Seed shadows generated by frugivorous birds in an eastern Mediterranean scrub

Fruits of the five common fleshy-fruit plant species in an Israeli Mediterranean scrub were removed by twelve bird species of which seven were transients. Fruits of shrubs Rhamnus palaestinus and Pistacia lentiscus were removed mainly by all-year residents, while fruits of a semi-parasitic dwarf shrub Osyris alba, a vine Rubia tenuifolia and a tree P. palaestina were removed mainly by transients. Rhamnus was visited by most bird species more often than expected from its relative abundance, and the highest density of bird-deposited seeds was found under Rhamnus. Scrub clearings were largely avoided by birds. Fruits of the two shrub species were deposited under conspecific adults more often, but reached a greater diversity of habitat types, than the semi-parasitic shrub and the vine, which depended closely on other plants. Fruits of the semi-parasite and the vine may reach few but high-quality deposition sites, whereas those of bushes and trees reach wider variety of habitat types. No relation was found between body size, taxonomic affinity or status of a bird species, and its dispersing efficiency. As no plant species is more successfully dispersed than another, but a trade-off may exist in dispersal attributes, there is also no "ideal' disperser bird species. -from Authors