Author: myip2014

Floating at the edge of a beaver pond I found these delicate little Fringed Heartworts, Ricciocarpos natans, 5-15mm across, about 1/4″, with a beech leaf top left for scale. Each ‘leaf’ (more properly called a thallus) is an independent plant, and they are not rooted to anything, but bob around happily on the surface like little dodgem cars..

They are a type of liverwort, related to mosses, and like them the vast majority are terrestrial. But this tiny thing is nearly always aquatic, though the mystery deepens below.

I scooped out a cup of water with about eight tiny plants, and took it home for closer inspection. The leaf (thallus) has an underwater fringe of purplish strands, and the leaf surface is covered in minute air sacs, each divided from the next by a single-celled membrane, which help it stay afloat, but also have pores that allow it to take in CO2 for photosynthesis.

Each plant has both male and female organs , and it reproduces by abscission, in other words it keeps branching, and eventually divides into two, each becoming a new plant. The one at bottom right is about to divide.

Underneath it looks for all the world like a Hawaiian hula skirt, or a tiny jellyfish (and in a dish when the water sloshes around they move in the most charming and animated way, so that it is quite hard not to mentally promote them from the plant kingdom to the animal kingdom):

The fringes are dark purple “scales” that act to stabilize it, and they can be up to 1/2″ long. They are very effective. When I casually tipped my cupful of plants into a new dish, every single one emerged from the turbulence the right way up.

Rather astonishingly, if its pond dries out, and it gets stranded on land, it stops growing scales, and roots itself in the earth by growing rhizomes instead.

Back in the pond, they provide a safe habitat for tiny invertebrates, sheltering them from the sun (or the bright lights of my kitchen), and hiding them from predators. In my scoopful of plants I inadvertently captured several of their charges.

Caught in the open, this mayfly larva scuttled back to the closest sheltering plant.

Another one had a minute caddis or stonefly larva underneath, which had decorated itself with a variety of things including what looks to me like a fragment of Fringed Heartwort leaf:

You could be excused for thinking it looks just as if the plant had captured this insect with a view to eating it, but they are not carnivorous, and the little caddis was swimming freely.

My final shot shows a translucent larva (on the left) of perhaps a Naidinae, something I had never seen before. Though it could just be a mosquito!

PS These Fringed Heartworts are found all round the globe, but they are thought to have split off from other lungworts after Pangaea split up, so they must have evolved on just one continent, and then they and their spores were carried across the world, probably on the plumage of birds.

This informative but rather technical article was very helpful in understanding this plant, by Singh, S. and B. Bowman (2023). “The monoicous secondarily aquatic liverwort Ricciocarpos natans as a model within the radiation of derived Marchantiopsida.” In Front. Plant Sci. Sec. Plant Development and EvoDevo. Volume 14 – 2023

All errors as always are my own!

The Gray Catbird, Dumetella carolinensis, gets its name from its “Mew” call:

Grey, with a black cap, the adults are bright chestnut under the tail:

Late this summer, the elderberries were ripening, much to the catbirds’ delight.

This one is a fledgling. It has no black cap yet, and its undertail is buff, not chestnut

It performed acrobatic manoeuvres to reach the berries:

And it used its wing to lift the bunch of berries closer to its beak:

Catbirds are related to mockingbirds, and like them they are accomplished mimics. Its song is long and complex, using snippets from other birds’ songs. It is able to control the separate sides of its syrinx to produce two notes either alternately or simultaneously:

The females sing too, but much less and more quietly.

Cornell’s Birds of the World says it is “believed to mimic at least 44 species of birds, gray tree frog (Hyla versicolor), and a variety of mechanical sounds”, although others say the huge song repertoire (170 syllables were recorded in a 4.5 minute song) is largely the result of improvisation and invention.

The elderberries were also being eaten by a hummingbird!! This behavior is rarely reported. I suspect that a catbird had punctured a berry, and the hummingbird came to the juice, just as it will come to sugar-water on a feeder. And the elderberries of course have bright red stalks!

