Sightings of Swallows are steadily increasing in the Mid Arun Valley as we stagger from late spring into early summer - hirondelles over Arun dale.
Most of our swallows have returned from South Africa, covering an incredible 200 miles per day and flying at speeds of up to 35mph (with a good tailwind!) This colossal effort is in order to exploit our summer glut of invertebrates and, ultimately, to produce offspring.
These striking birds have inky blue upper parts, a rich rufous forehead and throat separated from pale under parts by a smart inky blue chest-band. The tail is deeply forked, with males sporting longer tails than females. Just as a ridiculously expensive and law-breakingly fast sports car might pretend to advertise a successful male to female humans, a male sporting extra-long tail feathers, with rather more conviction, advertises genetic superiority to female swallows; for long tails are metabolically costly. Such top-quality males were amongst the first to arrive this spring, giving exclusive rights to the best real estate locations and the fittest females.
Barns and rural outbuildings provide ideal sites for construction of their cup-shaped nests which are carefully crafted from mud bound together with straw.. Last years nests are often repaired and reused.
Successful swallows will rear two broods during the summer by expertly catching a mix of wasps, beetles, flies, and even dragonflies and sizable bluebottles, and cramming them into the great red gapes of hungry hatchlings. Just a short month later these young birds are delighting all who care to watch with their dazzling aerobic dexterity, as they catch their own insects.
As this summer draws to a close, temperatures will drop and our aerial invertebrates will fade away. We will once again see groups of swallows gathering together and fuelling up for their 6000 mile journey to the southern part of Africa. Unlike other passerines that fly by night, resting and feeding during the day, swallows migrate in the daytime, effortlessly refuelling en route.
These little birds have nothing but the sun and the earth’s magnetic field to guide them. They have evolved to undertake this epic journey when just a couple of months old.
So this summer, admire the spectacle of swallows soaring, and swooping over the Mid Arun Valley. Come the autumn, keep an eye out for groups gathering ready to depart and wish them well.