Common grackle - nicotinoids are rapidly killing these birds.

Main:  Common grackle (male), Airdrie, Alberta.  Inset:  Great-tailed grackle, Arizona

While visiting Alberta this summer, I came across some common grackles.  They look similar to Brewer's blackbirds initially, but closer inspection shows that they are both larger and more colourful than them.  They belong to the same family (Icteridae) as their smaller cousins.  There are three species of grackle that live in North America: the common grackle (main), the great-tailed grackle (inset), and the boat-tailed grackle.  Only the common one can be found in Canada, and they are only found east of the Rockies.

The male grackle's breeding plumage is striking, with its bronzed-iridescent body feathers and deep blue/purple head.  The female, as is the case for all female Icteridae, is a mottled brown designed to prevent unwanted attention.  Unlike the male, the female does not have the bright yellow eyes.

Grackles are the number 1 pest of corn crops in the US.  They eat the seed, the sprout, and the cob on a mature plant.  They will tear at the encasement and peck at the available nibs of corn.  While they may not consume the whole ear, they render it unfit for harvest.  They can number in the thousands and cause enormous financial impacts to affected farms.

Common grackles are in "rapid decline", meaning that their numbers are falling quickly.  It is estimated that their population has been reduced by over 50% since 1970.  There are multiple reasons for this, but the use of nicotinoids as insecticides is perhaps foremost.  The chemicals are sprayed on corn seed or crops; infected insects are eaten, and the bird may die or become ill.  Also, since insect populations decline, food availability is reduced.

A single seed coated with nicotinoid may kill a small songbird or harm a larger bird.  Harm includes reduced breeding success, migration delays, and weight loss.  The half-life of these chemicals is 1000 days; it takes 3 years for nearly half of the sprayed chemical to break down.  The chemicals do not bioaccumulate, but exposure often results in immediate toxic effects.

The use of nicotinoids has had a deleterious effect on bee populations.  Not only are we killing many bird species, we are killing the very insects necessary for crop pollination.  We are, in fact, killing ourselves, albeit slowly.  But that's not news to anyone; we have been doing it for years.

Thanks for reading.

Eric Svendsen     www.ericspix.com