The cerulean warbler remains an elusive target for birders

Warbler excitement peaks in Northern Ohio during the first couple weeks of May. In fact, the Biggest Week in American Birding — the celebrated warbler migration event in Northwest Ohio that brings thousands of visitors from around the world and millions of dollars to the area — is still continuing for a couple more days. Although warblers come in a variety of brilliant colors, the color most commonly associated with them is yellow, and much of their attraction is that they are migrating through the area. But there are exceptions. The cerulean warbler is not yellow, and it is not migrating through. It is a striking soft blue warbler that breeds here in Ohio and across parts of the Midwest. Its migration, however, is still remarkable, extending to non-breeding areas in South America. Each year, it migrates through the southern United States and Mexico, making the dangerous journey across the Gulf of Mexico. As a blue warbler, the males are fairly easy to identify. The females are a softer blend of yellow and bluish-green. They forage high in the treetops, often more than 50 feet above the ground, and can be surprisingly difficult to see — essentially a sky-blue bird against a blue sky. One comic by Bird and Moon asks, "What your favorite migratory warbler says about you?" For the cerulean warbler, it jokes: "You got good looks of a cerulean warbler one time, and you won't let anyone forget it!" Sriram Udhaya, whose photos make up this story because I've never managed to get a good photo of one myself, said, "It took me about seven years to really learn their habitat, where they first show up, where they nest and the right timing to find them. In the beginning of migration, they're usually very hungry and actively feeding, and that's the key. You have to be there at the right moment to get those opportunities and photos." "All About Birds" suggests, "Focus on the sound and look for movement in the canopy without your binoculars first before trying to scan the canopy. They have a habit of foraging at the closest part of a twig and hopping toward the end, veering slightly upward through the canopy as they go. Brushing up on your tree ID might help you spot them too, as they often use white oaks, cucumber magnolias, bitternut hickories and sugar maples more than other species." Their song starts with three buzzy notes, followed by four fast warbles and ends with a higher-pitched buzzy trill. This is a great time to turn on your Merlin Sound ID app to see if it picks them up. Cerulean warblers nest throughout the Midwest, from Minnesota to Pennsylvania. In Lorain County, we are fortunate because cerulean warblers can often be found at Bacon Woods in Vermilion. They use spiderwebs to construct their nests and have even been known to reuse the spiderweb when constructing a new nest — suggesting how valuable it is. It is easy to witness the ecological doctrine of "survival of the fittest" in birds as they struggle to survive and produce offspring. This fitness is not necessarily related to being the fastest or strongest but rather being the best adapted for a particular environment. These adaptations can include camouflage or specialized behaviors — such as brood parasitism by the brown-headed cowbird, the broken-wing displays of killdeer or the extreme fat storage of the blackpoll warbler before migration. One of the coolest examples of this adaptive behavior is found in cerulean warblers. When leaving the nest, females will often "bungee jump" from it. She doesn't just fly from the nest; she drops below the nest with her wings folded against her body and only opens them to fly once she is well below the nest site. Why does she do this? The behavior helps conceal the nest's location from predators. Because cerulean warblers nest high in trees, this unusual strategy is surprisingly practical. Nests themselves are often extremely well-camouflaged, but one common way birders locate nests is by watching where adults repeatedly fly while carrying food or nesting material. Predators can do the same thing. "All About Birds" explains: "Researchers believe this helps conceal the nest location from predators by making it harder for animals like jays, squirrels, raccoons or snakes to visually track where she came from. It essentially allows her to disappear from the canopy without drawing attention to the nest itself." On their wintering grounds in South America, cerulean warblers are often found in mixed-species feeding flocks alongside tropical tanagers and other resident birds. The cerulean warbler is also a species greatly affected by habitat loss. The North American Breeding Bird Survey estimates a decline of more than 2.6 percent per year between 1966 and 2015, resulting in a cumulative population loss of roughly 74 percent during that period. In many regions, cerulean warblers are believed to exist in what biologists call "sink populations"— areas where birds may still nest and sing each spring, but where too few young survive to sustain the population long-term. Their future often depends on carefully managing forests to preserve the tall mature canopy structure they need, while also maintaining the small natural gaps and complexity that help the species thrive. The cerulean warbler is a beautiful and interesting bird. If you see one, be sure to tell everyone about it! Black River Audubon's monthly field trip will be Saturday at 9 a.m. at Wendy Park, 2800 Whiskey Island Drive, Cleveland. Meet up at a parking lot located off a driveway just past Edgewater Marina there is a driveway on the left that leads back into a big parking lot.