First breeding events of the pectoral sandpiper (Calidris melanotos) in north-east Greenland: a harbinger of breeding range expansion?

Tundra ecosystems are increasingly affected by the warming associated with climate change and the resulting poleward shift of animal and plant populations. The breeding ranges of some migratory waders nesting in the Arctic already appear to be shifting or expanding in response to the rising temperatures. The pectoral sandpiper (Calidris melanotos) is a wader whose breeding range normally extends from western Siberia to eastern Canada. However, three breeding events (involving three different females) have been documented since 2016 in north-east Greenland at two sites with long-term monitoring. These are the first records of breeding of this species in east Greenland, a region that is 1700 and 2800 km from the two nearest known breeding populations in north-east Canada and western Siberia, respectively. The three nests contained four eggs each, which were incubated normally; they did not hatch and were probably unfertilized. The origin of the birds is unknown, but these recent and repeated events, in a region where observation effort is generally limited, could indicate an ongoing expansion of the pectoral sandpiper’s breeding range in the North-east Atlantic region.