Showing posts with label Southern Hawker. Show all posts
Showing posts with label Southern Hawker. Show all posts

Tuesday, 31 July 2018

Egg laying Southern Hawker

On the way back from work I popped in my local wildlife garden. I was looking for dragonfly exuviae in the small pond when I gasped: A female Southern Hawker had materialised like out of nowhere and was hovering inches from my face. This is a large and inquisitive dragonfly, with a striking apple green, yellow and black pattern, which often approaches humans when they walk on their flight path. She took no notice of me and landed just by my feet, on the side of the pond-dipping platform. She was egg laying! I watched, mesmerised, how the tip of her abdomen appeared to direct proceedings, making searching movements on the pond lining, in a caterpillar-like fashion. After a few moments she flew low across the rushes growing in the pond, her wings clashing with the leaves. She landed nearby on the shore and started egg laying again. Taking her time, her abdomen appeared to 'look' for crevices amongst the mosses and litter, just a few centimetres over the pond surface.
 There was no male about. Hawkers oviposit on their own. 

Oviposition sites
Hawkers often lay their eggs endophytically, which means inserted into plants, mud or debris or wood on the pond margin, as opposed to exophytically, meaning dispersed on water. However this species appears to often chose odd places as substrate, and indeed, in the space of 10 minutes the female today had probed or laid in several places in the pond:
Probing on pond liner...
on mosses at the pond margin...
...on the decaying leaves of aquatic plants.
on the wooden panels of the pond-dipping platform.
 Having recently read the New Naturalist volume on Dragonflies, I wasn't too surprised. Philip Corbet and Stephen Brooks compiled a list of totally bizarre substrates chosen by Southern Hawker females to lay eggs. These included:
-A brown woolly jumper
-A wellington boot
-Someones ankle
-A dog's rump
-The skin of a Yellow-bellied toad

Corbet and Brooks remarked that in some of these cases the female might be just investigating the suitability of the particular substrate chosen, as opposed to ovipositing.

The Southern Hawker female hovered a few times by the pond and then moved on, hawking low along the garden path by the hedge a few times and exploring the bushes in the typical fashion of the Southern Hawker. This low flight is a behaviour that unfortunately, makes this species a frequent prey of cats.

More information
Klaas-Douwe B Dijkstra. 2006. Field Guide to the Dragonflies of Britain and Europe. Illustrated by Richard Lewington. British Wildlife Publishing. 320 pp.

Philip Corbet and Stephen Brooks. 2008. Dragonflies.  The New Naturalist Series. harper Collins Publishers, London. 454 pp.

Thursday, 2 July 2015

A Southern Hawker

As I was about to leave the park this morning on my way to work I checked around an area of trees for Speckled Woods. Instead, I noticed a large dragonfly flying about and landing on a horse chestnut branch. I approached and searched for it. I had clearly seen where it had landed, but it took me a while to find it again. There! hanging from a leaf was a hawker. It rested, about 4 m high at an angle away from the sun, so it wasn't a great spot for photos, but after a while I managed this shot showing its features. As I checked the photo tonight thinking it's a bit early for Migrant Hawkers, I was pleasantly surprised to find that it was an immature Southern Hawker, which I have never seen in the area. Southern Hawkers breed in small ponds or canals, and often in garden ponds. After the adult dragonflies emerge from their native ponds, they spend about month away from water while they mature. Then they will find ponds where to breed. They like to feed on woodland glades, often away from their breeding ponds.