ə - p ē ) ▁is ▁the ▁smallest ▁bird ▁native ▁to ▁the ▁United ▁States ▁and ▁Canada . ▁It ▁has ▁a ▁western ▁bre eding ▁range ▁mainly ▁from ▁California ▁to ▁British ▁Columbia , ▁and ▁migr ates ▁to ▁the ▁South western ▁United ▁States , ▁Mexico , ▁and ▁Central ▁America ▁for ▁its ▁winter ing ▁grounds . ▁It ▁was ▁previously ▁considered ▁the ▁only ▁member ▁of ▁the ▁genus ▁St ell ula , ▁but ▁recent ▁evidence ▁suggests ▁pla cement ▁in ▁the ▁genus ▁Sel as ph orus . ▁This ▁bird ▁was ▁named ▁after ▁the ▁Greek ▁muse ▁Cal li ope . ▁The ▁former ▁genus ▁name ▁means ▁" l ittle ▁star ". ▁ ▁Description ▁The ▁cal li ope ▁is ▁the ▁smallest ▁bre eding ▁bird ▁found ▁in ▁Canada ▁and ▁the ▁United ▁States . ▁The ▁only ▁smaller ▁species ▁ever ▁found ▁in ▁the ▁U . S . ▁is ▁the ▁b umble be e ▁hum ming bird , ▁an ▁accident al ▁v agrant ▁from ▁Mexico . ▁An ▁adult ▁cal li ope ▁hum ming bird ▁can ▁measure ▁ ▁in ▁length , ▁span ▁ ▁across ▁the ▁wings ▁and ▁we igh ▁. ▁▁ ▁Cal li ope ▁hum ming bird s ▁have ▁gl oss y ▁green ▁on ▁the ▁back ▁and ▁crown ▁with ▁white ▁under parts . ▁The ▁adult ▁male ▁has ▁wine - red ▁stre aks ▁on ▁the ▁g or get , ▁green ▁fl anks ▁and ▁a ▁dark ▁tail . ▁Fem ales ▁and ▁imm atures ▁have ▁a ▁p ink ish ▁was h ▁on ▁the ▁fl anks , ▁dark ▁stre aks ▁on ▁the ▁thro at ▁and ▁a ▁dark ▁tail ▁with ▁white ▁tips .