Hur anpassar sig Gyps-gamar (Gyps rueppellii och G. africanus) i Östafrika till oregelbunden och osäker födotillgång?
In East Africa live two species of Griffon Vultures; Rüppel?s Griffon Vulture (Gyps rueppellii) and African White-backed Griffon Vulture (G. africanus). One of the apparently most important factors limiting the population of these birds is food supply. Griffon vultures nest for eight months of the year, and are during this period geographically tied down to the nesting place. The living biomass in the East-African protected areas Masai Mara and Serengeti consists mainly of migrating ungulate populations of Wildebeest (Connochaetes taurins), Common Zebra (Equus burchelli), and Thomson?s Gazelle (Gazella thomsoni). The migration of these ungulates causes an irregular and unsure food supply for the Griffon vultures. In order to cope with this, Griffon vultures have developed anatomic, physiologic and ethologic characteristics. Griffon vultures have the advantages of being large and diurnal as well as good sight. Long necks and flat feet are adaptations for an easier opening of carcasses and spending long periods of time on the ground. Griffon vultures also elicit social traits such as local enhancement that benefit the whole population, nest in colonies that give protection, and are in principle monogamous which saves energy. A lot of energy is consumed by raising offspring, but this is well-invested time as the number of successful reproductions and nestlings that reach adulthood is high. Scientists agree that Griffon vultures are very well-adapted in their way of living.