From atop the old green tower site at Indiana Dunes State Park, birders are approximately 50-60 feet above Lake Michigan. When you’re twice the height of the beach pavilion, you are at a good vantage point to view migrating birds in the spring. With a south wind, the morning flight begins at dawn and continues for several hours before being reduced to a trickle. Some mornings, the birds literally shine as the rising sun behind us illuminates the passing birds. The necks on Red-throated Loons reflects back like a light bulb at times. When clouds interfere, the birds are mere black spots against a gray background. It’s here where body shape, flight style, and small call notes make the difference in identifying all that flies by.
Quite simply, 90% of the most recent flight can be narrowed down to four species. Of course, many other species go by that are worth noting and the main species going by will change as the spring progresses. The thousand blackbird counts will be replaced by thousand Blue Jay flights in May. But with cloudy conditions, notice how easily the main four species shake out in this style of sedentary birding.
Take the American Robin. We often know it’s a robin flying over, but when pressed to explain why it’s a robin, we may fail to accurately describe why we know. The Peterson Guide to Birds inside cover gave many of us our first peak at identifying birds by their silhouette. Here’s some photos taken yesterday in very cloudy conditions.
The photo is poor, but you can see it’s a robin. The orange belly and white vent is visible. Here’s the same photo, but darkened in Photoshop.
This image is more closely what our eyes would have seen yesterday morning. The miracle of modern day cameras can automatically compensate for the lighting and adjust the white balance and exposure. Notice right away the average tail projection past where the wings would ultimately fold down to. It’s easy to photograph birds and end up with shots that look like little bird bullets. You always catch them with their wings folded in. Not with robins. Their resting/gliding state is with the wings partially open. It begins to form a clear “caped” pattern. Think Batman (and Robin!), with his cape. Here’s a completely terrible, out of focus shot showing how robins look when they pass by. However, it illustrates the point.
At the old green tower, we won’t see this from any other bird in March, and most of April. Really, the only bird we’ll see in significant numbers that remotely looks like this are Eastern Kingbirds in May. Lastly, notice the side shot and the jolly belly. Our plump robins flying by at low level can be easily identified from similar birds by this too.
Grackles are much easier to separate when flying over. Their extra tail extension, longer wings, and long head are obvious at longer distances. The major problem counters have here is the fact that they mix with the other blackbirds, and force counters to estimate each flock by percentage of each blackbird for the final tally.
The largest groups in March are usually the Red-winged Blackbird flocks. Their constant call notes and occasional full song fill the sky during heavy flights. Counts of 10,000+ a day are common at the Green Tower. Like the robin, the tail extension is average, but the birds exhibit full wing beats. Males dominate early, as the first scouts arrive, but the flocks begin to show more females later in March. During this time, the careful eye can separate the males from females by size alone. Birders are also on the look out for Rusties, Brewers, and Cowbirds among them. Sound is a good indication when they are mixed in. Here’s a bullet bird below.
Starlings can be one of the easier to separate during heavy flights merely due to their tiny tails. Their triangular, kite like wings, smaller size, and short tail extension is usually enough in even the worst lighting.
Knowing the major four helps, but our paid counter must be able to recognize many other birds high in the sky as they go over, searching for any details and hints to it’s identity. It’s also good to be knowledgeable of potential new species, never seen at the site. Will our counter recognize a Lewis’s Woodpecker or Smith’s Longspur if it went by?
Today, March 15 saw another decent flight of 14,800 birds. New for the season were a single Eastern Towhee and Eurasian Collared-Dove. Robins, Grackles, and Blackbirds continue to dominate the count, but the first real Northern Flicker flight started, with over 40 birds seen passing by. It was also the best Common Redpoll flight of the morning, with 33 “chet chets” heard passing by.
Lastly, here’s three more shots taken on March 12, 2012, during poor lighting conditions. They are each common birds seen, and show slightly different characteristics that can provide enough clues to the identity. They’re great quiz birds (i.e. poor photos). Can you identify them? If so, tell us in the comments. Click them for a larger view.