Beavers in Wigry National Park
Beaver dam on Kamionka river.
European beaver is the most characteristic species of Wigry National Park (WNP).
The first beaver site located within the current boundaries of the Park was
described between 1944-1949 and located by the Czarna Hańcza river mouth leading
from lake Wigry. In order to protect the new beaver families settling down at the shores
of lakes and rivers in WNP, two partial reservations were established in 1959
and 1962. The first one, "Beavers' Refuge in Stary Folwark" covers the area
of 120 ha. and encompasses the Czarna Hańcza river mouth leading from lake
Wigry. The second reserve, "Zakąty Beavers' Refuge" was established near the village
of Zakąty in 1962. It covers the area of 7 ha. The long-term protective measures,
such as the foundation of the reservation, as well as the creation of Wigry
National Park, contributed to the increase of the numerical force of those
animals and facilitated their migration to neighbouring areas, resulting in the development
of a population of thousands of beavers in Suwalki region.
Beavers tend to build the lodges
within the proximity of human settlements
more and more often.
During the first
half of the 1990's, the numerical force of beavers in the Park oscillated around
250 individuals and has remained at this level until today. Such stable size of the population
proves that the animals have occupied all the possible water bodies and
watercourses. The inventory taking conducted by the staff of Wigry National Park
has shown that the area of the Park is inhabited by 64 beaver families. Knowing
that one site is usually inhabited by 4 beavers, 250 beavers were assumed to
live here. The hydrographical network of the Park provide
beavers with a diversified environment. Apart from drainage ditches, which are
inhabited sporadically in the wooded water areas, most of the beavers occupy
large lakes and rivers. The largest and longest watercourse, the Czarna Hańcza
river, has been inhabited by as many as 8 beaver families. A 15- kilometre long
section of this river is located in the area of WNP, and such a great number of animals
on this relatively short watercourse proves that beavers, having "saturated" all
possible water environments, focus on the most attractive areas with a rich food
base. The high concentration of their population in WNP forced the animals to
leave the afforested sites and settle in field areas.
One of the reasons for the mortality of beavers
in the park are the cases of running over by cars.
Man-made drainage canals and ditches made the task easy for them. In
the modern landscape, the field beaver sites link the groups of the once
dispersed population into one entity. In the area of the Park there
are 4 beaver families that adapted to the transformed environment by inhabiting
drainage ditches and small field water bases. Occasionally, beavers
establish their settlements within the close neighbourhood of man.
It should be expected that such areas, rich in food during winter,
will be attractive settlement spots for the other migrating animals.
In order to provide themselves with the proper water depth and to
facilitate moving and transporting food, beavers create floodings,
which resulted in 84 registered beaver dams in the area of WNP. A
relatively high number of 25 dams were built in the northern part
of Park, on Wiatrołuża river. Some of them are of rarely seen,
interesting construction. On the most shallow sections with a relatively
swift current, the dams have been built of stones. Due to limited
amounts of the traditional materials, such as branches and mud, the stone
dams a truly interesting construction.
A beaver near the Maniówka river.
habitats are used by many other animal species in the area of the Wigry National
Park. It has been repeatedly noticed that beaver sites are becoming inhabited by
the American mink. Otters are also frequent residents of beaver lodges. One case
was reported of a beaver lodge inhabited by both a beaver and an otter at the same
time. Beaver ponds are eagerly visited by many bird species, e.g. black stork,
crane or kingfisher.
concentration of beavers within the area of the Park is 43 inhabited sites per
100 km2. Because of such a high number of beaver families, the population
of beavers in WNP is beginning to suffer from the phenomenon characteristic of over-concentrated
populations - increased competition and the migrations that follow it lead to
the increased mortality rate of these animals. Moreover, the frequent contacts
between individuals also have a negative effect due to a higher
parasitation ratio. Internal parasites (trematodes) weaken the animals and often
cause their death. Beavers also die in result of being trapped under ice, run
over by a car or of mortal wounds acquired during a fight over the family area.
The natural reduction of beaver population by predators is relatively small in the Park.
The low concentration of large predators cannot be the reason for great losses
among beavers. The Słupie Protection District is the only place where killings
of whole beaver families by wolves were recorded.
Research concerning the beaver
- measuring the winter food supplies.
current number of beavers, complex hydrographical network of the Park and
the environmental diversity provide ideal conditions for conducting research
and observations of this interesting rodent. WNP, in co-operation with
scientific institutions and organisations, conducts a number of study
programmes on the functioning of the freely existing populations of those
animals. Apart from the scientific achievements regarding the biology and
ecology of beavers, the conducted research programmes, the researched
master's theses and the observations carried out by enthusiasts of nature
result in the thorough discernment of the influence of these animals on man's
Young beavers in beaver lodge.
beaver is the coat of arms of the Wigry National Park, as it will remain
a permanent element of the Park. When roaming the tourist routes, one can often
observe the signs of beavers' activity or, provided they remain silent and calm,
even see them swimming and feeding. Once they find a safe refuge, the beavers
are also active during the day. In order to facilitate
the observations of beavers, a special platform was prepared on the "Suchary"
educational path. Nature lovers who have not been able to see these interesting
creatures live can see them on film in the building of the Wigry National Park