AFRICAN CROPS THREATENED

Press, Volume LXXXIX, Issue 27209, 28 November 1953, Page 5

AFRICAN CROPS THREATENED

DEPREDATIONS BY BIRDS SCIENTISTS INVESTIGATE PEST (81/ a Reuter Correspondent) ™ JOHANNESBURG. Flocks of birds almost rivalling swarms of locusts in numbers and outrivalling them in sheer destruction of crops are feared to be threatening South Africa and possibly large areas of tropical Africa as well. A three-man team of South African scientists, headed by Dr T. J. Naude, chief of the division of Entomology, has been formed to study the menace and devise methods of control. Their investigations so far suggest that the progress of South African farming is removing nature’s brakes on the unlimited' multiplication of quelea, finches or waxbills—possibly the world’s most efficient destroyers of grain. If so, the fact that large numbers of quelea flocks have failed to leave the Union during the last winter for their usual breeding grounds in the tropical savannahs of Bechuanaland and along the Limpopo, is the prelude to bird damage on an increasing scale to the Union’s wheat crop, and probably foreshadows the end of sorghum growing. In many parts of the world, farming has converted harmless species of insect into major pests by providing conditions under which they can multiply without the normal break of seasonal famines.

It is feared that South Africans have removed nature’s limitations on the queleas (a) by providing water, which they need daily, in dams and irrigation schemes; (b) by giving them an almost year-round food supply by growing both summer grains and winter grains. If this is the underlying cause of the immense damage done by quelea flocks last autumn in the northern and far western Transvaal, . north-western and north-eastern Free State, and of the disquieting presence of winter flocks far and wide, even on the highveld ready to attack the coming wheat harvest, a major menace to South African food supplies has appeared.

Dr. Naude estimates that a fairsized flock of queleas, individually weighing little more than half-an-ounce, may collectively weigh 70 tons. If each bird eats roughly its own weight of grass seed or grain daily, as is usual, a single flock could eat up £2500 worth. Observation on the Springbok Flats in the Northern Transvaal during the last harvest, the first good one after years of drought, largely bears this out. One 250-acre field of sorghum which promised a magnificent yield of 12 bags to the acre was completely stripped of grain in three weeks, in spite of steps taken by the owner to prevent it. Eighty-four-acre crops of millet and sorghum were cleaned out in 10 days.