Tennessee Warbler

 

One bird I’ve seen every single year that I’ve been a birder but pay little attention to except to list it during warbler migration is the Tennessee Warbler. It’s among the tiniest within a family of tiny birds, weighing about double the weight of a Ruby-throated Hummingbird but 20 or 30 percent less than a chickadee.

Bird books don’t focus on the Tennessee Warbler much except regarding identification. It’s easily confused with the Orange-crowned Warbler and beginners may also confuse it with vireos.   

Tennessee and Orange-crowned Warbler pages from my ABA Field Guide to the Birds of Minnesota

Its 3-part song is one of the longest and loudest of warbler songs, and easy enough to learn that I figured it out my second year of birding, before I recognized hardly any other bird songs. Part of the Tennessee Warbler song is higher frequency than I can hear nowadays, but enough of the song is within my hearing range that I notice it even without my hearing aids. 

Birders count birds that we hear even if we don’t see them. Except on the most competitive Big Days, just about anyone who hears a Scarlet Tanager, Blackburnian Warbler, or any other brilliant singer will take at least a moment to try to see it, but hardly anyone bothers to look for a singing Tennessee Warbler, even when we’re moseying.   

I saw my first Tennessee Warbler on September 3, 1975—Russ and I spent Labor Day weekend visiting his parents up in Port Wing, Wisconsin, where I added 13 species to my life list. The most memorable thing about the Tennessee was that it was #100—a milestone species—but the intensity of seeing so many new birds in a short time blurred my memories. It’s impossible to savor one lifer when a dozen more are flitting about. And the little Tennessee was too busy living its own life to squander energy trying to grab my attention.   

This year, Tennessee Warblers have been impossible for me to ignore. With our unusually cold spring, trees were barely starting to leaf out as the fourth week of May began. Warblers normally fuel their migration on the tiny caterpillars that hatch right as leaves are opening, and this year that natural food was hardly available at all when a great many warblers were arriving.   

Most warblers are entirely insectivores, but a few species, such as the Cape May and Tennessee Warblers, add nectar and fruits to their menu in the tropics, and may also dine on sweeter fare during migration. I've watched Tennessee Warblers picking into the cherries on Russ's trees in August and on mountain ash berries in September. 

In the spring of 2004, a late one like this year, I was shocked to see Scarlet Tanagers eating suet. That was when I learned that Cape May Warblers may come to feeders for suet, oranges, sugar water, and grape jelly.  

This time around, in addition to Scarlet Tanagers ...

... and Cape May Warblers... 

... I've had a much rarer Summer Tanager spending several days visiting my oriole feeders... 

...and as many as 40 Tennessee Warblers coming to my feeders as well. By May 28, they outnumbered the Cape Mays in my office window feeder. And this year I have a way better camera than I did in 2004.  

It’s fun to see such tiny warblers, with their dainty, aerodynamic little heads, sitting near a big-headed chickadee, like scrawny football fans standing next to the padded and helmeted quarterback. 

Chickadees are well-known to be intelligent, but warblers are much smarter and more adaptable than most people realize. They have to be to figure out how to eke out a living when they're on their own during their very first migration, leaving the quiet boreal forest, the only world they’ve ever known. To get to the tropics, they must pass through all kinds of strange habitats. For starters, every single Tennessee Warbler must cross I-90, I-80, and I-10. If after a long, wearying nocturnal flight they find themselves in the middle of Minneapolis or Chicago or an Iowa cornfield, they have to figure out how to find food and safe resting spots or they’re doomed. They're drawn to the calls of chickadees, the one familiar sound they recognize in such strange places. But even without chickadees, they usually figure out what they need to do to get through another day.  

Back when I was rehabbing wild birds, I was constantly struck by how quickly warblers adapt to temporary captivity. So I wasn’t surprised that the warblers visiting this spring quickly figured out that behind the window, I was just part of the landscape. Whenever starlings fly to the window feeder, I charge up to the window and wave my hands to get them to fly off. Chickadees ignore that, and the Tennessee Warblers took their cues from them. They did fly off when I opened the lower pane to replenish the feeder but returned the moment I closed window. I open the upper pane to photograph birds in the nearby trees, and this past week I got the loveliest as well as closest photos of Tennessee Warblers I’ve ever taken.   

