“Unbelievable! You cannot believe how much damage they do” one local farmer responded when asked if he considered quelea [Roberts no 821] to be a problem. Farmers have given up planting millet because of the devastating effect of quelea on this crop. They also damage wheat and sorghum. Quelea occur in vast numbers and are regarded as ‘pest no 1’ in agricultural crop farming equaling the damage done by locusts. Quelea populations are said to be greater than any other single species of bird.
This is what Newman has to say in his book Birdlife in Southern Africa :
“The crown of notoriety undoubtedly goes to the Red Billed Quelea, a tiny, highly sociable species with the ability to take full advantage of agricultural development. Formerly a summer migrant to the Transvaal and Orange Free State, pre-war breeding south of the tropics was unknown. When the post-war agricultural revolution was made possible by the tractor, and vast acreages of crops provided food throughout the year, the quelea showed a great range expansion even into the Cape Province and Natal, where no reliable records were available before. It nested in tree plantations where rolling grassland had been, and where its natural predators were absent.`Today it is an international African pest second only to the locust; no small grain crop is safe, …”
Quelea occur in their millions in Botswana and their nesting colonies can be measured in hectares! The people build rough shelters in amongst their lands when crops are ripening so that they can frighten the birds away by banging tin cans and the like, There was a rubber tree in our garden in Mahalapye in which these birds used to roost and chatter away in “unbelievable’ large numbers. If a door banged loudly in the house the quelea would take off in unison and the force exerted was enough to break branches of about 70 mm diameter.
Quelea occurs in such enormous numbers that control is very difficult. In Botswana, at one time the Department of Agriculture used flamethrowers to burn nesting sites. but the number of birds did not seem to lessen. Nesting sites are sprayed with suitable chemicals: but the problem remains.
A flock of about 150 swooped into our garden in Clarens recently; scratched around for a while and then took off together in synchronized flight. They resemble flocks of weavers but are usually in far greater numbers, and their red bills are diagnostic. They are classified in the same group as weavers. Farmers say that the number of quelea in the Eastern Free State has increased enormously during the past few years. They feed largely on grass seeds If you see what looks like a smoke cloud in the distance it could well be a flock of quelea approaching in their millions. They fly in closely packed synchronized flight: one wonders how so many birds get the message to maintain this synchronization.
References: Roberts ‘Birds of Southern Africa, Newman ’Birdlife in Southern Africa’