Laura Erickson's For the Birds

Wednesday, September 29, 2021

Migration Update

Blue Jay

This has been a bizarre year thanks to the drought. Some trees haven’t started changing colors yet even as some have lost their leaves without changing colors at all. Some are turning beautiful colors, but it’s not been predictable.  

I’m worried about this summer’s fires throughout the country—such outsized fires must have killed a lot of birds as well as the food they depend on. The vast majority of birds weren’t in actual burned tracts, and many that were almost certainly flew to safer areas even if they lost this year’s nests and young, but many areas with no burning at all had dangerous air quality levels.  

When we humans are cautioned to stay indoors, we seldom think about the animals left out there to breathe in all the dangerous particulates. California dairy and beef producers report lower conception and birth rates in their herds, and preliminary data from a study out of the University of Idaho indicates that dairy cattle exposed to poor air quality and heat stress produce about 1.3 liters less milk each day. But few or no long-term systematic studies have determined exactly how much heat and smoke affect livestock so now a new three-year study is starting in Oregon. Considering how many people and corporations raise livestock, and how many local and state economies depend on it, it’s a little surprising that so little research has been done to find out how climate change is impacting the industry. It’s not at all surprising that no one is doing this kind of research about our backyard birds.  

I learned in my college ecology and wildlife management classes that wild species can easily recover from even large-scale disasters, but that assumes there exists a surplus population. For many species, that surplus has been dwindling year after year. Even as we see robins increasing—they’ve apparently got a robust surplus—we’ve been losing Wood Thrushes. Mallards are increasing as Redheads dwindle. Hunters used to tell me that to save any species, it should simply be designated a game bird and hunters would save all the habitat it needed, but that sure isn’t true of Northern Bobwhites, Spruce Grouse, Sharp-tailed Grouse, either species of sage grouse, or either prairie chicken. Pheasants are doing fine, but they’re not native to America. Wild Turkey numbers are way, way up almost everywhere, including places like northern Minnesota where they never lived historically, but that’s a case, like that of white-tailed deer and urban Canada Geese, where wildlife management went overboard, putting some habitats and ecosystems at risk.  

Wild Turkey
Wild Turkeys did not historically live in the Sax-Zim Bog!

Despite my worries, I can’t help but take heart from the many birds that are migrating through this fall. I thought last year’s Blue Jay migration through my neck of the woods was going to be the largest I’d ever see—they counted a full 50,646 at Hawk Ridge, mostly in September. But as of the end of the day on September 28, they’re up to 58,655 for this season, an increase of more than 11 percent as migration continues. On September 27 alone, they counted 1,547. My feeders are still hopping, but nowhere near as much as last week—on September 21, I took a photo of 24 Blue Jays crowded into my 3’ x 1’ platform feeder, all pigging out on sunflower seeds.    

Blue Jays at feeder

I led two field trips during Hawk Ridge Weekend. On September 18th, we birded the Western Waterfront Trail in West Duluth, the parking lot and trailhead across Grand Avenue from the zoo. Our list was just 34 species, and we didn’t see any real rarities even though eBird questioned our six Red-eyed Vireos as too many for that date. But all of us saw the three groups of two. eBird’s algorithms didn’t question our two Marsh Wrens, but those seemed way rarer to me.    

It was a lovely day but the birds were focused on feeding, not posing for photos, so I got only a few pictures of Yellow-rumped Warblers...

Yellow-rumped Warbler

... a very distant Swainson’s Thrush...

Swainson's Thrush

... a Great Blue Heron who posed nicely from a long way off...

Great Blue Heron

... a hawk that some participants thought was a Sharp-shinned because it appeared rusty underneath in the morning light but turned into a Merlin in my photos...


...and a poorly lit but lovely group of Wood Ducks with one female Northern Pintail.  

Wood Ducks and female Northern Pintail

My field trip on the 19th was to Park Point. We had only 26 species on this walk, but our hopes were high—in the days before, several people had reported individual and even groups of Sabine’s Gulls, which are very rare here, so we kept looking skyward as we walked some of the boardwalks to the beach, wending our way toward the airport. We saw quite a few Palm and Yellow-rumped Warblers, and on the harbor side we saw a couple of Black-bellied Plovers...

Black-bellied Plover

... and some extraordinarily cooperative Common Mergansers. 

Common Merganser

I was hoping we’d spot a longspur or something on the gravel walkway parallel to the airport runway, but there were too many dogs. Right after we’d turned around and were back near the boardwalk that birders call “the bridge,” one guy yelled out, “That looks different!” I looked up and sure enough it was different, six Sabine’s Gulls booking it from the lake toward Wisconsin. I was identifying and counting them and trying to get everyone’s attention, so didn’t manage any photos. (This photo from 2013 is from a pelagic trip out of Half Moon Bay in California.). 

Sabine's Gull

That sighting was very exciting for the handful of us who saw them. We kept looking up in case they returned, but no luck. As if to console us about that, a Merlin who’d been hanging out near the picnic area, probably picnicking on warblers, did some wonderful posing for us.  


It’ll be interesting to see how this year’s migration reports compare to previous years. I’m glad that one of my favorite birds of all, the Blue Jay, is doing well, and hope we adults get our acts together before my little grandson is ready to go on these field trips. I want to be able to share a wealth of natural treasures with Walter for many years to come.   

Chickadee at the feeder and Dr. Blue Jay in his hand.
Walter is happy to see chickadees at the window feeder as he holds his beloved "Dr. Blue Jay."


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