Avian vectors of invertebrate faunas

The history of invertebrate colonization of the Arctic following the last glacial maxima is unclear. It is likely that few, if any, invertebrate species survived the glaciation in situ but that all re-invaded the Arctic during the recent Holocene. Several routes by which the fauna could have arrived in Svalbard have been proposed, for example rafting, aerial plankton, with human traffic and birds. It is widely accepted that that soil dwelling creatures may accidentally attach themselves to birds and so may be spread to new localities during foraging of their inadvertent host or, perhaps more importantly, during bird migration events. It was hence generally assumed however that the incidence of miocroarthropods on birds was low. However, new work has indicated that these invertebrates are often very common on the birds. Indeed, there is evidence that they may complete whole lifecycles on the birds. While remaining controversial, this theory does have some substance. Conditions under the feathers and close to the skin appear to be ideal being warm, protected and with a ample food supply in the form of sloughed skin flakes and fungal hyphae, both of which form the natural food types for these microarthropods in the soil. Nonetheless, to date there has been no concerted effort to determine the importance of this dispersal to the creation of Arctic soil microarthropod diversity.
This project aims to describe and quantify the role of avian phoresy in the dispersal and colonization of high latitudes by soil invertebrates which are not normally considered to be phoretic, primarily oribatid mites and Collembola (Norton 1980, Krantz and Walter 2009, Hopkin 1997).
Molecular techniques will be used to discriminate the invertebrate fauna sampled from the birds with the local soil fauna. In addition, it will also be possible to determine if the ornithogenic soils provide a favourable microhabitat for colonizing species as has been suggested (Coulson et al. 2009).
The data gathered will have an importance to island biogeography theory as a whole and not only in polar areas. This is especially important in an era of environmental change.