Stealing Dragonflies

[Steve Kroenke]

Stealing Dragonflies

We have had about a week of rather cool weather in northwest Louisiana, particularly in the mornings. It has been in the upper 40s to mid-50s for several days during the early mornings and large flying insects are often a rare commodity to a huge colony of purple martins with a huge number of babies to feed. The temperatures have risen later though on occasion the martins had a difficult time finding many dragonflies and similar sized insects throughout the day. The weather is now becoming more seasonal.

This weather situation has led to several ?enterprising? martins to ?live a life of crime? in the mornings and steal dragonflies being brought in by their colony mates. This morning, May 18, 2006, was filled with crime as both male and female martins, ASY and SY alike, chased incoming martins laden with juicy dragonflies. The thief would grab the dragonfly while the victim would hold on and both martins would tumble toward the ground. Usually the thief, if he/she was a real pro would get the prize, fly fast and climb into the sky to escape other thieving martins! Then eventually he/she would fly back to their nest and deliver the stolen goods to their young. Other times, the dragonfly would be torn apart with one bird getting one portion of the body and the other martin the remaining piece. The most dramatic action would involve the thief actually following the dragonfly laden martin into its own nest! Occasionally, the thief would quickly emerge with the dragonfly or more often the thief would not succeed and be thoroughly disciplined and chased out. And rarely a dragonfly would be stolen several times in succession by different martins until the final one managed to elude the other thieves and disappear inside their nests! There is one SY female that has become a specialist in stealing dragonflies in the mornings and she pursues and takes on ASY males with gusto! I will monitor the avian ?Bonnie? and see if she continues her no good ways!

So far this ?stealing dragonflies phenomenon? has been an early morning affair during our current few days of cool weather. I did not see the behavior previously when the temperatures were warmer. Also, I have not seen the crime wave extend into the warmer afternoon hours when dragonflies are more active and easily caught. Since some martins are now accomplished thieves, I will monitor this crime wave and see if it continues during warmer mornings or perhaps even becomes a full day phenomenon. I am wondering when I should call the FBI!

Of course, this pirating behavior by martins is practiced by other bird species. Bald eagles steal fish from ospreys for example. In huge seabird colonies, you may observe intra-specific theft of food. The martin thief gets a meal without really having to fly far and fast to catch the speedy dragonfly and can stay closer to its nest site. Not too much work to get a handsome reward. But the victim of the theft must then return to the sky to hunt again and its babies did not get the food. So there is both a winner and loser.

Steve