A multivariate analysis was carried out in order to investigate the most influential habitat variables and related features in the selection of breeding cliffs by the Griffon Vulture in Crete. The species was found nesting in mid-altitude areas, close to stock-raising units, on high limestone cliffs, which were also well protected against the prevailing winds of the island. A principal components analysis, which explained 53% of the total variance of the variables examined, differentiated Griffon Vulture colonies in relation to their isolation from other colonies, accessibility to humans and proximity to food resources. In addition, a stepwise discriminant function analysis between breeding and random cliffs included the height of the cliff, its substratum, the altitude, and the distance to the stock breeding unit in a model that successfully classified 97.1% of the nesting and 88.2% of the random cliffs. In comparison to continental regions the Griffon Vulture colonies in Crete were located on higher cliffs but at a lower altitude. This fact should be attributed to the species nesting on steep coastal cliffs close to the livestock's wintering areas.
REFERENCES
B. Arroyo
,
E. Ferreiro
,
V. Garza
1990. [2nd National Census of the Griffon Vulture (Gyps fulvus): population, distribution, demography and conservation]. Serie Tecnica. ICONA. MAPA, Madrid. Google Scholar
O. Bahat
,
A. Kaplan
1995. Foraging behaviour in griffon vulture. Torgos 25: 18–26. Google Scholar
International BirdLife
2004. Birds in Europe: population estimates, trends and conservation status. BirdLife Conservation series No. 12. BirdLife International, Cambridge. Google Scholar
M. Bonneau
1976. [Structural draft of alpine Crete]. Bull. Geol. Soc. France 18: 351–353. Google Scholar
S. Cramp
,
K. E. L. Simmon
(eds).
1980. The Birds of Western Palearctic. Vol. II, Oxford University Press, London. Google Scholar
C. Daniel
,
F. S. Wood
1980. Fitting equations to data. Wiley-Interscience, New York. Google Scholar
J. A. Donázar
1987. [Necrophagous Birds]. In: Federacion de Amigos de la tierra (ed.). [Ornithological Yearbook 87. Birds of Prey]. Madrid. Google Scholar
J. A. Donázar
1993. [Iberian Vultures, Biology and Conservation].
J. M. Reyero
(ed.).
Madrid. Google Scholar
J. A. Donázar
,
O. Ceballos
,
C. Fernadez
1989. Factors influencing the distribution and abundance of seven cliff-nesting raptors: A multivariate study. In:
B.-U. Meyburg
,
R. D. Chancellor
(eds).
Raptors in the Modern World. WWGBP, Berlin, pp. 545–552. Google Scholar
J. A. Donázar
,
C. Fernandez
1990. Population trends of the griffon vulture Gyps fulvus in Northern Spain between 1969 and 1989 in relation to conservation measures. Biol. Conserv. 53: 83–91. Google Scholar
B. R. Egli
1997. Effects of grazing on the natural forests of western Crete. In:
V. P. Papanastasis
,
D. Peter
(eds).
Ecological basis of livestock grazing in mediterranean ecosystems. European Commission, pp. 103–106. Google Scholar
ESRI
1996. Using the ArcView Spatial Analyst. Environmental System Research Institute.
Redlands, California. Google Scholar
C. Fasoulas
2001. [Geological parameters of water management in Crete]. In:
P. Lymberakis
(ed.).
[South Aegean-Crete-Cyprus. Cooperation for the Development and the Environment]. Natural History Museum of Crete, Univ. of Crete, pp. 177–190. Google Scholar
C. Fasoulas
,
A. Kilias
,
D. Mountrakis
1994. Post-nappe stacking extension and exhumation of the HP/LT rocks in the island of Crete, Greece. Tectonics 13: 127–138. Google Scholar
C. Fernádez
,
P. Azkona
,
J. A. Donázar
1998. Density-dependent effects on productivity in the griffon vulture Gyps fulvus: the role of interference and habitat heterogeneity. Ibis 140: 64–69. Google Scholar
J. Fowler
,
L. Cohen
,
P. Jarvis
1998. Practical Statistics for Field Biology. Willey and Sons, West Sussex. Google Scholar
G. Handrinos
1985. The status of vulture in Greece. In:
I. Newton
,
R. D. Chancellor
(eds).
Conservation studies in raptors. ICBP Technical Publication, No 5. WWGBP, pp. 103–115. Google Scholar
G. Handrinos
1992. [Birds]. In:
M. Karandinos
(ed.).
[The Red Data Book of Threatened Vertebrates of Greece]. Hellenic Zool. Soc, pp. 123–244. Google Scholar
G. Handrinos
,
T. Akriotis
1997. The Birds of Greece. Helm- A and C Black ltd., London. Google Scholar
K. Hanna
,
M. P. Harris
,
S. Wanless
2004. Competition for breeding sites and site-dependent population regulation in a highly colonial seabird, the common guillemot Uria alge.
