September is the month for hawkers. Hawkers are medium to large dragonflies with a restless hawking flight. They have huge eyes which take up much of their head. They are mainly found over lakes and ponds but are also often encountered along woodland rides, hedgerows, gardens or in clearings in the vicinity of water.
The two most often seen in the Gardens are the very large and bold Southern Hawker (left) and the smaller Migrant Hawker (right). Both these species are widespread in Europe; the Migrant established as a resident only relatively recently, hence its name, but both now have established breeding populations in southern England, benefitting from gravel pits and reservoirs. The Southern Hawker is very territorial. It will chase other individuals away and will come close to investigate you if you are in its territory. It can be recognised by two large green or yellow "headlamps" on its thorax which are quite visible when seen a close quarters. The bright blue on the end of its abdomen also shows up well. The Migrant Hawker is smaller and neater, lacking the large "headlamps" and the blue tail. It is less territorial so you can often see several together. It also is quite curious and approaches quite closely. Both species can still be around in October, if the weather is favourable.
The only damselfly which you can still find in some numbers is the late emerging Emerald Damselfly. This name is a bit misleading, to my mind, since although its thorax and abdomen are both green in adults, in poor light it often looks greyish or blueish with (in the male) blue eyes, blue tail and blue at the top of the abdomen. Clear bright light brings out the green, but the best way of identifying it is to notice that it perches with its wings held out from its body at an angle, rather than folded back along the body as in most other damselflies.