The density of frugivorous birds in parcels of olive orchards in south
ern Spain was rated and compared with other habitats bearing fleshy wi
nter fruits, mainly wild olive shrubland and other natural shrublands
of the Mediterranean area. All olive orchards maintained high densitie
s of frugivorous birds throughout the wintering season (November-Febru
ary), and showed a very consistent species composition of frugivores.
In southern Spain there was a gradient in the density, proportion and
numbers of frugivorous species among different habitats; this gradient
was related to the level of habitat alteration. The density of frugiv
orous birds in the natural Mediterranean shrublands was higher than in
the wild olive shrubland and, in turn, higher in the wild olive shrub
land than in the olive orchards. Some frugivorous species disappeared
along this gradient, whereas others were favoured. Small-sized species
decreased most whereas some middle-size species were favoured. This i
s most probably because of the structural simplicity, the low fruit sp
ecies diversity and the large size of the fruits. In general, frugivor
ous species and specifically small-sized frugivorous species were more
frequent in southern than in northern Spain.