Laura Erickson's For the Birds

Monday, September 27, 2021

Camera Fun with Pileated Woodpeckers

Pileated Woodpecker 

A pair of Pileated Woodpeckers live in my neighborhood. They’re not banded or uniquely marked as far as my eyes can see, so I have no way of knowing for sure whether one or both are the same birds I had last year or the year before, nor even of knowing whether these two are the same ones I was seeing this spring before the nesting season. When it comes right down to it, when a male or a female shows up, I can’t even be sure they’re the same individuals who showed up a day or two before. 

Whoever they are, they show up at the same feeders time after time, which suggests they’re familiar with my yard, but as more and more Pileated Woodpeckers spend all or part of their lives in neighborhoods like mine, they may simply be familiar with feeders in general, recognizing good places to stop. They seem wonderfully tolerant of me with my camera, but again, birds living in neighborhoods like mine may figure out that people don’t pose much of a hazard to them.

My dream of course is for a pair of Pileateds to nest in my neighborhood. I can’t even imagine the joy I’d feel if they nested right in my yard! This year they were quite regular through winter, but disappeared right when nesting would have been starting.  

The only nest I’ve ever seen in my life so far was near Hog Island in Maine when I was an instructor for an Audubon camp. The nest was very far away, so my photos are poor but do show the babies sticking their heads out when a parent was at the cavity. They’re the only Pileated Woodpecker nest photos I’ve ever taken, so I have them up on Flickr with my finest work.  

Pileated Woodpecker chicks

Pileated Woodpecker chicks

My first wonderful Pileated Woodpecker photos were taken way back in November 2004, when a Rufous Hummingbird showed up at my feeder during a mild spell. Then we had a blizzard, so I kept a window open in my office with one feeder on the inside, just in case the little hummer needed a break from icy cold and wind. She flew in once or twice, but my big reward for keeping the window open was a Pileated Woodpecker flying into the box elder tree right next to the window, giving me my best shots ever. 

Pileated Woodpecker

Jeepers the neighborhood Pileated Woodpecker

Oddly enough, when I’m checking my flickr account stats, “Jeepers the Pileated Woodpecker” still gets a surprising number of hits. I also got pictures of “Jeepers”at a small suet feeder stuck to the window by two small suction cups. 

Pileated Woodpecker

The joy of photography comes as much from the possibilities of future photos as from the best ones I’ve already taken. I’m still shooting at pigeons and Blue Jays, so of course I always grab my camera when a Pileated shows up. When Russ and I got a new dining room window a few years ago, I grabbed my camera to see how clear the glass was, and the first bird to show up was a Pileated Woodpecker at my peanut butter feeder. So I focused and held the shutter down in burst mode. My photos were so clear that you can’t tell they were shot through the window, and in one of them, the Pileated’s tongue was sticking out all the way. That was thrilling—it’s the only photo I have of any woodpecker with its tongue fully extended. 

Pileated Woodpecker tongue!

Since I moved into my new home office, I find myself leaning out the window photographing birds a lot, and Russ set up a wonderful window feeder for me to get even closer shots. I’ve taken a few really good ones of birds at the feeder with the window open—when Evening Grosbeaks filled my feeders in the spring, I got some wonderful video and photos without any glass in the way. 

Wet Evening Grosbeak at my window feeder

But most of my photos of birds in that feeder are through the closed window, and birds can be messy eaters. Last weekend, after I put in a seed and nut mixture laced with capsaicin pepper, first a female and later a male Pileated came to that feeder. The window was closed, and my good camera was on the file cabinet right next to my desk, so grabbing it would have scared them off, but I did get a few photos and video through the glass with my cell phone.

Crappy pictures of a Pileated at my window feeder

Pileated Woodpecker at bird feeder

Last week I saw one at my feeding station. I was downstairs and didn’t have my camera handy, but when it flew off, I headed outside to see what other birds might be about. I didn’t get far—that same male Pileated was still in my yard, in a different box elder. He was very tolerant, letting me take pictures from only 12 or 15 feet away. My new mirrorless camera allows me to simply press a button right next to the shutter button to shoot video, and I got both cool close-up photos and video of him feeding—the best I have of that.

Pileated Woodpecker

Pileated Woodpecker

Then this Sunday, I leaned out my office window to photograph the male in the close box elder right at eye level. I got several in-focus shots of him digging in.

Pileated Woodpecker

Pileated Woodpecker

When I switched to video, my camera decided to focus on a tiny branch in front of the bird right when he pulled a big, fat, juicy grub—probably a wood-boring beetle—out of the tree. 

