Migration Update-May 9,2009

sunset
Returning from the field on Kingsford Lake

I’ve been slowly transitioning from the office to the field since May began, which has been a welcome change. The image above was taken during a recent boat trip to one of various field sites in the area. Our modest watercraft will be used extensively throughout the summer to access key sites along the western edge of Frontenac Provincial Park via Kingsford and Birch Lakes. Powered by an electric motor, our fiberglass vessel is appropriate for us in being environmentally sound and quiet, although perhaps a little lacking in the speed department!

The migration census scheduled for the 8th was postponed by a day and conducted instead on Saturday, May 9th. At the first step of the survey it was obvious that birds were plentiful, many of which were newly arrived to the area. I decided it might be instructive to examine habitat associations of migrants along Canoe Lake Road. The normal census route (CLR1) travels south along the narrow graveled road for 1.2 kilometers through a varied mix of habitats, which includes mixed-age deciduous forest stands, meadow and various successional habitats along edges. Cottage residences and farm fields create a more open landscape along the length of the route. Conversely, traveling north from the start point passes through a much less open environment with predominantly mature deciduous forest with fewer clearings and edge components. Yesterday morning, upon completion of CLR1, I returned to the start point and conducted a survey with the same methodology but this time in the opposite direction through the mature forests (CLR2).

Results

A total of 38 species were recorded along CLR1, which included seasons firsts of Barn Swallow, Barred Owl, Bobolink and a striking Cerulean Warbler during the final minute. A pair of Yellow-throated Vireos in a hedgerow near the large meadow was a treat along with first records of Wood Thrush and Ruby-throated Hummingbird for the spring surveys. A season high of six Ovenbirds was also a highlight of the survey. Upon return to the start point, I flipped to a new page of my field notes and began an independent survey of birds along the length of CLR2 (1km). There were some notable contrasts, the most apparent of which was the tally of 19 Ovenbirds, a substantial increase in density compared results for CLR1! A total of 40 species were recorded, consisting of thirteen not recorded at all on CLR1. Scarlet Tanager, Black-and-white Warbler, Great Crested Flycatcher and the aforementioned Ovenbirds were substantially more common in the mature, less fragmented habitats of CLR2. Results in the table below are likely reflective of species-specific preferences of habitat size, type, structure and continuity.

The stopover ecology of various species is a growing subject of study for scientists and for good reason. Migratory bird populations are dependent on the availability of viable habitats for rest and refueling. Without these “stopover sites”, most migratory bird species would fail to reproduce each summer. Relatively little is known about the characteristics and function of the Frontenac Arch as a stopover area for migrating birds. Simultaneous surveys of migrants in divergent habitat types on a regular basis in both the spring and fall would be an instructive first step toward a basic description of landbird migration in the region.

table

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s