Pride Month

Earlier this month, Orkney Field Club was invited by Pride in Orkney to help out with a wildlife event at Arcadia Park in Kirkwall. I happily volunteered as the park is a recently-created nature site in an urban environment, and although I have received records of damselflies being present during the last few Summers, I hadn't actually visited the place myself.

A recce during May encouraged me that this will be a brilliant place to highlight wildlife, as the site matures and is developed with wildflower planting, tree planting and the creation of umpteen pools.

One of the species of damselfly which had been reported from the park already this year was Blue-tailed Damselfly, and bearing in mind the organisation running the event, I thought this was a suitably interesting insect to promote on the day.

Blue-tailed Damselflies Ischnura elegans have, as their name suggests, blue tails. Most of the abdomen (tail) is black, but segment 8 is a bright neon blue. In fact, when the damselfly is roosting amongst vegetation, they can be difficult to see, and it's often only that blue spot which catches the eye.

The thorax (middle bit) of the insect is a different matter, with as many variations in hue as there are colours in a rainbow. Males can be green or blue, depending upon age, whilst females have five different colour forms: violet/lilac (form violacea) as an immature, which ages to either blue (form typica) or olive green (form infuscans); and an orange/pink (form rufescens) as an immature, which ages to a pale brown (form rufescens-obsoleta).

Truly a rainbow insect. Here's a selection of photos from times past.

Blue male

Green male

Pale brown female (Photo credit: Alan Nelson)

Pink female

Purple female

It may not have escaped your notice that some of those colours are shared by both sexes, which is both interesting and pertinent. For instance, the blue form female looks like a male, whilst the green form male looks like a female. This bending of genders occurs in many species of Odonata, and often is more prevalent at higher latitudes. It is thought that evolutionally, the ability of a female to mimic a male allows her more choice about the timing of mating. She can pretend to be a boy to avoid being pestered by a mate until she's good and ready, thank you very much. That immature males are green like some females is more open to debate, but suggests that the youngsters are removing themselves from any territorial disputes between adult males.

Unfortunately, on the day of the Arcadia Park Amble, I couldn't find a single one, just a few bumblebees, hoverflies and a butterfly. Gah!

However, if we were in any doubt about how Blue-tailed Damselflies flaunt the rules, there's another species in the Genus Ischnura, I. hastata, the Citrine Forktail of North and South America. In the Americas, it behaves as expected, but at some point in history, likely due to an extreme weather event, a small population appeared in the Azores at the other side of the Atlantic Ocean. This population is entirely composed of females, making it the only dragonfly or damselfly which reproduces by parthenogenesis. Boys need not apply.

Another flag for the Pride event

My thanks to Pride in Orkney for the invitation, their help on the day with finding insects during rain showers and a constant northwesterly breeze, plus giving me the opportunity to showcase Blue-tailed Damselflies in all their multi-coloured glory.

PS Should you happen to be wondering, the photo of the whole damselfly is a male. I had to double check!