Water in Winter - Pond Wildlife in the Cold Weather

Pond Wildlife in the Cold Weather

This is a really interesting article about aquatic life in the winter by the Prairie Ridge Ecostation in Raleigh. Dragonfly larvae, also known as nymphs, are active in the water now, eating mosquitoes, and getting ready to hatch in the spring!

Preview:

As the weather starts to cool, we will start to see fewer and fewer insects active at Prairie Ridge.  Because they are endothermic (“cold blooded”), many insects enter a dormant period during the cold months, often overwintering in some hidden, protected spot as eggs or larvae in a sort of suspended animation until spring or summer.  However, there are places on the Prairie Ridge grounds where you can find insects active year-round, where even on the coldest winter day you might still find insects going about their regular business: our stream and pond.

In spite of some of the difficulties that life in water brings for aquatic insects, it’s still a great place to live.  Most importantly, water is very thermally stable.  It takes a long time for water to heat up and cool down, especially in large quantities.  This means that aquatic insects often experience far less fluctuation in temperatures than their land dwelling relatives.  Many aquatic insects are also well adapted to living in a cool environment and are quite capable of carrying on with their regular lives in our relatively mild winters.  Short of freezing over (and maybe even then!), you will be able to find at least a few insects swimming around in our ponds and stream even on the coldest days of the year.

A trip to the pond and a few sweeps of a net will currently yield a surprising diversity of aquatic insects.

Many dragonflies overwinter as immatures (nymphs) in the water, so even though you might not see adult dragonflies flying, you can still find lots of nymphs that will emerge as adults next spring or summer.  Dragonfly nymphs are wonderful creatures, expert hunters with an amazing extensible mouthpart that they use to reach out, grab, and hold prey while they eat.  These highly visual predators are an important part of the pond’s ecosystem.