PS The catbird Mew call is given in various contexts, including when a recent fledgling is approached by a predator (i.e. me).

PPS Unless otherwise stated, all my sound files including these two are my own recordings. I just use Merlin, and my iPhone, so they are not professional quality. I do some editing to shorten the files by cutting out irrelevant stretches.

An even more bizarre group of organisms are the distinctly horror-scifi-movie-like slime molds. They actually hunt their food, crawling outwards as they sense delicious decaying vegetative matter.  This one rejoices in the name of Dog Vomit slime mold or Scrambled Egg slime mold,  Fuligo Septica:

This phase, the plasmodium, is one single cell with many nuclei, and has this extraordinary amoeba-like ability to shape-shift, clumping up, like here:

or fanning out across the forest floor, in search of food:

Time-Lapse photography (not mine!) shows it in action:

https://www.facebook.com/ScienceChannel/videos/2812668395470735

 Some slime molds are more delicate, like this Honeycomb Coral Slime Mold, Ceratiomyxa fruticulosa, known in Australia as Icicle Fairy Fans. The pine-needle provides some scale!

Some are jet black. This I think is Lindbladia tubulina. It is coating a leaf in the foreground, with more on the dead sticks behind it.

This unidentified white slime mould is trailing threads behind as it goes:

I end with my favorite, the aptly named Insect-egg Slime Mold, Leocarpus fragilis, creeping up the stalk of a plant, and completely engulfing the one lying on the ground.

The 2mm “eggs” are the fruiting bodies hanging from the slimy substrate. In due course they will release their spores, creating the next generation.

PS According to Wikipedia, there are 888 species of slime molds, or Myxomycetes, the plasmodial or acellular slime molds.

“All species pass through several very different .. phases, such as microscopic individual cells, slimy amorphous organisms visible with the naked eye, and conspicuously shaped fruiting bodies…. In extreme cases the organism can be up to 1 metre (3 ft 3 in) across and weigh up to 20 kilograms (44 lb).”

This is a male Scarlet Tanager in breeding season. Brilliant crimson with jet black wings. It is a bird of the deep woods, heard more often than seen.

It has a simple but pretty song:

This is a fledgling, having left its nest perhaps 10m above the ground at about 10 days old. It is seemingly all alone, and hungry.

But along comes papa, with a bug:

though he seems to have eaten it himself:

But the adult reappears, this time with what looks like a green caterpillar:

The fledgling moves further away, but the adult finds it:

and makes quite sure the chick doesn’t drop its meal as it frantically flaps to stay upright:

One last image, an artistic accident when Lightroom took matters into its own hands rather successfully:

Now you may have been thinking that surely this adult was a female, since it isn’t scarlet all over. But the female is a dusky olive, with no trace of red. It took me a while, but I eventually realized that this is indeed a male, and August is the month when they molt their breeding plumage and revert to their non-breeding plumage, a bright olive green (still with black wings). It is part-way through this process, hence the blotchy garb.

This chick is late in the season (the photos were taken on August 13th) and it will need to migrate from mid-September onwards. Let’s hope it makes it to its winter home in NW South America.

PS Scarlet Tanagers are not found in Europe, until November 2024:

https://www.bbc.com/news/articles/cg571eygj97o#

PPS The word tanager comes from Tupí tanagorá, via Portuguese tangará.

The wondrous diversity of the insect kingdom is under threat as our environment changes and shrinks (from an insect’s perspective, anyway). But I still find new ones all the time. Today I’m going to be disciplined, and restrict myself entirely to beetles. Just when you think you’ve seen them all, along come four new beetles all at once.

The Dogbane Leaf Beetle, Chrysochus auratus, a fragment of polished stained glass, is about 10mm long:

The color is structural, and varies depending on how the light hits it:

The Clavate Tortoise Beetle, Plagiometriona clavata, looks for all the world like a tiny 7mm long teddy bear. Its translucent carapace totally covers its body and legs, so it looks just like a tortoise. It has also been described as looking like a World War 1 US infantry helmet! In life, they’re brown or green, but turn black when dead, though I could swear it moved its antennae.

