Saturday , October 23 2021

They are gregarious and quarrelsome … and they come back!


They are back! Well, in some places.

Night grosbeaks are rather reigning in appearance and when they hit your eating station, you pay attention to them. Making love and quarreling, a flock of these birds can provide an entertaining spectacle as they compete for perch and who can take the most sunflower seeds.

This is a species that has what bird watchers call "winter disruption," in a few years these brightly colored birds don't exist and in other years you can go to the edge of bankruptcy to buy sunflower seeds for them. And when night grosbeak appears, often they are together their cousins, grosbeak pine and a handful of smaller finch species.

In the mid-1960s, our first backyard feeder in Orillia attracted these birds, along with several blue jays and chickadees. I am 10 years old and after seeing these brightly colored birds on the other side of the kitchen window, I was fixated on bird watching.

Over the years there was the arrival of the night grosbeak which became the winter spotlight.

However, in 30 years these birds began to become scarce, with some winters that did not have one grosbeak anywhere in southern Ontario. What's with that? This is an example of scientific curiosity for many people, and answers to setbacks are troubling.

But first, a little background of this bright yellow bird.

Evening grosbeaks were originally western birds with the Colorado River Basin being their home base. In the early 1800s there were records of these birds in high numbers which were inside cypress and pine in the region. For reasons unknown they then began to expand eastward from their range.

According to Birds of Simcoe County The book compiled by OE Devitt, the first local record of grosbeak night is in Barrie on May 24, 1886. In 1890 they have become a common sight, with the year being recorded as "the winter from a great invasion to southern Ontario and the New England state."

One factor that is thought to be behind this arrival is the simultaneous introduction of new tree species from the Red River Valley, Manitoba maple.

There are actually two species of night grosbeak trees closely related to the Manitoba maple for the supply of winter seeds, and the black evergreen northern Ontario for the summer nesting area. And herein lies some of the answers to this fluctuating bird population.

From 1940 to the 1970s, an insect called a spruce budworm was rampant in northern Ontario, and these protein-rich insects feed a lot of grosbeaks at night.

Beginning in the 1980s the forestry industry began an extensive air spray program to control this tree borer insect, and it worked well. Not only is the pine flower worm thrown back, so are all the other forest insects. There is no food for grosbeaks which means that very few young birds survive.

When the population was 1968 compared to the 2015 population, there was a 97% decrease! Along with loss of food comes a number of diseases targeted at sparrow, and the spread of salmonella, West Nile, and purple fin eye disease take the victims of weak birds.

But a small population of night grosbeaks survives, and when fir roundworms recover in a 40-year cycle, there are now enough birds to be recorded again in our winter bird feeders.

However, in August 2018 (ahh … August … warm weather, sunshine … oops, I digress) the Ontario Ministry of Natural Resources and Forestry added grosbeak nights to the famous Species At Risk, and listed them as Special Attention because the population is very low.

When the effects of climate change enter, one of the tree species that shows that it cannot maintain its current status is pine trees. If pine trees die or shift their growth ranges, insects that eat them will be affected and birds that eat insects will be affected and the diversity of winter birds in Ontario will be affected. So maybe you don't need to buy so many bird seeds. Hmm … that's not a good thing.

If you're lucky this winter to see evening grosbeaks, or pine grosbeaks, consider a bigger picture. These birds are literally "canaries in coal mines"; if they have to struggle to survive, maybe our fate is not too far behind.

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