Squirrel of Eurasia

The squirrel of Eurasia or ''' russet-red squirrel ''' is a small diurnal mammal, arboricolous Rongeur of the family of the Sciuridé S

Description

It weighs between 200 and 400 grams for a total size from 30 to 40 cm, the tail being as long as the body. Peeling lengthens and becomes denser in winter, which returns the " pinceaux" more visible ears, the color clearly varies the russet-red one with the brown-black according to the seasons, the belly is white. The tail in plume is used of beam and rudder when the animal climbs or leaps, but also as optical signal in period of coupling.

Habitat and lifestyle

Sciurus vulgaris since the end of the last glaciation recolonisé all Europe almost, of the polar circle in the Mediterranean as well as Asia of the North and the East of the Ural while passing by China and Korea and the island of Hokkaido (Japan). A less known species of squirrel lives in Europe: the Persan squirrel (Sciurus anomalus) which occupies the Greek island of Lesbos and the the Caucasus.

If it still abounds in Central Europe, it is in strong retreat, even locally almost disappeared in England and in some areas from Europe, either because of the degradation of its habitat, or of the continuations of the poaching, or more recently following food competition with the gray squirrel introduces of North America. The same evolution is profiled in Italy. And can expect that the Alps are crossed soon.

Sciurus vulgaris is arboricolous. One thus finds it near wood and in the forests, in particular in the old forests where it carries out an individualistic life, marking its routes of olfactive reference marks that it seems to be alone to recognize, and hiding seed stocks here and there. It loses its aversion for its congeneric only when food abounds as in the parks.

It regularly practices grooming to eliminate the parasites which can colonize its peeling. It practices for that the baths of dust or grass, also piling up for this purpose of grass, foams and the lichens in holes or stocks of trees.

Food

Sciurus vulgaris initially seeks it with the summit of the trees, especially in beginning and end-of-day: nut, hazel nuts, seeds of the trees, buds, barks, insects, eggs and young birds still with the nest but it can also go down to be installed on a stock of tree to open more easily collected seeds there, sometimes one even surprises it to explore garages and attics! Not having a pantry in its nest, the squirrel arranges masks without apparent logic, either on the ground, often nearly the foot of the trees, or in the trees, for example with the fork of branches. It was recently discovered that it consumes also important quantities of underground mushrooms (of the type Truffe of the stag); up to 80% of the contents of its droppings were spores of these mushrooms whose fructification is done under the ground. It is possible that one can thus explain the good germination of the nipples or hazel nut which it buries and forgets, these species living in symbiosis with such mushrooms. The squirrel, by forgetting some of its masks of food could thus contribute, not only with the plantation of many trees, but also with the dispersion of the Truffe S.

Nests

The squirrel builds several nests with small branches and brushwood, of round form and an external diameter of 50 cm, and of which the interior is papered of foam and grass. The entry of the nest is positioned downwards. They protect the animal, in particular at the time of the winter rest: Sciurus vulgaris does not make complete hibernation, it visits its hiding-places to take its food there, in the event of bad weather, it can hold several days without leaving. it occupies readily the nesting boxes that one offers to him, if there is food in the vicinity. It can then become rather familiar.

Reproduction

Sexual maturity is reached at one year, at the end of the winter, the male puts itself in hunting and enters the territory of the females which once fertilized, banish it nest. They change during 38 days from two to five small. They are born in the nest blind men and deprived of hairs which appear at the end of two weeks, towards 9 weeks, their eyes open and the incisors leave. It is the age to which they start to leave the nest, but the mother remains vigilant and takes them in its mouth to put them in safety at the first danger. At the time of the first exits, various aural signals make it possible to keep the contact, which does not prevent 80% of the young people from dying before one year.

Threats

Hunting and the poaching were a cause of regression or local disappearance at the beginning of the 20th century (one showed it to eat eggs in the nests, which it can indeed occasionally do, but the species-game did not benefit from its disappearance). The squirrel is threatened today by the pollution (of which the radioactive fallout of Tchernobyl in certain areas) and more generally by the degradation or the retreat of its habitat (fragmentation and increasing artificialisation of the forests); locally, mortality by collision with vehicles can be the first cause of mortality.

In particular in the poor and acid zones, the russet-red squirrel frequently corrodes bones of mammals, or wood of deer tribe. Two explanations seem to be complementary: there it could find a source additional of Calcium, and it would be for him a means of sharpening its teeth. The problem is that the mammals store in their bones approximately 80 % of the Lead which they accumulate in their life, like certain radionuclides or other pollutants. However of the very large quantities of lead of hunting or lead of war accumulated in the forest ecosystems.

Another threat is the competition of the gray squirrel become invasive. This last is larger and more extremely than the russet-red squirrel eurasiatic, and it resists a disease better that it hawks; the Coccidiose with Eimeria sciurorum .

The squirrel is as much of animals very sensitive to the diseases when it is weakened, which would explain why its densities increase the years when production of nipples, hazel nuts or cones is important whereas it regresses the years of food shortage (with fall of the number of small when food misses). It is possible that the increase in the number of ticks these last decades has it also affected. The squirrel can be infested acarina, lice, chips and ticks which all can convey microbes or parasites. Two chips would be clean for him: Monopsyllus sciurorum very common and Tarsopsylla octodecimdentata much rarer, which is found only in the cold zones. The large ditch ( Fasciola hepatica ), and the acanthocéphale ( Moniliformis moniliformis ), various larvae of Cestode S (whose hydatid of Echinococcus granulosus ) and two intestinal Nématode S counts among the internal parasites most frequent.

The squirrel does not seem to play a big role of transmission of human diseases, except perhaps for the bacillus of the plague which it can contribute to convey. Its predatory is the marten and the goshawk which drive out it especially the winter. The inexperienced young people or the old individuals are the most frequent victims. The predation takes part of the natural selection. It is a very sharp animal which easily escapes its predatory.

Solutions

The solutions for its protection and the restoration of disappeared populations are in particular:

the actions of limitation of the expansion of the gray squirrel, some preach its eradication in Europe, but is it still possible?
the protection of the wooded mediums rich in biodiversity,
ecological restoration of continuums and thus of biological corridors wooded or adapted to the squirrels (bridges of cords & small planks tended to the top of the roads or simple cords braided with the top of the small roads), while taking care that these infrastructures are not used by the gray squirrel to extend its territory even more quickly,
better comprehension and taking into account of its ecology.

Internal bonds

gray squirrel

External bonds

Photographs at various seasons
List of all the species, in the world

Beats-smg: Vuovery

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