An American Robin hunts worms

 

An American Robin (Turdus migratorius) with a just-captured earthworm. 

Last week, Shauna and I traveled to the Pittsburgh, Pennsylvania area on a whirlwind trip. I was to give a talk (moths) to the Garden Club of Allegheny County on Thursday, so we headed over bright and early on Wednesday to photography waterfalls around the Ohiopyle area.

Upon arriving at our cabin late that day after a photo outing, there was an American Robin on the lawn. Whoop de doo, you might think - robins are one of the most abundant and widespread birds in North America. That's one of their allures, to me. I can go to the wildest northern Michigan forest, midwestern prairie remnants, local parks, urban cityscapes, my back yard, and there they are. The big thrushes are nothing if not adaptable.

But robins are much more than adaptable. The robust caroling song is beautiful and a near ever-present sound of nature. They're showy, too - so much so, that if robins were rare, everyone would go ape over them. Their stout nests are remarkable architectural achievements: an adobe cup that dries to the hardness of a China bowl, and its neatly reinforced with grasses and other vegetation. And the color of the eggs spawned the name of a color: robin's-egg blue.

Anyway, as we took a moment to watch the robin, it suddenly lunged and caught a worm. Cool! Said I, then noted that photographing an American Robin in the act of snagging a worm was still on my bucket list. As there were several robins hunting the lawns, Shauna suggested that I go try and check that item off the list, so I did.

A male American Robin looks and listens for invertebrate prey in the grass. When one freezes, lowers its head and cocks it slightly, action is about to ensue. The robin is using its sensitive ears to listen for worms and other prey, as well as watching with keen eyes.

Bingo! The robin pounces! It has its head way down in the grasses and is about to come up with a favored prey item. I'm not sure the bird could even see the victim and may have divined its location entirely by ear.

PHOTO NOTES: I made all of these images with my Canon R5 and 400 DO II lens. It was coupled to the Canon 1.4xII extender, giving me 560mm of reach. That was plenty. Robins are fairly tame to begin with, and after a while this bird became used to me, and I was typically within 30-50 feet of it. I was shooting wide-open at f/5.6 (without the extender, the lens would be an f/4 of course). As robins in the midst of attacking prey can move with astonishing speed, I used a shutter speed of 1/2500. And, as almost always is best with animals, I was at or near ground level for these shots, to be on my subject's level. And the camera was on electronic shutter mode at 20 frames a second, to capture all of the action.

Unlike the worm in the first image, this one is a monster "nightcrawler". Here, the robin has just seized it and is working to tug the worm from the burrow. While such a task is fast and easy with a tiny worm, it is tougher when a big worm is involved. When under attack, the worm can bunch the powerful muscles that form rings down its body and plug itself into the burrow. Furthermore, worms are beset with rows of external setae - short stiff hairs - that can also help in holding it in place.

The robin tugs with all of its might. The bird is actually off of the ground and leaping/pulling backward. There were a few near extractions like this, and the worm would manage to tug itself further back into the hole. Then the robin would yank harder and in fairly short order it had won the battle.

The worm separates from the ground with great force, as if someone had let go of the other end of a Slinky. Its body coils sinuously as the pressure is instantly released, and the robin had it down the hatch shortly thereafter.

It should be noted that all of the large earthworms in this part of the world, insofar as I know, are not native. They are native to Europe and Asia and were brought over by accident in shipping material such as soils associated with nursery plants. It didn't take long for them to spread far and wide and increase enormously in abundance.

It didn't take long for the clever and adaptable American Robin to learn about worms and make them a large part of its diet.

Invasive honeysuckles and birds

 

A western Ohio woodland, its understory utterly dominated by Amur Honeysuckle (Lonicera maackii). While there are other species of Asiatic honeysuckles running amok in the Midwest, this one is by far the worst culprit in most areas I visit. It is firmly entrenched in our flora, much to the detriment of the indigenous plants.

As always, click the image to enlarge

It wasn't always so. The nonnative bush honeysuckles like Amur Honeysuckle weren't a major problem until fairly recently. In Lucy Braun's The Woody Plants of Ohio (1961), she devotes a scant two sentences to it. Braun knew it only in the wild from the far southwestern corner of Ohio (Hamilton County) but did note that it was "becoming abundant".

