Many of those who know me will be aware that I am particularly fond of a member of the crow family called a chough. The red-billed chough to be precise. My first encounter of a wild chough was while in was out birding a former patch in my native Cornwall. Ever since then I've been hooked. I volunteered with the RSPB helping protect and monitor nests around the Cornish coast and have developed what one might called quite a strong sentimental weakness for them.
The collective noun for a flock of chough is a chatter believe it or not. Now is a good time of year here on Oronsay to start seeing groups of chough feeding together. In the breeding season pairs will be on territories and keep themselves to themselves, often fiercely policing other chough near their nest sites. During late autumn/winter on Oronsay, the chough will usually be found down on the beaches foraging in the washed up kelp and seaweeds which begin to rot. This provides an ideal substrate for kelp fly larva, which are a vital food source for Oronsay/Colonsay chough.
Having previously been a volunteer on Oronsay I was able to further my experience with my favourite species. A large portion of my job application for my current post was me banging on about how much I want to work with chough! I simply can't get enough.
Today I was out on the reserve undertaking my absolute favourite duty, not that I think of it as a chore I hasten to add. Chough colour ring reading. Many of the chough that hatch on Colonsay and Oronsay are ringed as chicks in the nest. These rings are placed on their legs in different colour combinations. This allows an observer to identify an individual with provides us with fascinating insights on a whole range of factors in a chough's life history. Having marked an individual, a "resighting" by spotting its colour ring combination allows us to age that bird and so much more. We can determine what survival rates are for an area, how the population is doing from year to year. Which chough has paired up to breed with which. The data that can be gleamed from a couple of colour rings never ceases to amaze me. It also allows us to follow the fate of an individual bird which is such an incredible insight to gain on a completely wild animal. The idea sounds simple enough, but it does require quite a level of patience and determination to read rings accurately.
So in the photo we have a chough with rings on. We read the left leg first, then the right. Here we have Orange over Blue - Orange over metal. Admittedly the blue is somewhat faded which happens over time in the sun. The Orange ring on the bird's right leg has slipped over the metal BTO ring so it isn't currently visible. The metal ring is the generic ring placed on the chough as part of the BTOs ringing scheme.
Here we have Red over Blue on the left leg (again blue faded) and metal only on the right leg. A lot easier to see the rings when the birds are on short grass like this.
Quite often you'll find the chough digging around in the kelp so you have to patiently wait for them to "show off" their legs. This can be quite a frustrating task at times but perseverance usually pays off. Having good light and a decent spotting scope help too.
Photos can be a good way to read rings subsequently, but looking at these pictures it shows they can look like a different colour on the screen. The faded blue rings are readily identifiable in the field with good light compared to looking back at these photos.
Reading colour rings is very rewarding and provides brilliant data on the birds.
Not a bad way to spend an afternoon if you ask me.
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