Pileated Woodpecker

I wish the video had stayed in focus because it was fun seeing how hard he had to work to swallow the huge thing. Of course, this was the only time I’ve ever gotten photos or video of a Pileated pulling out a grub, so even though the photos I screenshot from the video are not in focus, they’re the best I’ve ever taken of that. I am always happy when I get a perfect photo of any bird, but I don’t take pictures in hopes of impressing serious photographers. Even out of focus, that gigantic grub makes me think WOW! And WOW! is plenty good enough for me. 

Pileated Woodpecker

Monday, September 20, 2021

Hot, Peppery Bird Food

Blue Jay

On January 31 of this year, my husband Russ set a small platform feeder on the window outside my new home office. I’d switched last year from the largest room in the house to one of the smallest when my daughter and son-in-law came to live with us. I didn’t mind losing the space—I'm close to retiring so was ready to downsize my stuff anyway, and my new office is nice and cozy.  But I was sad about losing my two large windows, one facing the backyard, the other looking into the branches of one of my box elders. As it turns out, the much smaller single window I have in my new space has given me some of the nicest photos I’ve ever taken, and the feeder Russ put in has increased the photo ops enormously.  

Grandma showing Walter a chickadee

The first birds to show up at the feeder were, of course, chickadees, but I cheated—all I had to do was whistle to get them to fly in for mealworms. Red- and White-breasted Nuthatches and a Downy Woodpecker keeping track of the chickadees also quickly found the feeder. 

All was well until February 4 when a gray squirrel jumped into it from an overhang about 2 feet lower than the feeder and about four feet away horizontally, an especially tricky maneuver when the overhang was slippery with ice. But that was the only time I saw a squirrel in the feeder for a few months. By the end of April, my feeder bird list was up to 13 species.  

Evening Grosbeaks in my window feeder

But with spring, a couple of squirrels became adept at the long jump. It was irritating, but not enough for me to close down the feeder until spring migration was over. The squirrels were a small price to pay for some lovely Indigo Bunting photos.  

Indigo Bunting

When I closed down the feeder at the start of June, my nesting chickadees could still catch my eye and I’d open the window to give them mealworms. But the window feeder was otherwise left empty all summer. The few times I filled it this fall, a squirrel showed up within an hour. 

But with this year’s amazing Blue Jay migration, I really really wanted to get the window feeder going again. Neither Russ nor I could think of a single way to close off access to those squirrels. So I finally decided to try some birdseed laced with hot red peppers. 

I used to counsel caution regarding bird food formulations with peppers. It seemed like anything that could burn our mouths and be such an irritant to our eyes had to be equally bad for birds even if they lacked the taste receptors to shun it. But I recently read about the evolution of peppers. Squirrels and other mammals chew fruits, breaking and grinding up the seeds, which damages rather than helps a plant’s chances of reproduction. Birds swallow chunks of fruits whole, so most of the seeds remain intact as they pass through the avian digestive system, and birds fly to many places over the course of a day, allowing them to “plant” those seeds over a large area. The bright colors of peppers evolved specifically to attract birds, and the pepper fruits are very nutritious, keeping birds coming back. So on September 11, I bought an expensive bag of what Wild Birds Unlimited calls “Fiery Feast” and put it in the feeder. 

Chickadees were first to come, grab peanut halves, and fly off, but Blue Jays weren’t far behind. My feeder is just 22” x 9”, and it’s hard for birds to sit along the edge against the windowsill, but I’ve had as many as 12 jays crowd in to pig out. We still have a big platform feeder and a small one, both filled with regular sunflower seeds, down in the regular, squirrel-proof feeding station, and every day all week jays have been crowding into all of them as well as visiting the birdbaths and spending time in the trees. I live right under Hawk Ridge where, as of the end of the day yesterday, September 19, they’d counted 48,523 jays, and apparently a lot of them want  a lunch break as they pass over. 

A squirrel jumped in two or three times that first day, and once or twice since then, but one taste and it jumped right back out. 

Blue Jays and chickadees haven’t been the only birds to visit the feeder. So far no other songbirds have stopped at it, probably because they don’t want to contend with the jays, but I’ve had both an adult female and a young male Red-bellied Woodpecker coming a few times each day. 

Red-bellied Woodpecker Hatch-year male

If that wasn’t good enough, one female flicker showed up this weekend, giving me several fairly good photos right through the window glass—I have always seen plenty of flickers in my yard, including at my birdbaths, but this is the first one in all our years on Peabody Street to visit any of our bird feeders. So that was of course very cool.  

Northern Flicker

Even better, I’ve had at least two Pileated Woodpeckers—a male and a female—coming to the feeder. 

Both pileateds and flickers are also attracted to ants, which are laced with formic acid, but I didn’t expect either to show up for seeds laced with hot peppers. I love how after birding for 46 years, I’m still learning.

