By Claire Eamer
In June 2004, Ducks Unlimited Canada staff flew their first survey of the wetlands at the Ddhaw Ghro Habitat Protection Area (formerly the McArthur Wildlife Sanctuary). The linked system of ponds and streams lies northeast of Pelly Crossing in the traditional territory of the Selkirk First Nation.
That spring, several hundred waterbirds, from swans to coots, had set up housekeeping in the ponds, marshes, and the surrounding forest, and were busy raising the annual crop of ducklings and chicks. The Ducks Unlimited observers counted 682 birds, representing at least 17 different species.
A few weeks later, fire struck the forest of Ddhaw Ghro, dramatically changing a busy family neighbourhood.
No one really knows what happened to the birds that were nesting in the area at the time, says Jamie Kenyon, Conservation Programs Specialist with Ducks Unlimited’s Whitehorse office. Most of them, even the ducklings, probably had a way to escape the flames. If they couldn’t fly away, they could at least swim to relative safety.
“Some of them may just have sat out in the water and watched the fire,” says Kenyon.
It would have been a spectacular sight. The fire swept through most of the valley in which the wetlands lie and through much of the surrounding area, Kenyon says. Like many forest fires, it moved so quickly that it skipped right over some patches of trees. As a result, its impact on individual ponds and streams varied.
“On a number of the ponds, it burned right to the pond edge. In some cases, fire burned the whole boundary of ponds,” says Kenyon.
Other ponds lost only part of their bordering forest, and a few ponds escaped the fire entirely, surviving as islands of trees in the midst of the burn. Five years on, those tree islands still stand out among the burnt trunks and green undergrowth of the recovering forest.
Kenyon has seen the post-fire forest of Ddhaw Ghro from a helicopter, during Ducks Unlimited’s annual counts of nesting waterbirds. The nesting surveys of the Ddhaw Ghro wetlands since the fire are providing some interesting information about the impact of forest fires on nesting waterfowl.
The bottom line is that forest fires don’t seem to bother ducks, geese, and other waterbirds much—at least, not for long.
The biggest impact was in 2005, the year after the fire. In early spring, when the waterbirds returned in search of nesting sites, the forest must have looked uninviting. The ashes of the 2004 fire still covered the ground, and the new post-fire growth had not yet appeared.
“There were a lot fewer birds in 2005 than in 2004,” says Kenyon. “Almost every species went down.”
The total count that year was 392 birds, a 43-per cent drop from the previous year. However, not every species dropped substantially. Scaup, the most plentiful birds in the wetland complex, suffered only a modest drop in numbers, from 197 to 171. And there were 43 northern shovelers, not significantly different from the 46 counted in 2004.
On the other hand, the numbers of ring-necked ducks, green-winged teal, blue-winged teal, mallards, and American wigeon were all well down.
But the next year was a different story. The numbers rebounded, with a vengeance, to a total of 887 birds. In 2007, Ducks Unlimited observers counted 871 birds, and the total shot up to 1066 birds in 2008.
The big winners are ring-necked ducks, northern shovelers, mallards (a whopping increase of 346 per cent between 2004 and 2008), American wigeon, goldeneye, and white-winged scoters.
Kenyon says a lot of the species that increased their numbers dramatically are birds that nest a fair distance from the ponds. He speculates that the fire might actually have improved nesting habitat. The willows and fireweed that spring up in the burned areas create dense ground cover and can hide a nest or a whole brood of ducklings from predators.
The annual nesting survey doesn’t provide detailed information about exactly how the birds used the wetland before the fire and how they are using it now, after the fire. Instead, it’s a series of snapshots that gives a big picture. And the big picture is generally good.
“The management implication is that waterfowl are not really an issue in fire management,” says Kenyon. The boreal forest is adapted to fire and, it seems, so are boreal waterbirds.
For more information about waterbirds in the boreal forest, go to ducks.ca or contact the Yukon office of Ducks Unlimited Canada at (867) 668-3824.
This column is co-ordinated by the Northern Research Institute at Yukon College with financial support from Environment Yukon and Yukon College. The articles are archived at www.taiga.net/yourYukon.