Species specialization limits movement ability and shapes ecological networks: the case study of 2 forest mammals

To counteract the negative effects of forest fragmentation on wildlife, it is crucial to maintain functional
ecological networks. We identified the ecological networks for 2 mammals with very different
degrees of forest specialization, the European badger Meles meles and the Roe deer Capreolus
capreolus, by differentiating 4 agroforestry elements as either nodes or connectivity elements, and
by defining the distance that provides the functional connectivity between fragments. Species
occurrence data were collected in a wide agroecosystem in northern Italy. To test the role of hedgerows,
traditional poplar cultivations, short rotation coppices, and reforestations as ecological network
elements for the 2 species we applied the method of simulated species perceptions of the
landscape (SSPL), comparing the ability of different SSPLs to explain the observed species distribution.
All analyses were repeated considering different scenarios of species movement ability
through the matrix. Model outputs seem to show that the specialist and highly mobile Roe deer
has the same movement ability throughout the matrix (2 km) as the European badger, a smaller,
but generalist species. The ecological network identified for the European badger was widespread
throughout the area and was composed of woodlands, poplar cultivations and hedgerows as
nodes and short rotation coppices as connectivity elements. Conversely, the ecological network of
the Roe deer was mostly limited to the main forest areas and was composed of woodlands, poplar
cultivations and reforestations as nodes and short rotation coppices and hedgerows as connectivity
elements. The degree of forest specialization strongly affects both species perception of habitat
and movement ability throughout the matrix, regardless of species size. This has important implications
for species conservation.