( ( ( A predator ) ( of ( ( ( ( ( ( rodents , ) rabbits ) , ) birds ) and ) ( the like ) ) ) ) ( , ( this ( ( is ( a ( sizeable snake ) ) ) . ) ) ) )
(ROOT (S (S (NP (NP (DT A) (NN predator)) (PP (IN of) (NP (NP (NNS rodents)) (, ,) (NP (NNS rabbits)) (, ,) (NP (NNS birds)) (CC and) (NP (DT the) (JJ like)))))) (, ,) (NP (DT this)) (VP (VBZ is) (NP (DT a) (JJ sizeable) (NN snake))) (. .)))
A predator of rodents,     rabbits, birds and the like, this is a sizeable snake.
(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.