Habitat selection and reproduction of the Lesser Grey Shrike, Lanius minor, in a coastal area of the Latium region (Monti della Tolfa).

Abstract

The status, habitat selection and reproduction of the Lesser Grey Shrike were stud- ied for 18 years (1992-2009) in a sample coastal area of the Latium region. The species is sympatric with the Red-backed and Woodchat Shrikes, and generally reaches the breeding sites after the 10th of May forming mono-specific colonies of 2-10 pairs. Breeding occurs away from woodland patches, at altitudes between 100 and 450 m a.s.l. in rough, low sloping pastures with no human settlements. Nests are built 3-7 meters high over wild pear trees and shrubs. Egg laying activity begins at the end of May, but reaches a maximum after the 10th of June. Brood size is 5.98 ± 0.66 SD eggs, which is larger than what observed for the two congeneric species in the area. Hatching can begin before the last egg is laid; 1.4% of the eggs is sterile and most of the pairs, unable to breed successfully, abandon the area. Chicks leave the nest throughout the second half of July, and they are still fed by the parents two weeks after their first flight. The number of successfully flying chicks per pair is high, while nest loss (24.6%) is lower than what observed in the other two species. Chicks are fed with insects and especially large grasshoppers, and preys are rarely “impaled”. Hunting success rate of prey items used by adults is similar to the Red-backed Shrike, but chicks are fed less frequently per unit of time. The progressive abandonment of breeding grounds is preceded by a gathering of individuals from the 10th of August, and continues throughout September. Since 2001 the breeding density has declined significantly and the extinction of the population appears unavoidable.