Thursday, June 17, 2021

Blue-winged vs. Golden-winged warblers: An interesting conundrum

 


A male Blue-winged Warbler along the Black River in Cheboygan County, Michigan on May 19, 2021. I heard the bird singing, and eventually managed a documentary shot on this dark, rainy day.

I photographed this Blue-winged Warbler in the Pigeon River Country State Forest, which is in the northern tip of Michigan's Lower Peninsula. While the species is old hat to those who live in the eastern U.S., south of Michigan, it's - for now - a rarity up here. In a dozen nearly consecutive years (missed last year - COVID) of intense natural history exploration up here, it is the first Blue-winged Warbler I have documented.

I'm not just missing them. The northern Lower Peninsula is at the northern limits - for now - of the southerly Blue-winged Warbler's distribution. eBird records remain sparse here, and most of them come from the last decade. Records will continue to increase, I am sure, and I am reasonably certain this will not be the last Blue-wing I encounter in this region.

While leading a group a few days after finding the Blue-wing, and only a few miles way from that spot, we encountered the bird above. It is a hybrid between the Blue-winged and Golden-winged warblers, and this hybrid form, which expresses dominant genetic traits of both species, is known as the Brewster's Warbler (At least for now. There is a movement, misguided in my opinion, to do away with all eponymous bird names). I revisited this spot on May 28 and made this shot. The bird was singing a more or less Golden-winged Warbler song, although it frequently elided the last syllable. Lawrence's Warbler is the other typical hybrid form but it is far scarcer. I've only seen it once, long ago. This absolutely stunning form - lemon-yellow below, bluish-gray above, with chickadee-like black bib, and prominent ebony eyeline, apparently results mostly from pairings of second generation backcrosses. Brewster's hybrids express mostly dominant genetic traits of the parent species; Lawrence's expresses recessive traits.

Golden-winged Warblers are reasonably common up here. To show how easy to find they can be, after working with the aforementioned Brewster's Warbler, I drove a few miles north to an aspen-dominated reverting clearcut and found and photographed this apparently "pure" Golden-wing for a hot off the press comparison.

PHOTOGRAPHIC NOTE: I love trying to shoot "creative blur" songbird photos. This fellow sat on this Bigtooth Aspen branch for some time, singing and preening. When songbirds preen, they often interject short violent shakes of their wings, tail, and body. The photographer should be alert for this behavior. As long as the head and eye are in focus, the shake shot will work, and create an interesting pose. Badly done, "creative blur" is just synonymous for a poor photograph. Because of the ample sunlight streaming in over my shoulder, I was stopped down to f/8. Even though my shutter speed was 1/1000 (ISO 320), it still wasn't nearly fast enough to freeze the action and we see the wings and tail in an interesting blurred fluff. Had I been more on my game, I would have probably had the shutter speed down to 1/200, though.

I "fear" I am bearing witness to the beginning of the end of the Golden-winged Warbler in the northern Lower Peninsula. I don't really fear this, though, and am rather more fascinated by the biological process of genetic swamping by the Blue-winged Warbler. When these two "species" come into contact, the process of hybridization commences, with the upshot being that within a few decades all of the Golden-winged Warblers will be replaced by genetically dominant Blue-winged Warblers.

The likely explanation for the prolific hybridization is that the two entities have only recently come into contact with one another. As European settlers opened up the vast eastern deciduous forest, the clearing of the landscape abetted the northern expansion of the more southerly Blue-winged Warbler. As it increasingly came into contact with the northerly breeding Golden-wing, hybridization occurred resulting in the genetic swamping that seems to be increasingly common. In my state of Ohio, the Golden-wings were largely vanquished by the 1940's. About 75-80 years later, I am witnessing this same phenomenon nearly 300 miles to the north of Ohio's Oak Openings region near Toledo, where Ohio's most robust population of Golden-wings was historically documented.

Sharp students of natural history might ask "If they hybridize and produce fertile offspring, why are Blue-winged and Golden-winged warblers separate species?" 

Great question.

"The Biological Species Concept defines a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring. According to that concept, a species' integrity is maintained by interbreeding within a species as well as by reproductive barriers between organisms in different species." (lifted from www.sciencedirect.com).

