Figure 3.

Terrestrial productivity is elevated in little auk colonies. Little auk colonies (black polygons; after (24)) and enhanced vegetation index (EVI) values below 0.25 (light green) and above 0.25 (dark green) in the northern part of the investigation area. The EVI image is from MODIS Terra, 28/7–12/8 2015 (33). Despite many EVI values missing along the coastline due to mixed pixels, the map clearly shows that EVI values above 0.25 are almost exclusively found in association with little auk colonies. In inserts (a–d), landscape photos illustrate the contrasting terrestrial productivity at colony and control sites. (a) Productive landscape in the catchment of the little auk colony on Savissivik Island (site 9); (c) productive landscape in the catchment of the little auk colony at Annikitsoq on the south coast of Cape York (sites 25–32); (b) barren landscape at the control site on Savissivik Island (site 10); (d) barren landscape at the control site close to Booth Sound (site 15–16). See figure 1 and electronic supplementary material, table S2 for exact positions.