In another week or so, I’ll start mixing in more affordable fare, keeping enough of the peppery food in there to remind the squirrels to stay clear. “Fiery Feast” is expensive and the birds eating it have big appetites—they went through a $36 bag in just one week. That’s a pretty steep price to pay to keep one feeder squirrel-free, but again, after birding for 46 years, I apparently still have a lot to learn. 

Pileated Woodpecker at bird feeder

Thursday, September 2, 2021

Interesting Acorn Woodpecker Research

Acorn Woodpecker

Last year, Storey published a book of mine, The Love Lives of Birds, in which we highlighted 35 species and their different approaches to acquiring a territory and mating.

Some species—swans, cranes, crows and many jays for example—famously mate for life and stay together throughout the year, whether they migrate away from their territory or not. Some, such as albatrosses, loons, and eagles, don’t maintain a year-round bond but return to the exact same territory each spring, ending up with the same mate year after year as long as that mate also returns.  

Many songbirds commit to a mate for a single season, but the following year are as likely to settle in with another bird as that former mate. Some, such as House Wrens, stick with a mate to raise one batch of babies but then both birds very often find another mate if they want to produce subsequent broods that same season. Some forge a temporary bond for just part of the nesting cycle. For example, Mallard drakes stay with hens after courtship only through the time the females build nests and lay their large clutches of one egg a day for a couple of weeks. When a female starts incubating those eggs and loses interest in sex, her mate is out of there. Grouse, turkeys, woodcocks, and hummingbirds separate the act of mating from nesting and raising young; males mate with as many females as they can attract, forming no discernible pair bond with any of them.

There seem to be almost as many mating and territory strategies as there are bird species, and so covering just 35 species barely scratched the surface—that’s less than 5 percent of the more than 700 species that breed in North America, and less than a third of one percent of the roughly 10,000 bird species in the world. I could have written huge chapters about a lot of other birds, and particularly felt bad leaving out one fascinating species, the Acorn Woodpecker. Several researchers I know, including ones I worked with at the Cornell Lab of Ornithology, focused years of research on this amazing bird.

Acorn Woodpecker

I saw my first on Mt. Lemmon in Arizona on 7 April 1982 (no photos), and even before I got a glimpse of the birds themselves, I was gobsmacked by what they had done—one entire side of a log cabin where we stayed was riddled with hundreds, maybe thousands, of holes, virtually every one stuffed with a single acorn. I knew from my reading that Acorn Woodpeckers made these granaries, but had no idea they could be so huge, storing so very many acorns.

Acorn Woodpecker tree

The granaries are constructed by family groups of a dozen or more individuals, who store the acorns communally, and cooperatively raise the young. Living up to their name and all the work involved in building, stuffing, and maintaining those granaries, Acorn Woodpeckers do eat a lot of acorns, especially in winter, but overall, their diet is surprisingly varied. They glean and dig out insects from trees as other woodpeckers do; catch flying insects on the wing; dig out sap wells to feed like sapsuckers; eat flower nectar; take small lizards, baby birds, and eggs; and eat some fruit and seeds. They also visit feeders for seeds, suet, and hummingbird nectar.

Acorn Woodpecker

We know from decades of long-term studies of marked birds that Acorn Woodpeckers have an unusual mating system called opportunistic polygynandry. Within a group, 1–8 males compete for matings with 1–4 females who all lay their eggs in the same nest cavity. The males and females share incubating duties. In addition to these core breeding individuals can be 1–10 non-breeding “helpers” that assist the breeders in feeding nestlings. As with many other birds, such as crows and Florida Scrub-Jays, in which one or more individuals help nesting pairs raise their young, helpers at Acorn Woodpecker nests tend to be offspring fledged by the group in prior years. Non-breeding Acorn Woodpecker helpers may be as old as 5 years old. Cohorts of males and cohorts of females tend to be related to one another—usually siblings—but the two cohorts in a flock are not related to each other. Yep—that’s one heck of a unique mating system.

Acorn Woodpecker

For many decades, long-term research projects studying birds like the Acorn Woodpecker involved marking individual banded birds with uniquely colored leg bands or wing tags and spending many hours in the field observing their activities. New high-tech equipment, from RFID tags to satellite transmitters of increasingly tinier sizes, are allowing researchers to get data on many more individual birds 24/7, even when no one on the research team is anywhere near. Newer, less expensive ways of testing DNA have taken the guesswork out of determining paternity and, in the case of Acorn Woodpeckers and other species in which multiple females share a nest, maternity as well. Now, thanks to two projects led by Sahas Barve of the Smithsonian National Museum of Natural History, one published last year in Current Biology and another published last month in Proceedings of the Society B, we know a lot more about the Acorn Woodpeckers’ unique mating system, and also about how territorial battles between flocks attract non-participating Acorn Woodpecker as spectators. 

