Honks › V formation and migration: why geese fly the way they do
V formation and migration: why geese fly the way they do
The honking skein overhead is one of autumn's best sights. Here is what we know about the V, and where the geese have come from.
The V and the line
Geese flying long distances often fly in a V, or in a long, slanting line known as a skein. Several explanations have been put forward, and the most widely accepted is that flying in the slipstream of the bird ahead can save energy, because the air flowing off its wingtips can give those following a little extra lift. Another benefit is that birds in formation can see each other and stay in contact, which helps in poor light and when a flock needs to stay together over a long route. Birds may swap the lead position, because the front takes the hardest work.
We have not confirmed details of the studies behind these ideas for this page, so treat them as the general explanation rather than a precise measurement. The BTO and WWT both publish research and news on migration if you want to read more.
Why the noise?
Geese call constantly in flight. The noise helps flock members to stay together, especially in the dark or in cloud, and it may help to keep a pair or family close. Families stay together through the first winter: young birds travel with their parents, which is one way they learn the route.
Where winter geese come from
| Goose | Travels from | Source |
|---|---|---|
| Pink-footed | Iceland (about 500 miles to Martin Mere) | WWT |
| Barnacle | Svalbard in the Arctic Circle (to Caerlaverock) | WWT Caerlaverock |
| White-fronted | Greenland and Siberia; do not breed in the UK | RSPB |
| Greylag | Wild winter birds in Scotland; resident feral birds elsewhere | RSPB |
The RSPB notes that for the white-fronted goose, two populations visit the UK in winter, one from Greenland and one from Siberia, with the Siberian birds having pink bills and the Greenland birds having orange bills.
When the geese arrive
WWT says pink-footed geese reach Martin Mere in autumn, around the start of winter, with numbers growing over the next couple of weeks. The exact timing changes from year to year with weather at the breeding grounds and along the route. If you want to catch the first arrivals, check the reserve's sightings pages in September and October.
Roosts and feeding grounds
Winter geese typically roost at night on water or mudflats, safe from foxes, and fly out at dawn to feed on grass, crop stubble and saltmarsh. In the evening they return in waves. That daily "flight line" is when you see the skeins overhead. If you want to find where geese roost, look for a large body of shallow water or an estuary near farmland, then go at first or last light.
Counting geese
Winter goose counts are one of the long-running monitoring projects in British ornithology. Reserve staff, volunteers and national surveys count the flocks regularly, and these counts show whether numbers are rising or falling. That is how a record such as the 45,800 pink-footed geese at Martin Mere gets recorded.
Can I help?
- Submit your sightings to the BTO's BirdTrack or your local recorder.
- Join a local bird group's winter goose count.
- Support the habitats geese need. The RSPB warns that brent geese rely heavily on protected coastal habitats, and that white-fronted wintering areas need protection from drainage.
- Keep disturbance to a minimum when watching.
What does the call mean?
A skein calling loudly overhead at night in autumn often means migration is under way. If you hear geese calling in the dark in October, it is likely pink-footed or greylag geese moving between roosts and feeding grounds, or newly arrived migrants.
For help naming the birds, see grey geese ID, and for places to watch the arrivals, where to see wild geese. The geese and the law page covers protection.
Frequently asked questions
Why do geese fly in a V?
The usual explanation is that flying in the slipstream of the bird ahead saves energy and that the formation keeps the flock in visual and vocal contact. Birds swap the lead.
Where do pink-footed geese come from?
WWT says those arriving at Martin Mere travel about 500 miles from Iceland.
Why are geese so noisy in flight?
They call to stay together, especially at night or in poor visibility, and families stay in contact.