These dainty, quietly winsome birds have been such a constant presence for over a week that I’ll be sad when they move on. They’re headed for boreal forest, mostly in Canada but also northern Minnesota and Wisconsin, where their reproductive success is tied to natural spruce budworm population cycles. Our short-sighted forestry methods to control these insects have led to declines in Tennessee Warbler populations, along with those of Cape May and Bay-breasted Warblers and Evening Grosbeaks. Tennessee Warblers are abundant enough that their population losses are not a major concern to conservationists, especially compared with other declining species, but then again, people once thought Evening Grosbeaks were too abundant to disappear, too. 

Walter's Beautiful Neighborhood

I’ve been taking my 1 ½-year-old grandson on little walks around the block lately. As with my own children at that age, Walter is fascinated by trucks and other large vehicles—lately, he’s especially taken with their big tires. On our walks, we always have to stop when any truck is parked nearby, and when one goes past, Walter always waves. And the drivers always wave back, whether they’re at the wheel of a city bus, a garbage truck, a street cleaning vehicle, a construction vehicle, or a big tractor trailer truck.  

A few times we've encountered the letter carrier or his red, white, and blue mail truck. One time we were passing right at the moment he was getting ready to carry a package and letters to Walter’s house, and he gave them to us. Walter was thrilled. Another time he was just about to get back into the truck to drive to the next neighborhood, and Walter watched as he closed the door, started the engine, and drove away, smiling and waving at the tiny boy who beamed as he waved back.  

When there isn’t a fascinating vehicle about, there are plenty of other things to notice. If we’re wearing boots, we stomp in every puddle. And Walter pays special attention to flowers. He softly touches purple or white violets and shakes his head no, confirming that he knows not to pick them. But he is always allowed to pick dandelions. At first he grabbed the flower heads, but after I picked a few at the base of the stem, he noticed that it’s easier to hold several dandelions at once by the stems than by the heads.  

Of course we look at birds. Robins are conspicuous just about everywhere, and we often see a Merlin on the corner—they must have a nest nearby. There are plenty of Blue Jays, crows, and chickadees about, and Walter recognizes them by sight and call.  

Because we’re moving so slowly and often completely stopped, quite a few pedestrians pass us by, and every single one of them smiles at this sweet little boy, who smiles and waves bye bye as they walk on. Walter knows firsthand how friendly and kind people are.  It’s always a beautiful day in Walter's neighborhood.   

On Wednesday, when Walter and I were in the living room, a brilliant red cardinal flew to his bird feeder and then to a nearby tree. While we watched, I made a cardinal whistle, and after the bird flew, we went to my laptop and I opened the cardinal page on my website, which has a nice closeup of a male and a play button to hear his song. 

Walter listened with interest and clapped his hands, but then said, “dee-dee-dee.” I said no, that’s what a chickadee says, and he said it again. I laughed and said, “Cardinals don’t say ‘dee dee dee.’They whistle!” He said “Chee-dee,” and I said no, this was a cardinal. Then Walter proved without a shadow of a doubt that he's smarter than I am. He patiently repeated “chee-dee” as he pointed to the tiny Black-capped Chickadee illustrations at the top of the webpage.  

I can’t even begin to express how dear this child is to me, and how happy I am that the world he knows is such a jolly, welcoming, safe place filled with birds and flowers and smiling people. After singing our three nap-time songs on Tuesday, and him saying nigh-nigh to Bear and Bunny and Dr. Blue Jay and Chuckie Chickadee and all his other animals before falling gently to sleep, I opened my computer to the horrifying news of yet another school shooting by yet another angry 18-year-old who could more easily purchase a rapid-fire weapon and an obscene amount of ammo than I can buy a package of Sudafed. And within hours there were reports about the instant rise in the market value of gun manufacturing corporations. One of my friends at an optics retailer told me they always have a big bump in sales of rifle scopes after every mass shooting.  

In America today, there are more guns than human beings—120 civilian-owned firearms per 100 people, including babies. It’s much more profitable to create a nation of mass shooters, vigilantes, and people arming themselves with military grade weapons out of fear than a nation where children can grow up secure in the knowledge that people are kind and smiley, not legally armed with everything they need to kill as many people as possible in churches, outdoor concerts, grocery stores, and elementary schools.  

