BirdAnalyst
BBS Route · Colorado · BCR 18

Nunn Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 88 species recorded across 27 survey years, still active.

88Species RecordedSpecies recordedDistinct species detected on standard-protocol BBS runs here across all years on record — a measure of survey breadth, not a complete checklist.Full methodology →
27Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1995–2025Span
3Observers

Bird Species Found on Colorado Nunn

Top 40 of 88 species by most recent count. Each links to its species trend.

Species recorded on the Nunn route.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →History
Horned LarkAlaudidae1822025+67%1997
House SparrowPasseridae1312025+423%1997
Lark BuntingPasserellidae1102025+58%1997
Common GrackleIcteridae752025+235%1997
Mourning DoveColumbidae702025+64%1997
Thick-billed LongspurCalcariidae492025+10%1997
Western MeadowlarkIcteridae462025+81%1997
Wilson's PhalaropeScolopacidae292014+625%2010
Red-winged BlackbirdIcteridae222025+176%1997
European StarlingSturnidae162025+163%1997
Brewer's SparrowPasserellidae142025-6%1997
Western KingbirdTyrannidae132025+339%1997
House FinchFringillidae122025+213%2010
Eurasian Collared-DoveColumbidae122025+646%2008
Northern ShovelerAnatidae122008n/an/a
Bank SwallowHirundinidae102025n/an/a
Grasshopper SparrowPasserellidae82025+195%1997
Ruddy DuckAnatidae82017+700%2015
Red-tailed HawkAccipitridae72021+300%2002
Rock PigeonColumbidae72025-12%2000
American White PelicanPelecanidae62025-18%2006
MallardAnatidae62021-41%1997
Chestnut-collared LongspurCalcariidae62021+880%1997
Brewer's BlackbirdIcteridae62006-9%1998
Barn SwallowHirundinidae52021+81%1997
Canada GooseAnatidae52021+191%2001
Lesser ScaupAnatidae52019n/an/a
Western GrebePodicipedidae42017+175%2002
American AvocetRecurvirostridae42021-44%2008
KilldeerCharadriidae42025-43%1997
Cliff SwallowHirundinidae42018+17%2002
Cassin's SparrowPasserellidae42025-38%2000
GadwallAnatidae42018-64%2009
Ferruginous HawkAccipitridae32018+150%1998
Bullock's OrioleIcteridae32025+167%1999
Lark SparrowPasserellidae32019+150%1998
Eastern KingbirdTyrannidae32019-20%1999
Burrowing OwlStrigidae32019-46%2010
Northern MockingbirdMimidae32021+0%2009
Green-winged TealAnatidae32017+50%2013

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. A route is a sample, not a census.