The BSC is the most common concept that defines species, although genetic analysis and the resultant data increasing play a role in drawing species lines. Genetic studies of these two warblers also do not bolster the case for separate species. They are 99.97% genetically similar. But morphology has apparently won the day, and the two are retained as separate species based primarily on their very different appearances.

WAY back in 1835, John James Audubon speculated that Blue-winged and Golden-winged warblers were the same species. Indeed, it seems that they should be considered forms or subspecies of the same entity. It's possible a bit of politics enters into the decision to retain them as separate species. Can you imagine the hue and cry in the birding community if these two "species" were lumped into one?

Independent of the human obsession with sorting and pigeonholing organisms, and the problems sometimes encountered when doing so, I will continue to enjoy the unfolding drama of the Blue-winged/Golden-winged clash in northern Michigan. Personally, I do not see this as a conservation issue - certainly nothing approaching the true conservation concerns surrounding the nearby breeding Kirtland's Warbler. Rather it is a case of long-term (or maybe short-term!) evolution playing out its hand. The Blue-winged form holds primacy over the Golden-winged form, and who are we to say that this is bad? I suspect Nature knows better than we as to what this "species" needs to expand and flourish.

Monday, June 14, 2021

Cedar Waxwing

 

An adult Cedar Waxwing might be the epitome of feathered elegance. I photographed this one on June 8, at Cedar Bog, Champaign County, Ohio.

Wednesday, June 9, 2021

Backyard fawn, again!

Last year, I wrote about a White-tailed Deer fawn that I found in my backyard on May 23, shortly after its birth. You can see that post HERE, and two follow-up posts HERE and HERE.

Here we go again. I looked out into the back yard this morning, and there was this. The fawn had to have been born in the last 24 hours. It's tiny, and still has trouble walking. The doe is quite attentive and stays nearby. This scene is 15 feet from my sunroom windows, and probably the most sheltered part of the yard. It's the same area where last year's doe (same one?) spent much time with her infants.

A brief video of the newborn fawn in my backyard. It is just learning to walk, and is pretty gawky and uncoordinated. That will change fast. But now, it's amusing to watch the fawn get a burst of excitement, break into a clumsy gallop, get about eight feet, and lose all synchronicity between its legs and fall down. It then just lays there and dozes off. You can get a taste of that uncoordinated clumsiness in this video. Sorry for the poor quality - I was handholding and trying to stay out of sight of the doe. That lens isn't made for video, apparently, and clicks a bit. But if you listen carefully, you can hear the fawn bleat a few times.

If this goes like last year, they'll be a staple in the backyard. And in a few weeks, if she was successful in having a pair, she'll bring the other fawn into the yard and then there will be three.

Monday, June 7, 2021

Nature: Giant water bugs vicious when it comes to attacking prey

 

Jim McCormac's finger provides scale to a giant water bug/Jim McCormac

Nature: Giant water bugs vicious when it comes to attacking prey

Columbus Dispatch
June 6, 2021

NATURE
Jim McCormac

Once one learns that mammoth insects sometimes called “toe biters” lurk in ponds, a person might be less inclined to wade bare-footed.

Formally known as the giant water bug, Lethocerus americanus, this insect is indeed intimidating. If looks could kill, an entomophobe might keel over on the spot.

Despite online videos overhyping the perils of the giant water bug, they’re fierce looking six-legged marshmallows. In fact, if handled or threatened, the bugs often freeze up and play dead. That’s not to say that caution isn’t warranted if handling one. They can pack a punch.

The giant water bug is a true bug in the order Hemiptera, and like many of its brethren it has a stiff tubular proboscis. If a person is foolish enough to get bit – which would normally entail goading the insect to defend itself – they’ll experience notable pain.

Giant water bugs frequent leaf litter and other plant detritus in the shallows of ponds and other water bodies. While the bug may be conspicuous when high and dry and exposed next to my finger, it’s virtually invisible in its aquatic haunts.

Woe to the lesser creature that happens by a lurking giant water bug. The prey is quickly ambushed by the bug, which swims it down in short order. Victims are seized by powerful forelegs, and the coup de grace is administered via the proboscis.

