Murmuration

Vita’s Guest Beekeeper Blogger writes:

It’s the off season for bees and swarms in Britain just now, but this brought back thoughts of spring and swarm-chasing. It’s a murmuration of starlings.

Whereas honeybees only fly en masse as a swarm and are led by scout bees to a new nesting site, starlings present a different and spectacular form of mass movement. In winter, usually from November to March, they roost together at night in sites that are often, but not always, a few tens of kilometres apart.

This group of starlings regularly roosts in north Winchester, about 30 kilometres from Vita’s HQ in Hampshire, UK. But before they settle just after the sun has gone down, they can give a stunningly beautiful aerobatic display. They arrive in a large group which often grows with smaller groups joining as if in display formation.

Why they do this is not clear. Roosting together in thousands generates a warmer microclimate for the nest site, swirling in flight may alert others to join in – and the spiralling flight will protect them against predators, which probably go cross-eyed trying to home-in on a single victim. They almost certainly communicate about good feeding sites, and the following morning they disperse in all directions.

I’m no starling expert, so you’ll find more information (and better videos) about murmurations here. Technically, scientists say they are scale-free correlations in a critical system, but still don’t quite understand them.

I am intrigued to know to what extent they follow the same rules as bees in a swarm to stop crashing into each other and to end up in the right place. With bees we know that scouts act as streaker bees to give directions. Having scouted possible nest sites, these streaker bees know where the new colony should end up and fly at top speed across the top of the swarm in the direction of the new home. When they reach the front, they drop down to near the base of the flying swarm, slow down and soon enough find themselves at the back from where they rise again to the top to give directions.

As to how they co-ordinate with each other, like starlings, bees may be responding to their seven closest neighbours in the swarm.

Oh, and next time, I’ll take a proper video camera … Here’s another glimpse:

Turlough 
Vita’s Guest Beekeeper Blogger