Rare Birds in Colorado
Our list for Colorado has 72 rare birds recorded regularly there: 10 residents, 13 summer visitors, 14 winter visitors and 35 passage migrants
Most likely in October
GBIF · Oct
Share of all bird records in Colorado in October, 2019–2024. Each month links to that month’s page.
All 72, most common first
ChukarAlectoris chukarResidentRare32–38 cmRecorded all year
Short-billed DowitcherLimnodromus griseusPassage migrantRare23–32 cmRegularly Apr–Sep
Mute SwanCygnus olorWinter visitorRare140–160 cmRecorded all year
Snow BuntingPlectrophenax nivalisWinter visitorRare15–18 cmRegularly Nov–Feb
Bay-breasted WarblerSetophaga castaneaPassage migrantRare14–14 cmRegularly May–Nov
Blue-headed VireoVireo solitariusPassage migrantRare12–15 cmRegularly Apr–Oct
Boreal OwlAegolius funereusSummer visitorRare21–28 cmRegularly Jan–Oct
Greater RoadrunnerGeococcyx californianusResidentRare52–54 cmRecorded all year
Hudsonian GodwitLimosa haemasticaPassage migrantRare36–42 cmRegularly May
Piping PloverCharadrius melodusSummer visitorRare17–18 cmRegularly Apr–Sep
Prothonotary WarblerProtonotaria citreaPassage migrantRare13–14 cmRegularly May
Grey PhalaropePhalaropus fulicariusResidentRare20–22 cmRegularly Sep–Nov
Mourning WarblerGeothlypis philadelphiaPassage migrantRare10–15 cmRegularly May–Sep
Philadelphia VireoVireo philadelphicusPassage migrantRare11–13 cmRegularly May–Oct
Arctic JaegerStercorarius parasiticusPassage migrantRare41–46 cmRegularly Sep–Oct
Gray-cheeked ThrushCatharus minimusPassage migrantRare16–17 cmRegularly May
Scarlet TanagerPiranga olivaceaPassage migrantRare16–19 cmRegularly May–Sep
Swan GooseAnser cygnoidesWinter visitorRare81–94 cmRecorded all year
Acorn WoodpeckerMelanerpes formicivorusSummer visitorRare20–24 cmRegularly May–Feb
Ruddy TurnstoneArenaria interpresResidentRare21–24 cmRegularly May–Sep
Muscovy DuckCairina moschataSummer visitorRare66–84 cmRegularly Jan–Nov
Alder FlycatcherEmpidonax alnorumPassage migrantRare13–17 cmRegularly May–Sep
Red KnotCalidris canutusResidentRare23–26 cmRegularly Aug–Sep
Data: EOD – eBird Observation Dataset (Cornell Lab of Ornithology), accessed via GBIF.org, CC BY 4.0. Records from 2019–2024, aggregated and filtered by Birdfact. How these lists are made