Dark-bellied Brent Geese Branta bernicla bernicla forego breeding when Arctic foxes Alopex lagopus are present during nest initiation

In an area north of the Pyasina delta in Taimyr (Russia), nest distribution, nest initiation and breeding success of Brent Geese Branta bernicla bernicla were studied in six successive summer seasons from 1990-1995 in relation to lemming and Arctic Fox Alopex lagopus abundance. Lemming abundance conformed to the well-known three-year cycle with peaks in 1991 and 1994. Wandering Arctic Foxes were numerous in 1992, one of the two years following a lemming peak. This was the only year in which foxes visited the small offshore island where Brent Geese used to nest. Although Brent Geese arrived in time that year, the majority did not even start to breed and disappeared. Thus the actual mechanism causing failure in 1992 was disturbance rather than predation and Brent Geese appeared to be able to forego breeding at the very last moment. In the unexpected absence of foxes in the second predator year 1995, Brent Geese incubated successfully on the small islands in our study area. However, they failed to raise their goslings as these were all predated, not by foxes but probably by gulls

Spaans B., Blijleven H., Popov I.U., Rykhlikova M.E. & Ebbinge B.S., ARDEA 86 (1): 11-20.