July 2nd, 2012 by

Climate change is a greatly talked about topic these days, and huge proportions of Canadian birds are feeling its impact and in serious trouble. As the ozone depletes, so do the habitats of these birds, causing a severe domino effect.

least flycatcher

Least flycatcher Photo: Seabamirum/Flickr

Since 1970, there has been a 12 percent overall drop in bird species across Canada. These shocking numbers were part of Canada’s newly released The State of Canada’s Birds, the first report of its kind for the country. Of the 460 bird species in Canada, 44 percent of them have declining populations, and 66 species have dropped so drastically that they have ended up on the endangered list. And scientists are finding it hard to pinpoint exactly what is causing these shifts in population. As Ted Cheskey, manager of bird conservation programs at Nature Canada and author of The State of Canada’s Birds, told Scientific American, “One of the concerns is … that climate change is happening so fast it’s throwing out of synchrony the food supply and cycle of migration.”

Much of the decline is largely due to loss of food supply and habitat. Some of the species in sharpest decline are grassland birds, migratory shorebirds and birds that eat insects in flight. Aerial insect feeders, like barn swallows, chimney swifts and flycatchers, have seen an overall decline of 64 percent. Part of this could be due to climate change causing many insect populations to peak earlier in the year than the birds expect. Because these insects are peaking earlier in the year, the birds are not able to feed them to their young when they are born in the spring.

When trying to cope with the warming climate, many species have shifted where they live and breed in order to stay in ideal temperatures. In turn, this shift alters their migration patterns. Birds that travel great lengths for food sources and breeding grounds are being greatly affected because they are not able to determine the status of their final destination. Species like the wood warbler suffer from the accelerated season changes because when they arrive at their destination, often, their food supply has already come and gone.

snow geese

Snow geese Photo: Glyn Lowe

There is a small silver lining to this report, though. A handful of bird species in Canada are thriving. Many waterfowl populations have found success living in wetlands like bogs and marshlands, where they have an abundance of food sources and nesting sites. Many duck and goose species have seen notable increases, like the snow goose, whose population has increased by more than 300 percent in recent years.

Knowing the effects of climate change on such a large group of birds in a specific area gives a good indication of how climate change is affecting our environment as a whole. This report brings to light the decline in bird populations, while also revealing the state of the ecosystems that the birds live in. Protecting areas where we have seen bird populations decline will also aid in protecting areas that have suffered harmful effects from climate change.