( ( In ( the ( predator-free area ) ) ) ( , ( ( rabbit numbers ) ( ( ( increased ( 8 fold ) ) ( in ( 12 months ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (DT the) (JJ predator-free) (NN area))) (, ,) (NP (NN rabbit) (NNS numbers)) (VP (VBD increased) (NP (QP (CD 8) (CD fold))) (PP (IN in) (NP (CD 12) (NNS months)))) (. .)))
In the predator-free area, rabbit numbers increased 8 fold in 12 months.
(ROOT (S (NP (DT A) (JJR fewer) (NNS predators)) (VP (VBZ is) (ADJP (RBS most) (JJ likely) (S (VP (TO to) (VP (VB cause) (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NP (NNS rabbits)) (VP (VBG living) (PP (IN in) (NP (DT an) (NN area))) (S (VP (TO to) (VP (VB increase))))))))))))) (. .)))
A fewer predators is most likely to cause the number of rabbits living in an area to increase.