Tuesday, June 12, 2012

Evaporating Pond

The pond is going dry.  It’s an annual event, but it happens differently each year.  This has been a year of extremes.  Excessive rains and flooding in late winter were counter acted by an early April drought.  The cycle has been repeated with late April floods and a May drought.  Blue Jay Barrens has had only one third of an inch of rain during the last four weeks.  For a well drained, shallow soil area, this means drought stress.

Butterflies have moved in to extract minerals and other nutrients from the pond mud.  Question Marks have been especially abundant this year.

Swarms of small, colorful flies walk the mud flats and skate across the water.  Their colors ripple from yellow and gold to blue and green as they shift position in the sunlight.

I haven’t identified the fly, but I’m guessing it to be a species of Dance Fly.  Since there are several hundred of those to choose from, that guess doesn’t narrow it down too much.

This is the extent of the water.  At this stage I’m always reminded of African water holes.  Exposed mud is trampled and vegetation is beat down by animals coming in to drink.  Except for my Water Garden, the next open water is about 800 feet away.  This pond is heavily used by the local wildlife.

Most of these tracks are from the nursing female Raccoon.  The water is shallow enough for her to wade all the way across, so she can be a very effective predator.

Unfortunately for the Raccoon, there’s not a lot to eat in the pond right now.  The early frog and salamander larvae have transformed into air breathing land dwellers.  There are only a handful of tadpoles left and they are transforming very quickly.  Backswimmers are the most abundant visible creature, but they’re not much to feed a hungry Raccoon.

Most of the Bullfrogs have either moved out or been eaten.  I only saw two and the water was almost too shallow to provide any cover.  If we don’t get rain today, the pond bottom will be baking in the sun by the end of the week.  I’m already thinking about next year’s salamander season.


  1. Very interesting. It is amazing how the pond repopulates when the water returns.

  2. I agree with Lois. In fact, I'm embarrassed to admit it, but I've always found the population of ponds (especially seasonal ones) by frogs and other critters to be a bit magical. How *do* the ponds get repopulated?!

  3. Hi Lois. Watching the repopulation is the fun part.

    Hi Aaron. Many amphibian species spend the majority of their lives on land and come to water only to breed. Temporary pools that dry up in the summer are ideal for this purpose because the loss of water eliminates aquatic predators that would feed on both adult and larva amphibians. Several invertebrates survive in the dry pool as eggs that hatch when the water returns and swarms of flying insects come to the new pool to lay eggs. Crayfish burrow into the pond bottom to find moist soil to take them through the dry season and snails burrow into the mud, retract into their shells and wait for rain. You can usually see life in the new pool just hours after the water arrives.