A Rough Breakup - Observation of the Week, 7/11/24

Our Observation of the Week is this remarkable scene captured by @cumaliyesil in Turkey: a female Goblet-marked Damselfly (Erythromma lindenii) with a male’s dismembered abdomen still attached to her body!

Cumali Yeşil credits the Libellen-Freunde Facebook group with really inspiring his passion for odonates (dragonflies and damselflies), particularly members Hartwig Stobbe and Jörg Teumer. He also heard about iNaturalist there, and joined up.

Being able to learn about all the living creatures from India to America instantly, being in the first place that scientific researchers and expert's identify species, as well as their deep knowledge and interest on the issue has increased my admiration of nature. I love being in nature and being with my family in my spare time.

Before heading to the Beyşehir district last month, Cumali checked out iNaturalist and wanted to observe goblet-marked damselflies, hoping to see how climate change has affected them. 

There was wildlife just by the thicket where people were swimming by the lake, chatting and having fun. It was a life that consisted of feeding, finding shelter, and the struggle for survival. All natural and out  in the open. To observe such wildlife has always affected me deeply.

On that day, as I was making observations, I noticed something strange by my side. I didn’t realize what it was at first, but then I was surprised and appalled as I looked closer.

A female goblet-marked damselfly was flying with a dead body of a male still attached to her! At first I tried to remove the dead body from her but I eventually had to leave her to her fate, which still saddens me. 

So how did this situation happen? Well, damselflies have a complex mating process which involves the male (in this species, males are blue) transferring a packet of sperm from the end of his abdomen to a site near the front of his abdomen. Using the cerci (or claspers) on the end of his abdomen he grabs the female behind her head. The female then arches the tip of her abdomen to pick up the sperm packet, making a heart or wheel shape. When she oviposits (or lays eggs), he either guards her from other males by hovering nearby or will continue to hold her with his cerci.

So what happened here? It’s likely that a predator such as a bird struck the male while he was still attached to the female, taking only his head and thorax and leaving the abdomen. Odonate expert @boudot_jp confirms that this does happen and has a photo of it in his book. I also reached out to @ronan_a, who told me

This gives us an idea of ​​the precision of attachment of the cerci on the female so that a connection is maintained as they move. I don't know if it is linked to an active unlocking system (requiring an action from the male) or to a particular engagement/disengagement movement. 

I've seen similar photos before…but I've never seen it myself in the field. It seems that, for European (and probably Palearctic and Nearctic) damselflies, this is quite specific to the Coenagrionidae family. 

A high school German language teacher, Cumali (above) tells me that the semi-aquatic life history of odonates is what attracted him to them. 

It’s inspired me to raise awareness in the community about the picnics or off-road races in the canyons where I make my observations. To further this, I have decided to to save and create odonate habitats with volunteer students at my school.

Even though my profession is not biology, my interest in biology and the anatomy of odonates continues to grow every day. The biggest contribution to my idea was mostly with the members in iNaturalist and their observations of different living species.

(Some quotes have been edited for clarity and flow.)

- PBS Deep Look has a great damselfly reproduction video.

- check out our profile of odonate identifier @@amila_sumanapala!

Publicado el 11 de julio de 2024 por tiwane