McGILL BIRD OBSERVATORY

WINTER POPULATION MONITORING

2005-2006 SEASON SUMMARY

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  OCT/NOV DEC JAN FEB MAR TOTAL
Number of days falling within winter season 31 31 31 28 27 148
Number of days of observation 14 14 15 12 12 67
Number of banding sessions 5 2 5 2 4 18
Number of birds (and species) banded 133 (11) 40 (4) 82 (12) 24 (7) 37 (9) 316 (18)
Number of birds (and species) repeat 66 (5) 32 (3) 52 (5) 12 (2) 28 (4) 190 (7)
Number of birds (and species) return 3 (2) 3 (1) 9 (4) 5 (4) 7 (2) 27 (5)
Number of species observed 38 30 26 21 31 52
Number of net hours 51.5 15.0 42.0 23.0 32.0 163.5
Number of birds banded per 100 net hours 258.3 266.7 195.2 104.3 115.6 193.3

Winter population monitoring at McGill Bird Observatory spans the 21 weeks (plus one day!) between the fall and spring migration monitoring seasons, and is considerably less structured than the programs run at those times.  Few bird observatories at this latitude operate through winter, so MBO has the potential to generate some interesting data on the winter distribution of birds.  However, the weather does tend to be rather limiting, so banding activities generally take place whenever conditions are favourable.

This was an exceptionally mild winter in Montreal, but with the warmer temperatures also came an unusual amount of rain.  As a result, we still ended up banding on average once every 8 days.  However, this is an increase over last winter, and not surprisingly all of the banding totals are higher as well.  The 27 returns (individuals last recorded over 3 months earlier) are a particularly interesting result.  The majority of these were Black-capped Chickadees, some from the previous winter, and others that were banded during migration or in summer, but have evidently stayed in the general area.  However, we also recaptured a Northern Cardinal, a House Sparrow, and a Slate-coloured Junco, each of which had been banded last winter, and not recaptured since.  While we can't prove that they were not here during the intervening period, at least we have evidence that some individuals appear to habitually winter at MBO.

The number of birds banded peaked within the first month of the season.  This is to be expected - not only were there still a few late fall migrants included in the November totals, but also a large flock of American Goldfinches was present then, which dissipated over the course of the winter.  Also, many of the birds present throughout the winter were banded in the early weeks, and showed up again later as repeats instead.  That we were still able to band dozens of 'new' birds in February and March is actually an interesting reflection on the amount of turnover that occurs here throughout the winter.  Just adding up the birds banded this winter with recaptures banded here in previous seasons, we know that over 400 birds used our feeders this winter.  If we factor in that for some species (e.g. Common Redpoll, Mourning Dove, House Sparrow) we only banded a small fraction of the flocks that we observed over time, the number could easily be increased to 600 at the very least.  Thank you to Wildlifers in Baie D'Urfe for supplying the seed to keep all those little stomachs full throughout the winter, and to Shawn Craik for doing the lion's share of stocking of the feeders.

In addition to the many repeats and the overall increase in numbers compared to winter 2004/05, highlights of the season included:

  • Over 40 Common Redpolls, a big increase over the single individual banded last winter

  • An overwintering Rusty Blackbird, which became only our second of the species banded

  • MBO's first sightings of Rough-legged Hawk, Golden Eagle, Horned Lark and Hoary Redpoll

  • MBO's first banding of Pine Siskins

Thanks to all the volunteers who helped out with the winter program.  Enjoyable and productive as it was, we are all looking forward to the return of spring migrants!

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2002- The Migration Research Foundation Inc.