It's long been assumed that for species in which the male and female parents both make fairly equal contributions to raising their young, monogamous pairs that defend a territory, not sharing resources with neighboring birds, are more successful than polygamous species in which males share their territory with other males. But the 2021 Smithsonian project found that that those male Acorn Woodpeckers that breed polygamously in duos or trios of males each fathered more offspring than males breeding alone with a single female. Females didn’t get the same benefit. Co-breeding duos of females produced the same number of offspring as the females that coupled up, but female trios left behind fewer offspring than either group.  

Acorn Woodpecker

Acorn Woodpeckers may provide an exceptional example of cooperation in their mate- and nest-sharing, but they have a violent, bloodthirsty, side, too, as research published last year by the same team led by Barve proved. A nesting group’s territory averages 15 acres with one or more granaries. Ownership is stable until there’s a death in the flock. If a breeding female dies, for example, coalitions of non-breeding “helper” females from other flocks will battle with the breeding and non-breeding females from the other flock, trying to take over from the homeowning females. Invading females may return day after day from their own territory. The term “battle” isn’t an exaggeration. Barve told a New York Times reporter, “We’ve seen birds with eyes gouged out, wings broken, bloody feathers and birds that fell to the ground fighting each other.”  

Thanks to the RFID chips which tirelessly record birds every time they appear near the RFID reader, we know that some tagged individuals fought for 10 hours at a stretch for four consecutive days. Although a great many birds in the vicinity have been tagged, one long-lasting battle ended up being won by an unmarked coalition of females.  

No one knows exactly how Acorn Woodpeckers get the word out, but soon after a death occurs, invaders arrive, and within an hour after the first blows, birds from other flocks arrive to watch. They may travel more than 2 miles and spend a full hour watching these battles. Spending so much time attending these battles just to observe must have some value—these birds would normally be spending those hours feeding young, searching out more acorns for their granaries, and defending their own territories to prevent the theft of acorns. Dr. Barve told the New York Times that studying other Acorn Woodpeckers must give them some sort of advantage. “They must immediately see all the big sibling coalitions in the area, gauge their body conditions and the quality of the territory they’re fighting over,” he said.  

Working out the evolutionary advantages for watching other birds fighting is tricky, and we can’t help but wonder whether the impulse for Acorn Woodpeckers to observe other flocks engaging in these fights is comparable to the impulse of people to spend a significant amount of time observing football, World Wide Wrestling matches, or the crazier reality TV shows. But I guess it’s nice to know that there's a counterpart to spectator sports in the world of birds. Maybe there really is nothing new under the sun.  

Acorn Woodpecker

Monday, August 30, 2021

Interesting Hummingbird Research

Ruby-throated Hummingbird 

My backyard is still buzzing with hummingbird activity, but I haven’t seen an adult male in two days, and numbers of adult females and young birds are starting to wane.   

The peak of hummingbird migration coincides with hurricane season, and as Ida bears down on the Gulf Coast precisely where our Ruby-throated Hummingbirds are collecting en route to Mexico, my anxiety is growing. I keep reminding myself that hummingbirds have been using this route for millennia, and even as I realize how climate change is changing everything, making storms, floods, and droughts on average both more frequent and more severe, these tiny little birds really are powerhouses. Many will succumb, but we oh-so-intelligent humans are supposed to take the long view, that the ones who do survive have the genetic makeup to make their own descendants more likely to survive these and even worse conditions. I try to remember that, but my binoculars focus on individuals, not populations.   

I never get to find out what becomes of the individual hummingbirds I interact with—the ones who let me photograph them, the ones who rest in the box elder twigs near my office window and give me so many splendid photo ops. Some hummingbirds over the years recognized me and knew how to catch my attention to fill the feeders. My favorite of all was a female Ruby-throat who would tap at my window to get my attention when wasps were giving her trouble. I’d crank open the window and lean out with my hand vacuum cleaner to suck up all the yellow jackets in and near the feeder while she hovered just a few inches away, trusting that I’d never turn that noisy machine on her. That was in 2004, before I was taking many photos. I often wondered if she had to deal with Hurricane Katrina. 

White-necked Jacobin

Fortunately for my mental health, a bit of fascinating news about a hummingbird research project , about a species that won't be affected by Ida, was just released, distracting me for a bit. It’s about a gorgeous tropical hummingbird, the White-necked Jacobin, which I’ve had the wonderful pleasure of seeing, over the years, in Costa Rica, Panama, Trinidad, Peru, and Ecuador. The adult males have a glittering brilliant blue head and breast, bright, iridescent green back and wings, and a flashy white nape and tail. Most adult females—about 80 percent—have much duller brownish green feathers. 