Walter woke from his nap to the same loving, happy world he knows—the world every baby deserves to live in—even as the NRA was in the midst of preparing for their big annual Memorial Day weekend meeting, this year in Houston, so close to where so many Texans are grieving. The NRA prohibits guns at these meetings, of course. And I wonder at what precise point America's grandmas and grandpas and mothers and fathers will say, “Enough.” And at what precise point Congress and the Supreme Court will finally listen.   

My Most Colorful Spring, and an Adorable Little Despot

This has been possibly the most glorious spring migration I have ever experienced. I’m way behind many years in the number of species I’ve seen so far this year partly because I’ve been so rooted to home first trying to avoid Covid and then sick with it. But also, thanks to the exceptionally cold April and May so far, migration is very late. Late migrants haven’t arrived in any numbers yet, but that means some earlier migrants have been staying put for a surprisingly long time in surprisingly large numbers. 

Harris’s, Lincoln’s, and White-crowned Sparrows were especially persistent. 

One Ovenbird showed up on May 13th and sang away just about all day every day through the 18th.  He foraged along my fence close to the house for a photo op, too. 

I’ve been inundated with some of the most colorful and photogenic birds of all. Rose-breasted Grosbeaks showed up on May 9—I had at least 20 on both May 13 and 14. 

Scarlet Tanagers showed up on May 10 along with my first hummingbirds. 

And Baltimore Orioles showed up on the 11th. Like the grosbeaks, I’ve had at least 20 on a couple of days. 

I saw my first Indigo Bunting on the 14th and have seen as many as three males at a time.

But of all the colorful birds I’ve seen, my favorite has been one particular little Cape May Warbler. 

Cape Mays eat insects year-round like other warblers, and on their breeding grounds they’re a specialist on spruce budworm. But during their winters in the West Indies, nectar and fruit provide 30 percent of their food intake. Indeed, their tongue has a brushier tip than other warbler tongues specifically to take in fluids more efficiently than other warblers can. Between their breeding and wintering ranges, Cape May Warblers also search for sweet food sources, and can become rather dependent on them during cold snaps when insects are harder to come by. I’ve seen individuals take over a Yellow-bellied Sapsucker’s sap wells, chasing off every other bird including the sapsucker! 

Cape May Warblers are considered an economic pest by vineyard owners in Indiana, Pennsylvania, and West Virginia because they puncture grapes to drink the juice. Over the years, I’ve seen them and Tennessee Warblers doing that to the fruit in Russ’s cherry trees as well.  

During their arduous spring migrations, Cape May Warblers have adapted to the human landscape by developing a search pattern for oriole and hummingbird feeders. I first discovered this in 2004 during another very cold May, when I had as many as 30 Cape Mays at a time feeding in my yard on oranges, jelly, suet, and sugar water. One even figured out how to hover at a hummingbird feeder. 

This year the first Cape May Warbler I spotted in my yard, on May 19, was a female or young male coming to my window feeder. 

By the 20th I had 8, and on May 21 and 22, I was up to at least a dozen—quite likely more. I have five different oriole feeders, with oranges, sugar water, and grape jelly, in different places in my yard. One adult male Cape May Warbler appropriated the one at my home office window feeder, along with a big chunk of the nearby spruce tree, for several hours on Saturday. 

Cape May Warblers are tinier than chickadees, but this little guy was bound and determined to keep everyone else away from his little empire. I watched him chase other Cape May Warblers along with 15 other species. The chickadees, Red-breasted Nuthatches, starling, siskins, goldfinches, and Blue Jay were not even competition—not one of them was coming to the fruit, nectar, or jelly.  And during his reign of terror, I couldn't get photos of the Blackpoll, Blackburnian, and Black-and-white Warblers in my spruce tree, even though none of them even looked at the bird feeder.  

