to seven hours. Rather over half of the day was spent foraging but other activities observed included exploration, running, sitting, grooming, digging, scent marking and vigilance.] During the winter it stops up the entrances to its burrow and hibernates in a nest of dry vegetation. Each individual occupies a separate chamber and during this period, the body temperature drops to 2.0 °C (36 °F), and the heart rate slows to a few beats per minute. During hibernation, the squirrel may wake up briefly for a few days and uses up the fat reserves accumulated during the summer, consuming about 90% of the fat stored in the body. In Bulgaria hibernation lasts from September to March.[
]
Breeding
After emerging from hibernation in the spring, mating takes place during April or May. The gestation period is about twenty six days and five to eight young are born in a chamber deep in the burrow. They are naked and blind and their eyes open at about 4 weeks old. The female feeds them for six weeks and soon after that they are ready to leave the burrow. They reach maturity the following spring and may live for eight to ten years.[
]
Status
The European ground squirrel is listed as being endangered by the IUCN in its Red List of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...
. This is because the population trend is downward and it is believed that, over the last ten years, the population has diminished by more than 30%. The southern and the northwestern and northern parts of the range are most seriously affected. The main threats are the conversion of grassland and pasture to cultivated fields or to forestry, and the abandonment of grassland and its reversion to unsuitable tall grass meadows and bushy habitats that do not suit the animal. Urbanization and road building have sometimes fragmented communities and prevented recolonisation of empty sites.
References
{{Authority control
Spermophilus
Squirrel, European ground
Squirrel, European ground
Vulnerable animals
Vulnerable fauna of Asia
Vulnerable biota of Europe
Articles containing video clips
Mammals described in 1766
Taxa named by Carl Linnaeus