130925-studie-wildlife-comeback-in-europe

3.1. European bison
Bison bonasus
Summary
The European bison, the largest herbivore in
Europe, went extinct in the wild in the early 20 th
century due to habitat degradation and fragmentation,
forest logging, and unlimited hunting and
poaching. Only 54 individuals with known pedigree
from 12 ancestors remained in captivity, and these
formed the basis for a large-scale breeding, reintroduction
and translocation programme, which
resulted in the re-establishment of a number of
wild populations. The species currently exists in
33 free-living, isolated herds of two genetic lines in
central and eastern Europe, with particular strongholds
in Poland and Belarus. Although the situation
of the European bison has undoubtedly improved
over the past 50 years, the species remains at risk
from its low genetic diversity and lack of connectivity
between populations.
Background
General description of the species
The European bison or wisent (Bison bonasus) is
the largest herbivore in Europe and one of the few
surviving megafauna species [1, 2] . A gregarious,
ruminant species, bison feed on up to 60 kg of
lichen, mosses, leaves, grasses, shrubs, acorns and
bark per day [3] . The social unit is the herd, which
shows synchronised daily activity rhythms [3] .
Movements relate mainly to feeding activity and
habitat utilisation is dependent on group size and
structure, and habitat preferences [3] . Mixed groups
of cows, young, calves and adult bulls are of varying
size dependent on the environment, while bull
groups contain two animals on average [3] . More
than half of males, which make up 25% of the bison
population, lead a solitary life [3] . Bulls become
sexually mature at three years but usually do not
take part in reproduction until the age of six due
to aggressive behaviour from older individuals [3] .
Cows reach maturity in the third year of their life,
giving birth to one calf between May and July,
although late parturition does occur [3] .
Distribution in Europe
The earliest record of European bison in Europe is
from the early Holocene based on fossil deposits
found in northern central Europe [1] . Other archaeozoological
evidence suggests that the species
was once widespread on the continent, reaching
from France to the Ukraine and up to the northern
shores of the Black Sea [1, 3] . Palynological finds
further point to bison inhabiting woodland
habitat such as deciduous, pine and oak forests [1] .
The species is thought to have declined initially
due to a changing climate [4] , while deforestation
and over-hunting were implicated in later range
contraction and population crashes [1, 4, 5] . Although
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