Although forest fires can be disastrous, they are beneficial more often than not. Forests need to burn every now and then to survive; otherwise, the trees’ reproduction rates decrease. This is because a thick litter composed of leaves and other vegetation builds up on the forest floor, preventing seeds from germinating. Meanwhile, the large trees become larger, creating a thick canopy that blocks out the light. Fires help by thinning the forest, which opens up the canopy and allows sunlight to reach the forest floor. It also reduces the litter which, if allowed to build up over decades, provides fuel for larger, more destructive fires, and recycles the nutrients from dead wood and leaf litter into mineral-rich ash. This is why many places, including Yosemite National Park and all of Canada’s National Parks, use controlled fires to burn away the excess debris on the forest floor. Fire aids in regeneration by providing ideal growing conditions.
Forest fires are beneficial to animals, too, by providing a new source of food. The new growth that develops after the fire provides food for moose and deer. Wood-boring beetles are quick to colonize newly burned trees, and these bring woodpeckers which feed on the larvae beneath the bark. The Black-backed Woodpecker is one woodpecker that specializes in the larvae of beetles which proliferate in newly burned areas.
When I heard that a Black-backed Woodpecker had been seen in the burned area of Stony Swamp this fall I wasn’t surprised; however, I was surprised that it had moved in so quickly after the fire. I figured it would take at least a year before any beetle colony became large enough to attract the attention of these uncommon boreal birds, and planned to check out the area in the spring. That plan changed when I saw the report, and I headed there on what turned out to be the last nice day of the season.
I accessed the area via the Lime Kiln Trail, which runs in a straight line between Richmond Road and Moodie Drive. I had only visited it once, and was disappointed by how unproductive it was for birds; the first section of the trail (about 0.5 kilometres in length) passes through a thin section of wood surrounded on each side by a large marsh. The woods here aren’t thick enough to attract forest-loving birds such as Wood Thrushes, Pileated Woodpeckers, or Ovenbirds, but are just thick enough to prevent a satisfying view of the marsh beyond. A couple of chickadees were looking for handouts, and a handsome Fox Sparrow was foraging for fallen seed on the trail.
At the end of the marsh, the path enters the larger forest after crossing a small boardwalk. I saw what looked like three small beech trees in a large open area and stopped to photograph their golden yellow leaves (if I’m wrong in my identification of these leaves, please feel free to correct me).
I found the ruins of the old lime kiln in an area dominated by cedars. Built by Francis Flood in the late 1800s on a miniature escarpment of exposed limestone bedrock, this kiln is one of the few remaining examples of a 19th century industrial lime kiln in Canada. Most lime producers went out of business in the early 1900s following the construction of newer and larger industrial kilns and the introduction of Portland cement from Europe. The Flood kiln ceased operation around 1906, and the site was abandoned and fell into disrepair. The ruins of the kiln were rediscovered in the early 1970s; the site was restored in 1999.
Just past the ruins I came across a chain blocking the trail and signs warning of unsafe conditions. It was not difficult to slip around it, and into the woods beyond. At first I couldn’t see any signs a large fire had roared through the area. Then, a few metres further, I stepped out of the forest and into a strange, blackened, barren landscape as alien as the moon itself. A few black, spindly tree trunks still stood while others lay at crazy angles. The ground itself seemed burnt, and I saw large numbers of small rocks that had cracked and broken from the heat of the fire. The whole area smelled faintly of a long-extinguished campfire, and I had to be careful not to brush up against any of the charred wood for fear of getting ashes on my clothes.
It was not an entirely dead world. A few green ferns had already taken root in the burnt area, as had a few other plants I couldn’t identify; though small, there were enough of them to make me realize the charred landscape would not remain black for very long.
Several insects buzzed by me, including a couple of Autumn Meadowhawks taking advantage of the warm fall day (it was 23°C). Birds flew by overhead, including three White-winged Crossbills which landed in the top of a tall spruce tree long enough for me to see their streaky yellow and red colouration and white wing-bars. (They were too far away to see the crossed mandibles.) I also heard a Pine Siskin as it flew over the burn site.
There were woodpeckers, too, of course. These were the only birds within the actual burn site, though I heard a Brown Creeper calling somewhere close by. Whenever I heard something tapping, I followed the sound to its source; usually the culprit was a Hairy Woodpecker working away at a dead tree. There were at least four of them in the burn site, along with a single Downy Woodpecker. Then I saw a bird fly out from a group of cedars. It landed on a trunk about five feet off the ground and had a solid black back, identifying it as a Black-backed Woodpecker.
It was a female, as evidenced by the solid black cap; males have a yellow patch on the forehead. She also had black and white barring on her sides and flanks, which helps distinguish this species from all other woodpeckers in our area except for the American Three-toed Woodpecker. Also like the American Three-toed Woodpecker, the Black-backed Woodpecker has three rather than four toes on each foot. These two species have lost inner rear toe (the hallux), which may help deliver stronger blows, but reduces these woodpeckers’ climbing ability.
The solid black back of this bird provides camouflage in its preferred habitat of recently burned areas; these woodpeckers disappear against the blackened wood of a burned tree. Even the barring along their sides resembles the pattern of burnt wood.
While Black-backed Woodpeckers may feed on spiders, centipedes, some fruits and seeds, and parts of the inner bark of trees on occasion, their preferred food is the long, white, larvae of the White-Spotted Sawyer (Monochamus scutellatus). When a forest fire breaks out, the distressed conifers release terpineol vapors into the air. Terpineol is a naturally-occurring alcohol that is found in pine oil and attracts White-spotted Sawyers searching for distressed trees in which to lay their eggs. The eggs are laid beneath the bark and, after hatching, the grub-like larvae spend two years feeding on the wood inside the dead tree.
The Black-backed Woodpeckers are able to detect recently burned areas from great distances. They prefer forests where most of the standing dead trees are nine inches in diameter or larger and still have bark. The woodpeckers usually stay for only two to three years after a fire. If the supply of dead trees and beetles is large enough, these woodpeckers may mate and raise another generation. While raising a family, a Black-backed Woodpecker may consume over 13,000 larvae in a year. These woodpeckers typically forage on the trunks of dead trees, on larger tree limbs and on fallen timber. They typically obtain food by stripping pieces of bark from the tree, but may also peck or glean insects from tree trunks, or make deep excavations into wood. It is thought that the Black-backed woodpecker is better adapted than other Picoides species at extracting wood-boring beetle larvae.
The female Black-backed Woodpecker hitched her way up the tree as I watched, tapping as she went. When she tired of working on that tree, she flew down and landed low on another tree close by. Shortly after that a Hairy Woodpecker flew in and landed on the same tree, making agitated squeaking noises. The Hairy Woodpecker began moving up the tree trunk toward the Black-backed Woodpecker, causing the Black-backed Woodpecker to flee. She landed on a nice horizontal trunk only about five feet above the ground, and I thought this would make for some stellar photography until a moment later the Hairy Woodpecker flew in and landed on the same trunk, repeating the process. Hairy Woodpeckers have been observed displacing Black-backed Woodpeckers from foraging sites in burned areas, which supports the belief that Black-backed Woodpeckers may compete with other Picoides woodpeckers for food resources after a forest fire. Eventually the Black-backed Woodpecker flew off to a stand of much taller trees, where I lost her against the black bark some 20 feet above the ground.
This was only the second time I’ve seen a Black-backed Woodpecker in Ottawa, and the sighting made my day. I’ll have to keep an eye on this site and see how long she stays. Hopefully the NCC won’t move in and begin removing all the burned trees in order to get the trail open again.