Acta Zoologica Academiae Scientiarum Hungaricae 47 (4), pp. 311–320, 2002 EFFECT OF HABITAT QUALITY ON THE HUNTING BEHAVIOUR OF BREEDING GREAT GREY SHRIKES (LANIUS EXCUBITOR) FUISZ, T. I. and R. YOSEF Animal Ecology Research Group of the Hungarian Academy of Sciences and Hungarian Natural History Museum, H-1083 Budapest, Ludovika tér 2, Hungary fuisz@zoo.zoo.nhmus.hu International Birding and Research Center in Eilat, P. O. Box 774, Eilat 88000, Israel E-mail: ryosef@eilatcity.co.il Hunting behaviour and use of different habitat types of a breeding Great Grey Shrike family was observed in a recycled landfill near Eilat, Israel. As Great Grey Shrikes were not observed to breed in the Eilat area for more than a decade, detailed observations of hunting site selection were conducted. Additionally, arthropod abundance and impaled prey items were monitored. The breeding pair established its territory on the boundary of the “Bird Sanctuary”, a former recycled landfill, where irrigation has facilitated the growth of dense vegetation inside the park boundary, while outside of it the sparse vegetation characteristic of semideserts is found. Huntings were categorised as either inside or outside of the Bird Sanctuary. White-water traps were applied to measure insect availability inside and outside the Bird Sanctuary. We found that the shrikes foraged preferentially within the Bird Sanctuary (Paired t-test, N=150, t-value: 3.63, P< 0.005). Diversity (revealed by Rényi diversity index) and abundance of arthropods were considerably higher inside the Bird Sanctuary (Wilcoxon Matched-pairs Signed-ranks test, z-value > –2.428, P = 0.0152). The monitoring of impaled prey items revealed that be- sides insects vertebrates were also taken. Interestingly two specimens of the poisonous Black Cone-headed Grasshopper (Poikylocerus bufonicus) were also impaled and consumed. Key words: Great-Grey Shrike, Lanius excubitor, habitat-choice, prey-availability, impaling INTRODUCTION Shrikes (Family Laniidae) are prominent birds of open habitats and are im- portant as indicator species of environmental degradation because they are preda- tory and closely associated with agricultural areas (HANDS et al. 1989, SAFRIEL 1995). Shrikes are at present of special concern because many of the 30 species are declining, or have become locally extinct (TUCKER et al. 1994, YOSEF 1994). Most long-term studies of previously robust populations of shrikes have documented drastic declines, mostly in the late 20th century (e.g., BUSSE 1995, PEAKALL 1995, PETERJOHN & SAUER 1995). Several factors have been suggested as causes for shrike population declines, but changes in human land-use practices may be the most likely explanation (e.g., Great Grey Shrike, Lanius excubitor, in Switzerland – BASSIN 1981; Red-backed Acta zool. hung. 47, 2001 Hungarian Natural History Museum, Budapest