The Swamp Milkweed Beetle, Labidomera clivicollis, sports a smartly tailored livery of orange and black:

These 10mm beetles are adapted to the poisonous milkweed leaves, but even so they eat the leaves from the outside in, avoiding the main veins. Some reports also say that they first sever some of these veins to reduce the sap flow. They’re not exactly camouflaged (!) but that aposematic coloring warns predators that they may not be good to eat.

The Crablike Rove Beetle, Tachinus fimbriatus, has wing cases (elytra) that cover only half of its wings and abdomen, which stick out the end, unprotected. It measures about 9mm. There are thought to be around 66,000 species of rove beetles, dating back to the Triassic, and they are mostly predators. This particular one feeds on rotting mushrooms.

PS My title is taken from the great scientist E.O. Wilson, who said: “In the intricate dance of nature, insects are the choreographers of biodiversity.”

PPS The Dogbane Leaf Beetle turns out to have fascinating adaptations for its specialized diet of dogbane leaves. Read more here:

https://en.wikipedia.org/wiki/Chrysochus_auratus

Phoebes often nest under eaves, and these ones nested inside a latticed shed that holds our generator!

The babies have now fledged, and are learning to fend for themselves. The yellow corners of the mouth are the gape that babies have, not yet all gone.

They are insectivores, flycatchers, often catching their prey in mid air. This one has been hanging around my beaver pond, perching in the overhanging trees,

and is hunting successfully:

They also snatch bugs from twigs, hovering the while.

I have been enjoying bath time. This fledgling has been well brought up, and starts its day with ablutions. According to Cornell’s Birds of the World, Eastern Phoebes swoop down from a perch and wet their head and breast, keeping their wings as dry as possible, then return to the perch to groom. This is incredibly hard for me to film, because you don’t know when they are going to launch, where they are going to hit the water, and the return trip perch-water-perch takes less than one second. This sequence is the best I have got, but it will give you a rough idea of their technique.

You can see that the top of its head, chin and breast are still damp.

As a linguist, I never met a new word I didn’t like, and “guttation” is no exception.*

I unearthed this splendid word when I was trying to understand what I was seeing on the surface of a crusty fungus growing all over a dead log:

It was oozing droplets, a few clear, many amber, and some black and tarry:

I eventually identified this fungus tentatively as Ionotus glomeratus. It doesn’t seem to have a common name.

The mechanism of guttation in plants is better studied than in fungi. Here is a strawberry leaf, exuding droplets of sap from the tips of its leaves:

When the ground is saturated, and the leaf is still growing the water pressure forces the sap up through the xylem until it sweats droplets from small structures called hydathodes. It happens mainly at night, when transpiration is suppressed, so it is best seen early in the morning. The liquid is not plain water, but is rich in sugars and potassium, so many insects consume it as an important part of their diet.

In fungi, we know less, but it is clear that the liquid here is also not just water, but contains a range of secondary metabolites. This unidentified mushroom is exuding a clear liquid.

And this Hemlock Varnish Shelf seems to be bleeding:

PS * The word “guttation” comes from the Latin gutta, meaning a drop of liquid. It has survived with its meaning essentially unchanged in many Romance languages: French as goutte, Spanish as gota, and Italian as goccia.

PS Not all plants do this, and nor do most fungi. The reasons are mysterious. In fungi, the droplets contain all sorts of chemicals, some of which seem to be poisonous to competing fungi. But their place in the ecosystem is still largely a mystery. Krain and Siupka 2021 say “researchers have already found numerous mycotoxins, antimicrobials, insecticides, bioherbicides, antiviral, and anticancer agents in exudate droplets. They belong to either secondary metabolites (SMs) or proteins and are secreted with different intensities.“

My game camera, positioned on a beaver trail, caught no beavers at all, but instead it caught a raccoon family hunting.

