Wednesday, 1 July 2015

Dragonflies don't like this heat

I arrived at work around 0755 and 23 degrees and stopped on the bridge across the River Ise from the car park. There was a female Emperor hawking around and 50+ Banded Demoiselles. By lunchtime, with temps around 35 degrees, the river had no activity. I went to Irthlingborough again to look for more Scarce Chasers, but perhaps the high temp kept them away. Along the new ditch, there were 8 Emperors including one ovipositing female. The males were hawking very low down, perhaps 5-10cm above the water instead of their usual ~1m. Their flights were brief, lasting 1-2mins before they would stop and rest up overhanging the water in shady sections, I managed a shot of one before he flew further away. Here they were clashing with the Broad-bodied Chasers and Black-tailed Skimmers. I guess this behaviour was a mechanism to retain their territories but not overheat in the high temps, which must have been 45+ in the sun. Activity was certainly lower than expected and I think the high temps were too much for them.

Tony Vials reports the first Brown Hawker, at Irthlingborough.

Male Emperor

Four-spotted Chaser

Black-tailed Skimmer

Black-tailed Skimmer