It's Been an Interesting (and Mysterious) Year: 2013

It's Been an Interesting (and Mysterious)Year: 2013

(Note: to read more about Cottonwood Pond and to learn the specifics of what is referred to here, please read the various blog entries from 2013, starting with February 11. All but one of them include photos.)

Cottonwood Pond has now been through its first calendar year, and it is almost a year since I began to visit, watch and explore it, to see what happens with a newly-formed pond.

There have been many mysteries found, and some solved. It's been a very interesting year.

I introduced Cottonwood Pond in this blog on February 11 as a good-sized depression made by the hole left by the root ball of a fallen Cottonwood tree in the bottom of our woods. The depression had filled up after rains (some from the storm that felled the tree), and it has managed to subsist throughout the year, despite extremes in the weather.

The top of the fallen tree was caught, far uphill, in the V of a double-trunk Red Oak tree. I have noticed that, over time, the upper part of the Cottonwood has sunk deeper into the V, causing the Cottonwood's trunk, near the root ball, to have less space between the trunk and the ground. In fact, if Mystery Mammal passed that way back in February, it could have just gone under the trunk at the other side of “little pond”, instead of having to walk along the trunk (see “Tracking”, December 2) to find an open spot further along the trunk.

The pond was wider at the north end back in February, and there was no pile-up of mud between the main pond and “little pond”. Chunks of mud were barely starting to drop from the rootlets of the root ball to the pond. The rate of this dropping seemed to increase over time, especially when the root ball was dry during drought, and whenever hard rains pelted it. This mud-dropping has been, doubtless, adding to the bottom of the pond, and may affect the depth.

On March 6, I had found a dead Fox Squirrel, assumed drowned, at the edge of the pond. By March 27, it was covered by algae. By April, there was no sign of the body. Thus, The Mystery of the Disappearing Squirrel Body.

During March, the first small burrow appeared on the bottom side of the root ball. Eventually, there would be more burrows on this side, and others on the top side, those almost hidden by vegetation. I have not yet witnessed creatures entering or exiting these burrows. The Mystery of the Small Root Ball Burrows.

On March 27, the pond's water was clear, and fine mud had settled over the debris on the bottom. I made the first measurement of the deepest part, using my handy-dandy homemade depth-measuring device. It was 21 ½ “ deep. It was the same on April 25, and I eventually surmised that the clay bottom held water, the only incoming water would be from precipitation and snow melt, and any excess would seep out of one corner to the creek slightly below. We had had much rain before April 25, but the pond had established itself via the seep. Thus, I had solved The Mystery of the Unchanging Pond.

By July 23, when the weather was hot and steamy, the deep part was only 11 ½ '' deep. By August 19, after a long dry period, it had shrunk to 5 ¾ “ deep. By September 15, it had become “Cottonwood Puddle”, almost a ghost of its former self.

Despite losing water to much evaporation (and gaining no more due to drought), life still hung on in its own way. In early April, when the water was green and murky, I was excited to find, for the first time, that there was at least one frog at the pond. In late April, there were signs of Worms, Crawdads and Raccoons, and Spiders skittered around the edges. Also, broken acorns were left by a Squirrel on the rotten log that stretches alongside the pond. My first look at a water sample under a microscope revealed blue-green algae and Paramecium. The water was much less clear by then, due to a lot of rain stirring things up, so less sunlight was penetrating.

I did not get back to Cottonwood Pond until the Summer Solstice, when I found Water Striders and Backswimmers, among other very small things. In late July, despite the loss of rainfall and the shrinking of the pond, I found more critters. A scoop with a long-handled sieve attached to a broom handle brought up many tadpoles – the first I had gotten to see here. I was excited that Frog Life was being perpetuated. The scoop also revealed a Water Scorpion, a Backswimmer, and Pond Snails. The water was murky, and the action of frogs jumping into the water and burrowing into the mud stirred up more silt. There were also Water Striders, Raccoon prints, and a Daddy-Long-Legs (on the root ball top), and my first sighting of canine prints in the mud near “little pond”.

When the water was very low, in mid-August, I still found tadpoles in the mud, the strange larvae and pupae of Phantom Midge, a very tiny Bosmina (“water flea”), and an aquatic larva of the Nymphula Moth, the first time I had heard of an aquatic caterpillar. I was learning much more about life in a new pond, and solving more mysteries. And, the canine prints appeared again, still a mystery. The Mystery of the Unidentified Canine Prints.

