Leviathan

A wise countryman, who helped us out with work in the garden, told me that, on cold winter nights, these birds cluster in huddles of 10 or 20 individuals, and that he had seen them emerging en masse from such an assembly under the roof of his own porch. Sceptical, I looked it up on the-Internet-that-knows-everything, and the British Trust for Ornithology - which sounds trustworthy - confirm that it is true, and says the clusters can number up to 50.

This endears me to them even more than their cute appearance and fussy, hyperactive behaviour, because they are mirroring exactly what our bees do in similar conditions. In common language they are huddling together to keep warm. To a physicist, they are minimising the surface area to volume ratio of their combined bodies, and thus minimising the rate of loss of heat that their bodies generate. In the case of bees, they dislocate their flight muscles from their wings and vibrate those muscles to generate more heat. I did not discover of the birds do anything similar, nor if they mirror the bees practice of rotating the individuals who are on the outside and in the middle of the cluster, so that no one individual gets too chilled

I also learned that, notwithstanding that they are called long-tailed tits, these birds are not actually tits at all, and are classified entirely separately from great, blue, coal and the rest

Thomas Hobbes has come up a couple of times today. Once as an answer in an episode of University Challenge (I mention it because it was the answer I got right). Also in a book I have just begun about deep human history - addressing the question of whether and how civilization today differs from our pre-historic past. Hobbes famously characterised human existence without civil society as "solitary, poor, nasty, brutish, and short", on the basis that, without a state to enforce order, human beings are, in their "natural" state, a pretty nasty piece of work

Co-operation and altruism in animals presents a bit of a challenge to this position. If long-tailed tits and honeybees can look after each other in winter, why can't it be that that is the default state of humans too? And if that is (was) the case, why are we so often not like that now? Well, maybe it's the fault of settled agriculture, or overcrowded cities, or the fruit of the tree of knowledge... something we did to ourselves

We are in deep waters, aren't we. I'll finish the book and get back to you. The tits, no doubt, will be back tomorrow