J. Anim. Ecol. 73: 367–376 Google Scholar
D. C. Houston
1974. Food searching in griffon vultures. E. Afr. Wildl. J. 12: 63–77. Google Scholar
I. Ispikoudis
,
G. Lyrintzis
,
S. Kyriakakis
1993. Impact of human activities on mediterranean landscapes in western Crete. Landscape and urban planning 24: 259–271. Google Scholar
M. Leconte
1977. Étude de la reproduction du vautour fauve dans les Pyrénées occidentales. Le Courbageot 4: 8–19. Google Scholar
M. Leconte
1985. Present status of the griffon vulture on the northern slopes of the western Pyrenees. In:
I. Newton
,
R. D. Chancellor
(eds).
Conservation studies in raptors. ICBP Technical Publication, No 5. WWGBP, pp. 117–127. Google Scholar
J. A. Ludwig
,
J. F. Reynolds
1988. Statistical Ecology. A primer on methods and computing. John Wiley & Sons, New York. Google Scholar
G. Lyrintzis
1996. Human impact trend in Crete: the case of Psiloritis Mountain. Envir. Conser. 23: 140–148. Google Scholar
B. F. J. Manly
1986. Multivariate statistical methods: a primer. Chapmann & Hall, New York. Google Scholar
S. Marincovič
,
L. Orladič
1994. Status of the griffon vulture Gyps fulvus in Serbia. In:
B.-U. Meyburg
,
R. D. Chancellor
(eds).
Raptor Conservation Today. The Pica Press, pp. 163–172. Google Scholar
P J. Mundy
,
D. Butchart
,
J. Ledger
,
S. Piper
1992. The vultures of Africa. Acorn Books and Russel Friedman Books, Randburg. Google Scholar
I. Newton
1991. Population limitations in birds of prey: a comparative approach. In:
C. M. Perrins
,
J. D. Lebreton
,
G. J. M. Hirons
(eds).
Bird population studies: their relevance to conservation and management. Oxford Univ. Press, pp. 3–21. Google Scholar
J. Parra
,
J. L. Telleria
2004. The increase in the Spanish population of griffon vulture Gyps fulvus during 1989–1999: effects of food and nest site availability. Bird Conserv. Inter. 14: 33–41. Google Scholar
C. J. Pennycuick
1998. Field observations of thermals and thermal streets, and the theory of cross-country soaring flight. J. Avian Biol. 29: 33–43. Google Scholar
A. S. Robertson
,
A. F. Boshoff
1986. The feeding ecology of Cape Vulture Gyps coprotheres in a stock-farming area. Biol. Conserv. 35: 63–86. Google Scholar
N. L. Rodenhouse
,
T. W. Sherry
,
R. T. Holmes
1997. Site-dependent regulation of population size: A new synthesis. Ecology 78: 2025–2042. Google Scholar
J. Seco
,
J. M. Vadillo
1990. [Distribution and status of the Griffon Vulture (Gyps fulvus) colonies in the upper Ebro and the Catabrian zone]. Doñana Acta Vertebrata 17: 153–163. Google Scholar
G. W. Snedecor
,
W. G. Cochran
1967. Statistical methods. Iowa State College Press, Ames. Google Scholar
G. M. Tsiourlis
,
P. Kasapidis
,
A. Parmakelis
,
M. Dretakis
1997. Effects of grazing on the structure of phryganic ecosystems in the Asterousia Mountain of Crete, Greece. In:
V. P. Papanastasis
,
D. Peter
(eds).
Ecological basis of livestock grazing in mediterranean ecosystems. European Commission, pp. 94–97. Google Scholar
G. M. Tucker
,
F. A. Heath
1994. Birds in Europe: Their conservation status. BirdLife Int. Conserv. Ser. No 3. Cambridge. Google Scholar
O. A. Vitovich
1985. [Comparative ecology of the Bearded Vulture and Griffon Vulture]. In: [Birds of North-West Caucasia]. Moscow CNIL, Glavokhoty Press, pp. 53–71. Google Scholar
S. M. Xirouchakis
2003. [The ecology of the Griffon Vulture (Gyps fulvus) on the island of Crete]. Ph.D. Thesis, Univ. of Crete, Heraklion. Google Scholar
S. M. Xirouchakis
,
M. Mylonas
2004. Distribution and density of the Griffon Vulture (Gyps fulvus) in Crete. Israel J. Zool. 50: 341–354. Google Scholar
S. M. Xirouchakis
,
M. Mylonas
2005. Status and structure of the Griffon Vulture (Gyps fulvus) population in Crete. Eur. J. Wildl. Res. (in press). Google Scholar
