The Dipper Cinclus cinclus is my favourite song bird. That lovely chinking song that bounces off the rocks and running water, such a nice sound to hear whether walking along an upland stream, or on your patch just 2 miles from the centre of Edinburgh!
Fortunately the latter applies to me, and it makes it very easy for me to enjoy this bird that is pretty unique when compared to our other British passerine species. For starters, the Dipper is the only passerine that makes a habit of fully submerging itself underwater. It does this to feed on whatever insects (and sometimes fish) it can catch under the surface.
Despite the fact I see this species on a regular basis, with at least 4 territories noted on my patch this past winter, I still have unanswered questions.
The first one is something that nobody really knows the answer to.The Dipper gets its name, not from the fact it dips under the water, but from the fact that it bobs up and down when perched on a rock or log or at the riverside. It is unclear as to why exactly Dippers do this but there are a few possibilities.
Firstly, it may be that this is a method of communication between individuals. Considering the habitat in which a Dipper lives (typically fast-flowing, rocky streams and rivers), it would make sense that the Dipper uses a visual means of communication as opposed to trying to be heard above the rushing water. However, I have observed Dippers bobbing with no other Dippers in sight. In fact they bob all the time when they aren’t out of the water, so I’m not so keen on this theory although I could be wrong. I’m sure someone somewhere will know why they would have a reason to constantly bob for communication.
The next possibility is that since the Dipper feeds on invertebrates underwater, it has to dip to better gauge where its prey is. A bird that does something somewhat similar would be the Grey Heron Ardea cinerea. When a heron sees a fish, it will move its head towards the fish to grab it, but then adjust its strike slightly so as to compensate for the fact that light refracts in water. The refraction of the light means the fish will not be exactly where it appears to be when looking through the surface of the water. This could be the explanation as to why Dippers must keep bobbing when perched at the water’s edge.
The final possible explanation for the obsessive dipping behaviour is that they are trying to blend in to their ever-moving habitat, becoming less visible in the water as it flows past. You might think that with such a brilliant white breast, the Dipper is bound to be obvious in an otherwise rather grey/brown background of rocks and water. However, if it is amongst the rapids where you get whitewater, this white patch does actually work quite well in concealing the wee bird. I have tested this theory myself and can see that Dippers are often harder to spot when they take on the same movement as their background.
One other thing that has always intrigued me was the fact that, when a Dipper is flying along one of its watery highways, it is constantly letting out that “zrik zrik zrik!” call. That was actually what inspired me to write up this post, since I was sitting on top of Agassiz Rock today looking down at the burn and could pick out this little black dot travelling back and forth, calling all the while.
Why would a bird want to be so easily heard? Sometimes it’s an alarm call, as was demonstrated today when a Kestrel Falco tinnunculus flew low over the burn. But most of the time it appears to just be calling because it’s travelling.
My most ridiculous theory is that they do this as a sort of echo-location. And now that I think about it more, I realise this is highly unlikely. The second theory I’ve come up with (couldn’t find any information on the web) is that they do this to signal to other Dippers that they are coming. If two Dippers are flying along the same narrow stream towards each other, I’d think it would be entirely possible for them to collide! Perhaps years of evolution has taught them that they need to let one another know when they are coming.
On the other hand, it could be as simple as the bird is proclaiming its territory. Although they already do this with that beautiful song. Speaking of which, I captured this video of what turned out to be 3 Dippers (I was only aware of 2 when filming) taking chunks out of each other in a dispute at the border of their territories. Quite an unexpected experience.
Try and see if you can pick out the possible explanations for why Dippers dip in the video, there’s quite a bit of footage showing typical behaviour: communication, feeding & camouflage.
Skip to around about 2 minutes to get to the action…
Not behaviour that I’d seen before they floated right in front of me as I sat on a log in the middle of the Braid Burn.
I hope that was an informative post and that you can find somewhere to watch Dippers yourself. I’m lucky in that we have loads of wee burns and rivers nearby that provide good habitat for this charismatic and somewhat strange bird. Bare in mind that Dippers have been known to move to the shores of lochs/lakes in the winter and even sometimes will be found along the coast in winter. Dippers are occasionally seen on the shores of Loch Leven but I’ve never personally seen one at the coast.