This map is from Tom Cooperrider's decidedly unsexily titled The Dicotyledoneae of Ohio: Part 2: Linaceae through Campanulaceae. The book was published in 1995 and gives a snapshot of the progress of Amur Honeysuckle in Ohio. Twenty counties have been added since Braun's publication 34 years prior. It should be noted that botanical works such as these rely on vouchered specimens as evidence, and there are relatively few botanists that collect and archive material in herbaria. By 1995, Amur Honeysuckle was undoubtedly in counties beyond those depicted on this map but was definitely not the scourge it is now.

Cut to today, and documentation of the horror show that Amur Honeysuckle has become. The orange squares representing reports congeal into blobs, so frequent are the observations. This is part of the iNaturalist map, which relies on peer-reviewed photos submitted by observers. Ohio is smack in the middle of this snippet of the map, and honeysuckle pretty well blankets the state. Good old Lonicera maackii is certainly in all 88 counties, and at least locally abundant in many or most of them.

How did it get here? Apparently, the original escapes came from the New York Botanical Garden, which began promoting Amur Honeysuckle as an ornamental in 1898. By the 1930's and '40's, wildlife agencies greatly exacerbated the problem-to-be by widely promoting honeysuckle as a ground cover, soil stabilizer, and wildlife food plant. As often seems to happen with invasives, there was a few decades long gestation period where the plant did not run amok, but probably largely stayed where it was put. In Ohio and this region of the Midwest, the spread probably began in earnest in the 1980's and the trajectory was obvious by the time of Cooperider's 1995 book. One need only glance at the iNaturalist map to see what has happened since.

Small wonder people were smitten with Amur Honeysuckle. It is pleasing in form, and sports abundant showy white flowers.

Alas, those flowers later become equally showy fruit, also abundant. Brightly colored berries probably evolved to lure agents of dispersal, especially birds. Birds are drawn to bright fruit, and it is to the honeysuckle's advantage to have its berries eaten by highly mobile winged creatures. A frugivorous (fruit-eating) bird might expel the seeds a long distance away, effectively playing the unwitting role of avian Johnny Appleseeds. Birds are surely the primary reason for the remarkably rapid invasion across a broad swath of eastern North America.

An American Robin (Turdus migratorius) sits among a sea of Amur Honeysuckle fruit. It is akin to a kid in a bowl of M & M's. The 50-acre preserve where I made this shot is in Columbus, and I visited last Sunday. The site was thoroughly infested with honeysuckle, and dozens if not hundreds of robins gorged themselves on the fruit.

A first-year White-throated Sparrow (Zonotrichia albicollis) caught in the act, berry in beak. This species is probably our most abundant migratory sparrow, and many were present here - same site as the robin above.

With abundant frugivores such as the American Robin and White-throated Sparrow (not a major frugivore but nonetheless they have a taste for honeysuckle berries) eating this stuff, it's small wonder that honeysuckle has spread so rapidly and continues to do so. Many other bird species eat it as well including a hyper-abundant nonnative, the European Starling (Sturnis vulgaris). What is curious to me is the apparent lag time from when Amur Honeysuckle began to be planted commonly (1930's-40's), to when it became an obvious and worsening invasive plant (1980's). I wonder if birds, confronted rather abruptly with a completely foreign plant, basically ignore it for a while, not recognizing a potential food source. Maybe it takes a few decades for the feathered crowd to develop a taste for the stuff and begin ravishing it in earnest. But once they do, the game is over.

Amur Honeysuckle is so thoroughly entrenched now that there is no way to eliminate the overwhelming majority of it. Localized control in targeted parks and natural areas can be successful but constant vigilance is necessary as new seed sources will be introduced annually.

We can hope that Amur Honeysuckle eventually runs its course, and fades out, as some invasive species seem to do. But there's no sign of that happening yet.

Nature: Patchwork-patterned piebald robin with mostly white head an astonishing creature

 

A piebald male American robin/Jim McCormac

Nature: Patchwork-patterned piebald robin with mostly white head an astonishing creature

Columbus Dispatch
May 29, 2022

NATURE
Jim McCormac

The American robin is widespread and ubiquitous, the most common native bird in Ohio. Other than in winter —and sometimes even then! — it is likely to be one of the first birds encountered when stepping outside.

