A new of species of the Agama lionotus Boulenger, 1896 complex (Squamata: Agamidae) from northern Kenya

Abstract

Kenya has a high diversity of agamid lizards and the arid northern frontier area has the highest species richness. Among the Kenyan agama species, Agama lionotus has the widest distribution, occurring from sea level to inland areas in both dry and moist savanna as well as desert areas. This species mostly prefers rocky areas, both in granitic/metamorphic and volcanic rocks, although it also makes use of tree crevices as well as man-made structures. Recently in Marsabit, northern Kenya, a small-sized agama species, distinct from A. lionotus, was collected within a rocky lava desert area. This new species is characterized by its small size (mean SVL ~83 mm) as compared to typical A. lionotus (mean SVL ~120 mm). Past studies have shown the value of adult male throat coloration for the identification of species within the A. lionotus complex. Herein we also highlight female dorsal color pattern, which is a key character for distinguishing the new species from others in the group, including the similar A. hulbertorum. As in A. lionotus, displaying adult males have an orange to yellow head, a vertebral stripe, a bluish body coloration and an annulated white/blue tail. But the most diagnostic character is the coloration of females and non-displaying males, which exhibit a series of regular pairs of dark spots along the vertebrae as far posterior as the tail base. In addition, females have a pair of elongated orange or yellow marks on the shoulders and another on the dorsolateral margins of the abdomen. This study shows that more cryptic species in the Agama lionotus complex may still await discovery. The new species was found inhabiting dark desert lava rocks but should additionally be present in suitably similar sites in the northern frontier area. This underscores the need to re-examine populations of Agama lionotus from different microhabitats in this country.