▁The ▁only ▁similar ▁birds ▁are ▁the ▁r uf ous ▁hum ming bird ▁and ▁the ▁Allen ' s ▁hum ming bird , ▁but ▁these ▁birds ▁are ▁larger ▁with ▁more ▁distinct ▁and ▁contrast ing ▁r uf ous ▁mark ings ▁on ▁tail ▁and ▁fl anks , ▁and ▁longer ▁central ▁tail ▁fe athers . ▁ ▁Hab itat ▁and ▁distribution ▁The ▁bre eding ▁habitat ▁of ▁cal li ope ▁hum ming bird ▁is ▁varied ▁among ▁open ▁shr ub ▁habit ats ▁and ▁alt itudes . ▁N est ing ▁usually ▁occurs ▁at ▁higher ▁alt itudes ▁in ▁the ▁Rock y ▁Mountains . ▁N ests ▁have ▁been ▁observed ▁from ▁as ▁low ▁as ▁ ▁in ▁Oregon ▁and ▁Washington ▁elev ation ▁to ▁the ▁tree ▁line ▁at ▁over ▁. ▁In ▁Mont ana , ▁the ▁minimum ▁elev ation ▁observed ▁for ▁bre eding ▁is ▁. ▁Open ▁mont ane ▁forest , ▁mountain ▁me adows , ▁and ▁will ow ▁and ▁al der ▁thick ets ▁may ▁various ly ▁serve ▁as ▁bre eding ▁grounds . ▁During ▁migration ▁and ▁winter , ▁they ▁also ▁occur ▁in ▁chap ar ral , ▁low land ▁br ush y ▁areas , ▁desert s ▁and ▁semi - des ert ▁regions . ▁They ▁nest ▁in ▁western ▁North ▁America ▁from ▁southern ▁British ▁Columbia ▁and ▁Al berta ▁south ▁to ▁Colorado ▁and ▁southern ▁California . ▁During ▁spring ▁and ▁summer , ▁they ▁move , ▁mainly ▁through ▁Arizona ▁and ▁New ▁Mexico ▁and ▁northern ▁Mexico , ▁to ▁winter ▁in ▁south western ▁Mexico ▁as ▁well ▁as ▁in ▁Gu atem ala ▁and ▁Bel ize . ▁ ▁Be havior ▁ ▁Cal li ope ▁hum ming bird s ▁are ▁a