I read the 2001 paperback of the originally 1998 book. It was edited by two US anthropologists/activists. The title should have read "Studies in Sub-Saharan Homosexualities". It features some dozen authors, virtually all of which seem to be Westerners also. Which may not make it easier to convince those who say that "African homosexualities" are a colonial invention. However, the content makes it clear that the colonialists' influence had been rather in the reverse, downpressing African homosexualities and brainwashing the new generations of the installed African elite. The term "homosexuality" is Western of course. Coined by an Austrian in Germany in the 19th century, melting Greek and Latin, describing a Western concept. (Which is also true for the term "heterosexuality".) Of course anywhere, you will find humans who fall in love and / or engage in sexuality which may be transcribed as homosexuality by the Western gender concept. There are many differing gender concepts in Africa, however, some of which get mentioned in this book, others not. Read for example When Men Are Women: Manhood Among The Gabra Nomads Of East Africa or Male Daughters, Female Husbands: Gender and Sex in an African Society, both books NOT describing homosexualities.
The book uses contemporary and colonial sources (such as colonial court cases against "homosexualities".) as well as studies in anthropology. For a more authentic grasp on the material, more African sources themselves would have been more helpful. Probably a matter of availability. Still, some African authors could have shed a more thorough light on certain concepts. Especially old colonial sources are bound to be vague and of the not quite overstanding kind. Elaboration on concepts is something else than these compilation listings in a nut shell.
Still, this book offers a nice updated and important Western entry into the subject matter. (There were German collectors and publishers of the entire world's "homosexualities" in the early 20th century). Can't wait to read some African perspectives some day.
This book covers more (Black) African peoples NOT than it does.
However much or little this book may be flawed, for the time being one shouldn't engage in a denial argument without having read this one.
You may be interested in Islamic Homosexualities: Culture, History, and Literature, the newer African Intimacies: Race, Homosexuality, and Globalization and the much, much older German Das Geschlechtsleben der Naturvölker..