( ( Food ( , ( habitat ( and ( weather conditions ) ) ) ) ) ( ( are ( ( the reasons ) ( why ( birds ( fly ( south ( during ( the winter ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NN Food) (, ,) (NN habitat) (CC and) (NN weather) (NNS conditions)) (VP (VBP are) (NP (NP (DT the) (NNS reasons)) (SBAR (WHADVP (WRB why)) (S (NP (NNS birds)) (VP (VBP fly) (ADVP (RB south) (PP (IN during) (NP (DT the) (NN winter))))))))) (. .)))
Food, habitat and weather conditions are the reasons why birds fly south during the winter.
(ROOT (S (NP (NP (JJ Many) (NNS species)) (PP (IN of) (NP (NP (NNS birds)) (PP (IN in) (NP (JJ new) (NN england)))))) (VP (VBP fly) (ADVP (RB south) (PP (IN for) (NP (DT the) (NN winter) (NNS months)))) (S (VP (TO to) (VP (VB find) (NP (DT an) (NN environment)) (PP (IN with) (NP (JJR more) (NN food))))))) (. .)))