The fly that isn’t

[Oops, I hadn’t meant to send this yet, but I hit publish by mistake!]

I’ve never heard of sawflies, and now I have seen two different ones, and the larva (caterpillar) of another. Just plain luck. (I do realize some of you probably think I am a little eccentric to get excited about a fly.)

North American Elm Sawfly

Sawflies are in the order Hymenoptera together with ants, bees, and wasps. All of these insects have two pairs of wings, unlike true flies, Diptera, which only have one pair of wings. You can clearly see the four wings in this photo. So they aren’t actually flies at all. They have a saw-shaped ovipositor, hence the first part of their name, but they are nearly all harmless plant eaters.

They have a life cycle with four stages, eggs, larva, pupa, and adult, and the adults only live for about 8 days, which maybe why I haven’t often seen them! These next two photos show the larva of the North Americans Sawfly in the photo above:

Here are the larva and the adult of one called, I think, Monostegia abdominalis.

The larva often congregate in large groups to feed, and rear up when startled. I’m not sure which species this is, but they are sawflies, not caterpillars, because they have a pair of prolegs on every segment, and no claws on the prolegs:

The Beast and the Beauty

I found a surpassingly ugly caterpillar the other day.

It took me a while to identify it, and even longer to understand the significance of what I was looking at. This unappealing grub transforms into more than one possible butterfly, in a twist on one of nature’s greatest mysteries that has become a famous evolutionary case study.

Round where I live in Maine, the caterpillar is likely to metamorphose into this (photographed last year):

This is a White Admiral, Limenitis arthemis arthemis. Notice the red spots and the blue scalloped border. But go a little further south, and it becomes the Red-spotted Purple, Limenitis arthemis astanyax, totally lacking the broad white wing bands.(photo from Wikipedia)

The southern form mimics the blue hindwing coloring of the very toxic Pipevine Swallowtail, Battus philenor, and their two ranges coincide. This “Batesian mimicry” deters predators. DNA evidence shows that the two colorations hybridize across a zone starting in southern New England, shown below in dark grey (from Ries and Mullen 2008)

Interestingly, the presence of even small numbers of the toxic model in the hybrid zone is enough to maintain some instances of the mimicking coloration. Only when there are absolutely no toxic models present, as in Maine, do the butterflies revert entirely to the non-mimicking coloration. The data are a wonderful example of the importance of citizen science, since they were all taken from the annual North American Butterfly Association’s July 4th Butterfly Surveys going back to 1975. If you’d like to take part in a count, click here for details:

The really challenging question is how lepidopterists decide whether these two wildly different wing patterns should now count as two species. Although they look entirely different, they can nonetheless interbreed and produce fertile offspring (hence the hybrids), so they are not genetically isolated from each other. *

The controversy continues.

*It reminds me somewhat of dogs. These two animals, a mastiff and a Yorkie, are both of the species Canis familiaris. Cross-breeding to produce a hybrid might be mechanically challenging, but the resulting Yorktiffs would no doubt become the height of fashion.

Flowers of the water’s edge

At this time of year, the trees are in leaf, casting deep shade, so the woodland wildflowers are mostly over. But the ones on the edges of our shrubby, swampy ponds get water and sunlight, and are flowering now. I thought I’d show you some of them, starting with the smallest blooms. No dramatic stories, just modest beauties in hidden places. Let us take our pleasures where we can.

Horned bladderwort , Utricularia cornuta , 1/4″ grows either in the shallow water, or on the muddy foreshore.

The “horn” is at the base of the flower, easier to see in the next photo.

High Bush Blueberry, Vaccinium corymbosum, 1/4-1/2″, is a tall bush that grows at the shoreline, producing its famous berries in late summer:

Sheep Laurel or Bog Laurel, Kalmia angustifolia, 1/3-1/2″, a relative of the better known Mountain Laurel, forms sizable clumps on the waterline:

Close to, the flowers form a tiny posy:

Rose Pogonia, Pogionia ophioglossoides, 1 3/4″, likes somewhat different boggy habitat. It is an orchid, and these were amongst reeds and grasses, hard to photograph from my kayak:

My last flower is the dramatic bizarre flower of the carnivorous Northern Pitcher Plant, Sarracenea purpurea, a sizable 2″ across. It also is found in swampy sphagnum bogs.

