The Hermit Thrush exposed

I was walking with a friend in the woods, when a small brown bird suddenly flew up from the ground in front of us. On a lucky day (for us), this suggests we have disturbed a mother, quietly tending her nest. And there it was, concealed under a few small ferns, right in the middle of the trail:

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And containing two stunning blue eggs:

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The mother usually doesn’t go far, but she is hard to see in the dappled woodland. This time, we found her, a hermit thrush, Catharus guttatus faxoni:

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Ground-nesting birds seem to be running a terrible risk of discovery, and indeed studies show that the best predictor of nest success is how well-concealed and camouflaged the nest and eggs are. So why do they have bright blue eggs?? Search me.

Hermit thrushes may have two or even three broods per year, especially if the first brood fails. This brood is extremely late, although luckily for these chicks this is a species that migrates very late, mid-October being common, so they should make it out before winter closes in. Like many Mainers, they over-winter in Florida.

Hermit thrush song is haunting, with short 1.5 second snatches, called song types, separated by 2.5 second silences. Roach et al (2012) studied Maine Hermit Thrush song in detail. Each song type is slightly different, rather like a nightingale, and a male has a repertoire of up to 12 song types. Each male’s repertoire is entirely different. A song bout can have up to 100 song types in it. Listen here:

Human hermits are usually shown in caves, but here is a ground-nesting human hermit: John Singer Sargent’s The Hermit (Il solitario)

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The Metropolitan Museum if Art website says “Sargent based this painting on sketches he had made in Val d’Aosta, in the foothills of the Alps, in northwestern Italy. … When approving The Hermit as the translated title of the picture, Sargent wrote to the director of the Metropolitan, “I wish there were another simple word that did not bring with it any Christian association, and that rather suggested quietness and pantheism.”

Robber ambushed

[Not for the faint of heart]

A tiny war was fought in my yard this morning. While deadheading my flowers, I found a fierce battle underway, between a Jagged Ambush Bug, Phymata sp., (right), and a Friendly Robber Fly, Efferia aestuans:

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Both were alive and moving, but the ambush bug had the upper hand, and its pale green proboscis was sunk into the robber fly:

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I went away for half an hour, and when I came back the ambush bug was alone:

Jagged Ambush Bugs

I searched for the robber fly, and found it lying intact but motionless on a lower leaf:

Friendly Robber Fly, Efferia aestuans

It may or may not have been alive, but it was certainly paralyzed: ambush bugs inject a paralyzing poison through their proboscis, and then eat their prey at leisure. This ambush bug had foolishly allowed its prey to slide out of its formidable grip, uneaten.

Ambush bugs are so-named because they lie in wait, extremely well-camouflaged, until woe betide the unwary bug that wanders too close:

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Below is the same one in close-up, carefully positioned on the yellowy-black centre of the flower where it is almost invisible:

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The biblical phrase “they lay in ambush” fits its posture perfectly, and makes me realize why “sit in ambush” or “stand in ambush” just don’t cover it.

Appendix: Extra detail for those other obsessives like me:

Wikipedia says Robber Flies  “..have three simple eyes (ocelli) in a characteristic depression on the top of their head between their two large compound eyes. They also have a usually dense moustache of stiff bristles on the face; this is called the mystax, a term derived from the Greek mystakos meaning “moustache” or “upper lip”. The mystax has been suggested to afford some protection for the head and face when the flies deal with struggling prey” . You can see one of the simple eyes pretty clearly in the closeup below, and also the bristly mystax (today’s new word.)

Friendly Robber Fly, Efferia aestuans

Beavers come and beavers go

Beaver ponds start small:

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and sometimes shrink again as quickly as they started,

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leaving wildflowers behind in the enriched and newly sunlit soil:

Allegheny Monkeyflower, Mimulus Ringens
Allegheny Monkeyflower, Mimulus Ringens
Spotted Touch-me-Not, or Jewelweed
Spotted Touch-me-Not, or Jewelweed

Multiple generations can create large wetlands:

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and of course open water:

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Beavers build and abandon lodges, then reoccupy them a year or two later for no apparent reason. Last year all my beaver ponds were bereft of beavers, but this year they are back. This one was caught by my game camera returning to the lodge with a huge bunch of ferns, perhaps for a family inside:

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This one was swimming round in a different larger pond, slapping his tail in warning, but circling back to try and work out where and what we were. Here comes that powerful one-foot long tail:

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and later a tail-slap with the tail at full stretch in a final salute:

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The tail is scaly, and is used as a rudder in swimming. The tail slaps are thought to serve as warnings to family members, and to drive away predators. It is also a place to store fat through the long winter.

PS Sadly, that muscular tail has caught people’s attention for the wrong reasons. Hunters in New England consider the tail a delicacy, and in Poland the tail of the European beaver (a different but pretty similar species) is apparently coveted by some elderly men:

https://www.thejournal.ie/polish-agriculture-minister-beaver-4673479-Jun2019/

 

 

 

 

 

 

The monarchs’ boudoir

[Some of you may not know that these stunning butterflies have become iconic in US environmental circles because they make an epic migration annually from New England to Mexico and back, depend entirely on milkweed, and their numbers are dropping.]

I do hope you are not sick of monarchs, because I have some very intimate photos for you this time around.

