|The Question: Recently, I saw a butterfly holding on to another butterfly beneath him. It caught my eye when the two began to spiral downward into a field of grass. The “carrier” was able to ascend again and flew off holding the butterfly that appeared to be one of his own kind. Do you know why the “carrier” was doing this?
Submitted by: Judy, USA
The Short Answer: The butterflies were mating. Here’s a short video clip showing monarch butterflies doing exactly what you describe.
Warning, this one is a little dizzying: http://www.youtube.com/watch?v=Z-kFgUVhK4I
According to Martin Olofsson, who studies butterfly behavior at Stockholm University in Sweden, when two mating butterflies are disturbed while copulating, they may try to fly away together, with one member of the couple as the carrier and the other going along limply as the carried. Interestingly, within a species, it is always the same sex that carries. In one species it’s males, in another it’s the females.
More Information: The data, Olofsson says, suggest that this behavior is about escaping from predators and not about “mate-guarding.” Mate-guarding is a collection of behaviors common in many animals, where males will guard their mate to prevent other males from fertilizing her eggs. In birds, fish and mammals this might involve chasing other males away from a territory. In insects, mate-guarding often involves staying physically attached to a female long enough for sperm to find their way to the female’s eggs, or for the female to stop being receptive.
It’s possible that in some species at least, the butterfly behavior of flying off with a mate may be a male’s attempt to hide the mated female from other males. Olofsson, points out, however, that females carry the males in some butterflies, so that makes male mate-guarding unlikely as a general explanation for this behavior. It might, however, be an added benefit, at least in those species where males do the carrying.
Thank you to: Martin Olofsson for his generous help.
chrissie carter Says:
Hi last week I saw a butterfly carry another one by its wings both facing same direction and was wondering if the butterfly being carried had died ? if so what was the butterfly going to do with its dead partner?
Faye Bell Says:
I saw a monarch butterfly carrying another by the wings both facing the same direction. What does this mean, I have never seen this before. Very interested to find out.
[Faye, I moved your comment from another article to this one, that is more relevant. Tom for AskaNaturalist.com]
Tom of AskaNaturalist.com Says:
I forwarded your comment/question about the behavior you observed to Dr. Martin Olofsson, who studies butterfly mating behavior. He said:
The behavior described by the observer is not part of a natural behavior in butterflies. However, monarchs and many other butterflies engage in quite extended courtship flights and in some species the male repeatedly flies closely over the female to make her perceive his sex pheromones. Potentially, during a short time period it might appear as if the male actually holds the female but this is not the case. Another explanation is that the observer observed a very very unlikely and odd event, or that the butterflies had got stuck to each other e.g. by spider web or something like that.
Wendy Dee Says:
I have a picture of two butterflies who seemed to have been mating and one died. It is clearly dead. I was wondering if I should pull them apart but did not in fear I would harm the living one. I did remove the ants from the dead one and move them to another spot. My question is a two part. 1. What causes this to happen? I’ve seen it several times in the past few years. 2. Would it be wise to attempt to help the living one or will they separate on their own? I’m not sure where to post the picture. Thank you for your time.
Tom of AskaNaturalist.com Says:
Wendy, I’m not sure. Could be that one of them was diseased. If you want to email me the picture, I would be interested to see it, and I’ll see if I can find anyone who might have any answer. Send it to firstname.lastname@example.org. Thanks, Tom
I have a same case it appears the butterfly was trying to get apart and before i could catch them (near big spider webs) the below one has died. I assume from the way the top one was slamming it into everything trying to get apart.
Easter day 2016…Today I saw a dead butterfly lying on the ground. It was yellow and I noticed it as a friend and I stood talking. A minute later another yellow butterfly flew by and seemed to notice the dead one. It fluttered down to the ground, picked up the dead one and flew away with it. It was very unusual. Any thoughts?
Susanne Oakley Says:
I saw 2 butterfly’s yesterday and one seemed to be pursuing the other as hadn’t hooked up but we’re very close to one another the whole time. At first they were right in front of me but didn’t have phone to film them and once I did got some great shots of my doggie trying to get them. Would like to share it but guess this doesn’t accept videos, but was very interesting and now I know what was happening.