( ( Study ( of communication ) ) ( ( ( is also ) ( essential ( for ( understanding ( animal behavior ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Study)) (PP (IN of) (NP (NN communication)))) (VP (VBZ is) (ADVP (RB also)) (ADJP (JJ essential) (PP (IN for) (S (VP (VBG understanding) (NP (NN animal) (NN behavior))))))) (. .)))
Study of communication is also essential for understanding animal behavior.
(ROOT (S (PP (IN For) (NP (JJ social) (NNS animals))) (, ,) (NP (NN communication)) (VP (VBZ essential)) (. .)))