Title:

Breeding, foraging, trapping and sexing of Damara Terns in the Skeleton Coast Park, Namibia

Author(s):
Publication Year:
1994
Abstract:

This paper details 6 years' monitoring of breeding Damara Terns Sterna balaenarum on Namibia's northwestern coast. We report new breeding distribution records, factors limiting success on the desert coast and detail two new methods of catching terns and a new sexing technique. Nests occurred as far north as the Cunene River mouth and occurred mainly on open gravel plains up to 8 km from the coast. Eggs occurred over an 8 month period with a peak in January. Of 66 nests monitored on a daily basis, 72% succesfully hatched, and most of those failing were taken by mammals. Incubation was slightly shorter than reported previously (19.2 d), and heavier chicks emerged from larger eggs. Adult plunge diving success was low and records indicate Skeleton Coast Damara Terns brought mainly needle fish Tylosurus sp. to their nestlings. Two new methods to capture adults were developed, noose catching and hand capture, both of which avoided nest desertions, and had success rates of up to 70%. Morphologically the sexes differed significantly in bill size, allowing a simple and efficient means to separate male and female terns. We conclude that Damara Tern populations are more extensive than previously thought and further ringing and monitoring of food resources is encouraged.

Publication Title:

Ostrich:

Volume:
65
Issue:
3-4
Pages:
264 - 273
Item Type:
Journal Article
Language:
en