sparrow

A Lesson in Careful Tree-Cutting

When Canadian biologist Chris Fisher drove through Banff, Jasper, Mount Revelstoke and Glacier national parks in May, he noticed that many trees were being cut down along the highways for various park projects. May is prime nesting season, so he wondered how the park service was managing not to disturb birds. After all, the Migratory Birds Convention Act prohibits killing, capturing, taking and disturbing of migratory birds or their nests from late April until mid-August. Wouldn't you be curious too?

Michael den Otter, an environmental assessment specialist with Banff, Yoho and Kootenay, confirms that safety upgrades, fence maintenance, and other infrastructure improvements are indeed requiring the cutting of trees along the highways, but he says that all the national parks are following the standards. “Most of the trees you see beside the highway were actually cut before the end of April. We try whenever possible to schedule our work so we’re not going into that bird breeding season.”

Sometimes it isn’t possible to schedule work so it doesn't interfere with nesting season, for instance in places where snow doesn't melt until quite late. In those places, there's a set of rules to follow that includes extensive nest sweeps. Biologists search for nests for three days during the week before cutting is scheduled. den Otter says, “If we find any sign of nesting birds, then that project will have to either mitigate that or it will have to be put on hold until whatever happens to be nesting there moves on.”

For example, a recent sweep found a dark-eyed junco along the Trans-Canada Highway during some tree removal in Yoho National Park. den Otter says, “We put a 100-meter buffer around that nest area and we’ll have to wait to complete that work in the fall when the bird fledges." A 100-meter buffer is higher than the standard, so it sounds like these folks are serious.

den Otter says the crews haven’t encountered many nesting birds in the areas along the highways where the work is being done. After all, it's a pretty noisy and disturbed area, not the deep, dense, old-growth forest that many birds really like. Still, dark-eyed juncos and white-crowned sparrows do prefer these edge habitats, and they are plentiful—and being allowed to do their thing while the projects wait. 

Fisher, the biologist, states that Environment Canada suggests not performing any nest sweeps in forested environments. “It’s their position that the likelihood of finding every single nest or the complexity of the habitat really makes it difficult to find all of the nests." He'd prefer that the national parks not even try to remove trees until after nesting season. 

Citizen Science with House Sparrow Eggs

House Sparrows (passer domesticus). Some of us enjoy their resilience, cheerful presence, and ubiquitous "Cheep!" Some of us can't stand seeing them everywhere, including in the nesting boxes we've set out for bluebirds. Love them or hate them, the fact is that they are an invasive species, brought here from England in the mid-19th century and thriving ever since in populated areas—often at the expense of other songbirds. 

A new citizen science project is now making use of House Sparrow eggs in ways that should satisfy both friend and foe.  The Sparrow Swap, out of the North Carolina Museum of Natural Sciences, asks volunteers for House Sparrow eggs to test for pollutants. The aim is to discover whether these birds, often regarded as pests, can help us monitor our environment. Meanwhile, taking eggs from nests provides another research opportunity, namely population control. Participants are given fake eggs to swap for real ones in hopes that the nesting sparrows will try to hatch them rather than build a new nest when they discover their original clutch has vanished. If this protocol works, it will provide the basis for an environmentally safe way to reduce the number of House Sparrows. 

Want to know more or participate? Look for "The Sparrow Swap" on Facebook or check out this website.