school garden

school garden

Wednesday, 1 June 2011

Pond News

The warm weather during May has woken up life in the school pond. Two pairs of frogs laid lots of frogspawn earlier and the tadpoles are now growing fast with many having grown small legs ready to leave the pond very soon.

young frog swimming across the pond

 However the most exciting news is that we have discovered lots of breeding dragonflies and damselflies. The nymph stages of these were seen in early Spring either walking across the bottom of the pond liner or positioned on a plant stem, waiting for prey. These nymphs will eat just about anything which they find or swims by - even a small tadpole. They have large spring-loaded jaws!

Damselfly nymph

Once the nymphs are ready to leave the pond they climb up a suitable plant stem which emerges from the water. This is often done in the early morning. Then the wonderful process of metamorphosis takes place - when a beautiful coloured insect emerges from the dull brown casing. As the insect emerges fluids are pumped into the wings to stretch them until they are perfectrly formed and then the same fluid is taken back into the body to extend the abdomen

an empty dragonfly nymph case (Click to enlarge)

The insects then bask in the sun for a while on the stem of the plant until they are ready to fly. The transformation is truely amazing.

Click to enlarge pictures of the dragonfly

 A recent pond dipping exercise found several very small newts and lots of Water Boatmen
 which were very evident rushing up to the pond surface to collect a bubble of air and then diving back down to the bottom of the pond.

A young Water Boatman-  you can easily see the oars!


klinsmann said...

These pictures are amazing. Are they all taken at the school garden?

Steve said...

I have to confess that they were indeed all taken in the school garden. Some bamboo canes were placed on the edge of the pond and have provided excellent perching posts for the larger dragonflies and thus helped the photographer. It is an old trick used to photograph kingfishers on a river. A handy perch right in front of the camera!