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RANKIN INLET
For more than 30 years, scientists and researchers have been monitoring the population of peregrine falcons in the Rankin Inlet area. Though the effects of one man-made threat to the species' health have been on the decline, the raptors are not yet out of the woods.

Peregrine falcon eggs were coming out with soft shells in the mid 20th century after the indiscriminate use of DDT pesticides throughout the world, but now that the substance has banned, it is starting to work its way out of the food chain. - photo courtesy of Laurent Nikolaiczuk/Arctic Raptors

Now referred to as Arctic Raptors, the research project has spent every summer since 1980 on the land and waters around Rankin Inlet, putting together data. Alastair Franke has been lead researcher since 2003, and lately his team has found the falcons' latest foe to be a change in rain pattern - an adversary that comes on the heels of another that the falcons had just about beaten.

"Globally, populations declined dramatically (in the 1960s)," Franke said.

Beginning in 1980, the research project was looking at a species that took a big hit from the use of dichlorodiphenyltrichloroethane (DDT), a chemical that was used indiscriminately as a pesticide during the early 20th century, before it was banned in the U.S. and Canada in the 1970s and most other parts of the world within the next 20 years.

The chemical is toxic and has a tendency to biomagnify (growing in concentration and toxicity) up the food chain, which resulted in peregrine falcons - at the top of their food chain in the Arctic - getting a massive dose of the chemical. Eggshell thinning caused by DDT put not only peregrine falcons but many other birds of prey in danger.

Since the ban on DDT use, and with a combination of human efforts and the chemical dissipating from the food chain, the peregrine falcon population recovered, and by 1999 it was no longer considered an endangered species.

"We have tracked those organochlorines over time, and the organochlorines at the population level have declined," Franke said. "If that's the case, then you would assume and predict that there would be an increase in reproductive success. Strangely, over that same period of time that we've tracked those organochlorines, we've also tracked a decline in success."

Peregrine falcon couples were having on average 0.65 less young in 2002-2009 than in 1982-1989.

"We wondered why that was."

What the researchers have noticed in the last decade is many newborn falcons are dying because of rainfall. Of course, rainfall itself is nothing new to Rankin Inlet - and in fact precipitation levels have remained constant, Franke said - but the type of rainfall the area is different than it once was.

"There isn't really much more rain than there used to be, it just falls differently ... instead of drizzling or small patches of rain, you tend to get these big storms coming through," Franke said.

There are close to two more days each summer that receive seven millimetres of rain, on average, he said.

To prove this, the team put out nest boxes - to protect nests from rainfall - and observed that rainfall could be attributed to a third of nestling deaths, according to a study paper written up by researcher Alex Anctil. Causes included succumbing to cold as their parents fly away to escape the rain or to hunt, or to starvation if they are abandoned. Wet, downy feathers lose their insulation properties, so without external heat from their parents, the infant raptors were in a precarious situation in the rain.

"Erase from your mind the mean fox coming around to snatch an egg or snatch a chick - it happens sometimes but it's pretty limited," said field technician Laurent Nikolaiczuk. "But if you have a nest site and it happens to be the chicks just hatched today, and tomorrow it rains 16 mm, a fairly large amount ... their odds of survival just became really bad."

Though the researchers involved with Arctic raptors are not climatologists, the accepted climate data they consult predicts that with a rise in temperature, changes in precipitation such as what has been seen around Rankin Inlet would be observed. From 1980 to 2010, the average summer temperature has gone up close to two degrees, to more than 5 C from 3.5 C, according to Franke.

Climate change could be the culprit behind low survival rates of peregrine falcon young, but Franke said the population itself isn't necessarily in danger - the same amount of adults are arriving in the area every summer to couple, from the places they winter all around North America.

This project is, however, painting an interesting picture of how climate change can affect a species, especially a top predator like the peregrine falcon.

To get a better grasp on the species' condition in the Arctic, the project is expanding in the territory. With the backing of numerous sponsors, including ArcticNet, the Government of Nunavut, the Nunavut Wildlife Management Board and Baffinland Iron Mines Corporation, research is being conducted on Baffin Island and in Iglulik.

Franke said the project wouldn't have been able to come this far without the support and help from the people of Rankin Inlet.

In the second and final part of this feature, Kivalliq News will look at the project as it stands today, the implications of its data, and the niche it occupies in Rankin Inlet.

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