In early June I was walking in a park in southern Ontario hoping to hear a certain warbler singing. That meant I spent a long time pacing up and down a short stretch of path admiring all the insects, reptiles and birds to be seen while I listened. My reward was not the emergence of the wanted warbler but instead a first-hand look at a truly intriguing encounter between a Swallowtail and a Robin.
Tiger Swallowtail butterflies are common in June. They are primarily interested in finding partners and/or laying eggs but they do sometimes stop to sip from flowers, sap, waste or puddles. So I kept an eye on a butterfly when it floated low over the still-wet-from-last-night’s-rain path.
To my astonishment, the Tiger Swallowtail began to try to drive an American Robin away from a particular part of the path!
Swallowtail Butterfly Attacks Robin to Try to Drive It Away
The Robin, which had been moving up and down the path hunting had paused beside what turned out to be a clump of wet, dead, slightly rotten vegetation. As it turned out later, the butterfly wanted to land on that sodden lump.
Not just once, or twice, but repeatedly, the Swallowtail dove at the Robin. It came within a few cm (inches) several times. The butterfly would circle past the bird and come back again very quickly. I actually watched the Robin flinch, twice, when the Tiger came very close.
After more than 2 minutes of these aerial attacks, the Robin eventually moved a few steps away, although I’m not convinced that it even knew what the Swallowtail wanted.
Very soon after it departed, the Tiger Swallowtail settled onto the wet clump of leaves and sipped delicately. It stayed there for four minutes “drinking.” I paced, slowly and carefully, around it taking photos and it did not budge.
Eventually, the butterfly moved up onto a leaf on a nearby shrub and basked. A few minutes later it left.
Why Didn’t the Robin Move Sooner?
I’m not certain but it seemed like the Robin was interested in catching other insects near and in the sodden leaves.
Do Butterflies Often Mob Birds?
It took a bit of searching but I have found other reports of mobbing behaviour from butterflies. There seem to be three common types:
Some Butterflies Will Defend Their Territories from Other Butterflies and Other Creatures
Red Admirals are known to be territorial in some situations. I had one come after me the other morning: It flew straight at me, then swerved and fluttered briefly around my camera lens. I’m still not sure if it was bothered by me or if it saw a reflection in my lens and thought it was chasing another butterfly.
Others report attacks by Red Admirals as well. James C. Trager, in the comments on the Prairie Ecologist website, says he has seen Hackberry Butterflies chasing anything large that flies into their territory.
Some Butterflies Will Defend Their Food Source
This is what I think the Swallowtail I watched was doing. It wanted to land on the wet dead leave mass and ingest the wet juices possibly to get minerals. The Robin was in its way so it drove it off and then very quickly landed and stayed perched even when I came quite close to take photos.
Other people report seeing this type of behaviour to defend flowers, sap and mud puddling sipping spots.
For example, the Prairie Ecologist, Chris Helzer, wrote on his website about Gray Copper Butterflies driving Regal Fritillaries away from milkweed flowers.
Some Butterflies Will Attack Other Butterflies
On the Prairie Ecologist’s website, in the comments, several readers reported that they had witnessed Fritillaries attacking Monarchs. They had even seen the Fritillaries landing on Monarchs as they emerged from their chrysalises. This damaged some of the Monarchs that had not yet pumped up their wings and hardened their bodies.
And Yes, Other People Have Seen Butterflies Chasing Birds
Tom H., in the comments on the Prairie Ecologist website, reports having seen a Common Banded Skipper chasing a Hummingbird away.
Steven M,. also in the comments, had seen a Monarch go after birds.
Marie Winn reports on her Central Park Nature News website that Ben Cacace watched a Swallowtail drive a pair of mallards into the water. The butterfly apparently actually struck the Mallard more than once on the head.
On BirdForum, a chat site for bird watchers, one person reported seeing Purple Emperors chasing birds, and another reported seeing a butterfly chasing a swallow.
In the comments on a Flickr photo of a Lorquin’s Admiral Butterfly, a reader confirms that they will attack birds. The Canadian Biodiversity Information Facility website posting for this Admiral also states this “This is a very pugnacious butterfly, often attacking any intruder in its territory, even large birds.” It cites a reference from 1981.
