European thrushes: Time to look hard
As has been mentioned before, birders in the northeastern states and Maritime Provinces have been on alert for two European thrushes: Redwing (Turdus iliacus) and Fieldfare (Turdus pilaris). Why on high alert? An unusually frigid winter in northwestern Europe and the UK, particularly around the New Year, drove incredible numbers of these thrushes to the extreme western limits of Britain and Ireland. As Dave Brown mentions, this situation could only increase our chances of finding one of these vagrants on this side of the pond.
Here is a brief (and certainly incomplete) summary of the status of these two thrushes in the New World:
REDWING (Turdus iliacus)
The Redwing breeds from Greenland east to Siberia and winters in southern Eurasia and northern Africa. The Greenland population was supposedly just established in the 1970s, indicating current westward expansion, and this population apparently continues to grow. Redwing is increasing in North America, with most records occurring over the past 7 years. For instance, the species has been an annual winter visitor to Newfoundland over the past 5 years, sometimes with multiple birds present in a year.
Closer to here, records include:
New Brunswick – 3 (Jan 2001, Mar-Apr 2003, Nov 2004)
Nova Scotia – 1 (Nov-Dec 1989)
Pennsylvania – 1 (Feb 2005)
New York – 1 (Feb 1959)
Rhode Island – 1 (Dec 2005)
FIELDFARE (Turdus pilaris)
Fieldfares are another widespread Eurasian breeder with a small population on Greenland, but in contrast to the Redwing, the Greenland breeders are apparently declining. No worries though…the species is doing well overall. Newfoundland has seen a drop-off in records over the past decade.
Here are records closer to home:
New Brunswick - 3 (1991, Feb-Apr 1997, Jan-Mar 2001)
Nova Scotia – 1 (couldn’t find the date)
New York – 1 (Feb 1973)
Massachusetts - 1 (Apr 1986)
Compare the dates of the Redwing records to those of Fieldfare, which mimics the trend in Newfoundland (Redwing UP, Fieldfare DOWN).
As the Latin names reveal, these two birds are very closely related to American Robin (Turdus migratorius). So it is not surprising that most North American records come from Robin flocks.
I decided to post this now because, although winter’s grip will be loosening over the next several weeks, we are right in the heart of the “European thrush season.”
Here’s the month-by-month breakdown, counting the ENTIRE duration of stay:
Nov – 2
Dec – 2
Jan – 2
Feb – 5
Mar – 3
Apr – 3
And here’s the month-by-month going solely by months in which the birds were FOUND:
Nov – 2
Dec – 1
Jan – 2
Feb – 4
Mar – 1
Apr – 1
Sure it’s a small sample size, but it may be legit. Here are a couple theories: 1) Perhaps these birds (and the Robins they’re with?) continue to move south through the winter as food supplies are depleted, reaching their southernmost point during the late winter. Or, 2) The first real thaws often occur during this time (for example, avg high temp here in CT rises 6 °F through Feb after reaching a nadir in Jan)…and during this time wintering Robin flocks become more visible by feeding on open lawns and fields.
While jogging around here one evening last week I noticed several small Robin flocks heading in the same general direction. I followed them via car to a roost site on private property. This evening I got around to asking the landowner for permission to observe the roost, which he graciously granted. While I was there I estimated about 600 Robins coming into the roost. I may have undercounted, as my chosen vantage point was not optimal. While not the largest Robin roost ever recorded (not even close…), it holds potential and I’m hoping to check on that roost again later this month. I only got a good look at about half the individuals as they came in.
If you happen to run into a flock of robins, take a close look at each one to ensure there’s not a Redwing or Fieldfare hiding in plain sight amongst them.