Male robins deliver a rich warbling carol that is a pervasive part of the avian soundscape. Everywhere one goes — urban park, backyard, the wilds of Shawnee State Forest, Lake Erie islands — there are robins. Over 4 million of them in Ohio. Nationwide, there are 370 million robins.

Birds as abundant as the robin can quickly become background blur. We get bored with them, another humdrum robin hopping on the lawn. That’s a shame, as the American robin is one of our handsomest songbirds. Were they great rarities, birders would drop everything and come running if one made a showing.

Even I — an avowed fan of the burly extroverted thrush — must admit to ignoring robins on occasion. However, I did quite the opposite when the odd robin that is this column’s protagonist came to light.

In early May, I was in southern West Virginia helping to lead trips as part of the New River Birding & Nature Festival. This region is awash in interesting and uncommon birds — broad-winged hawks, yellow-billed cuckoos, over 30 warbler species including rare cerulean and Swainson’s warblers, scarlet tanagers, rose-breasted grosbeaks and many more.

Even the palette of thrushes, including Swainson's, gray-cheeked, and wood thrushes, and veery, out-exotic their familiar stablemate, the robin.

However, when longtime festival attendees Don and Karen Stose of Clayton, Ohio, showed me a photo they had taken of a very unusual robin I was all ears. The bird had appeared the day before at their campground near Fayetteville. I asked them to call or text if it appeared again, and I’d try to get there ASAP.

Don rang the following day proclaiming, “It’s here!” Fortunately, we were just back from a field trip, and I made it to the campground in 10 minutes. The first bird I saw upon entering the facility was the gorgeous variegated bird, which promptly flew into a woodlot and out of photo range.

I sat with Don and Karen to wait him out. The allure of nearby turf grass was irresistible and the robin soon appeared on the lawn, posing like a supermodel.

The robin's aberrant coloration is caused by a genetic condition known as leucism (loo-siz-em). Defects in pigment cells cause afflicted animals to become whitish, or more commonly, a mix of whitened zones along with normally pigmented areas. The latter are often referred to as "piebald," although the patchwork pattern is formally known as hypopigmentation. White-tailed deer are perhaps best-known in this region for producing piebald offspring.

Leucism should not be confused with albinism, a different genetic anomaly in which the eyes become pink. Leucistic animals retain normally colored eyes.

The leucistic robin was a stunning creature with its mostly white head and upper breast dappled with charcoal scalloping. Scattered white patches adorned other parts of its body. Even the most jaded robin-watcher would drop his or her jaw in amazement at this bird.

Manifestation of leucism is a numbers game. The more individuals in a species, the more likely it will manifest. Thus, leucistic robins, red-winged blackbirds, white-tailed deer and other abundant species appear with some regularity.

Other than possibly making the robin more noticeable to would-be predators, leucism probably doesn’t affect its well-being. Here’s hoping this robin survives, thrives and astonishes other observers.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.

A piebald robin

 

As always, click the photo to enlarge

A striking leucistic American Robin. The animal has a genetic condition that suppresses melanic pigments, creating a "piebald" effect. Karen and Don Stose, attendees at the New River Birding & Nature Festival, found this bird and tipped me to it. It was but ten minutes from where I'm staying, so off I went for a look. And I'm glad that I did, even though more exotic fare such as Swainson's Warbler was close at hand. Fayetteville, West Virginia, last Friday.

Frugivores, plying their trade

A male American Robin deftly flips a berry into its gaping maw. This bird and many of his comrades were devouring a thicketful of Amur Honeysuckle (Lonicera maackii) fruit. I made this shot last Friday morning at Glacier Ridge Metro Park in Union County, Ohio.

The likely evolution of brightly colored berries is to serve as bird attractants. Enticing strong fliers to eat and thus disperse one's fruit is an effective colonization strategy. The migratory and localized nomadic tendencies of robins makes them ideally suited to the task.

Unfortunately, robins don't discriminate between native berry crops and introduced ones, such as this honeysuckle. There are three species of Eurasian bush honeysuckles that have become well established and highly invasive in Ohio and elsewhere in the Midwest, and the shrubs have taken over with great rapidity.

