While reading an African safari book by John A Hunter entitled "Hunter" (Harper & Brothers NY 1952) I came across this interesting tidbit:
"[Their] bows were beautifully finished and came to sharp points at the ends. I should judge that they pulled about seventy-five pounds. They are made from a tree called the mutuba and are a dark mahogany color. I was interested to see that there were no notches to hold the bow string. Instead, the Wakamba wrap strips of rawhide around the bow to keep the string from slipping.
The arrows were excellent, the most ingenious part being the special construction of the head. The head had a stem about as thick as a knitting needle and some six inches long. An inch or so of this stem was inserted in the hollow end of the shaft and held in place with tree gum. The poison was smeared on the remaining five inches of the stem. No poison was put on the head itself--not enough could be put there to do any damage unless the archer was after comparatively small game. Because the poison, though terribly efficient when fresh, rapidly deteriorates if wet or if exposed to sunlight, the Wakamba carefully wrap the poison stems with bandages made of soft antelope hide. These bandages are left in place until the last possible moment.
...The Wakamba bows are so powerful that they can shoot an arrow through a Masai buffalo-hide shield and kill the man behind it. As the Masai shields were tough enough to stop an Arab musket ball in the old days, this gives some idea of the penetration quality of the Wakamba weapons."
This book took place in Kenya in the early 1900's. He says the natives would not hesitate to hunt elephant with these bows. There is a photo of a bowman in the book but I don't know how to scan it. Looks long and round to me. Just thought some of you might find this interesting.