The other species were at least more realistic competitors. Hummingbirds, Tennessee Warblers, and other Cape Mays were at least in his weight category, but he also successfully drove off orioles, Rose-breasted Grosbeaks, a Gray Catbird, and my rare visiting Summer Tanager. The heaviest Cape May Warblers barely tip the scales at 15 grams—less than half an ounce, which is less than half the weight of those orioles, catbirds, and the tanager, and not even a third of what Rose-breasted Grosbeaks weigh! 

I finally lost track of him after so many other Cape May Warblers arrived, with three or four coming to that feeder at once so he couldn’t possibly keep them all away. But during his brief yet tyrannical reign, this little Napoleon truly was the emperor of Peabody Street. When he reaches the end of his migration in a lovely, dark and deep spruce forest, I hope he meets up with his Josephine and they produce many tiny new despots. 

Serendipity and the Patagonia Picnic Table Effect

Last week, I experienced a 24-hour period I’ll never forget. I’ve been scattering white millet here and there in my yard during this year’s amazing sparrow migration. On Tuesday morning, just a few minutes before I had to leave for my daughter’s house to babysit Walter, I spotted something I’ve never seen here in the 41 years we’ve lived on Peabody Street—a Field Sparrow! 

After living here so long, it’s unusual for me to add new yard birds, and this has been a most yearned for species. Earlier this month, I mentioned how with climate change we might start seeing Field Sparrows more up here, but I certainly didn’t expect one to turn up so soon, and in my own yard!  

When I took ornithology in 1976, I did my field research project on the Savannah Sparrow and inadvertently learned something cool about Field Sparrows. (Coincidentally, a Savannah Sparrow also showed up in my yard for a week or so, even singing a few times.) For my class project, I mapped out all the Savannah Sparrow territorial boundaries in my study area by playing tape recordings of their song. If I was on a Savannah Sparrow territory, that bird would fly in, and if I was on a border between two territories, or where three territories intersected, all the owners would respond. 

But wherever I was, the moment I played a Savannah Sparrow recording, I got a response from one or two Field Sparrows. Their beautiful whistled song is entirely different from the short, buzzy Savannah Sparrow’s. In class I’d learned that mapping territories is straightforward and simple, but as it turns out, real-life birds add a lot of wonderful complexities. And Field Sparrows are not just complex—they’re unpredictable in another unexpectedly wonderful way. One researcher documented a pair nesting less than 2 feet from a pair of Eastern Towhees, and both species fed the young at both nests. In another case, a pair of Field Sparrows and a pair of Common Yellowthroats actually shared the same nest, both incubating full clutches at the same time. I treasured Field Sparrows long before I knew that. It’s yet another case in which the more I learn about a bird, the more wonderful it turns out to be. So I was beyond thrilled to see one right here in my own backyard.

Before this, the most recent yard bird I’d added was a Wood Thrush last May, so this was a red-letter day for me, but I couldn’t stay home to savor it—I had to get to my grandson’s to babysit. I alerted a small birding network that the Field Sparrow was at my place and drove off. 

While Walter was napping and I was looking out his window, I discovered a pair of chickadees apparently excavating a nest cavity on the backside of a tree in the woods across Tischer Creek. From my daughter's property, I can’t see the hole, but I could see the birds disappearing and coming out with wood chips. I watched them for 15 minutes or so, and then one of them alighted on the tree closest to Katie’s window and fluttered its wings. Its mate alighted in the branch above it, fluttered its wings back, and sauntered closer and closer, both birds quivering and fluttering their wings. And suddenly I had a full, X-rated view of baby chickadee production. I couldn't get a photo, but this was through the window glass anyway. Yep—a red-letter day for sure! 

Right as the two birds were getting back to business as usual, my phone pinged with a text message—Jim Lind and Peder Swingen, who had gone to my place to get the Field Sparrow, had found a White-winged Dove right there on Peabody Street! 

Now it’s one thing to see a Field Sparrow in my yard—they at least belong in Minnesota. The White-winged Dove is a southwestern bird that was once fairly restricted to desert thickets—in Arizona, it specialized on saguaro seeds. Recently, it’s been expanding its range eastward—I see it on every trip now when I visit my son in Florida—and it’s also been expanding its range northward. The furthest north I’d seen one before was Kansas. In 2019, when I was on a road trip to birding festivals in Indiana and Maine, Jim Lind discovered one in Two Harbors. Jim has amazing rare-dove karma—he’s also the one who found an Inca Dove in Two Harbors—so it was fitting that he was the one who wrote the text message about this bird. 