White-necked Jacobin

But oddly enough, juvenile jacobins of both sexes are brilliant like the males! And even more oddly, about 20 percent of adult females retain that male-like plumage throughout their lives. 

Scientists collecting museum specimens have long known that when they skinned hummingbirds of some species, a small number of specimens that appeared on the outside to be males had, on the inside, ovaries rather than testes. Why this was and how those odd female birds interacted with other hummingbirds was extremely puzzling but hadn’t been studied until scientists at the Cornell Lab of Ornithology and the Smithsonian Tropical Research Institute set to work. The lead scientist on this project, Jay Falk, made this his Ph.D. research for Cornell. 

In Panama, Falk captured 436 jacobins between 2015 to 2019, and recorded the plumage type of each bird and whether it was a juvenile or adult based on tiny corrugation marks on the bill, which are significantly more abundant on juveniles than adults. He took tiny blood samples to get DNA confirmation of each bird's sex, banded and affixed each with a tiny RFID chip, and released them. Two females originally captured as immatures bearing male-type plumage were recaptured in at least one subsequent year as adults with the female-type plumage. But three females originally captured as adults bearing male-type plumage and recaptured in subsequent years retained that male-type plumage, and all adult females originally captured with female-type plumage retained that same plumage in any recaptures. The authors concluded that shifts from juvenile, bright plumage to dull female-type plumage occurs only during the immature period. 

The researchers set out many feeders with RFID readers, where they placed taxidermy mounts of juvenile and adult jacobins of both sexes and both plumage-types., and they recorded how many approaches by the marked live jacobins to those stuffed mounts were sexual and how many were aggressive. 

White-necked Jacobin

As far as sexual encounters, males clearly preferred females in the drabber female-type plumage. But they also attacked them aggressively much more than they attacked adult males, immatures, or adult females bearing the male-type plumage. Yes, the 20 percent of adult females in male-type plumage were attacked much less than the 80 percent bearing female-type plumage. 

Hummingbirds don’t form pair bonds—females have all the nest-building, egg laying, incubation, and childcare responsibilities. Scientists have always attributed the extreme sexual dimorphism in hummingbirds—those brilliant feathers on males and duller feathers on females—to sexual selection. They assumed that males compete with other males for the brightest plumage to attract the most females, and females bear dull plumage as camouflage during their nesting activities, but apparently the reality is more complex. The researchers observed and video-recorded females in the male-type plumage nesting successfully, so even though the study showed that given a choice, males preferred to mate with females in dull plumage, females in bright plumage were still successful in reproducing. They may have lost a bit of an edge in attracting males, but they had a real advantage when feeding, particularly at very busy feeding stations, where the brighter females visited feeders both significantly more frequently and for longer durations than the duller females. So both plumage types have an advantage for adult females, and evolution has kept both types alive, just as in our American Robins, males that are predisposed to migrate early have an advantage in years with early springs, while those that migrate later have the advantage in years with late winter storms. 

A lot of the news media headlined the story emphasizing that these females in male-type plumage had found a strategy to dispense with sexual harassment. If only human females could find such a simple solution!

White-necked Jacobin

Tuesday, August 24, 2021

Identifying and Misidentifying Birds

Rufous Hummingbird in Wisconsin, August 2007

In my blogpost about out-of-range hummingbirds, I quoted Scott Weidensaul, who noted that the out-of-range birds that appear in the East usually arrive here well after our Ruby-throats have disappeared for the season. That’s one of those rules that is virtually always true but has exceptions. For example, on August 11, 2007, I saw and photographed a Rufous or Allen’s Hummingbird at a feeder in northern Wisconsin. The homeowner noticed the little thing because it stood out by its aggressive behavior— even by hummingbird standards, it was exceptionally bellicose in chasing everyone from the feeder, a notable characteristic of Rufous Hummingbirds. They’re even tinier than Ruby-throats but more pugnacious—sort of the chihuahuas of the bird world. 

Selasphorus sp.-- probably a Rufous Hummingbird

On August 14 this year, Steve Patterson posted on Facebook’s KAXE-KBXE Season Watch a photo of a backlit hummingbird. 

