Thursday, 17 October 2013

Redwing Passage: 10 October 2013


I saw my first Redwing Turdus iliacus of the autumn on 7 October when 20 flew west over Henlow. The following few days were mild, at times warm, sunny, clear and calm; no further Redwings were seen or heard. Then the weather changed overnight and the Indian summer gave way to a cold blast from the north.

A few Redwings were noted flying over the school as I headed out on my usual walk around the fields north and east of Henlow Grange. In contrast to previous days, there was much less bird activity in the cold, blowy conditions and I had only a few Blackbirds and a couple of Mistle Thrush sightings to add to the BTO Winter Thrush Survey. Skylarks were more in evidence than recently with each stubble field seeming to hold a small flock, some numbering more than 40 birds but no Redwings were noted east of the River Ivel.

As I returned to Henlow, a flock of 103 Redwing flew over, heading west. At the time I thought they had probably come out of a roost in trees alongside the river. Continuing homewards along the drive to Henlow Grange more and more flocks of Redwing, each flock numbering between 50 and 150 birds, flew over, all heading west. In the twenty minutes it took me to walk home (from 09:00 – 09:20) more than 2000 must have passed by, all heading west at about tree top height.

Since December 2011, I have worked from home, converting one of the bedrooms into an office. This was quickly dubbed the Little Back Bedroom Bird Observatory by Jenny, my wife, who reckoned I spent more time looking out of the window than at the computer screen. On 10 October, she would have been right! By the time I had got a cup of coffee and checked my emails it was 09:50 and flocks of Redwings were still going over.

In the next hour (09:50 – 10:50), I counted 42 flocks of Redwings totalling 1447 birds flying west, roughly along the line of Coach Road, Henlow, at or just above roof top height. There were none high in the clear sky when I scanned with binoculars. Redwings were not constantly in view, flocks seemed to come through in pulses with two or three flocks in a minute followed by a lull. The longest period without any Redwings was 4-minutes. Flock size ranged from one singleton up to c.150 with most between 10 and 40 birds and an average flock size of 34 birds.

After a 30 minute break, I had to do some work, I returned to counting at 11:20 by which time the Redwing passage was much lighter. In the hour to 12:20 I only counted 9 flocks totalling c.200 birds. These seemed to track a bit further north-west than the earlier birds, flying across the Pyghtles rather than along the line of Coach Road. By 12:45 the movement seemed to have petered out and I recorded no further flocks of Redwing during the rest of the day.

Few other species seemed to be involved in the movement. Two flocks of Skylarks were noted, one passing directly over our garden at window height. The local finch flock, Goldfinches, Greenfinches and Chaffinches would often fly up and join a passing flock of Redwings, so it was difficult to determine if any finches noted were part of the passage.

Given the restricted view from my window, overlooking the backs of the houses along Coach Road and between the houses to the Pyghtles playing fields beyond, some of flocks passing over would only have been partially counted; anything flying directly over our house or to the south would have been missed. So, although these figures are undoubtedly underestimates for the number of Redwings moving over Henlow, they do give a snapshot of one of the most exciting migration movements I have ever witnessed.

And then came news from the vismiggers at the Pinnacle, Sandy where they counted 33082 Redwings in just under 5-hours watching!
Originally published in The Hobby 130:6


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