The Victor basking in its success.
So I’m not the first person to see this curious behaviour. I found it quite interesting to watch and at times amusing, too. I hope I’ll see a repeat engagement on another spring morning.
Related Reading
- Butterflies of June
- Sexing Monarchs (Butterflies, that is!)
- A Small Black and Blue “Monarch” is Actually an Admiral
- Butterflies Abound on Bergamot Blossoms
Join In
Have you seen butterflies chasing away birds, other butterflies, or other creatures? Please share your experience with a comment.
Last weekend I saw a tiger swallowtail harassing a redwing blackbird perched on a milkweed flower. I was astounded but I guess that is not the first sighting of butterfly aggression.
Interesting! Red Wingeds are not a bird I would want to take on if I was a Swallowtail. Thanks for sharing this!
For the first time in my life I saw a butterfly chase a red wing blackbird…I never heard of this phenomena. It was difficult to get a picture while both were in flight but I did manage to get a picture while the bird was in the grass with the butterfly about to attack…I’ll post the picture on my FB page in a little while.
Another one! The birds are under more butterfly attacks than I guessed! Thanks for telling us!
There is a beautiful Mourning Cloak that has been flying through my back yard over the past few days. I also have a Black Phoebe that has been in my yard for years… and loves to eat my bees.
I watched as the Phoebe approached the Cloak, the Cloak turned around on a dime and chased the Phoebe out of my yard one way…. Then back through my yard into a tree, where the Phoebe cried uncle and the Cloak leisurely flew away. I was amazed at the speed that the Cloak flew and turned. This all happened within about 10 seconds.
Wow! What a great scene to watch play out!
Today, Nov 8, 2015, I saw a butterfly chasing a bird. It was at Coronado-del Sol HS in Tempe, AZ. Every now and then, the bird would turn and try to attack the butterfly, but the butterfly was better at manouvering in small spaces and the bird couldn’t catch it. Then the bird would turn and fly away, with the butterfly in pursuit. Couldn’t say what kind of bird or butterfly but I’ve never seen anything like this before.
Wow! That’s one determined butterfly. I had never seen it before either. It’s quite amazing to see what we think of as a delicate fragile butterfly attacking a creature as large and strong as a bird. Thank you for sharing your sighting!
Yes! While relaxing at a WestPort Wa beach yesterday we witnessed a butterfly chasing seagulls! The butterfly sat on a small plant and every time a seagull flew by….up he flew and chased after the bird for at least 15’ as if to run him off! Very strange but very entertaining !
Neat! I find it so interesting that these small insects are willing to chase birds. Thanks for sharing!
I witnessed a butterfly chasing 2 swallows in san diego around a pool at a resort today. I was amazed. The 2 birds came back several times and each time the butterfly came from somewhere and chased them non stop in circles around the pool. It was quite a show. I saw the butterfly land on one of the big tropical leaves in the same spot at least 3 times, so maybe it was being territorial? The birds did not try and fight back at all.
That must have been quite something to see! Yes, I think that was territorial aggression. Thanks for sharing your sighting!
Just saw a gulf fritillary chasing a hummingbird from native passion vine. Gulf fritillaries lay eggs on that vine every year and their caterpillars will devour it.
More information from me, Nancy Broussard. This occurred at my home in Saint Gabriel, Louisiana
Very neat to see! Thank you!
I live in San Diego and have swallowtails who never appear to feed. They have always been aggressive towards each other, but yesterday I saw the dominant swallowtail chasing hummingbirds. My biggest concern, however, is that I have added milkweed and a butterfly garden and this swallowtail is chasing my monarchs away. Is there anything that I can do?
I don’t think there is much you can do, but such strong territorial behaviour likely won’t last too long as the breeding season for the swallowtails isn’t too long. Most monarchs near here will move over a flower or two but aren’t really that easy to chase off. Hopefully yours will push back too. Thanks for sharing your sighting!
Just witnessed three Great Spangled Fritillaries chasing away a tree swallow when it came close to “their” coneflowers. Quite impressive to witness. Didn’t know it was possible and then found this site
Wow! that sounds like quite a ‘gang’ of Fritillaries. Thank you for sharing your sighting of another act of butterfly assertiveness!
