▁nest , ▁and ▁in ▁case ▁of ▁colonial ▁nest ing ▁the ▁response ▁to ▁pred ators ▁may ▁be ▁commun al . ▁Other ▁species ▁attacked ▁and ▁mob bed ▁include ▁large ▁ra pt ors , ▁cor v ids , ▁and ▁fo xes . ▁ ▁Re production ▁begins ▁with ▁the ▁return ▁of ▁both ▁partners ▁to ▁the ▁nest ing ▁site , ▁at ▁which ▁point ▁both ▁male ▁and ▁female ▁will ▁start ▁displaying . ▁The ▁display ▁consists ▁of ▁various ▁sky - d ances ▁and ▁aer ob atic ▁figures ▁that ▁vary ▁according ▁to ▁each ▁individual . ▁Both ▁sex es ▁will ▁display , ▁cry ing ▁loud ly , ▁though ▁the ▁males ' ▁displays ▁are ▁more ▁frequent ▁and ▁spect ac ular . ▁Mont agu ' s ▁har riers ▁bre ed ▁for ▁the ▁first ▁time ▁when ▁two ▁or ▁three ▁years ▁old , ▁but ▁occasionally ▁one - year - old ▁females ▁may ▁attempt ▁to ▁nest . ▁P airs ▁form ▁on ▁the ▁territory , ▁when ▁returning ▁from ▁migration . ▁As ▁the ▁birds ▁are ▁tied ▁to ▁their ▁former ▁nest ing ▁sites , ▁they ▁probably ▁mate ▁with ▁the ▁same ▁partner ▁every ▁year . ▁The ▁nest ▁is ▁built ▁by ▁the ▁female , ▁always ▁in ▁tall ▁veget ation . ▁It ▁is ▁a ▁simple ▁construction ▁made ▁of ▁grass , ▁used ▁only ▁for ▁one ▁season . ▁The ▁female ▁l ays ▁ 3 ▁to ▁ 5 ▁eggs ▁which ▁are ▁inc ub ated ▁for ▁ 2 7 – 4 0 ▁days . ▁The ▁young ▁leave ▁the ▁nest ▁after ▁ 2 8 – 4 2 ▁days ▁and ▁are ▁independent ▁two ▁weeks ▁later . ▁ ▁The ▁males