Pond Ecology at Central Valley and Circleville

In the last few weeks I’ve had the chance to do my ecologist-in-residence visits at the Central Valley Elementary School in the Monroe-Woodbury School District and the Circleville Elementary School in the Pine Bush School District where some of the students had a chance to be aquatic ecologists looking for animal life in the pond. This is one of my favorite sessions and one that the students and teachers all enjoy.

I bring in buckets of pond water (my favorite ponds to get samples from are at the Landis Arboretum in Esperance, NY – but you can find any of these creatures in most ponds throughout the Northeast). I explain how an aquatic ecologist tries to understand how pond organisms live, thrive and survive. I explain some of the equipment that an aquatic ecologist might use to investigate the pond environment. The students get to use my “uncamouflage” equipment (see my upcoming Aquatic Ecology Field Kit write-up coming soon) to capture and observe the many small creatures of the pond.

After a short time of capturing pond life we settled in for my final overview. I have taken some of the smallest samples and placed them in a special slides (available from Carolina Biological Supply Co., called “deep well slides”) that are used with old style slide projectors. I call these slides, "special aquariums" that can be used to magnify the pond animals, taking something that might be a quarter of an inch large and making it look about 30 or 40 times larger. We have the chance to look at the same enlarged creature and learn about "who is who, what they do, how they grow and where they go".

Here are a few of the creatures we recently found. All of these creatures are in the pond now as winter approaches. They will live under the ice through the winter and will be ready to continue on with their life cycle when the warm weather melts the ice on the pond next spring.

The scud or side swimmer is a kind of freshwater shrimp. They belong to a group of arthropods called amphipoda. They are scavenger, eating dead plant and animal material. They then are eaten by a lot of larger pond animals and thus are important parts of the food chain.

They often are easy to see but hard to catch. They are easy to see because they spend a lot of time swimming rapidly around in the water. They are hard to catch because as soon as they stop in a bunch of pond plants or detritus they disappear with they good camouflage.

One of my favorite creatures to show students is the phantom midge or gnat. It's called a phantom because it has a transparent (see-through) body. What a great adaptation for living in the water, to have a body that is see-through. Many times you don't notice that there is a midge larva in view. You see a few pieces of what looks like dirt floating in the water and then you see them wiggle around and notice the outline of a larva's body. Those little specks of dirt are the float bladders inside the midge that help it sink or float. You can also see it's digestive system.

The phantom midges or gnats are hunters. They use their antennae to catch small aquatic organisms and pull them to their mouths so that they can eat them. Here in this picture you can see these antennae. They look like a hook on top of the larva's head.

This past sample had hundreds of mayfly nymphs, most of them just about a quarter of an inch long. I suspect that most of these had hatched from eggs just before the cold weather arrived. They will live in the pond along with the other creatures we were capturing through the winter and be among the first of the pond insects to grow up and leave the pond next spring.

Mayfly nymphs are hunters in the pond. They will eat other small pond creatures like daphnia and copepods, along with aquatic worms and other insects.

When they are ready to leave the pond they will climb up out of the water on to a rock, or log, or dock, or something sticking out of the water and shed their exoskeleton one last time. This time their new exoskeleton will have something none of their past exoskeletons have had, wings!

When they leave the pond, though, they will have no digestive system. That means that the adult mayfly will not live long, but it leaves extra room for eggs in the females. They quickly find mates and lay eggs in the water for their species to continue on.

Here is a damselfly nymph. They are hunters while they live in the water. As they eat and grow they become to large for their exoskeletons and shed. Sometimes we are lucky and find the cast off exoskeleton they leave behind when they do.

When they are ready to leave the water they do the same as mayflies and climb up on to a dry area and shed their exoskeleton that also has new wings. They pump up their wings so that they are fully extended. The wings dry off and harden and off flies the damselfly to be a winged hunter chasing down and catching flying insects. One of their favorite insects to eat are mosquitoes.

I always leave the leach as the last of the critter to look at. What most people know about leaches if fiction from movies that they see, or folk tales that they've heard. Scientists are interested in the facts, not fiction. Here are some of the facts about leaches.

Most of the leeches that we find in a pond do not suck blood. They are either hunters or scavengers. All leeches have a suction cup tail that can grasp on to an animal like a duck or turtle. When the animal travels to another pond the leach takes a ride and can end up in a new pond far from where it started.

Blood sucking leeches get a bad rap. When they bite you usually don't feel it (not like deer flies or horse flies), after they bite it usually doesn't swell up or itch (not like mosquito or black fly bites) and to my knowledge there are no diseases passed on by leaches - not like a lot of other biting organisms like ticks [Lyme disease] or mosquitoes [West Nile virus or malaria]. They are important parts of the food chain, eating small animals or scavenging and then being food for larger animals like fish and if you eat the fish that you catch in a pond food in turn part of the food chain that ends in you.

