Uncommon Birds in Colorado
Our list for Colorado has 81 uncommon birds recorded regularly there: 11 residents, 25 summer visitors, 24 winter visitors and 21 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 81, most common first
Red-breasted MerganserMergus serratorWinter visitorUncommon52–58 cmRegularly Oct–Apr
Solitary SandpiperTringa solitariaPassage migrantUncommon19–23 cmRegularly Apr–Sep
Long-billed DowitcherLimnodromus scolopaceusPassage migrantUncommon27–30 cmRegularly Mar–Nov
Great White EgretArdea albaSummer visitorUncommon80–104 cmRegularly Apr–Oct
Evening GrosbeakHesperiphona vespertinaResidentUncommon16–22 cmRecorded all year
Sharp-shinned HawkAccipiter striatusWinter visitorUncommon24–34 cmRecorded all year
Black-crowned Night-heronNycticorax nycticoraxSummer visitorUncommon58–65 cmRecorded all year
MerlinFalco columbariusWinter visitorUncommon24–33 cmRegularly Sep–Apr
Sand MartinRiparia ripariaSummer visitorUncommon12–14 cmRegularly Apr–Sep
WilletTringa semipalmataSummer visitorUncommon33–41 cmRegularly Apr–Sep
Lesser Black-backed GullLarus fuscusWinter visitorUncommon52–64 cmRegularly Sep–Apr
Least FlycatcherEmpidonax minimusSummer visitorUncommon12–14 cmRegularly May–Sep
Pectoral SandpiperCalidris melanotosPassage migrantUncommon19–23 cmRegularly Aug–Nov
Williamson's SapsuckerSphyrapicus thyroideusSummer visitorUncommon21–25 cmRegularly Apr–Jan
Greater White-fronted GooseAnser albifronsWinter visitorUncommon64–81 cmRegularly Oct–Apr
Marsh WrenCistothorus palustrisResidentUncommon10–14 cmRecorded all year
Ross's GooseAnser rossiiWinter visitorUncommon57–64 cmRegularly Oct–Apr
DickcisselSpiza americanaSummer visitorUncommon14–16 cmRegularly May–Sep
Sabine's GullXema sabiniPassage migrantUncommon27–33 cmRegularly Aug–Oct
Lewis's WoodpeckerMelanerpes lewisResidentUncommon26–28 cmRecorded all year
American Three-toed WoodpeckerPicoides dorsalisSummer visitorUncommon21–24 cmRecorded all year
Stilt SandpiperCalidris himantopusPassage migrantUncommon18–23 cmRegularly May–Oct
Semipalmated SandpiperCalidris pusillaPassage migrantUncommon15–18 cmRegularly Apr–Oct
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