Corvids have always been a fascination for me. But it's only since working in the radio department of the BBC's Natural History Unit that I've had some of the best opportunities anyone can ask for to get close up to some of our most intelligent birds, indeed some of our most intelligent animals in the world.
Last winter I had the privilege to visit a raven roost in Shropshire, however last week I had the pleasure to spend a day with academics from Cambridge University, looking at cognitive behaviour in corvids, specifically jackdaws. I'll post more about the programme next week. I've long known jackdaws roost in the winter in large numbers. In fact back in 2009, fellow blogger Jane from Urban Extension, posted a video of a jackdaw roost in Dorset.
So from that little embryo, this posting arose. Late this afternoon I headed off into the fields around the village. This area of Wiltshire is remote. It is this remoteness which gives the area a sense of isolation, yet as the crow flies, Reading is 50 miles away. Jackdaws however are lovers of human activity. Indeed in Britain their numbers are doing well as these resourceful and beautiful birds both forage on the detritus of human life while, nesting in the cavities and chimneys of our houses.
In the centre of the village, stately trees dominate the green. There, in the sun, on top of the trees, a hundred or so jackdaws, noisily chattering to themselves. Jackdaws are monogamous and do pair for life. Look at jackdaws and 9 times out of ten they are in pairs, flying, preening and even, though this is impossible to see food passing as a pair bonding behaviour.
So what happens in these winter roosts? From November through to about March, jackdaws and rooks gather in increasing flocks. The morning flight from a roost is different to that in the evening and it was an evening roost I sought today. From the first signs of a setting sun, so about 3.30pm in January, small groups of 50 or so birds will begin to leave their foraging areas and alight on trees. This is pre-roosting behaviour. Noisily they chatter while not really doing much. Occasionally they'll preen one and other, or fly about, but jackdaws do spend a lot of time doing nothing. Eventually as the light begins to fade, these pre-roosts begin to combine and head over to the roost site. Many roost sites may be hundreds of years old, so finding one is a piece of history. And that was my quest tonight.
Taking my cue therefore, I followed these black birds, down the aptly named Dark Lane in the direction they were heading. It was not long before I found a sizable jackdaw and rook flock, probably five or six hundred in total.
Around the countryside, many trees were sprinkled with black confetti, black chattering confetti to be accurate. Now at this point, these flocks should all begin to combine until one super flock develops, something akin to the well known starling murmerations. What is different and extraordinary with this jackdaw and rook flocking, is precisely that, it is two different species working in unison, both flocking and displaying together.
Tonight though, this didn't happen. On two fields agricultural operations were going ahead. Maybe this changed these birds behaviour. Certainly the mixed corvid flock took full advantage of the newly turned soil. Indeed so did I. That wonderful wet earth aroma drifted across the countryside, so while I stood watching the birds, the farm machinery and the developing sunset, my senses took my mind back to a distant, primeval countryside, where for hundreds of years these birds have been roosting in these same woods, watched over by countless agricultural workers I'm in no doubt.
More birds came in and took advantage of the direct sowing, even more gathered in trees behind me. But where do they roost I wondered?
By now the sun was setting rapidly, giving me a brief opportunity to take a scenic photograph or two of these wonderful skeletal trees dotted around this Wiltshire landscape.
As the sun dipped below the horizon, the jackdaws and rooks headed in a westerly direction. I followed across field after field. Above me a lone song thrush sang it wonderful piercing song, each phrase repeated. Many's the time I have heard a song thrush in full voice, never to have found it. Which is strange given that they usually sing a-top a tree, but that song is for another thrush, and not for me.
And then as I waked towards the sunset and the developing flock of corvids, they about turned and headed back east. Loose flocks drifted like black paper billowing out of a fire, across the now orange sky, the chattering of the jackdaws far out competing the relatively more silent rooks. As they flew back to where I had come from, it was obvious that pairs flew together. Obvious too the size difference between rooks and jackdaws.
Why rooks and jackdaws spend so much time together is a bit of a mystery. Protection from the bigger rook could be one reason for jackdaws to combine their numbers. It is possible the larger rook assists the smaller jackdaws by probing deeper into the soil and allowing the jackdaw to feed on the spoil of the forage. But we just don't know. I like mysteries, mysteries make us quest for knowledge, search for experiences and as I did this evening, venture out in cold conditions to allow my senses to be enveloped by the winter night drawing in.
But for the roost, I do not know. After heading east again, these birds kept flying. Jackdaws can forage up to 30 miles from their roost site, so although I thought I had a good idea where it was, they fooled me and escaped the camera's lens. There is always tomorrow. That is the fun of wildlife watching. I may have lost the roost, but I gained a brown hare hunkered in the middle of a field; I gained a flock of over 100 fieldfare, and I gained a wonderful spectacle of 40 or so lapwing rising from the shadows and heading east in their distinctive flap flap flight. That is wildlife watching at its best, the unexpected often outshines the planned or expected. Which is how this final photograph came to be. Walking back along Dark Lane, the colours intensified, the silhouetted trees grew taller, and maybe just a little bit more menacing. One last opportunity for an image of a wonderful dusk in deepest Dark Lane Wiltshire.