When it has been pollinated, the enormous ovary in the center swells up into a bumpy scaly peach-like globe:

Doesn’t it remind you of Little Shop of Horrors?

PS: A couple of these plants were mentioned in 2019 in a post on carnivorous plants, if you want to see the gory details of how they eat:

PPS: I rather like this page:

A Bald Eagle’s Day at the Beach

This is not my first Bald Eagle post, but I had an encounter the other day that I think justifies another installment. I was out in my kayak on Charles Pond, a lovely quiet corner of Western Maine much of whose shoreline is now protected by the Greater Lovell Land Trust. An eagle lives there, and is often seen in a tall pine tree:

He was there when we put in, but he then moved over to a sandbar, and settled in. We stayed some way off, but slowly drifted closer. It was flat calm, not a breath of wind. There were three crows lurking nearby, which made us think the eagle had a kill, but we couldn’t make it out. The eagle bent down to the water as if to drink, , and came up with something in its beak that looked like a crayfish, or a salamander, or a small dead fish:

From this angle, he is remarkably unimposing, more like a fuzzy chocolate brownie than the lord of the skies.

So was he hunting, or scavenging? Eagles scavenge a lot, but when they hunt it is normally fish they go for, and from the air or from a perch, not on foot. Stalmaster however states that they will wade in right up to their bellies, submerge their heads, and strike with their beak. This one did indeed get his neck wet, as you can see here, but not his whole head.

Then it wandered around a bit, posing nicely,

and bent again to the water fixing its gaze on something in a way that looks like hunting to me.

Another drink, ending with a plume of water:

A short burst of speed,

and a little more posing.

After a while, it flew up into a nearby snag, and apparently ventured into the nesting territory of a pair of Eastern Kingbirds.

They dive-bombed this enormous eagle, quite fearlessly, for several minutes, getting pretty aggressive, flaring their tails out in a territorial display:

and the eagle clearly didn’t like it one bit, rather the way I react to being buzzed by deer flies:

A female Bald Eagle weighs up to 12lbs, and an Eastern Kingbird weighs 1.3oz, so it’s hardly an equal match.

Eventually the eagle flew off to find a more peaceful perch.

PS: Some extra detail on bald eagle hunting methods: “Another less common technique is wading in shallow water where smaller fish are available.  According to Stalmaster, an eagle will wade up to its belly, submerge its head, and strike with its beak….

Bald eagles have a tendency towards species of fish that inhabit shallow water or are surface feeders and therefore vulnerable.  Young eagles are much more likely to “catch” fish that have washed up on shore or fish that are floating rather than swimming.” ( from :

Stalmaster, Mark. 1987. The Bald Eagle.

Insect origami

Who hasn’t looked at a bird’s nest and admired the skills of its avian architect? Now I ask you to turn your attention to what lowly insects can do. A variety of insects and spiders use leaves to manufacture a shelter for their young. This nest, more properly called a nidus, is the work of a Leaf-rolling Weevil:

She is 1/8″-1/4″ long, and her Latin name is longer than she is: Synolabus bipustulatus (or should I say Synolaba bipustulata?):

She lays a single egg then rolls the leaf up around it. When her larva hatches, it eats the leaf material from the inside.

Every year, the hydrangea outside my door hosts a colony of shelters made by the Hydrangea Leaf-tier Moth, Olethreutes ferriferiana, a species of tortricid moth. This one is made of two leaves. The caterpillar lays down a line of silk cement on the inside of the outer leaf edge, and then somehow brings the edges together, enclosing a bud, which provides it with food..

If you cut one open and look carefully, you find the caterpillar,

or, in an older one, a pupa. (You can see the marks where the caterpillar ate the inside of the leaf.)

My hydrangea thrives every year, so I don’t worry about the leaf packages, I just admire the handiwork.

