( ( ( Although , ) ( ( these birds ) ( can ( be ( quite ( noisy ( as ( mating season ) ) ) ) ) ) ) ) ( ( draws nearer ) . ) )
(ROOT (S (SBAR (IN Although) (, ,) (S (NP (DT these) (NNS birds)) (VP (MD can) (VP (VB be) (ADJP (RB quite) (JJ noisy) (PP (IN as) (NP (NN mating) (NN season)))))))) (VP (VBZ draws) (ADJP (JJ nearer))) (. .)))
Although, these birds can be quite noisy as mating season draws nearer.
(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.