By: Jessica L Graham

This one is going to end up being a two-parter because a lot happened at this particular site and I really, really would love feedback or ideas on what is happening, especially if you know a lot about dippers.

At one of our waterfall sites, we have a nesting pair. It all started out very normally. We located the nest in early May, caught and banded both the male and the female the next day, then continued checking the nest regularly for fledglings.

Five days after we banded the pair, I go back to check on the nest and what do I see? Three adult dippers just, hanging out. In the photo below the female is over to the left side (a bit blurry because she was exhibiting what I think was copulatory behavior, based on this video), an unbanded bird in the middle, and the male on the right.

This is weird to me. Dippers are generally solitary birds except when seen in pairs. They are also known to be territorial, so it was very strange to see these three adults together. I decided to take a video and gather as much evidence as I could of what was happening. At this point, all three dippers take flight and the unbanded bird tackles the female into the water. I thought unbanded was going to drown her! The video is next – sorry for the shakiness. I was zoomed way in so any movement was way over the top. I’ve also included a shorter, zoomed in version of the physical altercation below in case anyone wants to see it.

At the end of the video, all three birds seem okay again. The unbanded bird and the male are doing a bit of self maintenance and foraging while the female is still doing her thing. The unbanded bird even went to and from the nest a couple of times! Unfortunately, I did not get video of that. I was at this nest for almost an hour and apart from the couple minutes of fighting, everyone seemed fine with their situation.

I’ve been struggling to wrap my brain around this interaction. My first hypothesis was that it’s an example of communal care. Not something dippers are known to do, but hey, maybe it’s a new breeding strategy that helps individuals survive in this isolated, vulnerable population. Maybe the unbanded bird is a fledgling from last year that decided to help with its parent’s nest instead of breeding itself – but that’s complete speculation on my part. What happed next makes me doubt this hypothesis a bit more, but I do think it would be interesting to see if these three are related!

The next day, we headed down as a group to band the mysterious unbanded bird. Buckle up—things are about to get even more wild in part 2!

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A big thanks to Melissa Riley, Jess Speiser, Kailey DeVries, Alec Baker, and Abby Domagall who all visited this site with me when banding these birds! You’re all officially witnesses.