MAMMALS

  

 Overview
 Insectivores
 Rodents
 Even-toed
 ungulates
 Carnivores
 Species
 protection
 WNP home

  

Text:
Wojciech
Misiukiewicz

Photos: 
Wojciech
Misiukiewicz
Jan Walencik
Marek
Barszczewski
Lech
Krzysztofiak
Maciej
Romański

Drawings:
Ewa Przytuła

Webdesign: 
KAJA
 
2004

  

  

  

Rodents Rodentia

  

The European beaver

The name for this order of mammals is linked to the specific properties of their teeth. The incisors are chisel-shaped and grow constantly, staying permanently sharp because the enamel covers only their front surface. Among mammals, rodents have the highest numbers of offspring, as females can produce several litters per year. 

  

Rodents are ubiquitous animals. They occur in highest numbers in lowlands, along forest edges, they are least common in peat bogs and in high zones of mountains above the dwarf pine belt. Many rodent species are pests in farmlands and forest plantations. They also constitute medical and veterinary hazards because of their contributions, as vectors, to the outbreaks of contagious diseases.

  

The European beaver

The European beaver (Castor fiber) is the largest European rodent. In Mediaeval times, this species was one of the most common animals in Poland. However, centuries of exploitation by hunting as well as the transformation of its natural habitats caused a near extinction of the species. It is thought that within the present national territory of Poland, beavers were almost entirely extinct by the second half of the 19th century.

  

The first sites of beavers’ colonies within the limits of the present Wigry National Park were recorded near the outlet of the Czarna Hańcza river from Lake Wigry in 1944-1949. In order to protect the refuges of incoming beaver families, settling along lake shores and river banks, two reserves of partial protection status were established: Ostoja Bobrów Stary Folwark and Ostoja Bobrów Zakąty in 1959-1962 (Polish ostoja means ”refuge”). Many years of species protection and establishing reserves, as well as giving the Wigry region its national park status, have contributed to a gradual increase in numbers of these animals and have enabled them to colonize adjacent areas, bringing the total number of beavers throughout the Suwałki region to almost ten thousand.

  

Some 250 beavers live within the Wigry National Park

The credit for successful restoration of the European beaver in Poland is due above all to late Professor Wirgiliusz Żurowski. In 1976 he began the implementation of a programme ”Active Protection of the European Beaver in Poland”. The main assumptions of the programme were: protection of existing sites and the artificial introduction of beavers into suitable habitats throughout Poland. Professor Żurowski developed the concept of resettlements, methods for capturing, transporting and introducing beavers in new sites, as well as for monitoring the success or failure of new populations.

  

In the early 1990s the number of beavers in the Wigry National Park was some 250 individuals and the population has maintained this stable level up to the present. The omnipresent tokens of foraging by beavers: felled trees, dams, lodges and burrows, can be found upon Lake Wigry and other lakes of the Park. Beavers can also be seen near small forest lakes (sukhars), rivers or even drainage canals and small ponds among open fields.

  

The muskrat is an alien species
which penetrated into Poland
across the border with Czechoslovakia

The muskrat (Ondatra zibethica) is a typical amphibious species. This alien species penetrated into Poland in 1929 from Czechoslovakia where it had been brought in 1905 from North America. The enormous fecundity of this species (3-4 litters per year, up to 14 young in a litter), resulted in its expansion into Central and Eastern Europe. This invasion has been finally stemmed by, among other measures, introducing another alien species from North America, the American mink (Mustela vison), which has become the muskrat’s most formidable enemy.
The muskrat lives on banks of various bodies of water. It digs deep burrows in steep banks with a nest chamber and many corridors with underwater entrances. The burrows are inhabited by entire families, and adjacent burrows form colonies. Before winter comes, the muskrats build pile-shaped nests made of reeds and rushes. They provide not only a shelter, but also constitute a food reserve for the difficult winter period. The name of the species reflects the presence of musk glands situated near the anal glands. The musk glands are used by males to mark their territories in the mating seasons.

  

Even though the environment in the Wigry National Park is favourable, the muskrat is relatively rare. Some small colonies can be found on the shores of Lake Wigry, in the Powały Protected Area, and also within the Lipniak Protected Area where it lives by small bodies of water situated among open fields.

  

The water vole is a typical amphibious species

The water vole (Arvicola terrestris) lives on river banks and wet meadows, and – less frequently – in gardens, forest edges and plantations of deciduous trees. This vole digs a burrow in the bank, with a gallery leading directly underwater. The drier the habitat, the more extensive the underground systems with a nest chamber, storage spaces and galleries. Water voles live on diverse vegetable matter and small vertebrates. They may sometimes undercut tree roots and damage crops. When occurring in large numbers, water voles may inflict certain level of economic damage.

  

The water vole is a good swimmer and diver. Because its mouth can shut behind the incisors, similarly to other diving rodents, it is capable of feeding on underwater plants. Water voles spent the winters in burrows away from water. Their life-span is two years.

  

The bank vole is a common rodent in Polish forests

The bank vole (Clethrionomys glareolus) lives in almost all types of woods or forests, preferring moist, shrubby biotopes. A good climber, it moves skilfully on tree trunks and among the branches. It digs shallow underground corridors or makes hidden pathways in dense undergrowth. The bank vole has many young in a litter, they grow fast and mature after 8-9 weeks. It is principally a nocturnal animal, but comes also out during the day to feed on seeds, buds, bark, lichens and sometimes to prey on small animals. When its food is in short supply, the bank vole feeds on the bark of young trees and may sometimes be treated as a pest, particularly in forest plantations.

  

The yellow-necked mouse can climb trees.
It makes its nest in holes in trees, rotting fallen trees,
bird nest-boxes.

The yellow-necked mouse (Apodemus flavicollis) is a reddish-brown rodent with a characteristic crescent yellow spot on the chest. This species makes seasonal migrations. In autumn and winter it may sometimes enter buildings situated in woodlands. Its activity is chiefly nocturnal and it feeds on seeds, fruits, mushrooms, plant shoots, buds, and insects. This mouse digs deep burrows or occupies the burrows of moles and voles. Sometimes it makes nests in rotten stumps and holes in trees. Occasionally, it may take over bird nest-boxes, even those placed high above the ground. Yellow-necked mice move by jumping; when frightened they can make jumps of 50 to 60 centimetres.

   

   

  

 

  

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