( ( In England ) ( , ( birds ( ( were ( said ( to ( ( pick ( their mate ) ) ( for ( ( the season ) ( on ( February 14 ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NNP England))) (, ,) (NP (NNS birds)) (VP (VBD were) (VP (VBN said) (S (VP (TO to) (VP (VB pick) (NP (PRP$ their) (NN mate)) (PP (IN for) (NP (NP (DT the) (NN season)) (PP (IN on) (NP (NNP February) (CD 14)))))))))) (. .)))
In England, birds were said to pick their mate for the season on February 14.
(ROOT (S (NP (NNP Birds)) (VP (VB pair) (PRT (RP up)) (PP (IN with) (NP (NP (DT the) (JJ same) (NN bird)) (PP (IN in) (NP (NN mating) (NN season)))))) (. .)))
Birds pair up with the same bird in mating season.