I see the vultures circling over Bitrague hill. Given today’s wind direction there is probably an updraft there keeping them aloft but in this hilly region, it’s certainly not the only place with a suitable updraft. There are about ten vultures. How did they collectively decide to circle over that hill and not somewhere else? I suspect they didn’t all have an equal voice in the debate. Perhaps they all follow a lead vulture. Or perhaps there’s a more complex hierarchy in which each vulture follows its immediate superior. I notice that they look content with their choice, wheeling around on the wind, each bird moving independently but staying in touch with the others. Continue reading The problem of making collective decisions →