Sometimes in the woods I find elegantly folded leaf nests, like this fortune cookie shape:

or this one with a strip of leaf like an obi wrapped around it.

You can see the silk strands that sew it together.

These might also have been made by caterpillars, or perhaps by nursery web spiders to hide their egg sacs. I didn’t have the heart to destroy one to find out.

PS If you find this sort of thing fascinating, as I do, I highly recommend Tracks and signs of insects and other invertebrates: A Guide to North American Species, by Charley Eiseman and Noah Charney.

A Fawn

A few years ago we bought the abandoned house and barn next door. Our old neighbors had a lovely garden, now completely overgrown. In the middle of the field is a clump of peonies, now in bloom, so off I went, with the dog , to cut some for the house.

I bent down, secateurs in hand, and froze:

Right in the middle of the clump was a tiny exquisite fawn:

Our only species of deer here is the White-tailed Deer, and they are giving birth right now. A new-born fawn is around 8lbs, and can’t really stand at first. So the mother takes it to a sheltered spot called a “form”, and leaves it there while she goes off to forage, returning several times a day to feed it. For the first few weeks it stays quite motionless if a threat approaches, and this one didn’t move a muscle as it looked straight at me:

The small dark marks between its eyes and its ears tell me it is a male: those are the spots where the antlers will emerge when it gets older.

My dog, a beagle with a nose like a missile homing device for squirrels, never noticed this fawn (I dragged her away rather fast, of course). There are two reasons for this. First, the young fawn’s scent glands are not yet producing much scent. And secondly, the mother licks it clean after birth to remove any smells that might attract predators, like me and my beagle.

Does often have twins or even triplets. and they then stash them in different places, presumably to decrease the odds of a single predator killing all of them. So this one may have had siblings nearby, but I didn’t go hunting for them.

One was enough to delight me beyond all measure.

The Fawn

by Edna St Vincent Millay (1956)

There it was I saw what I shall never forget 
And never retrieve. 
Monstrous and beautiful to human eyes, hard to 
He lay, yet there he lay, 
Asleep on the moss, his head on his polished cleft 
small ebony hoves, 
The child of the doe, the dappled child of the deer. 

Surely his mother had never said, “Lie here

Till I return,” so spotty and plain to see 
On the green moss lay he. 
His eyes had opened; he considered me. 

I would have given more than I care to say 
To thrifty ears, might I have had him for my friend 
One moment only of that forest day: 

Might I have had the acceptance, not the love

Of those clear eyes; 
Might I have been for him in the bough above 
Or the root beneath his forest bed, 
A part of the forest, seen without surprise. 

Was it alarm, or was it the wind of my fear lest he 
That jerked him to his jointy knees, 
And sent him crashing off, leaping and stumbling 
On his new legs, between the stems of the white 

Vantage points

A pond is home to many creatures who live in it, on it, or around it. But sometimes, no matter where you live, you really want a better view. In my pond there is a biggish flat rock, completely surrounded by water. It is a long way from shore, but it is always worth a look through my binoculars. In the last ten days I have seen five different visitors using it to rest on, sunbathe on, seek refuge on, or hunt from. Here they are. Not the world’s best photos, because of the distance, but I hope you enjoy them anyway.

The first thing I saw was a big snapping turtle. It swam past me the other day:

and a day or two later there it was on The Rock:

Snapping Turtle

This one obviously hasn’t read the books claiming that they mostly sun themselves by floating around in the water. And I have seen it there on three different occasions now.

Next, I saw a Canada Goose. There were seven or eight on my pond in early spring, now down to two or three, and no goslings.

Canada Geese

The one on the pinnacle of The Rock was apparently sleeping on one leg. Why do birds do that, I wonder?

Goose on the rock

(This really is the same rock, just taken from a slightly different vantage point on the opposite shore.)

I have a Hooded Merganser:

with eight ducklings on the pond:

and one day there they were, all up there on The Rock.

This was a bit worrying, since I now knew that the Snapping Turtle liked The Rock, and snapping turtles love a tasty duckling for dinner. Indeed, the next hooded merganser I saw had only four ducklings. Was it the same one, with only half her family left, or a different one? I may never know.

