Cerulean Warbler (Setophaga cerulea)
By Kristen Sweinhart
Standing on the road near the Duneside Shelter and Trail 2 inside the Indiana Dunes State Park, I wondered what the medical diagnosis code for ‘warbler neck’ might be. It was a silly moment in my head where my nurse brain collided with my bird brain. I had been a nurse for many years, but I was just a fledgling birder. That spring morning, on an Indiana Dunes Birding Festival tour, our guide pointed out a small bird flitting around waaaaaay up in the tops of the tall oak trees. He had us listen for the buzzy song which was distinctive once I knew what to listen for – an ascending “beer, beer, beer, zee-zee-zeeeeee.” All I could really see of the bird was the plain white underside with a small dark band around the neck and some dark streaking on flanks. “Not much to look at,” I thought to myself as I struggled to follow the bird with my entry-level bins and my novice aptitude. But it was a lifer for me and lifers are always exciting! It was what I learned about the bird following that moment that really captured my attention.
The Cerulean Warbler (Setophaga cerulea) is an uncommon summer resident in Indiana. They start arriving in our area in late April, but by late July they begin migrating south for the winter. They breed in deciduous forests with tall trees. This once abundant member of the Wood Warbler family is listed as vulnerable by the IUCN and as Endangered within the state of Indiana. Data suggests that populations declined 72% between 1970 and 2014. Loss and fragmentation of habitat in both the breeding grounds of the United States and Canada as well as the wintering grounds in Venezuela, Ecuador, Colombia, and Peru is believed to be the main underlying reason for decline. Loss of key tree species (especially oak, sycamore, elm, and chestnut) is another factor. It is also possible that Cowbirds who lay their eggs in the nests of other species may be able to find this warbler host more easily as tracts of forests become smaller. The Cerulean Warbler’s affinity for the treetops often make them difficult to study, but it’s encouraging that there have been many independent scientific teams conducting research and conservation efforts all along this bird’s migratory path.
A few years after seeing my lifer Cerulean Warbler, I found myself in the same spot in the state park. It was a dreary morning in mid-May marked with drizzle and some wind. I heard the call and I knew the bird was close. Suddenly, a beautiful male Cerulean Warbler was in sight! I could see the white underbody and dark streaking on the flanks and the dark band around the neck that I had seen before, but now I could also see this striking blue bird with dark streaking on the back and two white wing bars. The weather must have encouraged him to get a little bit lower in the canopy that day and I am so lucky to have been there to see it. I was reminded that even when things look gloomy and it’s a pain in the neck, I should keep looking up.
Cerulean Warbler photo by Mark Welter.