Birds are the reason. Along with Cedar Waxwings and European Starlings (an invasive bird), American Robins are doing much of the heavy lifting in regards to honeysuckle dispersal. All three are highly frugivorous (fruit-eating), at least seasonally. It's very common to see mobs of these species stripping honeysuckles of their fruit, and they will expel the seed-rich fruit far from where they ate it, most likely. One could not design a better plan for a botanical takeover.

Other species of birds eat honeysuckle fruit, but I single the trio above out due to the sheer force of their numbers and strong tendency to harvest fruit crops. Collectively, those three species comprise about 9.5 million individuals in Ohio alone and that's a lot of honeysuckle harvesting power.

We can't blame the birds for this invasive scourge - well, maybe the starlings - but hopefully we can learn from our mistakes. The landscape industry and fish and wildlife agencies pushed these honeysuckles for a long time, touting their "wildlife" values and aesthetic properties (I would agree with the latter - they are quite showy). It should be very apparent by now that woody plants, especially shrubs, that develop colorful bird-dispersed fruits have a great chance of vaulting the garden fence and going rogue. Perhaps the nurseries could become more visionary and avoid selling these plants BEFORE they become problems. 

 A stone's throw from the fruit-plundering robins was this Eastern Phoebe. A tough flycatcher, phoebes will try to ride out the winter if conditions give them half a chance. This one was staying near a small stream on this chilly morning. Their odds of finding insects are higher around water. But on a few occasions I watched the phoebe duck into a patch of Multiflora Rose (Rosa multiflora) and scarf down a few berries. When push comes to shove, and food is of the essence, phoebes will turn to fruit. But because of their low numbers and ephemeral frugivory, they probably play a very minor role in invasive plant seed dispersal - certainly nothing even remotely approaching the gangs of robins, starlings, and waxwings.

HERE'S A POST from 2014 from a site where I caught a number of species in the act of honeysuckle plundering, and talk a bit about why honeysuckle is bad for birds and ecology. Here's ANOTHER POST about robins and global warming that you might find of interest.

Robins, waxwings, and honeysuckle

Amur honeysuckle, Lonicera maackii, cloaks the understory of an Ohio woodland. This plant, and a few other closely related species, would get my vote as worst invasive species of upland habitats. This post is meant only as a (mostly) pictorial offering of evidence as to how the honeysuckle gets scattered far and wide. If you would like to read in more detail about the evils of these shrubs, CLICK HERE.

The first photo in this post was made in early spring, when the honeysuckle was just leafing out. Later would come (admittedly) very showy flowers. Pretty flowers and beautiful fruit are the main reasons that these shrubs were imported to the New World. What a mistake that was. Honeysuckle now runs rampant, and chokes out all manner of native species.

An American Robin perches jauntily in a sea of tasty berries. It, and many others, were plundering a small patch of Amur honeysuckle shrubs in Jasper-Pulaski Wildlife Area last Saturday. I was in Indiana to see and photograph the spectacular congregation of migrating Sandhill Cranes, and will soon post about that experience (once I get my myriad photos sorted).

A robin, caught in the act. At least a dozen robins were raiding this shrub, and consuming several to a dozen berries with each foray. They and the other fruit-eating honeysuckle birds can strip a sizable shrub in a day or two.

Down the hatch goes a honeysuckle berry. Shrubs that produce brightly colored berries are generally doing so to attract birds. The showy fruit is irresistible to robins and other frugivorous birds. While the soft pulp is quickly digested, the hard seeds within are much tougher to digest, and some of them will pass through the bird's digestive tract intact. They will be expelled later, quite likely some distance from the source shrub. This is one of many ways in which plants "migrate".
  

Were these the fruit of some native shrub, I would be much prouder of this photo. After all, it is a reasonably crisp shot of one of our most elegant birds, the Cedar Waxwing. But alas, the debonair chap sits among more of the nasty Amur honeysuckle.

Like robins, waxings are huge fans of berries and a flock can intake great quantities in short order.

I would think that eating one of these berries, were you the size of a waxwing, would be akin to you or I eating a large melon. There were at least as many waxwings working over the honeysuckle as there were robins. In the relatively short period that I monitored their activities, the birds probably ate hundreds of berries.

