Abstract :
[en] Over the time, ungulates have seen their populations continuously
changing under the e ect of direct, i.e. hunting pressure, and indirect,
i.e. land-use changes, human activities. Under control until recently,
ungulates have progressively adapted to these modi cations and are
now able to cope with human-shaped environments, consequently
their number and range have greatly and worryingly increased.
More particularly, among ungulates species, the wild boar Sus scrofa
raises important concerns due to its environmental, economic and
social impacts on modern societies. Understanding the ecology of
ungulates species and their ability to survive within highly dynamic
and seasonal ecosystems, such as agricultural environment, is thus
necessary to better mitigate their negative impacts and to sustainably
manage growing and expanding populations.
Although only recently studied, movement ecology of animal is an
important species trait that allows animal to adapt to rapid environmental
changes. Considering movement as the resulting interaction
of the animal’s internal state, navigation and motion capacity as well
as of the e ect of the surrounding environment (“external factors”),
provides a clear conceptual framework enabling to study patterns,
mechanisms and processes, such as coping with land-use changes.
In this thesis, we study the case of an expanding wild boar population
in Southern Belgium and consider the movement ecology of
the species to understand how wild boar colonize and ourish in
agroecosystems. More speci cally, the thesis aims at i) reviewing
quantitatively and qualitatively the scienti c literature about wild
boar movement ecology, and ii) analyzing the spatial response of wild
boar to agroecosystems in terms of movement and habitat selection
across three spatial and temporal scales.
The literature review highlights that wild boar is the least studied
ungulates species in terms of movement ecology.We suggest that this
is likely due i) to the relative complexity of tting tracking devices
to this species, and ii) to its generalist diet making the species not
suitable to test foraging hypotheses. Among existing studies, a large
part focuses on the role of external factors (e.g. hunting, landscape
features) on movement while others components of the movement ecology framework (internal state, navigation and motion capacity)
remain poorly studied. However, when assuming behavioral similarity
between wild and domestic boars, experimental studies on
captive animals show how wild boar can develop complex movement
strategies by using their highly developed cognitive and sensory
abilities, and spatial memory.
The spatio-temporal analysis suggests a scale-speci c response of
wild boar to agricultural habitat. At the intermediate scale (landscape,
seasonal), wild boar uses seasonal habitat shift strategies towards
agricultural areas, while at broader scale (regional, decades), wild
boar avoids this habitat, preferring the forest habitat to spread and
extend its occupancy range. This results in a contradiction with our
preliminary hypothesis that increased area of cultivations providing
cover (maize, rapeseed, cereals) facilitates wild boar population expansion.
Furthermore, we show that besides the use of forest habitat,
high population density is a major driving factor of the colonization
of agroecosystems by wild boar. The ne-scale analysis (home range,
daily), highlights the large variety of spatial behaviors (area restricted
search, central place foraging, nomadism, dispersing) wild boar is
able to use to cope with heterogeneous environments.
In terms of management of the species, the results of this thesis suggest
that it is required to lower the population density in order to limit
the population spread into agroecosystems, not only at the margin
of expansion but all over the species’ range. Furthermore, we recommend
developing more exible control strategies taking into account
both the spatial abilities of the species and the complexity and dynamics
of the environment. For example, the creation of a seasonal
landscape of fear could be promoted, i.e. reducing attractivity of agricultural
lands by increasing risk sensation (e.g. hunting with dogs all
along the growing season). However, in our opinion, the success of
any management strategy requires rst to tackle the issue of the decreasing
number of hunters observed in large part of Europe and to
improve communication among the di erent stakeholders (hunting
associations, farmers, public administration). Indeed, while ungulates
have progressively adapted to human-induced changes, the capacity
of humans to adapt to this new human-ungulate relation is questionable.
