More than two hundred Welcome Swallows have recently taken up residence on a Tennyson dairy farm. Apart from their roosting site in a large machinery shed they are most obvious when the herd of more than five hundred cows is moved on to a fresh area of Lucerne to graze. Then the flock of birds swoop and wheel, just above the foraging dairy herd, obviously catching numerous insects on the wing.
This process is repeated several times a morning, as the cows are moved on to fresh strips of pasture. Over areas recently vacated by the herd the swallows swoop and feed even lower, often less than a metre above ground level.
Lucerne, Medicago sativa,is a perennial flowering plant in the pea family Fabaceae,cultivated as an important forage crop in many countries around the world. It superficially resembles clover, with clusters of small purple flowers followed by fruits spiralled in 2 to 3 turns containing 10-20 seeds. Lucerne is native to a warmer temperate climate such as that of Iran (where it is thought to have originated). It has been cultivated as livestock fodder since at least the era of the ancient Greeks and Romans.
It was a popular option during initial irrigation early last century, when it was grown as fodder for horses. Up until comparatively recently it was primarily grown as a hay crop. The development of more versatile varieties, and more sophisticated management practices has seen it now being widely used as a dairy pasture.
Irrigated Lucerne stands apear to be a host to a range of insects, as both Stubble Quail, Coturnix pectoralis, and Australian Pipits, Anthus novaeseelandiae are regularly recorded . This creates an interesting equation for any wildlife biologists out there, to calculate the number and weight of insects eaten by this flock of Wellcome Swallows, and their role in IPM (Integrated Pest Management) programs.