A long time ago, birders in Southeast Arizona used to stop for a break at a roadside picnic spot called the Patagonia Rest Stop,. People would take a break from birding at the picnic table and restrooms. But then somebody noticed a rare bird. When word got out, more and more birders stopped for more than just a break. With so many eyes scrutinizing every inch of this small roadside picnic spot for one rare bird, other rarities were noticed as well, even though this was just a regular old roadside rest stop surrounded by plenty of much better Arizona habitat. When acquisitive birders gather at even the most ordinary spot, any rarities that might be there are going to be noticed. This phenomenon is called the Patagonia Picnic Table Effect. And it certainly was on display in my backyard Tuesday! 

I get so much fun and joy babysitting Walter, and virtually never feel like there’s something else I’d rather be doing, but to have such an extraordinarily rare bird in my own yard right that moment was a little more than I could handle. Katie was in the middle of an important meeting, but my son-in-law, who couldn’t be considered a birder by any stretch of the imagination, is most understanding about his mother-in-law’s obsessions. His workday was far from over, but he offered to multi-task so I could add this exceptional bird to my state, county, city, and backyard lists. 

Several birders were in my backyard when I got there, as was the dove. And befitting that Patagonia Picnic Table Effect, several of the birders were sitting at my picnic table! I didn’t get any good photos—the bird stayed in a tangle of dogwood and Virginia creeper while feeding on the ground and perching on my fence, and after 15 minutes or so, it flew off. Most of the birders disbanded and I went into the house.

Ten or 15 minutes later, the White-winged Dove was back, and for the next few hours, the bird and birders came and went. It was at one feeder close to the house but the window was closed and I didn’t want to risk scaring it away, so the photos I took there were through the glass. 

Starting at first light on Wednesday, I searched everywhere in my backyard. The dove was gone but the Field Sparrow was still there. 

Eventually I went upstairs to fill my home office window feeder, when what to my wondering eyes should appear but a greenish yellow tanager! I’ve seen more Scarlet Tanagers than usual this year. As of Wednesday, all of them had been gorgeous males. 

Now I was finally seeing a female, but she looked wrong for Scarlet. Her wings and tail didn’t show a trace of black—they were much closer to the color of her back—and her bill looked a bit too long. She was a Summer Tanager! Yep, within less than 24 hours, I'd seen three extremely rare birds in my own backyard!  

Summer Tanagers are seen in northern Minnesota much more often than Field Sparrows or White-winged Doves—indeed, one turned up in my own neighborhood, a few blocks from my house, in October 1981, my very first autumn in Duluth. I saw a stunning male along the Red Cedar River on the Michigan State University campus in May 1976, but the field guide map showed them south of Michigan and I was too inexperienced to trust my own eyes or judgment, so I didn't add it to my life list until the following month when I saw one where he was supposed to be, on Skidaway Island in Georgia.  

Summer Tanagers have always wandered, so random appearances up here are not really indicative of climate change, but increasing sightings of them are consistent with both temperature and vegetation changes due to warming. As with Red-bellied Woodpeckers and cardinals before them, these random sightings are growing more common, so eventually a male and female will meet and nest up here. And one day, probably not in my lifetime but quite likely in my children's, the species may become established here. 

The tanager has stuck around through at least today (Sunday), and most of the birders who have come to see her have managed to get at least a glimpse. She’s been coming to my office window feeder as well as my other oriole feeders, and spends much of her time at my neighbor Jeanne Tonkin’s house as well. 

I don’t know how long she’ll stay around our corner of Peabody Street—the White-winged Dove was not seen again after Tuesday, and the Field Sparrow disappeared on Thursday—but it’s sure been lovely hosting this exceptional trio. I can’t imagine I’ll ever have a 24-hour period again in which I add three new birds to my yard list. Serendipity? The Patagonia Picnic Table Effect? It’s fun to have cool terms for birding phenomena, but really, I’m just grateful to be hanging out on this planet for yet another spring to witness yet  another of the myriad miracles of migration.