Thistle Birds!

Oct 04, 2012

By Steve Blight

The American Goldfinch is probably our best-known member of the finch family. Found in our area in all seasons, its “per-chick-o-ree” flight song and undulating flight pattern are good ways to identify this diminutive seed-eating bird. Known by some as wild canaries or thistle birds, they are found throughout much of North America – from the Atlantic to the Pacific and from Mexico all the way north into the southern boreal forest.

Goldfinches are well adapted to human-modified habitat. Their preference for weedy fields, hedgerows and shrubby areas fits perfectly with the settled areas found throughout much of Ontario south of the boreal forest. In the Kingston region, goldfinches have been identified as the 12th most common breeding bird. No significant population increases or decreases have been observed in southern Ontario, but significant increases in goldfinch numbers have been seen in more northerly areas. Overall in Ontario the goldfinch population has been estimated at about 4 million birds!

Goldfinches are considered to have the most seasonally and sexually varied plumage of all the finches. This trait is known as “dimorphism” – the males are brilliant lemon yellow and black during the breeding season, with the females a variable but duller yellow all year round. By late fall the males have lost their bright colours and much more closely resemble the female.

Goldfinches have a couple of breeding characteristics that set them apart from almost all other local birds. First, they are strictly vegetarian. Most birds take in some insect or other animal food at some point in their life cycles, but not the goldfinch. They rely strictly on seeds throughout the year, enjoying those produced by thistles and other similar plants. They are easily attracted to feeders in winter where they will happily take sunflower or nyger seeds.

Their reliance on seeds may have led to the second interesting difference. Unlike so many birds that nest in the spring, goldfinches begin the business of nesting surprisingly late – towards the end of June, with egg laying taking place in July. This timing works out well as the young begin needing large quantities of food at about the time when their favourite food plants are producing seed. In fact active nesting can go as late as into September.

Goldfinch migration is tricky to fully understand. Large flocks of goldfinches have been observed migrating through banding stations in both spring and fall, yet there is always plenty of goldfinch activity left behind throughout the winter. Where the migrants and winter residents originate from is not well known.

Nests are constructed from plant materials and lined with plant down, often from thistles. No wonder they are known as thistle birds – they rely on these coarse but plentiful plants in so many ways. Built by the female alone, the nests are usually found in the terminal forks of small deciduous trees or shrubs such as hawthorns, dogwoods or serviceberries.

Soon it will be time to clean up your feeders and stock them with seeds for the winter. Time to get ready to welcome the thistle birds!

Please feel free to report any observations to Lorraine Julien at This email address is being protected from spambots. You need JavaScript enabled to view it.  or Steve Blight at This email address is being protected from spambots. You need JavaScript enabled to view it.