Each month we focus on a species that benefits from Fair to Nature farming practises. During June, that species is the Migrant Hawker dragonfly (Aeshna mixta). Brian Walker, Trustee of the British Dragonfly Society, tells us a bit about this large, colourful insect…
Migrant Hawker is a fairly large dragonfly which can be found across a wide range of standing water habitats and often at some distance from water. Unusually for a Hawker dragonfly, males are not particularly territorial so that significant numbers may be found together at favoured sites. It is generally not on the wing until July, with peak numbers being seen in the second half of August, when populations on the south and east coasts are augmented by immigration from the continent.
Male Migrant Hawkers look predominantly blue in flight and this distinguishes them from the main confusion species in their current range, Southern Hawker, which appears pale green and blue in flight. They are most likely to be spotted in flight, although they do seem to perch on bushes and trees more readily than other Hawker species.
As with all dragonfly species, Migrant Hawkers spend the majority of their lives in the water as a larva feeding on insects and other aquatic creatures. They appear to be able to tolerate small levels of pollution and even brackish waters, but they do depend on vegetation in the water margins into which the females can lay their eggs.
Migrant Hawker has recently expanded its range north and west in Britain and has recently started to occur in Ireland and Scotland. This is one of the changes in dragonfly populations thathas been highlighted by the “Atlas of Dragonflies in Britain and Ireland*” published in 2014, based on records collected by British Dragonfly Society. Monitoring dragonfly populations is an ongoing project and the Society welcomes all records of dragonflies seen via their website http://www.british-dragonflies.org.uk/. While Migrant Hawker and a number of other species with a more southerly distribution are expanding their ranges in Britain, almost certainly influenced by climate change, several species which depend on specialised habitats are struggling as their favoured habitat is lost and becomes more fragmented.
*Atlas of Dragonflies in Britain and Ireland edited by Steve Cham, Brian Nelson, Adrian Parr, Steve Prentice, Dave Smallshire and Pam Taylor published by Field Studies Council.
Migrant Hawker photos copyright of Brian Walker/British Dragonfly Society
To read previous Species of the Month please click on the months below: