( ( Migratory birds ) ( ( can ( have ( ( ( two springs ) and ) ( ( two ( mating seasons ) ) ( in ( a year ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Migratory) (NNS birds)) (VP (MD can) (VP (VB have) (NP (NP (CD two) (NNS springs)) (CC and) (NP (NP (CD two) (NN mating) (NNS seasons)) (PP (IN in) (NP (DT a) (NN year))))))) (. .)))
Migratory birds can have two springs and two mating seasons in a year.
(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.