Tuesday, November 25, 2008

Varied Thrush hits window

Dorothy MacDonald, a neighbour in nearby Burleigh Falls, heard that dreaded "thump" at her kitchen window yesterday. When she ventured out into the fresh snow she found the warm, lifeless body of a bird that was unfamiliar. Dorothy checked her field guide and correctly identified the plump, robin-like bird as a Varied Thrush. She alerted local naturalists who facilitated the deposition of the specimen at the Royal Ontario Museum.

During some winters, this species ventures east of its normal range in the Rocky Mountains.

Wells and Rosenberg (1997) analyzed data for Varied Thrush from Project Feeder Watch and noted biennial peaks in abundance of birds seen at feeders within the regular wintering range in the west. Interestingly, these peaks did not correlate with irruptions into eastern North America.

So far this fall, there have been several sightings in Ontario. Another bird was reported to have hit a window near Baptiste Lake, about 60 km north of here. Fortunately, this specimen also made it to the R.O.M.

UPDATE - May, 22, 2009 Tony Bigg offered this photo of another Varied Thrush from the Burleigh Falls area, taken on December 11, 2008.

There are a few historical records. Sadler (1983) noted a single county record of a bird photographed by Michael Dumas near Buckhorn in December of 1980. The last report of Varied Thrush in the Stony Lake area was of a pair of birds, likely a male and a female, coming to the feeder of Dawn McArthur on Hull's Road, at the east end of the lake, January 17-26, 2001. Among several local naturalists who saw at least one of the birds was Larry Boyce, who enthused:

Once again visited Nephton and this time was rewarded with great views of the male varied thrush. I was only there from 4:10 to 4:55 and the bird only showed for 10 min., from 4:20 to 4:30. The deep rich colours of the bird were especially gorgeous against the backdrop of fresh white snow. He spent only a min. or two on the ground, the rest of the time in one of the front yard trees. He did seem wary & skittish and it was my movement trying to get a bit better look that scared him away. While there a pileated flew over, the same as the other evening when I was there. Two or possibly 3 brown creepers worked the large pine that is beside the garage.

Yesterday I was up in the afternoon for a walk in the Petroglyphs with my wife. We checked the street and the yards for the thrush, both at 11:15 and at 1:00. No thrush then but we did have a great walk in the park.

We had a great opportunity to observe this species wintering in northern California in 2006. These photos showing both sexes were taken near Woodside in San Mateo County (click to greatly enlarge).
click to enlarge


Range map linked from the Cornell Laboratory of Ornithology.

Salder, D. 1983. Our Heritage of Birds: Peterborough County in the Kawartha Lakes. Orchid Press. Peterborough, Ontario.

Wells J. V. and Rosenberg K.V. 1997. The Rise and Fall of the Varied Thrush. Birdscope, Spring 1996, Volume 10, Number 2: 1-2.


jvooz@yahoo.com said...

For a good overview and some hypotheses on why the Varied Thrush may occur outside of its "normal" range I would highly recommend reading;

Keith AR. 1968. A summary of the extralimital records of the Varied Thrush, 1848 to 1966. The Journal of Bird-Banding, 39: 245-276.

It's a good read.

Anonymous said...

We have been seeing a female varied thrush at our feeder in Mason County, Michigan for the last 2-3 weeks. I'm a novice birder, and contacted an experienced birder to confirm. Looks just like the bird we've seen.