ON the evening of August 5th on the coast between Frinton and Walton a large passage of swifts was seen following the low cliffs. These scimitar-shaped birds spend only three months in N Europe before returning to Africa. Fitted with a miniature tracking device a UK summer resident has been shown to have wintered in Mozambique, making a 14,000 mile round trip. Recorded at altitudes of up to 10,000 feet and with appearance on radar they have been called angel birds. This contrasts with the folk-name of devil bird coined because of their dark plumage and screeching calls They do not breed in their first three years and remain continuously airborne during this time as able to rest on the wing by closing-down part of their brain. Unrelated to similar looking swallows or martins they are allied to nightjars and hummingbirds as Apodiformes. Rudimentary legs deter landing apart from creeping into their nest cavities. Tall buildings are favoured under eaves, and low aerial “screaming parties” of local swifts careering up to 60mph have been a distinctive summer sound of local towns like Clacton and Walton. Recent surveys show a substantial decline nationally and measures are being taken in an attempt to reverse this trend. Aerial invertebrate food supplies and breeding sites are key factors. Although originally nesting in cliffs and caves, swifts successfully adapted to human structures but modern buildings have less suitable crevices for them. A campaign has been launched to fit nest boxes and even hollow Manthorpe swift bricks. A similar scheme for barn owls has proved successful in dramatically reversing their decline.

Older motorists will notice that windscreens are no longer smeared by insects on warm summer evenings as fifty years ago. The decline in insects and other invertebrates is a matter of concern as basis of the food chain for much life.

Swifts have both large eyes to see in low light, and jaw bones for a wide gape to catch small prey. Up to a thousand at a time are stored in a throat pouch to feed the young.

Nestlings develop deep sternums to support powerful pectoral muscles they expand with press-ups in the nest preparatory for a life of aloft. Essex’s Wildlife Trust and Birdwatching Society are joining a national Save Our Swifts initiative to map breeding and encourage box schemes – contact

For your diary: Thurs Sept 28th 7.30pm - Wildfowl & Wader Counts in Walton Backwaters – an illustrated talk by Kevin Marsden & Geoff Empson at the Naze Centre, organized by EWT Tendring Group