When one considers the overall numbers of robins, waxwings, and other species of fruit-eating birds, it's small wonder that invasive berry bushes such as honeysuckles spread so prolifically.

Sumac creates biological hotspots!

Your narrator's car, perched along the verge of a Jackson County, Ohio lane, deep in the boondocks. I was down there yesterday to participate in the Beaver Christmas Bird Count - about the 20th year that I've done this count. Tis the season for bird counts; the count period began Saturday. I started doing CBC's when I was just a young lad, long before I had a driver's license, and have participated in nearly 100 to date.

The weather isn't obvious in the photo, but it was dismal. The temperature at 8 am was 34 F, and rose to only 37 F. Frosty temps are no problem, but the nonstop rain that ranged from light to moderate showers was an issue. To me, there are no worse weather conditions than drenching rain at temperatures just above freezing. Makes it much harder to find birds.

One unfortunate aspect of covering the same turf for many years is the negative changes one sees. Last year, the open area above was a wet thicket buffered by goldenrod meadows. For many years I pulled Swamp Sparrows and many other species from this plot. No more - cleared, and drained.

Sorry for the dreaded white sky background in these photos, but there's nothing I could do about that. White skies are the absolute worse for photographic backdrops, and we get a lot of those skies in Ohio winters.

On a more uplifting note, I was cruising this backwoods lane when I came across a nice thicket of Smooth Sumac, Rhus glabra. It's the plants on the left, adorned with reddish-brown clusters. Sumac is a gold mine for birds in the winter.

Here's a closeup of the fruit of Smooth Sumac. Each panicle is loaded with (apparently) tasty and nutritious fruit, and come lean times, frugivorous (fruit-eating) birds dig into them with gusto.

As I trolled up to the sumac, window down, I quickly heard and saw American Robins. Lots of robins. I estimated about 95 birds were flying around, dropping in to pluck sumac fruit, whisper-singing, and generally greatly enlivening the woods. This first-year robin stands guard by a nice cluster of sumac fruit.

One effect of having a big flock of active robins in a large woodland is that their hustle and bustle attracts lots of other birds. The sumac entices the robins. Their conspicuous activity draws many other birds who then forage in the vicinity even though the hangers-on aren't necessarily after the sumac's fruit. I probably had at least a dozen species in the mixed flock with the robin nucleus. In the songbird world, plants ultimately orchestrate the show.

Our young robin digs in. He and his brethren plucked many a berry in the time that I hung out and watched. Some of the fruit will probably pass through the ravages of the birds' digestive tracts intact, and thus new sumac colonies may spring up elsewhere. Birds do not get their due as avian Johnny Appleseeds.

The robin sates its hunger, one berry at a time. Just that one sumac panicle hosts hundreds of fruit.

In winter, this is the species that I key in on the most around sumac thickets, the Hermit Thrush. Sure enough, it wasn't long before I heard the distinctive low chuck call note. Shortly thereafter, the thrush flew in and also began harvesting sumac. Were the weather not so unpleasant, I probably would have found more than this one Hermit Thrush. They are more common than is generally thought in winter; searching sumac is key to finding them.

Every yard would benefit from having an assemblage of sumac. Native plants such as these are incalculably more valuable to birds and other animals than the all too common nonnative garden fare. In the sumac world, at least in this part of the world, the best bang for the buck probably comes from the aforementioned Smooth Sumac, and Staghorn Sumac, Rhus typhina. See if you can find some at an enlightened nursery, and stick 'em in the yard.

In the above photo, we see Smooth Sumac in full flower in mid-summer. The oceans of tiny greenish-yellow flowers attract legions of interesting pollinating insects. When I am out and about, camera in hand, and spot flowering sumac I always veer over for a look. I've obtained many a great insect image at these flowers.

By mid-August or so, the sumac thickets are sporting bright reddish-brown candelabras of long-lasting fruit. Come winter, it is there to provide sustenance to robins and other thrushes that are trying to ride out the northern winter.

Keep in mind next summer's Midwest Native Plant Conference in Dayton, Ohio: August 1st thru 3rd. That's an awesome venue to learn more about native flora, buy quality plants, and generally have a great time.