HI there from Wellington, New Zealand –
It’s Summer here, and while we ate our dinner outside a few days ago we saw the most extraordinary site. A sparrow suddenly flew around us, zigzagging from side to side and up and down – brushing my head once – as it furiously chased an insect. This was a site in itself as in all my years of living alongside sparrows in NZ and the UK, I’ve not witneseed this behaviour. What we absolutely couldn’t believe tho, was that a red admiral butterfly was close on the sparrow’s tail, matching every swoop and turn the insect and sparrow took! If someone had described it to me I wouldn’t have believed it! I wish there had been time to film it, but at least I wasn’t the only one to see it so I know I wasn’t seeing things!
What an amazing thing to get to watch! And thank you for sharing it with us!
We are in Wellington New Zealand. I am seeing red admiral butterflies, sometimes one, sometimes a mob, chasing Monarch butterflies. What is this about
That sounds fascinating! I’m not familiar with NZ wildlife, so I couldn’t tell you what’s happening for sure, but I suspect your butterflies, like ours, are very territorial. If so, they are chasing the Monarchs out of their range. Thanks for sharing!
While mowing a large bowl shaped field in West Virginia a few summers ago i noticed that there were no barn swallows that usually hunt while Im mowing .Out of nowhere a swallow turns in front of the tractor with an ajax hot on its tail . the butterfly matched the swallows every move .I was dumbfounded at the speed of this butterfly and how long it kept up the chase .i watched them for at least one minite before they went out of sight over the hill.
Wow, that must have been amazing! Thank you for sharing another sighting of a butterfly vs bird flight!
On several occasions I have observed a common buckeye chase away other butterflies including sulfurs, a viceroy and a zebra swallowtail. If another butterfly flew within about 10 feet of the buckeye, it chased them about 30 yards away and then returned to its previous spot. The spot the buckeye was protecting was a gravel road on a farm.
That must have been quite something to watch–sounds like he was defending his territory against anything with wings!
I live in a Chicago suburb and planted a milkweed and butterfly bush this Spring in hopes of attracting Monarchs. The milkweed has been blooming a while now (no sign of caterpillars) and the butterfly bush began blooming profusely several weeks ago. One Monarch arrived about 2 weeks ago, another joined in last week and a third arrived today! They chase little sparrows in the yard. It’s very amusing!
I’m glad the butterflies have found your plants–and thanks for sharing another sighting of butterflies chasing birds!
I have a lot of Monarch butterflies and they regularly chase Swallows! This is just South of Auckland on the Firth of Thames, New Zealand.
wow, you amazing to see! Thank you for sharing this!
Today I saw a Monarch chase a Fritillary repeatedly. There is a tiny milkweed it seems to have been guarding. Los Angeles. CA. Jan. 25, 2019, noon.
Yes, it probably is defending its territory. Thanks for sharing–especially since we have 4 inches of new snow today, so no butterflies up here in Ontario for a while!
Three times I saw a Monarch butterfly chase a Mockingbird away from my fig tree. I was amazed and at first thought I was wrong. Not after the third encounter. Wish I were fast enough to film it.
That would be worth a video! Thanks for sharing this unusual behaviour!
I have a hummingbird feeder in my yard in front of living room window, in southern Minnesota. July 23, 2019 I saw a small butterfly drive a hummingbird away from the feeder. I could not believe it. Butterfly was very fast – may have been a fritillary. He kept dive bombing and flitting around hummingbird until the bird left and butterfly settled down on feeder.
Wow – what a fun and interesting thing to watch! I’ve seen wasps chase hummers so I’m sure a large butterfly could succeed too.
I had the privilege to witness an incredible sight between TWO Monarchs and a Dove today. I work at a greenhouse so it’s quite common to see several butterflies flying around, eating, laying eggs As I headed out towards the back of the nursery, I caught quick movements in my peripheral. I looked over and froze with shock! Mouth agape, I watched on as a Monarch Butterfly dive bombed a Mourning Dove! The confused Dove, (I’m sure!) darted this way and that in a desperate attempt to escape the irritated winged insect. As she swooped up towards to roof of the barn, yet another butterfly that was nearby came in for its own aggresive charge! Finally the Dove landed on the ridge and the butterflies twirled in a circle and slowly flew away.