At night, I heard Cicadas and Katydids all around, and saw many Fireflies.

There was another strange critter I had seen on the pond - a long, pale pink worm-like creature that looked as if it had many short legs. It was coiling and uncoiling on the surface, and a small black object had dropped from its “legs” to the water below. With some searching, I had found that it was an aquatic caterpillar called Hygraula that can survive in low oxygen conditions because it has haemoglobin. Most of those “legs” were actually cilia. It has two tentacles at the rear that is uses to catch prey that is floating by, and then it uses the cilia to transport the prey along the body up to its mouth – thus the strange movements I saw. This also explains the small black object, which was (possibly) a Backswimmer that had been caught, but the caterpillar had lost grasp of it during transport. This was the second type of aquatic caterpillar that I had learned about in 2013, or in my whole life. I learned, too, that many other species of Hygraula live in leaf litter. I evidently did not write a blog entry that included this animal. Whenever I find my photos of it, I will post them in a “past-time” blog entry. The Mystery of the Long Pale Pink Wiggly Many-Legged Worm was solved.

By the time Cottonwood Pond had become Cottonwood Puddle in September, I still found Pond Snails and Raccoon prints, and wondered what else might be there, perhaps biding its time under the mud.

By October 11, there was finally ample rain, and Cottonwood Puddle became Cottonwood Pond again. I found more Raccoon prints, more frogs, and a Woolly Worm “walking the plank” on a branch extending over the murky, rain-disturbed water.

In early November, fall colors surrounded Cottonwood Pond and the pond's surface glimmered with a cover of fallen leaves in various colors and shapes. I learned about another critter when I spotted a white speck hopping on the pond surface – the Colembola, or Springtail. Here was another creature sometimes referred to as a Water Flea. Neither “water flea” that I had found in the pond was a true flea.

By mid-November, leaves were choking the creek, covering the pond, and starting to sink to the bottom, where they could provide cover and nourishment for more life.

Always, a variety of birds flew, roosted, called, sang, and probably nested overhead. I did see a couple of birds visit the pond after the winter storm, perching on root ball rootlets. For some reason, I never saw deer prints around the pond, though many deer pass through our woods (I see many prints elsewhere). The Mystery of No Deer Prints.

Early December brought deep snow cover and a frozen pond and creek. I was able to track Mystery Mammal across “little pond”, under the fallen Cottonwood, an here and there in the vicinity. I also came across tracks of Squirrel, mice, birds, Raccoons, and others.

On December 21 came the torrential rains (over frozen ground), the big snow melt, and the flood, which undoubtedly brought new organisms and nutrients to Cottonwood Pond. Temporary creeks flowed, through soils and leaf litter, down the slope above the pond.

Plant life has flourished around the pond, though no aquatic plant life has appeared yet. On and around the root ball grew Stinging Nettle, grasses, Elderberry, Pokeweed and other plants. Near the pond grew Poison Ivy, Honewort, Jumpseed and Clearweed. Nearby, the Jewelweed attracted Hummingbirds, and I also found blooms of Chicory, Monkey Flower, Sweet Cicely, Cleavers, Mayapples, Prairie Trillium and Jack-in-the-Pulpit, as well as various ferns and mushrooms.

The pond has already been through many phases in its first year: formation, rains, drought, revival, leaf-filling, winter storm, hard freeze, thaw, and flood. It has been fascinating to watch its development and to learn more about ponds and their associated life. I have become reacquainted with concepts such as bioturbation, nutrient cycling, Biological Oxygen Demand, eutrophication, trophic levels, periphytic algae, and others.

I look forward to the pond's second year, 2014. What weather events will affect it/ What new critters will I find? Will there be aquatic plants? What else will I learn?

There are things I would like to do in the new year:

• watch from uphill at the edge of the woods at dawn and dusk (especially when there is snow cover) to see what is moving about;
• watch, very silently, near Cottonwood Pond for frogs, burrow animals, and anything else;
• spend more time near Cottonwood Pond at night;
• test for things such as Dissolved Oxygen, visibility, air and water temperature, on a consistent basis;
• make or obtain the items to do these tests;
• keep charts of the results;
• do more frequent sampling for biota;
• spend more time at the microscopes;
• identify all of the birds I see and hear around the pond area;
• solve more mysteries;
• stand on the ice of the pond in my ice skates and get my picture taken.