A chemical cocktail is injected which rapidly immobilizes the prey. Other agents quickly go to work, dissolving its innards. The giant water bug then sucks out the contents via its proboscis, like a grisly milkshake.

Admittedly this is a horrible fate by human standards, but fortunately the bugs cannot do us real harm. However, we can be grateful that giant water bugs are not truly giant, like the size of a lunker muskellunge. Then swimming would be an exercise fraught with peril. Kayakers would be capsized, seized, and reduced to dried husks, their bodies left afloat like gruesome buoys marking the presence of the terrors below.

While giant water bugs can’t kill people, they are a rare case of an invertebrate capable of killing vertebrates. Small fish and amphibians are regularly captured. Crustaceans too, and crayfish are often a dietary staple. Other insects make up the bulk of the prey, though.

Females lay around 100 eggs, and place them on underwater vegetation. The male guards them until hatching, ensuring their safety.

On April 13, John Howard and I were exploring a small lake deep in Shawnee State Forest in southern Ohio. The waterbody was full of red-spotted newts and other interesting aquatic creatures. John saw a giant water bug jet from cover, drew his net like a quick-draw shooter and bagged the beast.

We found another, and were quite pleased with the finds. True to their generally passive demeanor, the bugs played dead while we manipulated them for photos. Once we had our fill of these fascinating creatures we released them back into the depths.

Like most bugs, giant water bugs are capable of flight and that’s how they disperse and colonize new sites. They can be attracted to lights, and occasionally turn up on walls by nightlights. Maybe, if you are really lucky, one will appear at your porch light.

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.

Saturday, June 5, 2021

White-tailed Kite in Ohio!

 

A White-tailed Kite wafts by my position yesterday. Bernie Master and I headed over before the crack of dawn to see this great (for Ohio) rarity.

This is a species with a broad distribution, but normally nowhere near Ohio: Western states from Oregon through California, Mexico, Central America, and broad swaths of South America.

Ohio's first record came from Coshocton County in May 2020 but was not widely seen. It was discovered and well photographed by Ian Ruppenthal. I do not recall for sure, but I don't think anyone was able to relocate that bird.

This bird was discovered in Harrison County on May 31 by Mary Grey and Larry Helgerman, has since been seen by scores of people, and is still present. One must wonder if it is the same bird as the 2020 sighting, as the two records are not far apart and both in similar reclaimed stripmine habitat. Perhaps Ian's 2020 bird ventured to this spot last year, and avoided detection. The two sites are only about 50 miles apart - nothing for a bird with the flying ability of a White-tailed Kite.

This species can be a nomad, and there are a number of records from eastern states. It'll be interesting to see how long it sticks.

Monday, May 31, 2021

Nature: Brood X will bring out black-billed and yellow-billed cuckoos who feast on cicadas

 

A black-billed cuckoo in northern Michigan, where it is common/Jim McCormac

Nature: Brood X will bring out black-billed and yellow-billed cuckoos who feast on cicadas


NATURE
Jim McCormac

In my last column, I wrote about the impending eruption of Brood X 17-year cicadas. They’re in full cacophonous swing now. If you live in an emergence area, you know. Depending on one’s outlook, the cicadas are annoying pests or a rare opportunity to witness one of nature’s greatest entomological spectacles.

The black-billed cuckoo would take the latter viewpoint. Cuckoos are voracious cicada predators and take full advantage of emergences such as Brood X.

Cuckoos are fascinating and poorly understood birds. Two species occur in Ohio: the aforementioned black-billed cuckoo, and the more common and wide-ranging yellow-billed cuckoo. Although they look like songbirds, cuckoos do not belong to the giant order Passeriformes, which includes songbirds. They are much more closely related to owls.

While yellow-billed cuckoos nest commonly statewide, black-billeds are most frequent in the northern third of the state, but even there are outnumbered by the former.

Brood X should turn that distribution and abundance status on its ear this year. Black-billed cuckoos — yellow-billeds, too — converge on cicada emergences in big numbers. It’s as if the birds have their own Nextdoor app to clue them in. The mechanisms that allow them to locate cicada emergences is not understood.

One would think that a bird that’s bigger than a robin would be easy to study. Not so. Cuckoos are quite secretive and given to skulking in dense vegetation. Their loud, distinctive calls are often the only evidence of their presence.

