ERS 346 Outing #3

TIME & DATE: 2019/10/14 @ 13:45
DURATION: 195 minutes
LOCATION: Bruce Trail/Crawford Lake, Halton Hills, Ontario
WEATHER: 11°C, gentle breeze (3 on Beaufort Scale), 50% cloud cover, no precipitation
HABITATS: Talus cliff (escarpment), mixed forest, meromictic lake, cedar swamp

We hiked in along the Bruce Trail entrance off of Canyon Rd, heading southeast toward Crawford Lake Conservation Area. Immediately, we were within a forested ecosystem. It was mostly mixed with Sugar Maple, White Ash, Ironwood, Black Cherry, Basswood, Paper Birch, Yellow Birch, Eastern White Pine, Eastern White Cedar, Eastern Hemlock and Red Oak. Two Northern Chipmunks scurried through the mixed forest, and I could hear two Red Squirrels up in the trees chirping at each other. Some of the ash and maple trees were covered in the silk tents of the Fall Webworm Moth. Their limbs were bare from the caterpillars.

Suddenly, the valley deepened, the forest turned damp and the ground was mucky. All around us were Eastern White Cedar, as the forest transitioned to a cedar swamp. The ground was moss covered and only Royal Ferns grew in the understorey. My mum and I checked under a couple of logs and rocks, hoping that we’d come across a salamander because we thought that this looked like perfect habitat for them – but alas, no salamanders. We could hear a couple of birds calling to each other above us, but I don’t really know what species they might have been.

We climbed up out of the valley and followed the ridgeline of the Niagara Escarpment. We paused at a lookout and I counted six Turkey Vultures soaring in the calm breeze above us. One Turkey Vulture posed for onlookers on a nearby snag. It’s likely that the topography in and around the escarpment creates a nice uplift of air that allows the vultures to scavenge easily from the air, gazing at the valley below. A sign posted next to the lookout said that Turkey Vultures can soar for as long as two hours without ever flapping their wings.

As we continued up the path toward Crawford Lake’s famous meromictic lake, I saw a couple of trees with obvious woodpecker drill holes. Some of the holes were larger – perhaps belonging to a Pileated Woodpecker; others were smaller and lower to the ground. My guess is that they perhaps belong to a Downy Woodpecker. Along the side of the path, we spotted a bird’s nest hanging low in a Basswood tree (maybe 1.5 m off the ground). The nest was small – only about the size of my palm – and iNaturalist suggests that it probably belonged to a vireo. I wondered why the nest was so low to the ground; wouldn't that make it easier to predate?

At the lake, I didn’t see anything except for a Red Squirrel. I do, however, know from previous visits to this lake that several species of fish, including Rock Bass and Sunfish species, as well as amphibians like Northern Leopard Frog inhabit the lake. These species of fish are pretty good generalists and can often be found in diverse ecological conditions. I suppose that is why they are able to survive despite the anoxic waters deeper in the lake.

Posted on October 15, 2019 09:48 PM by