Under the conditions prevailing at Kilifi G. pallidipes is evenly distributed throughout all vegetation types with the exception of cultivation from which it is at all times almost entirely absent. There is a preference for the denser vegetation in the dry season from which the tsetse spread out into the lighter vegetation in the wet and humid seasons. There is never at any time any concentration of G. pallidipes along the edges of extensive thicket or forest.

The distribution of G. austeni is similar to that of G. pallidipes except that there is no tendency to spread into lighter vegetation in the wet season.

There is some reason to think that G. brevipalpis prefers thicket of medium density and does not share with G. austeni a preference for tall heavy thicket.

G. pallidipes was the only species staged for hunger, except for austeni in the Sokoke forest. Males are replete at all seasons. G. austeni showed a remarkably large proportion of recently fed males.

Pupae and pupal cases of G. pallidipes were found on the floor of the coral rag thicket and forest. G. austeni and G. brevipalpis showed a preference for the undersides of large logs.