Photo copyright 2021 by Steve Patterson

He took it for a Ruby-throat, though he wondered a bit because the bird’s throat was more speckled than most Ruby-throats. When I saw the photo, I immediately focused on the spread tail. The outer three feathers, like a Ruby-throated female’s, were tipped with white, with a darker section above that; the rest of the tail appeared quite orangey or rufous. Also, the bird’s sides looked browner over a more extensive area than most Ruby-throats’ do. I was certain that it was a Rufous or a very similar but even rarer possibility, an Allen’s. When I told Steve, he sent another photo he'd taken of the same bird. The sides didn't seem as rusty as I'd have expected, but my preconceived notion kept me from looking too carefully.

Photo copyright 2021 by Steve Patterson

Steve, who generously and frequently contributes his photos and insights to that KAXE forum, gave me permission to share his photos on my blog. As I studied them, I suddenly realized my initial impression was wrong—the rufous color of the tail feathers was simply an artifact of the backlighting. When I started focusing on the central tail feathers, which lacked white tips (as they should for all three possibilities—Ruby-throat, Rufous, and Allen’s) I suddenly realized that those central tail feathers in Rufous and Allen’s are dark-tipped, which would have been clear in the photo despite the backlighting. 

Rufous Hummingbird
This real Rufous Hummingbird is in range, in New Mexico in July 2013. 

The fact that the rufous color extended all the way to the tips of those central tail feathers made it clear that rufous was not the true feather color. The bird really was what Steve originally thought, a Ruby-throat. Oops! I was wrong. 

Again, during the peak of migration, just about every hummingbird we’re ever going to see in the Upper Midwest will be a Ruby-throat. Giving them more attention just in case is still warranted, and sharing our sightings of outliers is important. But when we post sightings of rarities on eBird, a valuable tool for researchers as well as list-keeping birders, we will always be asked for documentation, which virtually always requires clear photographs. With active birds such as hummingbirds, those photos can be essential for accurately identifying the birds in the first place. 

If I’d seen but not photographed Steve’s bird in that lighting situation, I’d have submitted it as a Rufous or, more generically because of the even more remote chance of Allen’s, as a Selasphorus sp. Although eBird would have let me count it that way on my own private list, the sighting would probably have, quite rightfully, been rejected by the eBird reviewer for their scientific database despite my certainty that the bird had so much rufous coloring. Had I taken the photo and submitted that to eBird as a Rufous Hummingbird, the reviewer or a researcher down the line would have noticed the problem with the central tail feathers and, again, rejected the sighting. 

We birders can’t help but be embarrassed, even mortified, when we make a mistake. Some birders at all levels think eBird's requests for documentation are personal attacks on their birding skills. But the whole point of identifying birds is to, well, identify them. Accuracy is essential in such a geeky hobby, isn’t it? Our lifelists and other birding lists are meaningless if we don’t have enough humility to clear out erroneous IDs when we realize an error or don’t have enough information to absolutely confirm a sighting isn’t something else. Rather than focusing on hurt pride, good birders learn from their mistakes. By admitting errors publicly, those of us who write field guides and lead field trips can help others avoid those same mistakes. 

Double-credted Cormorant

I’ll never forget when a Yellow-billed Loon was sighted along Brighton Beach in Duluth in October 1987. I heard about it while I was counting at the Lakewood Pumping Station, and was told it was working its way up the shore. This was in the days before cell phones and text messaging, and the original sighting was a good 45 minutes before I heard about it, so I decided to pull over everywhere I could as I worked my way toward the beach. Three or four other very experienced birders were also arriving when I pulled into my very first stop—our group included some of the top birders in the state. We scanned the water and almost instantly spotted the bird—that low-slung loon shape and what appeared to be a solid yellow bill, subtly upturned.  

We were of course thrilled—this was only the second sighting ever of the species in Minnesota. We all got great spotting scope looks, and then something about it struck me, and I suddenly realized it wasn’t a loon at all, but an immature cormorant. Everyone looked again, and sure enough. And we all made it down to Brighton Beach where Kim Eckert still had a spotting scope pointed at the real Yellow-billed Loon. 

It was embarrassing of course, but a good lesson about self-delusion when you are expecting to see a good bird. It was also a good lesson in how swimming cormorants do have a loon-like silhouette, and that the way cormorants hold their head slightly uptilted can be a little similar to how Red-throated and Yellow-billed Loon bills are slightly angled upward. 

Even as I was figuring out how important this lesson would be in helping new birders with waterbird identification, the mortification was too much for the others, most of whom had been birding even longer than I had at the time. They swore us all to secrecy, to never ever divulge that we had made that egregious error. I couldn’t help but tell the story on myself many times over the years, but I never did mention who else was with me there. 

Misidentifying birds goes hand-in-hand with identifying them, especially when hoping for an occasional rarity. There’s no shame in making a mistake—the birds truly do not care what species we think they are. But being incapable of admitting a mistake—well, that IS a shame.   


