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A favourite food is fresh young
grass, but this is not so common in an arid environment. Another
preferred food is the Prickly Pear cactus - Opuntia which
has responded, possibly in a counter-evolutionary response to the saddleback
tortoises that are able to reach high up, by developing an
arborescent (tree-like) form with hard woody branches low near the
ground and most of the cactus "pads" higher up where they are less
likely to be eaten.
Galapagos Tortoises are often found
with small birds - finches - around them or even perched on the
shell. A special relationship has evolved between the reptiles and
the birds whereby the tortoises allow the finches to eat the ticks
and parasites from the tortoise's skin. The bird arrives front of
the tortoise to announce its presence and the tortoise stretches out
its neck and legs to expose areas where the skin is thinnest and
where parasites prefer, the birds then hop about and feed themselves
while relieving the tortoise of its irritations in the process. |
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