Even at the late spring date of this column, cuckoos are still arriving. They have a long trip to get here. Black-billed cuckoos winter in western South America, from Colombia south into Peru. Next to nothing is known of cuckoos in their tropical haunts.

In 2016, when periodic cicada Brood V emerged over much of eastern Ohio, I was stunned at cuckoo numbers. It seemed that everywhere I stopped, cuckoos of both species would be calling. In areas where the black-billed cuckoo would normally be unusual, they were commonplace.

Billions of easily captured, six-legged flying steaks make for easy pickings, and small wonder cuckoos capitalize on the bounty. They are well-known for exploiting caterpillar outbreaks, too, and when food is plentiful breeding success spikes.

Food outbreaks can trigger an unusual behavior in cuckoo reproduction: brood parasitism. Ample nutrition allows female cuckoos to produce an excess of eggs. They’ll dump some in other birds’ nests, in the hopes that the unwitting hosts will raise the cuckoos. Host species include American robin, chipping sparrow and gray catbird. Sometimes even yellow-billed cuckoos fall victim.

Our cuckoos seemed to have evolved with insect booms, especially those of caterpillars and cicadas. Feathered nomads, they congregate where the outbreaks occur. Unfortunately, natural insect cycles are not what they used to be.

Naturalists described “flocks” of cuckoos descending on insect emergences in the late 1800s. No one sees such numbers these days — there are far fewer cuckoos. Ill-devised “pest” management and massive alterations to forested habitats have wrought havoc on natural insect cycles, including periodic cicadas. The animals that evolved to exploit these booms, thus providing natural controls, have also been greatly reduced in number.

But for cuckoos in the Brood X zone there will be food aplenty, and hopefully scores of little cuckoos will result.

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.

Thursday, May 27, 2021

Kirtland's Warbler forages in Jack Pine


A Kirtland's Warbler forages in a Jack Pine. The relationship between the bird and tree is intimate. They only breed in near monocultures of the pine, and only pines between 5 and 20 years of age, or thereabouts. Small cherries and oaks are scattered about, and the birds will often use those as singing perches, and will also hunt caterpillars in them. The "Jack Pine Warbler" is doing well, with about 2,300 pairs, nearly all of which breed in the northern part of Michigan's Lower Peninsula, where I made this photo while scouting prior to the arrival of groups that I would be leading. The date was May 19.

In the late 1970's-early 1980's their collective population dipped below 200 pairs and doom seemed to be on the horizon. So, the current 5,000 or so birds may not seem like many but compared to four decades ago it's a bonanza. The Michigan Department of Natural Resources and U.S. Fish & Wildlife Service deserves kudos for implementing major management activities that have greatly benefitted the birds.

Kirtland's Warblers can be quite tame, and in the past I have had them approach within a few feet of me when laying on the ground observing them. One memorable bird came so near I was sure it was going to hop onto my leg, and its loud boisterous song practically hurt my ears.

I've led tours up here for about 12 of the last 13 years (Covid scrubbed last year) in conjunction with NettieBay Lodge. This morning, we were back in the elfin Jack Pine forests bright and early, Kirtland's Warblers singing all around. This group is keenly interested in botany, and we found ourselves looking at a sedge at one point. I saw a movement to the side, glanced over and there was a gorgeous male Kirtland's Warbler only 10-12 feet away in a small oak. Needless to say, we got good looks. Just prior to that, we had stopped at a clearcut in an early stage of succession, enjoying a cooperative Mourning Warbler. On the breeding grounds, they are not the shrinking violets that they tend to be in migration, and males will often tee up on conspicuous perches where they'll sometimes sing for five minutes or more at a time.

At that same spot was a Blue-winged Warbler, the second one that I've found since being up here on the current trip. And these are the first of this species that I've found up here in twelve years of fairly intense exploration during the breeding season. There are somewhat ominous overtones to the arrival of these Blue-winged Warblers, and I will try to write about that later.


Blue-winged vs. Golden-winged warblers: An interesting conundrum

  A male Blue-winged Warbler along the Black River in Cheboygan County, Michigan on May 19, 2021. I heard the bird singing, and eventually m...