Monday, August 23, 2021

Hummingbird Outliers

Rufous Hummingbird at feeder, November 2004

One of the first things we birders in the eastern half of the continent learn is that the only hummingbird that ranges here is the Ruby-throat. Like all good rules, this is true, but like most good rules, there are important exceptions. As August works its way into September, the hummingbirds at our feeders really are just about entirely Ruby-throats, and because that is true, few people scrutinize them just in case there’s an inconspicuous outlier among them. But the outliers may be more than curiosities and cool checks on our birding lists. If we keep track of them over the years, especially in the context of citizen science projects such as eBird, our records may help provide valuable insights into such environmental issues as climate change and tropical deforestation.

Over the years, I’ve seen a handful of non-Ruby-throated Hummingbirds in Minnesota and Wisconsin: an Anna’s Hummingbird in Grand Marais in November 1991 (a species normally found in the far West from Arizona and Baja California through Oregon, Washington, and sometimes along the Pacific Coast of Canada and southern Alaska), and a Calliope Hummingbird in the Twin Cities in December 1994 (this one doesn’t have as limited a western range, nesting in the Rockies, regularly migrating through Wyoming, Colorado, and New Mexico, and more birds now and then wandering east). I also saw a Mexican Violetear in La Crosse in October 1998 (a tropical species, but occasionally a stray individual turns up in the United States). No one seems to have worked out a pattern to the violetear's wandering, but some individuals may have a weird genetic mutation that sends them in the wrong direction. 

Some of these outlier hummingbirds do die while out of range, as all hummingbirds eventually do even within their range. No one knows if a significant number of them ever find their way back to their natural range, but it’s possible that in a future where their normal range no longer supports them due to fires, droughts, deforestation, or other issues, those with a wandering gene may be the ancestors of survivors in the murky future. A changing climate will change the ranges of a lot of wildlife, benefitting a few species even as it wipes out others.  

The western hummingbird that wanders east the most often is the Rufous Hummingbird. I’ve seen them in Minnesota and Wisconsin on a few occasions, including in my own backyard every day for over two weeks in November 2004 (when I took all the photos used on this blog post). 

Viola the Rufous Hummingbird

The brilliant naturalist and hummingbird-bander Scott Weidensaul was one of the first to suggest that Rufous Hummingbirds are almost certainly in the process of evolving a new migratory pattern and wintering range. On his website, he states:

Changes in the landscape, and the ever-warmer winters of the past century, may be combining to make the East and especially the Southeast perfectly hospitable to these birds. Those that survive and return to their breeding grounds are, in all likelihood, passing on their once-unfavorable genes to new generations. Banding studies in the East suggest the number of wintering hummingbirds is increasing dramatically, and that we may be seeing the rapid evolution of a new migratory route and wintering area for these birds.

Although most Eastern homeowners take down their hummingbird feeders when the last rubythroats depart in September, these western species don't usually appear until much later in the fall - October, November or even December in the latitude of Pennsylvania. For that reason, it's a good idea to leave at least one feeder up and filled through at least Thanksgiving, even if it freezes at night - and to contact a bander if you have a hummingbird in late autumn or winter.

These hummingbirds do not need to be "rescued," as they sometimes are by well-meaning but misguided people who think it is better to keep them in captivity, or ship them south. This is illegal as well as unwise. The hummingbirds are healthy and well-adapted to their new situation, and have already migrated thousands of miles to get there. Please enjoy them, but don't interfere.

Rufous Hummingbird at feeder, November 2004

Tuesday, August 17, 2021

Tiny Miracles

Ruby-throated Hummingbird at bee balm

The seasonality of life can be entirely different within just one single species, sometimes varying by age, sex, or both. 

Take Ruby-throated Hummingbirds. From the end of June through the first half of July, a lot of people up here were emailing me or complaining on Facebook about how few hummingbirds were coming to their feeders. That’s the time of our summer season when adult female hummingbirds are focused on raising young and searching for high-protein insects to feed them. They raise one or two broods each summer, each clutch of two eggs in a brand-new nest that the female built. 

Ruby-throated Hummingbird

After laying the eggs, she spends about two weeks incubating them, then three weeks feeding the nestlings by regurgitation, and then stays with the fledglings for another week or so. And most adult males, not focused on baby care but still interested in mating with females who may be starting second broods, spend their time closer to where the females are than at our feeders. On my corner of Peabody Street this year, one female must have been nesting in a tall tree in mine or my neighbor’s backyard—I saw her almost daily, sometimes several times each day, but always high in the trees, never near my feeders. The few times I got a glimpse at a male, he was up there, too. 

