Tuesday, September 21, 2010

North American Migration Count

This past Saturday, Maureen and I helped out with the North American Migration Count for Daggerwing Nature Center. For those of you who don't already know, we've been volunteering there every weekend since May, starting as front desk greeters, and soon afterward we began to lead boardwalk tours identifying and discussing the plants and animals in the center's wetland habitat. We're always looking for additional ways to become involved at the nature center, and when we were asked if we'd like to help with the count, we jumped at the opportunity.

The North American Migration Count is a a semi-annual bird census, where the goal is not only to mark down which species are sighted, but also tally the approximate numbers for each. In my mind it seemed an easy enough task, perhaps with the exception of the occasional identification challenge from some of the more secretive birds. In reality, we were surprised right from the start at the sheer magnitude of some of the species we saw, which is what ended up being the real challenge. Our best efforts were further complicated by the fact that birds refuse to stay in the same place once you've counted them.

We hit the boardwalk at 7 am sharp, with clipboard and binoculars in hand. Almost immediately we began seeing wave after wave of White Ibises overhead - a truly awesome sight, but also nerve-wracking when you're responsible for trying to count as many as you can, or at least to sense how many individuals to each flock. Maureen took the first shift with the clipboard and tried to keep up as Daggerwing's manager and I called out, "30 White Ibis… 25 White Ibis…30 Common Grackle… another 30 White Ibis." This lasted a good 10-15 minutes before subsiding to a more easily manageable/less stressful pace, by which time we had already seen most of the day's ibises (400) and Common Grackles (150).

A little farther down the boardwalk, Maureen spotted one of the few warbler species for the day: a single Worm-eating Warbler. We also had a Prairie Warbler and several Blue-gray Gnatcatchers later on, but overall, a quiet day for warblers.

Our biggest surprise was seeing a shorebird standing on a small island of mud, several feet away from a Florida Softshell turtle. Shorebirds are tough, and we're far from experts. My best guess was Willet, but Maureen insisted that it was much too small. Even at that distance, I had to concede that she was right. Plus the wings were too dark, and I could just make out some white patterning. Maureen didn't have her camera with her, but we did have the point-and-shoot. We tentatively marked down Solitary Sandpiper, but it wasn't until the next day that we were able to have our hunch confirmed from our picture. That made it a life bird for us!

The only other identification that gave us any difficulty was of a soaring Buteo. It was obviously a dark-phase bird, but it didn't have a red tail, which would have been a give-away clue. It flew away behind some trees, leaving us in suspense for several seconds, hoping it would come back so that we could have more time to pin down the ID. We finally decided that it was a juvenile Red-tailed Hawk - the only dark-phase individual I can remember seeing in the past couple of years.

We ended the count around 10:45, which gives you an idea of how thorough we were, given that we only walked .6 mile. Our final tally for the day was 41 species.

Other highlights included:
A group of 10 Eastern Kingbirds
All of the local woodpeckers (Pileated, Red-bellied, Downy, and Northern Flicker)
Several Red-eyed Vireos
2 Belted Kingfishers
1 Black-crowned Night-heron


  1. Hopefully these are not silly questions: why do a census count in such a specific location as the Daggerwing Center, or anywhere for that matter? I'm assuming that migratory routes cover a wide area, so why bother trying to count? Do the same birds follow a very specific route every year? I understand accounting for different species, but not their numbers. Sounds like a nice morning nonetheless.

  2. Good questions, Steve! The migration count is actually done all over the country on the same day. In the fall it's always the third Saturday in September. Areas are divvied up amongst birders within each county, and then all of the final counts are sent to the county's compiler. With all of the data in hand, ornithologists are able to determine which migration trends are happening and match them up with past years.

    By estimating numbers, they're also able to track population trends. Many species are facing declines due to climate change, habitat loss, habitat fragmentation, and other problems. Other species are able to exploit those changes and their numbers are rising. Censuses help to determine which populations require special attention.