Oceanic birds as dispersal agents

Discussion and experiment on hypotheses which invoke birds as possible agents of trans-oceanic dispersal of plants and invertebrate animals have in the past been confined mainly to consideration of vagrant or migrant passerine birds, or other land birds of various kinds. In this restricted field neither experiment nor observation has given much support to the idea that viable organic units, either plant or animal, are likely to adhere for long or in significant quantity to either feet or feathers. The possibility that oceanic birds and in particular petrels could be a more significant and likely factor in such dispersal has only become apparent as a result of the more critical study which has been devoted to this group in the past twenty years and to consideration of the banding results that are now available from the cool temperate zones of both hemispheres.