I first learned about this set through StampCafe's excellent site. It continues a series of sets issued showing birds endemic to Ethiopia: others were issued in 1989 and 1993. The birds, of course, are all new species for my collection. I was pleased to receive the set in my regular supply of new issues surprisingly soon after the issue date, 29 November 2001. The set is a fine addition to my collection.
Since adding this set, I have discovered an Ethiopian site showing all the illustrations used on these stamps and a few from previous sets. The pictures were apparently used in an Ethiopian Tourism Commission magazine, published in 1987. The artist is Jill Poole, from a clear signature on one of the pictures.