Interactions between the Black Redstart (Phoenicurus ochuros) and St. Lucie Cherry (Prunus mahaleb) in rocky habitats

We investigated interactions between the Black Redstart (Phoenicurus ochrur os) and the St. Lucie cherry (Prunus mahaleb) in two rocky areas in northwe st Spain. Black Redstarts are responsible for about 30 % of P. mahaleb frui t consumption in these areas (604 of a total of 1 854 observations of birds feeding; 56 trees. 4 years). On average 14 % of food deliveries to nestlin gs comprised P. mahaleb fruits (total 8 nests, 3 years; range for individua l nests 7-28 %). The proportion of deliveries comprising fruits was higher during the second half of the nestling period than during the first half. B irds generally alighted on rock after leaving P. mahaleb plants (74 % of ca ses). Nine-month seed-survival experiments performed in the study area indi cate significant variation among the three substrate types considered (gras s, rock, rock-under-nest).