Of Birds, Cats and the Urban Landscape

by Don Scallen –

There are ten species of birds that commonly nest in suburban Georgetown: Mourning Dove, Black-capped Chickadee, House Wren, American Robin, European Starling, Northern Cardinal, House Finch, Chipping Sparrow, Common Grackle and Brown-headed Cowbird – a nest parasite.

One other, less common nesting species is the Chimney Swift, relying on the specialized nesting habitat of uncapped chimneys.
I have observed another three species nesting one time in suburban Georgetown: American Crow, Tree Swallow and Baltimore Oriole. Blue Jays and Red-winged Blackbirds are probably occasional nesters as well.

I can write about this with some authority, because I’ve been a resident of suburban Georgetown most of my life. I realize that homeowners fortunate enough to live along Silver Creek ravine may entertain other nesting species on their properties. Kerry Jarvis and Melitta Smole, former HNPNC members, attracted Great-crested Flycatchers and Screech Owls to bird boxes on their ravine lot for example. Downtown Georgetown, with its mature tree canopy, may also provide habitat for a few other species.

Regardless, town and city-scapes have a very low diversity of nesting birds. This contrasts with the higher diversity found in natural areas surrounding those urban centres. Consider the results of the second Atlas of the Breeding Birds of Ontario (2001-2005.) The atlas project divided Southern Ontario into “squares” measuring ten by ten kilometres. The “square” that held most of Georgetown also contains forest, wetland, fields and agricultural land. This “square” harboured 60 species of confirmed breeding birds, six times greater than the number nesting commonly in Georgetown’s urban area. Evidence gathered – primarily by club veteran Ray Blower – also identified 35 additional species as probable breeders and 17 as possible breeders.

Some specific comparisons of various categories of breeding birds between the atlas square and urban Georgetown are instructive.

Category Number of breeding species in atlas square Number of breeding species in Georgetown urban area
Warblers 8 confirmed, (8 others possible or probable) 0
Sparrows 5 confirmed, (5 others possible or probable) 1
Swallows 5 confirmed 1 rarely
Woodpeckers 5 confirmed 0

 

This low diversity of nesting birds in Georgetown applies almost certainly to other urban areas throughout the province. The urban landscape is simply not suitable for most birds. Birds avoid nesting in our towns and cities because of our roads and how we landscape our parks and yards. We remain wedded to our lawns. (I’m guilty – my front yard is still largely cropped grass.) Our yards lack the cover, the plant diversity, the water, the insects, which birds need to survive. As housing density increases, and it will, the situation will become even bleaker.

Some may invoke free-roaming cats to help explain the lack of bird diversity in urban areas. After all, studies have found that cats kill billions of birds (and small mammals) annually. While cats are almost certainly a major problem in rural areas where they can gain access to fields and woodlands, they shouldn’t be blamed for the low diversity of birds and mammals in urban settings. I suspect that if, miraculously, all of Georgetown’s cats were kept indoors starting today, the town’s diversity of birds would change little. The same ten species would continue their residence; the rest would continue to keep their distance.

Homeowners, both urban and rural, need to be more humble. It is disingenuous to condemn cat owners for letting their pets roam, while we habitually fire up the lawn mower for another diversity-reducing shearing of our grass. This applies to suburbia, but also to the ridiculous swaths of turf that surround rural estates. Yes cats are killers, but those that roam urban environments have little impact on an environment already severely compromised by us.

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