We know that a week or two of cold weather is coming, but what about the birds - do they know?
Birds that feed mostly on earthworms (below) cannot get them when the ground is frozen. Some of the thrushes are flexible and can switch to fruit, but at least six wintering waders depend on earthworms – Curlew, Snipe, Woodcock, Ruff, Lapwing and Golden Plover.
Let’s just consider the Golden Plover, because they have become a big winter feature at Rye Harbour with daytime roosting flocks of up to 3,000 provide a spectacle for our visitors, especially when a Peregrine stirs the flock up. They roost on the reserve because there are large, open undisturbed areas inside the fencing.
The Golden Plovers, with their large eyes and excellent hearing, feed mostly at night on earthworms in sheep grazed fields with short grass throughout Rye Bay. At night the worms come closer to the surface.
During recent icy nights the Golden Plovers have not been able to find much food in the frozen soil, so they have not roosted on the reserve, but have continued feeding through the sunny days as the ground has warmed. Because Rye Bay is near the “warm” sea and in the south of England we get far fewer frosts than much of Britain, so it’s a good area from earthworm feeders… most of the time.
But colder weather is coming very soon and the ground may not thaw for many days and so what will the Golden Plovers do? Have some already headed south before the big freeze, or will they move when they get hungry? It’s probably been a good winter so far for earthworm feeders, mild and wet bringing the worms close to the surface. The birds will have put on a lot of body fat and this will keep them going for a few days (how many?) when little or no food is available. But perhaps most importantly the stored fat provides an emergency fuel tank that can, as a last resort, get them to warmer places like, France, Spain, Portugal or Morocco.
So, during the next week or two, when you are warm at home with the heating on and a kitchen well stocked with food, with howling, freezing winds outside and perhaps snow and ice, think of the Golden Plovers out there considering “Should I stay, or should I go?”
Get it wrong and individuals will not survive this cold spell, but don’t be despairing, Natural Selection has “created” the Golden Plover by only allowing the very fittest to survive and breed. It’s a very tough world out there...