Tuesday, January 6, 2009

Dearborn CBC

RRBO has been coordinating the Dearborn portion of the Detroit River Christmas Bird Count (CBC) since 1995. The count is held each year on New Year's Day. This year, the 53 species found in Dearborn on count day tied our previous high total. A Wood Duck at the Ford Rouge Plant was a new species for the Dearborn portion of this count. The big news this winter has been the push of White-winged Crossbills into our region. Unfortunately, none were found on count day, but they were found in several locations in the days following the count, so they are added as "count week" birds. This is also a new species, bringing the cumulative species total to 85. Here's a photo of a male crossbill taken by my husband Darrin O'Brien in our east Dearborn back yard on 3 Jan. We were lucky enough to have a flock of 26 crossbills, and a few Pine Siskins, visit the spruce trees.

One of the annual challenges is counting the hoards of birds that hang out at the nine or so sunflower/wildflower fields planted by Ford Motor Company around Dearborn. After trying several strategies, we now devote a single team (usually Darrin and I) to spend most of the day concentrating on getting accurate counts of birds in the fields. This helps prevent double-counting if the birds move from field to field, and allows a team to spend the necessary time to make good estimates on what are sometimes very sizable flocks of sparrows or finches.

This year was made a bit easier, as the largest field, on the south side of Hubbard at Southfield, was not planted this year. Another, at Southfield and Rotunda, was plowed under in fall. Still, we had our work cut out for us. The photo below is the field on the north side of Hubbard at Southfield. I've underlined myself in red! This field had the most birds this year. It took us a long time, but we feel comfortable with our count of over 2400 House Sparrows here. These fields have a lot of benefit to wildlife, but the downside is that they have certainly helped boost the House Sparrow population, which has skyrocketed in the last few years. Our final total of nearly 3500 House Sparrows set a new high record.

Another group of birds that has begun to overwinter in these fields are blackbirds. Last year the Rotunda and Southfield fields had a staggering 1300 Brown-headed Cowbirds. This year the blackbird flock was more modest. Here's about half of them. Most were Red-winged Blackbirds, along with some cowbirds and a single Common Grackle. Raptors have taken advantage of all the small birds in these fields, and once again we have a wintering Merlin here. We had plenty of opportunities to watch it hunt!

If we have time in the afternoon after going through the sunflower fields, Darrin and I hit a few other spots. We had this female American Kestrel dining on a mouse near Miller Road and Wyoming.

It's always nice to have a hot cup of coffee when adding up the numbers back at the EIC on campus. Here I am with Jerry Sadowski (in the Crocs that match the rest of his outfit!), Greg Norwood (in ball cap), and Gary Hutman, all veterans of the Dearborn count. Jerry and Greg are in charge of counting on campus, and Gary covers Rouge Park (in Detroit, but within the larger count circle).
The final story is the continuing saga of the lack of crows since West Nile Virus wiped them out in this area. Up to 2003, it wasn't unusual to count well over 200. That year, we counted 18. Since then, we haven't had more than 8 in any year. Blue Jay numbers, however, have remained pretty constant.

You can view the results of all past Dearborn CBCs on the RRBO web page.

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