For anyone unfamiliar with raccoons, they are charming:

Nevertheless I know many people loathe them because they get into their trash and cause havoc, or indeed attack their bird feeders, as this video shows:

But those clever hands are designed for a different kind of foraging. In their natural habitat they eat aquatic invertebrates, like crayfish. They hunt at night, and have very sensitive forepaws, or hands, which they use to search in shallow water for their prey.

The video below was taken deep in the woods in the pool just downstream of a beaver dam. I have spliced together several videos. At first you see a single adult, questing for food at the water’s edge. Half way through, the adult is joined by four babies, each of whom is copying its parent’s technique. The mother and first baby appear together briefly at 22 or 23 seconds in, at the left of the frame, and then wander off, but there are three more babies to come.

You can see that they are not looking into the water (and anyway it’s nighttime!), but trusting entirely to their hands.

The moral of this tale is that if raccoons still have access to natural habitats, they sensibly prefer crayfish to garbage, as do the French, who particularly like theirs in a bisque .

(photo from https://honest-food.net/crayfish-bisque-recipe/ )

PS The five fingered raccoon forepaw, or hand, has no opposable thumb, but it can be used to grasp in several ways.

The diagonal lines show the different ways the hand can fold to grasp something, and the asterisk shows how they use a scissor grasp between two and three digits. (Drawing from Iwaniuk and Whishaw 1999.)

In addition they use both hands together, and roll food between them. The hand is especially sensitive when wet, and the fingers end in tiny vibrissae, or whiskers, that allow the raccoon to sense food without actually touching it. For those who enjoy a little more detail, Welker and Seidenstein 1959 studied how much of the sensory area in the cerebral cortex of a raccoon is devoted to its hands. The answer is a lot, nearly 4 times as much proportionately as in a rhesus monkey, for example. The brain has specialized areas for each digit, and also for five different areas of the palm. You can see why it is sometimes said that raccoons “see” with their hands.

We should all wish for contractors like these.

Yellow-legged Mud-dauber Wasps, Sceliphron cementarium, were diligently collecting mud from small puddles in an abandoned rock quarry near me. They would spit into the mud, and push it together into a tiny ball (by her front left legs):

in their enthusiasm they go head-down in the mud:

Once it was formed into a nice ball:

they clutch it to their abdomen, and fly off:

I tried but failed to get a mid-air shot!

I never found their nests, but a similar technique is used by the Catskill Potter Wasp, Ancistrocerus catskill, who used her mud to sculpt two of these tiny edifices in the corners by my back door.

They are destined to be the sarcophagi for paralyzed sawfly larvae, onto which the wasp lays an egg, after which she seals the whole thing up.

The egg will hatch into a larva which will then feed on the sawfly larva, pupate, and emerge as an adult wasp.

Now that the next generation was fully incarcerated, I was trying to decide whether to slice it open to inspect the contents, when something unexpected happened.

The wasp built an addition, and poking out of it was a tiny grub.

Then the wasp herself appeared, all 1/2″ of her, dangling a paralyzed grub of some kind as food for her offspring.

She stuffed it into the chamber, and once she had left I took a photo through the tiny opening:

It looks rather ferocious…

The food supply was evidently complete, because less than two hours later she had sealed it all up, and started to construct another cell.

This time I got photos of the process. She carried in her lumps of mud:

and used wet liquid mud laid down in rows rather like making a coiled pot.

Once she had inspected it,

she then settled in bottom first, and stayed for some time, presumably laying an egg.

She emerged, one last check, then left for the day. Next morning, she returned, and sealed this one up too:

Then she started another:

In aggregate she built six or eight chambers, and then finally the process seemed to have come to an end. The entire condo was given an additional mud cladding. It is 1″ across at the top, and 1 3/4″ long.

And she left, job done.

I read that the adult wasps would not emerge till the spring, but I was keeping watch just in case, and blow me if one morning I glanced at these muddy storage units, and discovered that two of the cells had escape hatches:

By my estimate, this was about a month from when the eggs were laid. One week later, there were four holes:

The next generation is launched.