De vangst van sterns en het verwijderen van ringen in Afrika een probleem

In the West African winter quarters the practice of catching European terns has traditionally been widespread. Birds are caught for food or for pleasure. Although in some countries measures have been taken to discourage these practices and the incidence of catching terns seems to have decreased in Ghana, recent research indicates that terns may sometimes be caught to obtain the rings as a trophy. Some birds appear to have been released after the ring has been removed. An analysis of ringing recoveries of Dutch Sandwich Terns was carried out, revealing that of 48 ringed birds captured, at least ten birds were released alive after removal of the ring, while 14 birds were released with or without ring and of 14 more individuals nothing was recorded (Table 1). Thus, the analysis of ringing recoveries of European terns may not be useful to determine mortality rates. A further analysis of the scope of this problem seems to be necessary.