I couldn’t believe it, and then did I gain a whole new perspective on the butterfly.
Wow! That fight sounds even more impressive than the one I saw! If you’re like me, you’re probably wishing you had a video to show your friends!
I’m in Tampa and when we released our monarchs, they were attacked by smaller, bright yellow butterflies. I’d never seen that.
In the mesh containers we have for the caterpillars we put milkweed plants, of course, but they fight like sea cows over particular leaves. They rear their heads back like said sea cows and bash into each other. Even the smaller caterpillars defend their leaf like it’s the last one.
Sorry for my slow reply. Thanks for sharing your very interesting sighting! I haven’t seen that behaviour and it sounds really interesting!
Just watched a monarch chase a swallow multiple times from my deck here on Vancouver Island…. They don’t even compete for the same food. Swallow just seemed to ignore it as she can fly faster with more agility.
I think these role reversals are fascinating! Thanks for sharing yours!
Dan Tibbs… found your site when I explored to see if it was possible a butterfly would chase a bird. We live on Lake Ontario in the Niagara Region. Lots of birds and butterflies abound. We have a butterfly bush and it attracts many. I saw a redwing black bird darting across the back yard with a monarch following close. The bird did a couple of swoops which were matched by the monarch. The bird suddenly turned and the monarch followed suit. The bird was now pursuing. The monarch put on a great display of maneuverability which the bird couldn’t match. Suddenly the bird did a 180 turn to make a retreat. The monarch was again in pursuit. The bird climbed then dove outmatched by the monarch. The monarch gave up and the bird made good his escape. The monarch fluttered a victory lap and disappeared from sight. The whole display lasted no more than 10 seconds excluding the victory lap… I had decided to keep my clockwork orange discovery to myself until I read all the other reports of butterflies chasing birds. Now I have story to tell my grandchildren with out fear of being locked up.
Wow, thanks for the great story and as you say, another amazing role reversal!
Surprised to see a small (1/3 size of a monarch) butterfly chase a hummingbird. I wouldn’t have believed it but they made 2 laps through my back yard and patio before the hummer escaped. Orange County, CA.
Wow! That would have been amazing to watch! And very pretty too.
Thanks for the insight. I came across your article because I have been searching for the answer too some behaviour involving large Birdwing butterflies and Ashy Woodswallows(AW) in my garden here in Thailand
The butterflies actually chase the birds. The AW are extremely fast fliers but the butterflies are equally adept. The birds seem unfazed by the butterflies attention but clearly the butterflies want them gone.
I guess the Birdwings might be protecting a flowering tree that attracts them too my garden. That said the AW take their prey on the wing so they are hardly a threat to the butterflies food source!
Once again thanks.
That must be very interesting to watch–Thank you for sharing that this happens around the world!
Here in North Texas we see butterflies chase after swallows as they fly to catch insects. The butterflies chase them in the air from behind and stay with them in speed and with every turn and dive. It is remarkable to watch. This is the only site I could find that addresses butterflies and bird interaction. I am trying to video it but their flying is so fast its hard to keep track.
That is a very interesting sighting! I wonder what benefit the butterflies are gaining? Thank you for sharing. It’s very interesting to me to hear of these different types of interactions.
This is exactly what I witnessed in Iowa. If the monarch hadn’t kept doing this, I would have talked myself out of believing what I was seeing!
It really is surprising to see a butterfly do this!
I live in Iowa, United States, and I found this article from searching “monarch chases bird,” as that was the very thing I witnessed while watching a patch of milkweed a monarch was hovering around. It attacked every bird that tried to enter the airspace around it. I was actually hoping to watch it lay an egg, as I’ve only witnessed that once in my life, I have watched monarchs over many, many years, but I’d never witnessed anything like this. If it hadn’t happened again and again, I would have thought I was only interpreting its behavior as defensive.
I’m so glad to have found others have witnessed the same!
There is a small but steadily growing group of us who have seen these types of ‘attacks.’ I find it really interesting!