Hermit thrush. (Matt MacGillivray)

May 4 is designated as a Global Big Day. This is a day when citizen scientists around the world take time to document as many birds as they can. The Global Big Day is organized by eBird, which is a database maintained by Cornell Lab of Ornithology. It allows ordinary citizens like you and me to track the birds we see. The Lab uses the database for research on birds.

During the first weekend in May 2018, more than 30,000 people around the world participated in the Global Big Day. After it was over, 7,000 different types of birds were documented worldwide. Here in Oxford County, a group of 15 “citizen scientist” documented 25 different types of birds at Valentine Farm in only two hours.

We were delighted with mixed flocks of warblers including yellow-rumped, black-throated blue, black-throated green mixed in with blue-headed vireos, a hermit thrush (photo by Matt MacGillivray) and ruby-crowned kinglets. At times, the birds hopped on the trail and swarmed the low branches just feet away, seemingly oblivious of our group. It raised the question, “Why were all these birds together?”

We don’t really know the answers to questions like these, but science has given us some clues. It turns out, it is not uncommon for mixed flocks of birds to be migrating together at night. A number of factors from genetics, weather and geographic features can funnel species together as they move north. Under certain conditions, exhausted birds will land together in these concentrated flocks and are sometimes referred to as “Fall Outs” by birders. After resting and feeding, these birds move on, dissolving into the northern forests.

Although we never know what will show up this May 4, it is always exciting. You are invited to join us for a bird walk at 8 a.m. We need citizen scientists like you to help us document the birds at Valentine Farm Conservation Center (VFCC). No matter your skill level, you are likely to learn something new. And, with a little luck, you’ll see some amazing birds.

Speaking of learning something new, join us from 5:30 to 7:30 p.m. on Friday, May 3, at VFCC for a class where we will review the migrants we expect in our area at this time of year. It is free and appropriate for all levels of birders.

James Reddoch, of Albany Township and Boston, leads birding events for the Mahoosuc Land Trust which celebrates 30 years conserving the natural areas of the Mahoosuc Region. Visit Mahoosuc Land Trust at 162 North Rd., Bethel, or at www.mahoosuc.org. To learn about events or to contact James, email info@mahoosuc.org.


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