Litter Critters #2
August 19, 2013
Despite an extensive dry period, our woods are lush and
green. This is a place where moisture mostly keeps its place, sheltered
by trees, respired upon by leaves, tucked into this low area between slopes.
The bright crimson ball of fruit from a Jack-in-the-Pulpit
shouts from the brown floor of dirt and debris. The plant has fallen
over, pulled down by the heavy fruit. The dying, bug-chewed leaves can no
longer function as a counter-balance, as they did when there was only the
single, graceful spathe floating above the small white “Jack”, the size of a
Q-tip.
An old broken tree becomes a constantly changing sculpture,
the work of various small organisms, as well as the woodpeckers and other birds
that are attracted to this “bug buffet”.
Mid-August heads toward the climax of “spider time”.
Spiders have been occupied with harvesting the plentiful smorgasbord of insects
that is summertime, using a great realm of designs to accomplish this: lacy orb
webs stretched between tree limbs, bowl-and-doily webs among the tall plants,
webby tunnels near the bases of trees, simple nets stretched over the grass,
and so many more. The lack of rain has left many webs relatively
undisturbed for a longer period of time than usual.
A Cut-Leaved Grape Fern stretches outward the lacy fingers of
its sterile leaf near the ground, while stretching a beady fertile frond upward
toward the sunlight that peeks through the canopy.
The creek bed is only mud now, stippled with animal prints,
worm trails, crayfish chimneys and fallen leaves. Dappled sunlight
sprinkles the bed with shadows of maple leaves.
The lowland of our woods is filled with Jewelweed, lime green
leaves and stems speckled with bright orange spots of flowers. The small,
quick movement of a Ruby-Throated Hummingbird darts between flowers.
The seep is almost dry. There hasn't been water seeping
from pond to creek in a very long time. But, it still sports a galley of
tall grasses and Poison Ivy.
Poison Ivy leaves are beginning to lose moisture and curl
under, some carrying the red blush of approaching autumn.
The cornflower-blue blossoms of Chicory dance against a
background of Jewelweed plants.
Here at the edge of Cottonwood Pond, Jewelweed extends one
orange flower toward the sunlight while long, wiry stalks of tiny Jumpseed
flowers wave overhead. Frilly seed heads of Honewort reach over the pond.
Glistening strands of an orb web seem to tie the plants together.
Receding pond water allows the raccoons even more space to
search for food in the mud and shallow water.
Some of that food has been, no doubt, the frogs that have
been living in Cottonwood Pond, and the more numerous tadpoles before them.
The pond has shrunk considerably from lack of rain, its only
watery input. But, there is still life rippling beneath, on top, and
around the pond.
A scoop of the long-handled sieve through the bottom of the
pond brings up a squirming, slippery wad of tadpoles in various sizes.
Frog life continues.
Another scoop reveals a world that thrives in a pond,
generally unnoticed by large organisms such as ourselves. The clear,
squiggly one on the right is the larvae of the Phantom Midge. In adulthood, it resembles a small mosquito,
but it is not capable of biting mammals (instead, it sips nectar). This
larva is almost transparent (thus, the designation “phantom”) and its organs
and eye spots can be clearly seen.
You can see a good close-up side view of the Chaoborus
punctipennis larvae by viewing this page:
Something really super-cool to see is a video of a live
larva, made through a microscope. At the
time he was making the video, this photographer did not know what the creature
was, and his amazement is evident. Check
it out: www.youtube.com/watch?v=Wp_LfV89qJM
You can also see antennae projecting from the head, though
these are usually held downward. These
antennae are actually modified into grasping appendages. The larva captures food (such as small insect
larvae, and tiny crustaceans such as Daphnia), impales or crushes the prey with
these modified antennae, and then brings the food to its mouth. Here’s another fun video, though much
shorter, in which you can see a larva moving in the water, then capturing food
and eating it:
The little critter on the left is a pupa (between the larval
and adult stages) of the Phantom Midge.
You can see that it, too, is practically transparent. To see highly close-up photos of Phantom
Midge pupae, check out this site:
blogspot.com/2013/03/phantom-midge.html
What do you think?
Cute? Ugly? Scary? Amusing? Just
plain weird?
Completing the Little Critter Triangle above them is a fat
little Water Flea, probably of the genus Bosmina (what a nice name). These
tiny round creatures are flattened, and are surrounded by a sort of armor that
protects them, somewhat, from predators.
