To assay the effect of area and predators on invasion success, spiders
were introduced onto islands that were large, with lizard predators;
large, without lizard predators; or small, without lizard predators. S
hort-term survival was greater on islands without than with predators;
area had no effect. Spiders initially increased substantially on both
groups of islands without lizards, but after 5 years they nearly died
off on small islands while persisting on most large islands; populati
ons in the presence of predators never increased above initial sizes.
Results show how predators as well as area are important in determinin
g invasion success.