The Arrow Spider

The familiar spider’s web can be made by any of many species of orb-weaver spider. Most orb-weavers are shades of brown, grey or black, but not this one, in the Maine woods.

She waits in a hole at the center of her web. She is a female Micrathena sagittata orb weaver spider, only 8-9mm long, 1/3 inch. (The male is much smaller and more discretely colored, so it is rarely seen .)

Her abdomen is arrow-shaped (the two rear prongs are black, so they don’t immediately stand out from the background in the previous photo). She has spines at the sides and on her back, easier to see in this side shot:

She is named after Athena, the goddess of weaving, and sagittata meaning arrow-shaped, the same root as Sagittarius the Archer.

Elsewhere in the world there are other spiders with hardened abdomens with variously shaped spines. I saw this one in Koshi Tappu in Nepal three years ago.

It rejoices in the name of Hasselt’s Spiny Spider, Gasteracantha hasselti. Surprisingly , genetic analysis shows that they are not closely related to the American Micrathena, so the armored exterior seems to be an example of convergent evolution, with clear defensive advantages.

And the colors? Red and yellow often stand as a warning to would-be predators that you might be poisonous. Or they can be an enticement to potential mates, as they are thought to be in the Painted Turtle,

Or both? who knows??

Peeps in transit*

The Least Sandpiper, Calidris minutilla, is the smallest shorebird in the world, weighing in at 20-30 grams, a maximum of 1 oz. It is dwarfed by a nearby mallard:

I stumbled on these sandpipers on Monhegan Island, a perfect speck of land 12 miles off the coast of Maine in the North Atlantic.

Least Sandpipers breed in the sub-arctic Canadian tundra, then stop off here to recharge their batteries before embarking on a heroic nonstop transoceanic migration of 3,000 to 4,000 km to their wintering grounds in northeastern South America. 

This group of about six..

was having a morning wash and brush-up:

Notice their greenish legs, the only sandpiper with legs that color. I think these were juveniles, who migrate later than adults: by now the adults are arriving in South America.

They eat amphipods, especially the mud shrimp, Corophium volutator, which makes up to 88% of their diet in the Bay of Fundy. (Photo from Aphotomarine)

They wade around as the tide goes out, searching for these amuse-bouches:

Soon they will take off for southern climes, only to make the return journey again next spring.

* Collectively, tiny shorebirds are sometimes rather charmingly called “peeps”, hence my title.

Chipmunk choices and choice chipmunks

The humble chipmunk is so familiar to us in Maine that we take it for granted. They forage beneath our bird feeders, and balance on the Love-in-a-Mist seed heads:

So, we think of them as flower and seed-eaters. And occasionally mushrooms. This puffball has been peeled by a chipmunk, exposing its purple interior:

But not so fast: sometimes they surprise us. This one is eating….

a large black beetle:

He/she ate everything except the odd leg, and then had a good grooming session:

and to my fascination he was clearly eating something he found in his fur. Fleas? Ticks??

I checked, and indeed insects are a known part of their diet.

The second surprise this past week was quite different. Look at these photos, taken by my son on his iPhone just up the road from the house:

Believe it or not, this too is a chipmunk. There have been stories of these melanistic variants popping up in our area, but this is the first one seen round our house. I am hoping to encounter it again. But I do miss the stripes.

PS There seems to be no scientific literature to speak of on melanistic chipmunks, and they are generally said to be very rare. Melanistic squirrels, on the other hand, are widely distributed, particularly in more northern climes. In squirrels, melanism is thought to convey two advantages. First, in dark Northern evergreen forests they may be better concealed in the shadows. Second, they are better at absorbing heat, an advantage in cold climates.

The mushroom: a small, mysterious miracle

Summer is noticeably winding down. And the mushrooms are coming out. When I walk each day, I always hope to see mammals, birds, reptiles, things that move. But it doesn’t always happen. And when they do appear, they can be fleeting and impossible to photograph. Mushrooms, blessedly, stay put. And they are exquisite.

Here is a gallery, all resplendently pushing up through the leafmold during the past week. Some have gills, some are veiled, some have a spongy underside (boletes), some look exactly like coral. Some are edible, some could kill you. Just admire them.

Tyrant parents

This is an Eastern Kingbird, Tyrannus tyrannus. Quite a name to live up to.

Their name betrays their nature. Fiercely territorial, they are fearless against intruders into their airspace, even eagles:

or Great Blue Herons:

Let alone a more evenly matched Belted Kingfisher (on the left below; the kingbird at top right has satisfactorily upset him and is moving on)

In flight their white tipped tail feathers make them easy to identify:

They usually nest in trees, but close to water they sometimes nest low down, like this pair on my beaver pond. They used a nest site from last year, either theirs or a redwing blackbird’s, and rebuilt the nest. The female is on the nest, and the male is standing guard, as he does for 50% of the time. Between them the nest is only left completely unattended about 11% of the time.

By June 28 she was firmly ensconced:

Incubation takes 16-18 days, so I calculated July 15 as the latest possible hatch date, and kept watch from my kayak, from a respectful distance. By July 17, something had changed. She was now sitting on the edge of the nest, gazing lovingly down, so although I couldn’t see into the nest I was fairly sure something had hatched:

And indeed the parents were arriving with food, first tiny things like little caterpillars, then with larger dragonflies, like this one on July 22:

They also catch bees and wasps, and kill them and remove the stings before feeding them to their young. They are kept busy, making an estimated 5-6 feeding visits per chick per hour, which would add up to 150 visits to this trio over a 10-hour day.

The parents didn’t seem to mind if I let my kayak drift closer, and I finally found a spot where I could see through the twigs, close enough for my zoom lens. The babies are thriving on July 23:

But they are definitely hungry!

Their eyes open at 4-6 days, and the sheaths that will be the proper feathers emerge at day 5, so this one below, quills on its chinny-chin-chin just p[okiong through, is well on its way, and is ambitiously trying to flap its minute wings:

Once the young fledge, they still need 2 weeks more feeding. And by mid-August the southerly migration to South America begins, and they will be gone.

But instead this story has a sad ending. Two days later, I returned to find the nest entirely empty.

One adult was still standing guard, but of the chicks there was ne’er a trace. Not even a feather floating on the water. They were much too undeveloped to have fledged, so I fear a predator swooped, and probably gulped all three in one mouthful. Bald Eagle, Great Blue Heron, hawk, Belted Kingfisher, who knows. That unattended 11% was enough.

PS: This is not an endangered species ( roughly 26 million in the US), but their population has dropped by 38% between 1970 and 2014. Factors probably include increasing forest cover as farms return to woodland in the North Eastern US (which is of course generally good news for our planet), and the plummeting insect populations that are decimating aerial insectivores.

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