De. Bakaloudis et al., Habitat use by short-toed eagles Circaetus gallicus and their reptilian prey during the breeding season in Dadia Forest (north-eastern Greece), J APPL ECOL, 35(6), 1998, pp. 821-828
1, The area surrounding and including Dadia Forest, north-eastern Greece, i
s well known for its diversity of breeding raptors, including many species
of conservation concern. Dadia Forest has been exploited by humans for many
centuries, but more recent social and economic changes have stimulated pro
posals that the forest should be subject to habitat management to protect t
he fauna of the region.
2. We examined the distribution of reptiles over nine different habitat typ
es with a view to assessing the importance of these habitats for foraging b
y short-toed eagles Circaetus gallicus. In addition, data on the diet of th
e species were collected from direct observations at nests.
3. The short-toed eagle relies heavily on snakes for food. The most importa
nt prey species was the grass snake Natrix natrix, although the Montpellier
snake Malpolon monspessulanus and large whip snake Coluber jugularis is al
so featured prominently as prey items at certain nests. Montpellier snakes
and large whip snakes were distributed across all habitat types, but grass
snakes were concentrated in areas of mainly intensive, but also non-intensi
ve, cultivation.
4. Analysis showed that short-toed eagles concentrated their foraging effor
ts in three habitat types: intensive and non-intensive cultivation and gras
slands. Grass snakes were abundant on cultivated land but relatively scarce
on grassland. Forested areas were largely avoided by foraging eagles. The
data show that for the short-toed eagle the distribution and abundance of p
rey items on the ground does not reflect food availability.
5. The possible effect of changes in habitat management on the short-toed e
agle population in Dadia is discussed, in particular the establishment of e
xclusion zones that could result in progressive canopy closure.