Does ingestion by birds affect seed germination?

Fleshy fruits from 14 plant species were fed to bulbuls Pycnonotus xanthopygos and blackbirds Turdus merula. Mostly, the birds did not produce a specific effect on germination, but seeds ingested by blackbirds usually showed substantially higher germination percentages than those ingested by bulbuls. This tendency can be partially explained by the longer retention times of seeds in digestive systems of blackbirds, which might cause a stronger effect of seed coat abrasion and hence better germination. -from Authors