an interim volume summarizing the latest data on the world 's threatened birds, species which were given full treatment in Collar, N. J. & Stuart, S. N. 1985. Threatened Birds of Africa and related islands.the ICBP / IUCN Red Data Book, Part 1 Cambridge: I C B P& I U C N Black - cheeked Lovebird Agapornis nigrigenis has been documented as threatened in Botswana (noted by the authors as possibly occuring), but since this species is not on the Botswana.