Excess rain in the Arctic has been deadly for adolescent Canadian peregrine falcons.
The rain is believed to have been brought on by climate change, and may be posing as much of a threat to the birds as the chemical DDT did before it was banned, a University of Alberta news release reported.
University researcher Alastair Franke and Alexandre Anctil of the Université du Québec believe they have found "unequivocal evidence" the rain is responsible for the mass bird kill.
The rain is believed to interfere with the falcons' reproductive success. The team looked at breeding records dating back to the 1980s. They also monitored falcon nests using motion-sensitive cameras. The cameras showed one third of the nestling deaths could be attributed to rain.
"The nestlings died from hypothermia and in some cases from drowning in their flooded nests. Without constant parental care, they are most vulnerable to cold and wet conditions in the first three weeks of life," Franke said.
The population of peregrine falcons in Canada have been steadily declining over the past 30 years.
"We knew DDT was no longer an issue and based on field observations, we wondered whether changes in climate were responsible for high mortality in recent years," Franke said.
Starvation was shown to be another factor in the birds' deaths.
"We were surprised to find that a considerable number of chicks raised in nest boxes later died of starvation despite having been spared from the direct effects of rain" Franke said.
The team believes rain could be making the birds' prey scarce.
"[The study has] improved our understanding of the direct effects of long-term changes in weather patterns and have identified the potential importance of indirect effects," Franke said.
The study highlights how big of an effect even small environmental changes can have on the ecosystem.
