What's up with Northerly Island?
Northerly Island is one of Chicago's top birding locations, with a bird list in excess of 230 species. It is well known among birders as one of the best spots in the area to find Ammodramus sparrows, especially Nelson's Sparrow (photo at left © Josh Engel) and Le Conte's Sparrow, shy and uncommon birds that love Northerly Island's grassy patches. It has also hosted many rarities in recent years, including Sage Thrasher and Brewer's Sparrow, not to mention the first record for Illinois of Black Meadowhawk, a dragonfly. As we approach the peak season (late September to late October) to find these sought-after birds, I thought I'd give an update to the status of Northerly Island as a birding destination, given the recent park district-approved habitat destruction and the extensive ongoing construction in the park. You can read about the possibly shady deal involved in expanding the park's amphitheater here; it was for this expansion that much of the grassland habitat favored by these sparrows was removed.
The map below gives an idea of the current conditions at Northerly. While it may look like there is plenty of habitat left (green shading), the best areas for finding these sparrows were the yellow shaded areas in the center of the island indicating where grassland habitat was removed and the east shoreline in the area that is now an inaccessible construction zone. Northerly is still worth a visit, in particular the green-shaded area along the east shoreline is good for migrants, including grassland sparrows, but there can be no doubt that the number of Ammodramus sightings (along with Sedge Wren, Bobolink, rails, and other grassland migrants) will be far below normal this fall.