North Cave Wetlands – 02/10/12

I headed out to this location on an overcast morning and a strong southerly wind blowing, with no signs that it would brighten up or improve. As I walked along Dryham Lane there was no evidence of any invertebrate activity so I settled down in the hide overlooking Main Lake. The Little Grebes Tachybaptus ruficollis were active close to the hide, a brief bit of sun presenting a nice photo opportunity, as an adult swam past the hide.

Little Grebe - Tachybaptus ruficollis

Little Grebe – Tachybaptus ruficollis

After watching the grebes for a short while, I headed towards the most productive area for insects around the edge of Carp Lake. Initially there was very little activity, however the sun finally came out, prompting some dragonfly activity. You really know that autumn is with us, as we are now down to the season end stalwarts, with only two species present. Migrant Hawkers Aeshna mixta were hunting for food in the sheltered area, with their characteristic bouncy flight and constant changing of direction. Once you are aware of their flight characteristics, anything else flying with a more direct flight action is always worth a check, as it’s likely to be another species. The only other species present was Common Darter Sympetrum striolatum, some of the mature females now taking on a reddish hue, making it possible to confuse them with males. There were good numbers of each species present, both into double figures, the latter being more numerous. Going forward it’s going to be lot harder to find these stunning insects, as they naturally reach the end of their allotted life-span, and the weather takes its toll.

Migrant Hawker - Aeshna mixta

Male Migrant Hawker – Aeshna mixta

Migrant Hawker - Aeshna mixta

Female Migrant Hawker – Aeshna mixta

Common Darter - Sympetrum striolatum

Male Common Darter – Sympetrum striolatum

I wasn’t expecting to see much butterfly activity, so was pleasantly surprised to find this obliging Comma Polygonia c-album. Even more of a surprise was a male Common Blue Polyommatus icarus, still active along the northern edge of the reserve, struggling to fly in the strong winds. Both these species have strikingly different survival strategies for the winter. The ‘blues’ days as an adult are now numbered, October being a late date to still be finding them. Their eggs will hatch and the caterpillars will over winter, pupating in spring to emerge as adults in late spring, starting the process again. The Comma on the other hand has several months to live. It will be actively feeding, to enable it to hibernate through the winter as an adult. When it emerges from hibernation it will breed and start the next phase of its life cycle next spring.

Comma – Polygonia c-album

Comma – Polygonia c-album

Common Blue - Polyommatus icarus

Common Blue – Polyommatus icarus