07/27/2012 07:11 EDT | Updated 09/26/2012 05:12 EDT

Ottawa wildlife feeling heat from dry summer

The dry summer has put stress on a wide range of native wildlife in the Ottawa region, from warblers and fish to beavers and bears, according to wildlife observers.

Along the Rideau River, the signs are visible in yellowed trees and low water levels. But Carleton University biologist Michael Runtz said the signs are all around.

"Many plants are dying. The lack of water has had an incredible effect," he said.

While smaller plants are struggling to survive the drought, trees are simply shedding their leaves early to conserve water, Runtz said.

But the impact on the food web can still be felt, as insect grubs and caterpillars that depend on the plants suffer.

"Those insects formed a big part of the diet of certain birds. And even in the forest, birds … like vireos and warblers … glean caterpillars off leaves. Well if those leaves are dried up and the caterpillars can't sustain themselves, there's less food for those birds," said Runtz.

Runtz also said the low rainfall will affect berry and nut crops, putting a strain on animals such as chipmunks and bears, who will need to travel further afield to obtain the food they need.

Lower water levels

Low water levels and higher water temperatures also leads to an increase in algae blooms, which puts a stress on fish in the rivers and streams.

Christie Spence, head of lands management for the NCC, said low water levels are also affecting the beavers in Gatineau Park. Beavers need high water levels where they build their lodges to ensure the lake or stream does not freeze all the way to the bottom in the winter where they have built tunnels out of the lodge. If water levels get too low, they'll abandon their homes, said Spence.

"Probably about 50 per cent of our resident population have left the park, and they'll go to the rivers and typically come back in the fall when it's moist again … assuming it is moist in the fall," she said.

Runtz and Spence said if the dry summer is simply seasonal variation, the region's wildlife should bounce back. But if it's a sign of long-term changes urged on by global shifts in climate, then big changes could be coming for many of these animals.