They weren’t the only ducks that liked The Rock. This delicate wood duck with six ducklings (three hiding behind her) had been frequenting one end of the pond.

And with all six ducklings she climbed up on The Rock to enjoy the view:

For all these ducks and their families, the appeal of The Rock is twofold. Firstly, it is land, so water predators like otters or mink can’t reach them. But it is also an accessible piece of dry land. Most of the shoreline is overgrown with reeds, bushes, and a wide variety of undergrowth, so getting out of the water isn’t easy. The Rock is different. Secondly and most importantly, it is an island, so they are also safe from land predators like foxes and coyotes.

The final occupant (so far) is a Great Blue Heron. A single one is hanging around this summer.

Great Blue Heron

Here he is in the distance on The Rock:

Heron on The Rock

For him, it is a an excellent perch from which to hunt. Most of the time he was looking fixedly down at the water waiting for a passing fish:

Heron on The Rock

Beaver lodges can also be used as perches, but more often by birds or mammals. They present too much of an obstacle course for animals with short legs that can’t fly, like turtles or ducklings. Maybe I’ll talk about them another time. For now The Rock reigns supreme.

“The fall of a sparrow”*

When I was growing up in southern England, there were sparrows everywhere, and we took them for granted. Children fed them breadcrumbs as they hung around the tables in outdoor cafes. They looked like these Cotswold ones, and when I grew up I eventually learnt their proper name was the House Sparrow, Passer domesticus:

The UK has a second species, the Tree Sparrow, Passer montanus, but until quite recently I never knew that worldwide there were many many species of sparrows. In fact around here in Maine there are twelve fairly common ones, and four more that are seen occasionally. To me they were just what birders call LBJ’s, or Little Brown Jobs. Who cares? Well, we all should. Because in England they have declined precipitously since my childhood, with house sparrows down 71% and tree sparrows down a horrifying 93% from 1970 to 2008, and that’s what can happen if no-one pays attention.

To encourage those of you reading this in the US to look more closely, here are the seven species I have photographed here in Maine. The larger number of species here relates partly to the greater land area, and partly to how birds are classified as, for example, sparrows vs finches. You will see from their Latin names that they are unrelated to the Old World sparrows, and indeed they are not all related to each other! Don’t worry if you find it hard to tell them apart, so do I, and if I’ve got any of them wrong, do let me know.

I’ll start with the American Tree sparrow, Spizelloides arborea, which stays here most of the year, even February:

The Song Sparrow, Melospiza melodia, is here from early spring to late fall, and it breeds here. It is quite a large sparrow with a black spot in the middle of its breast:

A more familiar pose in this shot:

And it has a healthy appetite, even tackling sizable dragonflies (unfortunately, since they keep down the mosquito population):

I particularly like the Chipping Sparrow, Spizella passerina, with its orangey-brown head. It is a summer resident.

The White-Crowned Sparrow, Zonotrichia leucophrys leucophrys, just migrates through. The first shot is an adult, heading north in the spring, and the second shot is a juvenile on its way south in the fall.

The Swamp Sparrow, Melospiza georgiana, isn’t seen so often because it lives, surprise surprise, in swamps, but here is a rather scruffy one:

My second-to-last is probably my favorite, the White-throated Sparrow, Zonotrichia albicollis, with its white throat (obviously) and bright yellow by its eyes (Birders have a name for this patch of feathers, the “lores”). It breeds here in Maine, and some even winter over.

My seventh (and last) is sort of cheating: it turns out that the European House Sparrow emigrated to the US 150 years before me, in the mid-1800s, when one Nicholas Pike released 16 sparrows in Brooklyn, and here it is in Maine:

I hope you never look at sparrows as just LBJ’s again.

PS The species I still haven’t seen are the Field, Fox, Savannah, Lincoln’s, and Vesper sparrows.

PPS You might want to read this short Smithsonian piece about our relationship with sparrows. Among other things, it tells the terrible saga of Mao Zedong’s edict that all sparrows should be destroyed, and the consequences.

