( ( ( ( Animal behavior ) , ) ( ( ( especially communication ) and ) ( social organization ) ) ) . )
(ROOT (NP (NP (NNP Animal) (NN behavior)) (, ,) (NP (NP (RB especially) (NN communication)) (CC and) (NP (JJ social) (NN organization))) (. .)))
Animal behavior, especially communication and social organization.
(ROOT (S (PP (IN For) (NP (JJ social) (NNS animals))) (, ,) (NP (NN communication)) (VP (VBZ essential)) (. .)))