Observations on diet and drinking behaviour of radiated tortoises (Geochelone radiata) in Southwest Madagascar

Abstract

Radiated Tortoises (Geochelone radiata) fed on 29 species of plants comprising 18 families. Grasses comprised 58.1% of observed plant diet followed by Opuntia at 7.6%. All other observed plant feedings were less than 5% each and together comprised a total of 23.3% of the diet. Animal derived matter and miscellaneous items comprise 11.0% of the diet. Diet was compared with that of the Leopard Tortoise (Geochelone pardalis) in South and East Africa. Geochelone radiata was also observed drinking freestanding water after rains. Water was imbibed through the external nares from small shallow pools (ranovato) that collected in crevices on flat rocks. This paper presents only preliminary observations on G. radiata diet. To obtain a full understanding of dietary requirements, more intense studies must be undertaken which include fecal analysis, germination trials, and a measure of relative abundance of plant life found in the habitat.