The consumption of Wild Cherries Prunus avium (L.) by frugivorous birds and mammals was studied in an area in northwest Spain in summer during July–August 2005, analysing in particular how the fruits were obtained by terrestrial seed-dispersing mammals. During the study cherries were practically the only ripe fleshy fruits available in the area. They were consumed by a variety of birds (16 species), with a very high mean rate of feeding visits (136 birds per hour for 10 trees, n = 4091 feeding visits). Most of these visits were by a priori seed-dispersing birds that usually swallow the fruits whole, in particular the Spotless Starling Sturnus unicolor Temminck, Blackbird Turdus merula L., Blackcap Sylvia atricapilla (L.), and Garden Warbler Sylvia borin (Boddaert). However, the large sizes of the cherries (10–17 mm) and the fact that they were often removed with the stalk attached hindered this to a great extent, especially in birds with small gape width (Sylvia warblers, with gape width <10 mm, accounted for 32% of the total feeding visits). Failure in handling the cherries and their falling to the ground was therefore common, as it was the alternative strategy of pecking the pulp without ingesting the large cherry seed. Most of the fallen cherries had been handled by birds (89% of 1241 cherries collected beneath eight trees), and 52% of the handled cherries still had the stalk attached. The cherries were frequently consumed by seed-dispersing mammals (1133 cherry seeds in 51 droppings of hedgehogs, mustelids and canids). More than 99% of the cherry seeds in mammal droppings were intact (potentially viable for germination). Considering their shoulder-heights (40 cm at the maximum) and the characteristics of the cherry trees (1.92 m mean distance from the ground to the lowest branch, n = 77 trees), seed-dispersing mammals were unlikely to have reached the branches directly from the ground without climbing. The non-climbing species (European Hedgehog Erinaceus europaeus (L.), Eurasian Badger Meles meles (L.), Red Fox Vulpes vulpes (L.) must have obtained all the fruits after they had fallen, and as a whole these species were precisely the main cherry dispersers among the mammals (94% of the total cherry seeds in mammal droppings). Western Polecats Mustela putorius (L.) and Beech Martens Martes foina (Erxleben) consumed cherries and could climb the trees to eat the fruit, and Stoats Mustela erminea (L.) did not consume cherries. Two conclusions in this study are relevant within the European context: 1) not all oversized fruits that often fall to the ground due to the action of seed-dispersing frugivorous birds are wasted, in terms of potential dispersal, and 2) non-climbing terrestrial seed-dispersing mammals can feed on the fruits that have fallen from shrubs and trees not necessarily after post-ripening natural abscission.
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