Tree Defenses
Do you think this small palm in Belize tries to discourage small
animals from eating its fruit? Perhaps it wants birds to eat the fruit to
scatter the seeds further - perhaps small animals could break the seeds open
and destroy them, whereas birds might eat the fruit and pass the seeds through
their systems unharmed...
It is felt that some small trees evolved with spikes to protect
themselves from being pushed over by giant sloths after their fruit. The giant
sloths are extinct, but genetic memmory lats a long time...
This is an "ant acacia" tree. On the right you will see some small
ants on the leaves. These ants never leave the tree - they get everything they
need from this tree. Why?
Notice two things: the small yellow spots on the leaves, and the hole
in the thorn. The yellow spots are "protein buds" which the tree provides for
the ants to eat. The holes provide shelter for the ants. In return the ants are
very protective of their tree - killing any caterpillars that try to eat the
leaves, and even preventing vines from growing up the tree!
Of course - this picture also points out that many trees in the
rainforest have thorns! And some have very irritating sap that you don't want
to touch!
© 2001 Stephen Blythe