Tuesday, 28 August 2018

Southern Hawkers abound in August

This August, with its extreme contrasts in weather conditions, has been a good month for Southern Hawkers, dragonflies with character. They are seen each summer here, but not in large numbers - this year there have been more than usual, patrolling the same locations as usual, with some venturing further from the rivers as they are strong flyers, even in overcast weather.


Southern Hawker dragonfly male  (Aeshna cyanea) on elderberries.
This dragonfly has veered off the usual territory along the river to investigate the young hedgerow along a footpath which consists of many different hedgerow species - Elder, Dog rose,  Guelder rose, Hawthorn, Willow, bramble and more on a very hot day. The Elderberries hang in large bunches, but most are not yet ripe.
This doesn't trouble the Southern Hawker, which is a carnivore, despite giving the appearance of making a meal of the berries - it is just hanging on, in a typical resting pose, clinging to the fruits.
The hot weather has been beneficial to all kinds of insect life and dragonflies have found abundant prey to feed on.
These Hawkers perch with wings outstretched but are called hawkers as they spend most of the time flying, patrolling, prospecting for breeding sites along the river, and challenging rival males when encountered. Their choice of a river breeding site is important as the larvae spend over two years developing in the water, feeding on tadpoles or small fish. They will not survive in polluted waters. Once emerged in their adult form, the type of terrestrial riverside habitat they find is also a key to their survival. The mowing of riverside grass will be very detrimental to their survival as adults. This is true for many dragonflies. 



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