Friday, 12 June 2015

Sun, sex and suspicious parents: damselflies get the same hassle

Summer’s damselfies are lifting off in glittering droves. The azure damselflies (Coenagrion puella) have coloured up and the air can seem full of bright blue cocktail sticks deftly exploring the grass and rush swards, or perched up sunning themselves. Times are good in the heat. The males particularly are fidgety, landing for a few seconds then flitting up to argue. They seem unable to leave each other alone. Females tend to be cannier keeping out the way, only venturing out into public when ready to mate and provoking a rash of males to chase after them. These two are mating, the male the bluer one, the female a delicate green, hiding away  a bit in the reeds because other males will attempt to barge in, crash landing to knock them apart. Females will mate with several males. This makes life fraught for all concerned. Males endlessly pester. If a male mates with one female then unwisely abandons her another male can come in, mate and physically remove the first males sperm (I am sure you can find out how but be careful what you web search for). As a result it is much more usual for pairs to stay together for a while, the males going in for what is called mate guarding. The female uncurls from this mating wheel whilst the male maintains his hold around the back of her head with special claspers. They can fly off in this tandem, surprisingly fast. The male keeps a firm hold when they land, his legs folded, sticking up over the females head like an ornate hat whilst the female dips her abdomen into the water to lay her eggs. They still get hassled by single males, but at least they don’t have their parents turning up, unlike in the TV series

No comments:

Post a Comment