Rc. Vanapeldoorn et al., DISTRIBUTION AND DYNAMICS OF THE RED SQUIRREL (SCIURUS-VULGARIS L) INA LANDSCAPE WITH FRAGMENTED HABITAT, Landscape ecology, 9(3), 1994, pp. 227-235
In a four year study data on the presence of red squirrel were collect
ed in an agricultural landscape by counting dreys in 49 woods ranging
from 0.5 to 14 ha, and differing in quality of habitat and isolation.
Logit regression analysis showed that the area per woodlot covered wit
h conifers is a good predictor of squirrel presence for each year and
during the whole period, but the significance of the regression decrea
ses with time. During the study the number of woods occupied by red sq
uirrel increased, and smaller woods and those without conifers also be
came inhabited. This trend is in accordance with the positive effect o
f time in regression analyses on the presence of the species and on th
e colonization of woods, and it suggests an increase of squirrel numbe
rs in the area. Addition of several isolation variables in the regress
ion analyses showed significant effects in different years, and the ef
fect of isolation was independent of time. In the first two years the
area of habitat around a woodlot, the distance to the nearest woodlot
larger than 30 ha, and the density of possible movement corridors have
significant effects on the presence of red squirrel. In the last two
years, with presumably a high number of squirrels, the (short) distanc
e to the nearest woodlot and also the area of habitat around woods hav
e significant effects. It is concluded that the spatial dynamics of th
e population can be understood as the outcome of individual spatial be
haviour, rather than as the result of metapopulation processes.