 Tortoises share a mutualistic relationship with some species of Galápagos finch and mockingbirds . Small groups of finches initiate the process by hopping on the ground in an exaggerated fashion facing the tortoise . The tortoise signals it is ready by rising up and extending its neck and legs , enabling the birds to reach otherwise inaccessible spots on the tortoise 's body such as the neck , rear legs , cloacal opening , and skin between plastron and carapace . The birds benefit from the food source and the tortoises get rid of irritating ectoparasites . 
