| GRIFFON VULTURE (GYPS FULVUS) DISTRIBUTION AND DENSITY IN CRETE |
STAVROS M. XIROUCHAKIS A1 and MOYSIS MYLONAS A2
A1 Natural History Museum of Crete, University of Crete, P.O. Box 2208, Heraklion 71409, Crete, Greece
A2 Natural History Museum of Crete, University of Crete, P.O. Box 2208, Heraklion 71409, Crete, Greece and the Department of Biology, University of Crete, P.O. Box 2208, Heraklion 71409, Crete, Greece
Griffon vulture (Gyps fulvus) distribution and local density during 1996- 2002 as well as the main characteristics of the species' activity sites in Crete are described. Total area of occurrence has been estimated at 7000 km2 (85% of the island). 5500 km2 (67%) accounted for its vital range, namely breeding and foraging, with spatial and temporal differences in correspondence to transhumant livestock. In total 68 activity sites were detected: (a) 34 colonies, of which 62% on average were occupied by laying pairs in any one year; (b) six deserted colonies; and (c) 17 summer and 11 winter roosts. Most of the sites were found in southwest and northeast Crete on rocks of calcareous substrate. The species nesting and roosting sites were found on dolomitic and platy limestone cliffs, respectively. Mean altitude of activity sites was 650 m (SD = 442 m, range = 120-1900 m), whereas mean altitude of active colonies was 453 m (SD = 225 m, range = 120-1100 m). Cliffs were on average 182 m high (range = 40-540 m) facing southeast with a significant directionality for active colonies (southeast) and summer roosts (northwest). The distribution of activity sites was clumped, while the nearest neighboring distance was 6.2 km (range = 900 m-22.5 km). The spacing of active colonies was random with a tendency towards aggregation. The mean nearest distance between active colonies was 11 km (range = 9.1-13.3 km) and their average density for the species vital range was one active colony per 262 km2. The latter figure implied that each breeding group had a foraging range at a radius of ca. 9 km from the colony's cliff.
The references of this article are secured to subscribers.