Monarch life starts when two consenting adults meet:

Monarchs mating

The male grasps the female’s abdomen with his claspers, and hangs on. Usually he is the one on top, and she dangles underneath. The mechanics are mainly shielded by their wings, but I caught a glimpse:

Monarchs mating

They remain joined for anything between one and eighteen hours! They can fly around while conjoined like this: here the one on the left is being towed backwards and upside down through the air by the other:

Monarchs mating

This pair started in my flowerbed, flew up high into a small birch tree (I stood on a ladder to photograph them), descended to a goldenrod, and then flew up into a huge spruce, at which point I gave up.

In the fullness of time, the female lays her egg, and eventually a tiny caterpillar emerges. (I showed you the egg and first stage caterpillar in an earlier post.)

A caterpillar is basically a tube. Food (milkweed leaves) goes in one end:

Monarch caterpillar

and out the other:

Monarch caterpillar

Just like toddlers, they grow inexorably, and eventually they split their skins, to reveal a new one waiting underneath. (Why don’t human children have a new set of clothes waiting underneath the old ones?) Anyway, in this photo the old discarded shriveled skin is sitting in a little heap just behind the freshly garbed caterpillar, whose antennae are still bent and floppy, showing that he/she has only just emerged.

Monarch caterpillar moulting

Exemplary mothers

Nursery Web spiders lay their eggs on a silk pad, and then wrap the whole thing in several layers of thick silk until it is spherical. They guard this egg sac carefully, carrying it around with them. This one was on a milkweed pod: it is a Pisaurina brevipes.

Nursery web spider with egg sac

In closeup, you can see the six eyes, and also the short furry pedipalps; they use their jaws and pedipalps to carry the egg sac.

Nursery web spider with egg sac

The sac contains a few hundred eggs. When they are ready to hatch, the ever-vigilant mother builds a tent-like web structure and places the egg sac inside it. This nursery is what gives the species their name. When the young emerge they are fully formed tiny spiderlings, and stay inside the tent for about a week, while she guards them.

This different much smaller unidentified species has an egg sac too:

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To the right, just visible behind the leaf, is a predatory insect lying in wait, so these eggs may not have long for this world.

Some spiders hang their egg sacs from a thread. I think these exquisitely decorative hanging egg sacs are created by the Common House Spider, Parasteatoda tepidariorum, although the photos I can find online don’t have this marvelous oriental lantern shape, so it is possible it is some other species.

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Next time you shudder at a spider in your bathtub, try to remember their softer side. Louise Bourgeois’s giant Spider sculpture (1996) was conceived of as a tribute to her mother, who was a weaver, and its protective posture reminds me of all the maternal spiders out there.

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Marmite for plants

Most plants create their food by photosynthesis, with minerals extracted from the soil via their roots, but some have a more sinister strategy. If the land is nutrient-poor, they supplement their diet with essential minerals from passing insects.

The Round-leafed Sundew, Drosera rotundifoliaentices the bugs in with sugary droplets, too sticky for them to escape from. (The grey specter towards the top of the photo is not the remains of a sundew onslaught. It is the exoskeleton of a dragonfly nymph, from which the dragonfly has long since emerged unscathed.)

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Then the leaf tentacles close over its victim, as you can see on the right below,  and the leaf absorbs the nutrients.

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The round-leafed sundew above was growing on the edge of a pond in sphagnum moss, and it is green.  This red one below was in a very dry area:

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Most online sources talk about the red coloration as the norm, and I have not been able to work out why my pond-side ones are green. Lastly, although they may seem so alien, like normal  plants they have flowers:

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In another way to catch the unwary, the pitcher plant, Sarracenia purpureadrowns them in its vase-shaped leaf:

Pitcher plants at Holt Pond

And the Horned Bladderwort, Utricularia cornuta, has tiny bladders under the swamp water. When an insect touches the minuscule hairs on the bladders, it triggers the opening of a teensy trapdoor, engulfing the poor bug. And yet, the flowers are exquisite, giving no hint of what perils lie beneath.

Horned Bladderwort

PS For those who don’t know, Marmite is a dark brown salty spread made from yeast that British kids are raised on. It elicits strong pro/con reactions, and is now used by extension to describe people, as in “Boris Johnson is a Marmite politician.”

PPS The function of the red coloring of many carnivorous plants is unknown.  It has been shown not to help attract insects, nor to be useful as camouflage.

“Stiffen the sinews, summon up the blood”*

It’s butterfly season here in Maine.

Butterfly wings are made of two chitonous membranes that are nourished and supported by tubular veins. The veins are astonishingly strong, as I think you can see in this close-up of an Eastern Swallowtail wing .

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When a butterfly first emerges, its wings are all scrunched up. As they unfold, we talk of a butterfly “drying” its wings, but in fact the veins are being pumped full of blood to form a skeleton over which the membranes can stretch, very much like the unfurling of an umbrella canopy as the spokes extend. This is a Monarch, soon after emerging from its chrysalis:

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And here it is with veins distended and wings all outstretched:

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Butterfly wings are covered by tiny scales, which are what give them colours. Here is the Eastern Swallowtail again, in closeup. The individual scales are visible.

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This is a British Common Blue:

Female Common Blue

and this is a très chic French moth, Saturnia pyri, Grand Paon de Nuit (Great Peacock of the Night).

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Like many moths, this one has large scales, which make the wings look hairy or shaggy.

Butterflies can normally fold their wings together, but some Lepidoptera, like these two different Plume Moths, can also fold them into narrow bands,

Plume Moth, feeds on wild grapes

or even roll them up tightly:

Plume Moth, feeds on wild grapes

Tiny, delicate creatures, but a marvel of engineering.

*Henry V, Act 3, Scene 1.