As early first broods of hummingbirds fledge, many mothers lead their offspring to natural food both for the chick’s sake and their own. They visit the colorful flowers we associate with hummingbirds, but even more often to the drabber flowers high up in shade trees and other inconspicuous feeding spots. 

Hummingbirds burn a lot of carbs in their day-to-day lives, and incubating eggs is even more energy-intensive, but producing those eggs requires protein, and the growing nestlings and fledglings, building body mass, muscle, and feathers, need even more protein. Locally native herbaceous flowers, shrubs, and trees provide both high-carb nectar and high-protein insects. When females start a second clutch, their newly independent first brood continues feeding mostly where their mother taught them for days or even weeks before they discover feeders. But some mothers do introduce their young to feeders. When two or three hummingbirds feed peacefully at a feeder without any chasing, that’s usually a mother showing her young a new food source.

Ruby-throated Hummingbird

Once adult females start incubating a second clutch of eggs or it’s too late in the summer to start a second brood, they lose interest in sex, which is when adult males lose interest in them. When no more interested females remain near a male’s territory, even as the child-rearing season continues for the females, adult males transition from their mating season to their bulking up, pre-migration season.

Ruby-throated Hummingbird

Those males enter their migration season weeks before adult females or young hummers. By late August it’s rare to see a hummingbird with a red throat. 

The depleted mothers take much longer than their mates to reach migratory condition. As fledglings reach full independence, they also focus on bulking up—the last chicks to fledge, here and further north, are usually the ones visiting our feeders into September. They know they must migrate. It’s not our feeders holding them north—they simply cannot head out until their bodies are in the best condition and at the right weight.  

Ruby-throated Hummingbird

This year’s drought, impacting both herbaceous plants and trees, may have affected nesting success, and it’s almost certain that poor air quality from so many fires has taken an even larger toll on birds than on humans—birds can’t retreat indoors with air filters when their lungs start hurting. That’s the sort of health situation that doesn’t outright kill birds or humans, but compromises health and can mean life or death in a physically demanding situation. 

Ruby-throated Hummingbird

Fall migration isn’t a single straightforward season for Ruby-throated Hummingbirds—first comes the moseying part when they head to the Gulf Coast, mostly by day, resting and feeding along the way as opportunities arise. 

The Gulf of Mexico represents a fork in the road, and they have two options. Some strike out directly over water to the Yucatán Peninsula, a minimum of 500 miles away if they started out at exactly the Mississippi Delta and if they arrive exactly at the tip of the Yucatán. The journey is usually significantly farther than that depending on where they take off and land and how much the wind throws them off course. No matter how long the journey, these birds take off after a big breakfast and fly every moment of the rest of that day, throughout that night, and well into the next day before they reach landfall to finally rest and eat again. Ruby-throats in the best physical condition to start with seem to be the ones who take this direct over-water route.

The ones moving along the coastal land route have a much longer journey, and not less treacherous—either way, all these tiny birds are making this difficult passage during the peak of hurricane season. Just thinking about that makes me terrified for them, but even the tiniest birds are far less likely to be consumed by fear than we lesser beings are. 

Ruby-throated Hummingbird

Our Ruby-throats don’t breed during their time in the tropics, but it’s hardly a vacation. They must compete for food with the dozens of hummingbird species already there, most of which are larger and already familiar with the landscape. And there are a host of tropical dangers such as bird-eating spiders, a host of small raptors, and large flycatchers. And some snakes lurk within the foliage of tropical plants to strike out at any bird that might approach the flowers. The first time I was in Costa Rica, I set up a microphone and recorder at a feeding station. When I returned, a few hummingbirds were chattering aggressively at the cord while moving in hovering flight along its length—they must have thought it was a snake, and I felt very guilty that my equipment had disturbed their day.  (You can hear the 10-minute recording of hummingbirds flying by, some cursing the microphone cord, here. I don't have a photo.)

Despite all the dangers to and fro and in between, every year sometime around Mother’s Day, hummingbirds reappear in my yard. Every single one of these birds that weighs only an eighth or a tenth of an ounce (you could mail at least 8 of them with a single postage stamp!) survived its long migration down to Mexico or Central America, the treacherous season in the tropics, and its long migration back here. Imagine that! And if that’s hard to believe, I can barely wrap my head around an even more incredible fact: there are four records of hummingbirds listed on the Patuxent Bird Banding Lab website who were caught, all alive and healthy, more than 8 years after first being banded. (All four of them were quickly released after recapture.) All four had been originally banded as an adult, so they were each a minimum of 9 years old when retrapped and released. Some or all may quite possibly have been even older than that!

Some people look up to the heavens in search of miracles. Me, I just direct my eyes to my hummingbird feeders.   

Ruby-throated Hummingbird