/ 7 November 2002

Swallows sing a new tune

New, miniaturised radio-tracking devices will help save South Africa’s most endangered bird, the blue swallow, from extinction.

The Mail & Guardian reported two weeks ago that a land-claim settlement in Kaapschehoop, Mpumalanga, could be the kiss of death for the bird that scientists describe as the most likely to become extinct next [Feathers fly over blue swallows].

Only 80 breeding pairs of the swallows still exist in South Africa. Last year only 37 pairs successfully raised offspring.

The transmitters have become so small they can even be attached to insects. It is the first time the technology will be used in South Africa.

The small tracking devices will give a group from the University of Natal and Ezemvelo KwaZulu-Natal Wildlife the ability to study the microhabitat of the blue swallow more precisely than has been possible in the past.

Dieter Oschadleus of the department of statistical sciences at the University of Cape Town says the miniature radio-tracking systems open exciting possibilities to scientists. The technology allows scientists to study birds and small animals that could not be fitted with the bigger and heavier transmitters used before.

“In the past we could only use radio tracking on larger birds. The use of the devices on smaller birds can be applied to many future projects,” he says.

Oschadleus explains the small transmitters can also be used to study pest species such as the red-billed quelea, a small bird that breeds quickly to form vast flocks that destroy farmers’ grain crops. “We don’t understand the movements of these birds, but with this technology we can get a better idea of their movements and maybe even warn farmers in advance when the birds are coming,” he says.

Steven Piper, the professor supervising the blue-swallow project, says the equipment will first be tested on common swallows to ensure it poses no risk to the endangered birds. The project will be launched next September if the equipment passes muster.

The 0,3g transmitter will be glued to a tail feather of the blue swallow. It sends out a signal every few seconds, instead of one every few minutes as the older transmitters did.

“I will be able to overlay the flight paths of the birds over the land around the nesting area to determine the birds’ exact habitat preferences,” says James Wakelin, who will carry out the survey.

The information will be used to ensure that the blue swallow’s habitat remains intact.

“If the habitat is properly managed, the animal numbers will hopefully increase on their own,” Wakelin predicts.