Working at four sites that ranged from the oilfields of Prudhoe Bay to the remote National Petroleum Reserve of western Arctic Alaska over a period of nine years, a team led by Joe Liebezeit of the Wildlife Conservation Society looked in nearly 2,500 nests of four species of shorebird and one species of songbird, and recorded when the first eggs were laid in each nest. They also measured the amount of snowmelt in the nesting plots at different intervals in the early spring.
The results indicated that the birds advanced their nesting an average of between four and seven days over the study period, which was similar to the general observation of 0.5 days per year that has been recorded in the few other studies of nest initiation in the Arctic. They also suggested that the timing of nest initiation was more tightly linked to snowmelt than to other variables such as nest predator abundance and the seasonal flush of new plant growth.
‘It seems clear that the timing of the snowmelt in Arctic Alaska is the most important mechanism driving the earlier and earlier breeding dates we observed in the Arctic,’ said Liebezeit. ‘The rates of advancement in earlier breeding are higher in Arctic birds than in other temperate bird species, and this accords with the fact that the Arctic climate is changing at twice the rate.’
This story was published in the August 2014 edition of Geographical Magazine