*My title comes from Hamlet “There is a special providence in the fall of a sparrow”. Shakespeare uses this to suggest that we must resign ourselves to death as being all part of God’s plan, but as far as the sparrows go, I say let’s fight for their survival. This means preserving their habitat and protecting their migration paths.

Even snakes can fall in love

I was with fellow docents for the Greater Lovell Land Trust, plus four remarkable children, looking for dragonflies hatching. Two people had seen two water snakes earlier in the week, and to our delight, one emerged from the pond:

This is a Northern Water Snake, Nerodia sipedon, not poisonous, but quite bad-tempered, and a distinct deterrent to what is now (in the UK) called “wild swimming”. This was about 2 feet long, but they can grow to 5 feet. It meandered around, and disappeared. But not long after, it reappeared alongside a much larger one, and they headed for the hills:

The bigger one is the female. They didn’t go far, and curled up in a very cosy embrace:

We watched as they bundled up together, impossible to disentangle one from tother:

The two snakes encircled each other, looking unnervingly like a solitary two-headed snake:

At intervals the smaller male endearingly rested his smaller head on the female’s larger one:

All of this is part of the foreplay, really; the male rests his cheek on the female and rubs her gently. Eventually, he aligns his body with hers, and tries to get the crucial parts into alignment.

From time to time they convulsed, briefly, and this video makes it pretty clear what was afoot; we were nothing but voyeurs:

Then they moved off, now twisted into a braided skein:

As they moved, the smaller male lay almost motionless balanced on the back of the powerful female:

How do the mechanics work? Snakes have openings under their bodies near (but not at) the tail, called cloaca. The mechanics of mating involve lining these up so that the make can insert one of his two hemipenes to deposit his sperm, and then seal it in with a copulatory plug (which also keeps any other males out).

Since the action all happens underneath, closeups are heard to get. Here I think they are just disconnecting; the female’s tail is on top, and the male’s body is belly-up.

I’ll end with one more video:

We left them alone. In 3-5 months she will give birth to as many as 36 live babies, each about a foot long..

PS For 2000 years, intertwined snakes have been a symbol of faithful love. This bracelet is from the 1st century AD, from Roman Egypt:

Prince Albert gave Victoria a snake engagement ring , here is the inscription on the inside:

Some of this jewelry does not appeal to my 21st century taste, but this 19th century enamel and diamond bracelet is on my wish list, though occasions to wear it would be rare:

The first blush of spring

We associate red leaves with the fall, but every photograph in this post was taken this spring. These plants don’t stay red, they turn green, but why do they start off this way?

No-one knows, but a recent suggestion is that the “juvenile reddening”makes the tender young leaves less discernible to some insects that might devour them, and the associated chemicals make them unpalatable.* Below is a hawthorn:

And a beech:

All sorts of plants start like this. Here is a Wild Sarsaparilla:

And here is a fern:

The phenomenon is found not only in many trees, like this maple:

but also in many tiny plants, like this miniscule fern:

And then the red leaves turn green, and the flowers appear. Hard to believe this Striped Maple is the same plant as the one in the very first photo:

*A little more science. The chemical that makes the leaves red (in fall or spring) is called Anthocyanin, and the tree uses energy to produce it, so it must serve some beneficial purpose. It seems to be more common in young trees than in mature ones, and in poor soils. It may protect somewhat against drought, and late frosts. One theory was that it acted as a sunscreen, but recent work has debunked that idea, leaving the insect-deterrent effect as the leading contender for now.

“Compared with red phenotypes, green phenotypes suffered greater herbivore damage, as judged by the number of leaves attacked and the area lost to herbivory. .. The decreased reflectance in the green spectral band and the concomitant leveling of reflectance throughout the 400-570 nm spectral range may either make red leaves less discernible to some insect herbivores or make insect herbivores more discernible to predators, or both. Moreover, excessive herbivory may be additionally discouraged by the high phenolic concentrations in red leaves.”

Karageorgou and Manetas 2006