Decomposing Deer

Last year during my ecologist-in-residence at the Central Valley Elementary School we observed turkey vultures circling around what turned out to be a dead deer. During my visit this year with Mr. Petersen's class we went to check out what happened to the deer. We only found bones, mostly vertebrae and ribs along with one scapula, one femur and one humerus. Here's what I think happened to the dead deer as it decomposed and passed energy on to other organisms and returned nutrients to the environment.

The picture to the right shows a broken femur. I think the deer was hit by a car and ended up with a compound fracture of the femur. The impact of the car did not kill the deer right away and the deer was able to run up along the rock wall away from the highway. Through the action of running the sharp edges of the broken bone probably severed the femoral artery, resulting in the deer dieing.

The compound fracture would have left a gaping wound that the flies would have landed on to lay their eggs. That's why that area of the deer was more quickly consumed than the area of the upper body and head. Normally the place the flies would most likely lay eggs if there is no break in the skin would be the eyes, mouth and nose, among other open areas of the body. Notice in the picture to the left how the head area has had very little effect from fly larvae.

As the flies consumed more of the flesh of the area of the hind leg (the broken femur), that left a large opening for vultures to begin to eat the dead deer. The area shown in the picture to the right shows the affects of vultures and possibly other scavengers as they began eating the deer for food.

All of this is nature's way of recycling nutrients and passing along energy in the food chain. With the actions of the scavenger and decomposer organisms dead animals are returned to the earth and results in the continuation of life.

This kind of study and analysis is something that a terrestrial community ecologist would investigate.

Outdoor Education Conference

I just got back from the New York State Outdoor Education Association annual conference. As it is every year, it was great conference. I never compare one year to another (I learned this in my years as a summer camp counselor - every year had its high points, and there was nothing to be gained by comparing one year to another). The highlights for me is always the auction - I have a blast doing it. We raise money for the Association's endowment. People have a great time (at least that's what they tell me). I'm already looking forward to next years conference which will be held September 24-27, 2009 in Fishkill, NY. The focus of the conference will be the Hudson River and local environs, as 2009 is the 400th anniversary of Henry Hudson's exploring the Hudson River.

I am trying to think what workshops I should submit for consideration to the conference committee. I think the site will lend itself nicely to a nature songs and stories campfire workshop. I might also offer to do a nature trail mapping session.

One of the key note speakers at this years conference was David Sobel who spoke on place based learning. It was an inspiring presentation that dovetailed with a workshop that I lead on integrating environmental education across the curriculum - exploring how outdoor environmental education can help teachers teach math, science, language arts, art, physical education and music. We had a spirited discussion, with a lot of good examples of nature centers, outdoor education centers and BOCES programs that provided service to schools to help them take advantage of the outdoor natural environment to stimulate learning in all areas, not just science.

I am still left though, with the question of how do we encourage all schools to take advantage of the real world to inspire and excite students in learning? It is encouraging to see the excitement of Richard Louv's book "Last Child in the Woods" has created. In fact there is legislation at the Federal level called Leave No Child Inside that is slowly moving though the halls of Congress. Newsweek in it's September 15 issue had an article on "eco-education". But it's all small steps when you think of all the schools there are and how little teachers take students into the real world to facilitate learning. I am resolved to try to contact school administrators that I know and get their opinion on how more action in bringing the real world to the classroom might happen. It would seem to me if there is to be a shift in the attitudes of schools regarding teaching in outdoor environment and immediate community surrounding the school that it will require a multi-prong approach involving pre-service (teacher preparation at the college level) teacher training, the classroom teachers, school administrators, parents and those involved in providing enrichment programs using the natural environment (nature center, outdoor center, museum, and parks program staff).

recent bell top elementary school visit

I just finished my annual ecologist-in-residence visit at the Bell Top School in the East Greenbush CSD in Troy, NY. My visit culminated with my nature tunes and tales assembly program that was highlighted by a performance of "The Lorax" by Mrs. Gigglio's 3rd grade class (special appearance by Peter as the Lorax).

We investigated general ecology, insect study (including capturing a pair of mating walking sticks), aquatic ecology (study pond water organisms in water samples from the Landis Arboretum in Esperance, NY), mammals and trees.

One of the things that I empasize with all these classes is that scientist do research to find answers to the questions they come up with. An example of this has a fun side to the learning opportunity. In my tree exploration walks I end with a short discussion of how we humans use trees - for lumber, food, paper, inspiration, enjoyment, etc. I then procede to show them how I can use an acorn cap from an oak tree to make a whistle. The shrill whistle produces a group of ear plugging young scientists asking "How did you do that?" My response - "You'll have to do some research."

I suggested that they might google "acorn cap whistle" with mom or dad's help not knowing if there was indeed a site that would show how. Indeed there is! Check the link I have here or search for yourself.