migration route. Birds like to travel so that the temperature, pressure and humidity work with the tailwinds. Strong winds can blow birds off of their regular migration route. For example, the effects of a large storm lead to a higher presence of the white-rumped sandpiper on the King George Islands. Effects of climate change The warming of the climate has led to changes in the number of individuals and the length of their stay in the South Shetland Islands. White-rumped sandpipers are now observed more frequently in this area as a result of both long and short term climate variations. The higher air temperatures, which occur as a result of the northern winds, bring warm, moist air which creates more open habitats and better food resources that allow these birds to persist and survive. Migration routes, as well as both winter and summer foraging grounds, may also be altered. Behavior Vocalizations One of the white-rumped sandpiper vocalizations consists of a repeating "pip, pip, pip …" Their call has a distinctive metallic "tzeep" note which makes them easily identifiable among a flock of shorebirds. It resembles the sound of two pebbles scraping against one another. Diet Their diet consists primarily of small invertebrates including: molluscs, crustaceans, polychaetes, annelids and both adult and larval insects. They are mainly reported to eat aquatic invertebrates. Although it was previously thought they only consumed invertebrates, it has been shown that seeds and moss also make up a portion of the white-rumped sandpiper diet. This discovery lead to the idea that they might be opportunistic feeders depending on time, season and habitat. Stones and algae have also been found in their stomachs but these are most likely ingested by accident. The stones are of the same general shape and size as the seeds so it could be a case of mistaken identity. Algae could also be accidentally ingested through aquatic feeding. While on mudflats, the white-rumped sandpiper forages by probing in shallow waters and in mud but can also pick up some items from the surface. When they are in the tundra, they must probe deeply in the moss and other vegetation. Nesting The females build the nest which is a cup-shaped depression in the ground. The nest is lined with pieces of lichen, leaves and moss which can occur naturally or can be added by the female. The nests are generally well hidden in a