Lek Behavior in the Uganda Kob

THANKS TO Robert Ardrey's colorful description in his "Territorial Imperative," the territorial behavior of the Uganda Kob, Adenota kob thomasi (Sclater 1896), on traditional breeding grounds (TGs), or leks, is now fairly well known. It was my wife, Jimmie, who suggested to me, while on a field trip in Murchison Falls National Park in March 1957, the seemingly absurd idea that we were observing territorial behavior among some male Uganda Kob. Territorial behavior on conventional leks had been well known among birds, such as the prairie chicken, sage grouse, black game, and ruff, probably for centuries, but no one had previously reported this type of behavior among terrestrial mammals. Among mammals, the closest approach to avian lek behavior was in fur seals, sea lions, and elephant seals. Recent research has now shown territorially to be widespread among other African antelopes, including the Puku, Thomson Gazelle, Grant Gazelle, waterbuck, and impala. Probably most antelopes have some form of territorial behavior. The Uganda Kob is unique, however, in exhibiting the highest expression of ritualized territoriality on permanently located leks. In this respect it also provides a clear example of convergent behavioral evolution between birds and mammals. The lek consists of a cluster of 30 to 40 circular territories (10 to 15 meters in diameter) in an area about 200 meters in diameter. In the Toro Game Reserve and vicinity, located in the Semliki Plains of western Uganda, about 13 such leks serve as centers of orientation for social units of 1,000 to 1,500 kob. The total population consists of about 18,000 kob in 400 square kilometers of habitat. Between the leks are widely spaced single territories (STs) that appear to be important in the social organization of the population, but not in breeding. Attachment of both males and females to a "home" TG was confirmed by nearly 9,000 observations on 301 tagged and 83 naturally marked individuals. About half the males were found within 500 meters of their TG 90 to 100% of the time, and a comparable probability occurred also for females when the distance was extended to 1,000 meters. Only one male