Merriam-Webster describes them as “a genus of water fleas resembling, in
profile, microscopic elephants.” What do
you think they resemble?
They are filter-feeders, going for algae and very tiny
protozoans (one-cellular organisms). With the first pair of legs, this Bosmina
grabs at particles. The second and third
pair of legs have a mesh-like structure that does the filtering. Bosmina females carry 9 to 12 eggs in early
summer. When conditions are favorable,
Bosmina reproduce very rapidly and their population greatly increases. This, of course, supplies more food for their
predators.
To see some close-up photos, go to:
people.cst.cmich.edu/mcnau1as/zooplanktonweb/bosmina.html
To see a Bosmina swimming, or spinning around (set to music,
even), see:
All of these tiny critters eat organic debris, algae, and
microscopic beings smaller than themselves, and much more plentiful. In
turn, these three organisms, and those like them, are eaten by larger
organisms, not as numerous. It's all a pyramid, with great numbers of
microscopic organisms at the bottom, and moving up to the pointed top with a
much less number of large predators.
It all starts in a place like this. What an incredible world exists in a small
spot of water.
Then I found this strange, tiny critter with many segments
and many pairs of legs. If it were terrestrial, that description would
lead me to think “millipede”, but this is from the murky bottom of the
pond. There are aquatic larvae that somewhat resemble this, but if they
have any appendages along the sides of their bodies, they are setae (hair- or
bristle-like structures).
This definitely has working legs.
Thumbing through a Golden Guide called Pond Life (great
little book for just exploring), I come across something odd – a moth that
lives under water in its larval stage. I had only known caterpillars to
be terrestrial. This was new to me.
The genus name of the moth is Nymphula (another nice
name). According to the description of the larvae in the book, “Some
build silk-lined cases of leaf fragments. In other species the pupae
develop in cases attached to plants above water.” Fascinating. As
difficult as it must be to find either kind, I am going to keep a sharp eye out
for these. Of course, I don't yet know what living arrangement this
specimen took in Cottonwood Pond.
It's a whole different world in a pond, and I feel privileged
to have a peek at it now and then, discovering strange-looking animals I never
knew existed.
Oh, yes – the Nymphula larva can lift up its head. It
was a wee bit threatened by my poking around in the collection dish. Of
course, I let go of all the Little Critters – back into Cottonwood Pond.
It is time to explore the other side – the top of the root
ball, the “little pond”, and the fallen Cottonwood tree.
The top of the root ball is an even more lush forest than
before. In fact, it is hard to see that it is a root ball – it looks more
like a hillside.
Stinging Nettle is in bloom. Despite being surrounded by
stems and leaves covered with stinging hairs, I find these foamy flowers
beautiful. The flowers are wind-pollinated, but the plant helps out when
the ripened anthers explosively catapult pollen grains into the air.
I find more fresh canine prints nearby. I still suspect
Coyote.
The “Little Pond” on this side is nothing more than a mud
hole – a rather gooshy mud hole.
Back to the “Big Pond”. A lush Pokeweed plant is
growing from the side, tall, branching out more broadly near the top to capture
more sunlight. It bears pedicels of deep inky purple fruit, almost
black. Birds are active in the canopy. Some of them will probably
be enjoying these juicy fruits.
I pick up my homemade depth measuring device (large rock tied
to garden twine hung from a broomstick) and lower the rock into the deepest
part of the pond, untwisting the twine until I feel the rock hit bottom.
It takes no time.
I re-twist the red twist-tie at the new “wet spot”, which is
rather near the rock, gather my things and go indoors. As I had done
before, I set the rock on the kitchen floor and hold up the twine next to a
ruler. In the past, I needed to use my yardstick. This time, a
regular foot-long ruler suffices.
The red twistie marks 5 ¾ inches! That means the
deepest part of the pond has shrunk 16 ¾ inches from my very first measurement
of 21 ½ inches, taken on March 27, 2013.
How long will it be before Cottonwood Pond becomes Cottonwood
Puddle? What Little Critters will adapt to “puddle life”? That is
what I will be finding out – unless, that is, we get many days of heavy rain
and the basin is filled again. It doesn't seem likely.
Reid, George K., Ph.D. (under the editorship of Herbert S.
Zim and George S. Fichter); Pond Life: A guide to common plants and
animals of North American ponds and lakes; Golden Books Publishing Company,
Inc.; Racine, Wisconsin; 1987.
A moth with an underwater larva?? Interesting indeed. I hope it pupates and you get a shot of the adult.
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