As we begin our annual trend into fall and winter, I’m reflecting on a cool late May morning when I watched a parade of migrant warblers passing through the partially leafed out trees along a northwoods lake. The trees had become alive and there was movement everywhere. Each of these birds has an amazing story to tell.
The Canada warbler I saw had come from South America, using its amazing navigation system, probably flying over the Gulf of Mexico after molting and fattening up on the wintering grounds, refueling in coastal Louisiana, and making its way to claim a territory, either nearby or to the north of me. The ability of birds to navigate is nothing short of incredible.
Quite a few Tennessee Warblers, rather poorly named, moved past. So many questions came to mind. Are they related? Are they part of the same breeding population traveling as a cohort? Are they all males or all females? Are they first year birds returning from their first experience in South America, adults only, or a mix? And those plumages, which are frustratingly variable to birders. Some birds have an eye stripe almost like a Red-eyed vireo, others tending towards being yellowish. Some with quite bright green backs (even to me, a partially red-green color blind male). Having looked at a few hundred specimens in the hand, it’s clear why they present identification challenges.
A male Blackburnian warbler made me stop in my thoughts. It’s a spectacularly colored bird, maybe the jewel of the northwoods. Not far behind is the American Redstart, which settle in our northwoods and points north. Three male yellow warblers, who stay locally and raise families, were fighting continuously, each competing for the best territory.
A male Blackpoll warbler flitted by. Used in my ornithology class as a champion long distance migrant, it is always thrilling to see this species, even if it’s not in the same league as the Blackburnian, color wise. According to some, Blackpolls have lost almost 90 percent of their population over the last 40 years, making a sighting even more special. The extent to which the decline of the Blackpoll warbler is because of humans is unclear, because their breeding grounds are pretty far north, although ecologically degraded stopover points could be an issue. Its fall migratory journey involves an 1,800 mile nonstop flight from the maritime provinces across the Atlantic to wintering grounds in South America. This journey presents formidable challenges. Perhaps global climate change has made the weather conditions they face on the overwater journey now even more treacherous, and could play a role in population declines. However, there are approximately 60,000,000 Blackpoll warblers estimated to exist, and hopefully they can adapt to climate changes and recover, as they certainly have in the past, given the history of glaciation in North America.
Seemingly in an instant, bird activity ceased. Had all the migrants passed through? Did summer instantaneously arrive? I spotted a bird a bit larger than a robin perched on a dead branch in a tall birch along the waterfront. It was a Merlin, a bird-eating falcon. Looking for breakfast. Unfortunately, predators get a bad rap because people watch too much Disney, where everything lives happily ever after. Sure, it would be unfortunate for a Blackpoll Warbler to have migrated 1,800 miles south to winter, survive the winter (with new plants and foods, different weather, new competitors and predators), and migrate back north only to end up being eaten by a Merlin a couple hundred miles from its intended nesting site. But it would be a win for the Merlin. We need a common sense understanding of how nature works. Raptors eat birds, and it’s irrelevant whether we like it or not. Merlins and Blackpoll Warblers have co-existed for thousands of millennia and neither is extinct. You should enjoy a Merlin eating a Blackpoll Warbler as much as you do marveling at the latter’s migratory feats.
Perhaps as a commentary, a Tennessee Warbler on a small branch, faced away from me and pooped. It seemed directed at me, although that’s probably giving me too much credit. As if to compensate, another male Blackpoll Warbler foraged by and the parade continued. I’ll reflect on that day later, when snow and ice cover the northwoods, and wish the warblers a happy South American winter! I look forward to seeing them again in May after their arduous journey.
Bob Zink is a book author and a regular contributor to Outdoor News.