E-bird recently created some fascinating animated visualizations of bird migrations, combining observations submitted by nearly 200,000 bird watchers, including many of us.
E-bird noted: “The results are spectacular. For the first time we can watch migration happen at the scale of continents for more than just a few species,” - and we agree - the results ARE spectacular. We used this as an excuse to reach out to some local bird experts for their thoughts.
Take a deep dive into this new tool with us. Click on the linked bird names below (the link will open a new tab in your browser) to view the animations. Try it out with the Red-eyed Vireo. Notice that you can pause the animation and then scroll though the weeks at your own pace. This bird is so common for us - we hear it in every woodland, all summer long. Surprising to see how few there are in the middle of the state during the nesting season in June and July - but of course, that’s where the prairie is in the Prairie State, and this is a woodland bird.
Migration the Chicago Way
Doug Stotz, Field Museum: In a recent presentation, Doug talked about how our region’s greatest avian importance is for migratory birds, sharing a list of migrating warblers that he thinks should be considered in our conservation strategies because the bulk of their population passes through Chicago. The migration animations confirm Doug’s observations.
These four warblers winter in very different places, but they all concentrate in Chicago during migration:
Golden-winged Warbler (watch the birds disappear on one side of the Gulf and magically reappear on the other!)
Nashville Warbler (wow are there a lot of these reported in the Chicago area compared to the rest of northern Illinois!)
Cape May Warbler (same! Is it the deep dish pizza??)
Palm Warblers REALLY love Chicago. What’s with those birds arriving the first week in April when there are almost no other Palm Warblers in the state? Are they emerging from hibernation??! See Josh’s thoughts below for a more rational theory. (Hint: these warblers spend a lot of time on the ground). They also seem to stay later in May, and hang on in early November when the rest of the state looks empty.
Other migrants Doug mentioned were Mourning, Connecticut, and Blackburnian Warblers. The maps bring home just how important Chicago natural areas are for warblers passing through the “corn and soybean desert” of Illinois (remember the Red-eyed Vireo map? Most warblers don’t like those ag fields either).
Where’s the rest of the map?
John Bates, Field Museum: “The Veery animation shows why cutting off maps can hide things we need to know more about. As an evolutionary biologist, I'm drawn to what we can learn about the past as reflected in present patterns. Veery's breeding range extends west to the Rockies, but the entire species moves eastward in the Fall and then makes the jump to the Yucatan and South America. I think that may say something about the hard wiring of migration as a species’ breeding range expands. At the same time, the western breeding Veeries may have been an isolated population at some point during glaciations. What is not shown in South America is that data suggests this species largely ends up in southwestern Amazonia at the height of winter, and I wonder if patterns like this tell us something important about the landscape history of South America. So these data and the way they are presented here offer a lot of food thought.”
Who knew Rails could fly so well?
Stephanie Beilke, Audubon Great Lakes: “It looks like a large proportion of the Sora population stops over in Illinois before spreading out across their breeding range. It makes sense as Illinois is directly between Florida, where many individuals seem to overwinter, and the northwesternmost point of their breeding range in Canada. Last year, Michael Topp recorded 159 Sora at Grant St. Marsh in nearby Indiana on May 3. I counted 30 Sora at Big Marsh on May 8, 2017 during Audubon Great Lakes' Calumet Marsh Bird Survey. It goes to show just how important Chicago area wetlands seem to be for marsh birds like Sora at the population level, especially during migration - and how greatly wetland restoration here can benefit species that really depend on high quality wetlands for stopover habitat as well as breeding areas.
Since Sora and other rails are disproportionately affected by window collisions, it also reminds me of what is at stake with the Bird Friendly Building Ordinance passing in Chicago.
Rails are generally known as better walkers (and decent swimmers) rather than skilled flyers, so it's impressive to see just how far they can travel during migration.”
Disappearing Act
Josh Engel, Red Hill Birding: “The Henslow's Sparrow abundance animation map is striking to me, for a couple of reasons. It shows that Henslow's Sparrows have not adapted to urban environments. Its breeding distribution appears to be centered on Illinois and Indiana, but Chicago is a hole in the breeding range. Henslow's Sparrow is also incredibly hard to detect during migration, and that shows on the map, too. In late October, after they have completely departed their breeding grounds and before they have arrived on their wintering grounds, the map is entirely blank!”
Your turn!
What’s interesting to you? Let us know in the comments. And stay tuned next month for some more insights - this time from national experts.