▁mig rat ory ▁bird , ▁generally ▁leaving ▁their ▁bre eding ▁grounds ▁earlier ▁than ▁most ▁birds ▁( although ▁not ▁as ▁early ▁as ▁the ▁r uf ous ▁hum ming bird ) ▁to ▁take ▁advantage ▁of ▁the ▁late - sum mer ▁wild flow ers ▁in ▁the ▁mountains ▁of ▁western ▁North ▁America . ▁They ▁are ▁believed ▁to ▁be ▁the ▁smallest - b od ied ▁long ▁distance ▁migr ant ▁in ▁the ▁world . ▁ ▁These ▁birds ▁feed ▁on ▁ne ct ar ▁from ▁flowers ▁using ▁a ▁long ▁extend able ▁tongue , ▁drink ▁sap ▁from ▁holes ▁created ▁by ▁sap su ck ers ▁or ▁catch ▁insect s ▁on ▁the ▁wing . ▁While ▁collect ing ▁ne ct ar , ▁they ▁also ▁assist ▁in ▁plant ▁pol lin ation . ▁Pl ants ▁preferred ▁for ▁pol lin ating ▁include ▁paint br ush , ▁pen st emon , ▁col umb ine , ▁tr ump et ▁g ilia , ▁and ▁ele ph ant ▁head . ▁They ▁will ▁also ▁occasionally ▁catch ▁and ▁eat ▁small ▁insect s ▁and ▁sp iders . ▁ ▁Ad ult ▁males ▁usually ▁arrive ▁on ▁the ▁bre eding ▁ground ▁before ▁females , ▁from ▁mid - A pril ▁to ▁early ▁May . ▁The ▁male ▁claims ▁and ▁vig or ously ▁def ends ▁a ▁nest ing ▁territory ▁in ▁which ▁he ▁will ▁bre ed ▁with ▁many ▁females . ▁The ▁male ▁takes ▁no ▁part ▁in ▁raising ▁the ▁young ▁and ▁often ▁actually ▁vac ates ▁the ▁bre eding ▁grounds ▁by ▁the ▁time ▁the ▁young ▁h atch . ▁The ▁female ▁usually ▁builds ▁an ▁open ▁cup ▁nest ▁in ▁a ▁con ifer ▁tree ▁under ▁an ▁over