You’ve probably seen geese flying in a tight V-formation, and you may have wondered why.

It seems that the upwash from the wings of the lead bird gives a bit of extra a lift to the birds following on either side, and thus reduces their energy consumption - an effect that continues down the line to the tails of the V. That really matters on a long migratory journey, but the lead bird obviously has to work a bit harder than the rest. So it came as no surprise when some recent studies showed that birds took turns in taking the lead, thus sharing the extra burden.

But something slightly different emerged from a fascinating new study.

Researchers attached lightweight GPS trackers and accelerometers to wild white-fronted geese belonging to four family groups setting out on their long migration from the Netherlands to northern Russia. This meant that they could not only see exactly where each bird was in the formation, but also how fast they were flapping their wings.

It turned out that only the parents ever took the lead. Usually the father, but sometimes the mother - depending on the wind conditions. The mothers had to flap their wings faster when they were out in front, but the fathers apparently did not need to.

It makes good sense for the parents to take on this leadership role, because it increases the chances of their offspring surviving the rigours of the long journey - and thus having a chance to pass on their genes to future generations (so-called ‘kin selection’).

But this system probably also helps the young, first-time migrants to learn the route they need to follow in future, where best to stop for refuelling, how best to avoid dangers - and indeed how to fly most efficiently.

In groups of homing pigeons, less experienced birds follow more experienced flock members, and this helps them to learn routes. Further experiments will be needed to see whether this is also true of young migratory geese.