Berry consumption by the American Robin, Turdus migratorius, and the subsequent effect on seed germination, plant vigour, and dispersal of the Lowbush Blueberry, Vaccinium angustifolium

The American Robin, Turdus migratorius, is a major frugivore of the Lowbush Blueberry, Vaccinium angustifolium. Laboratory observations established that young robins were capable of rapidly consuming large numbers of berries. After each experimental feeding, excreta were collected, seeds extracted and sown. Germination of excreted seeds was reduced by approximately 17% compared to control seeds. Corroborative evidence was obtained from subsequent field studies in 1985, 1989, and 1993 where the germination success of V. angustifolium seeds from 157 robin excreta collected along the edges of four Nova Scotia blueberry barrens showed a 24% decrease in germination compared to those of control seeds. In 1993 in vitro studies, seeds extracted from fresh fruit were free from pathogens except for a few yeasts; seeds extracted from rotting fruit were largely infected by Botrytis, Aureobasidium and Cladosporium spp., but seeds extracted from robin faeces were invariably infected by bacteria and Mucor spp. as well as 17 additional pathogens.