BirdAnalyst
BBS Route · Pennsylvania · BCR 28

Doubling Gap Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 89 species recorded across 12 survey years, no longer active.

89Species 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 →
12Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1966–1977Span
3Observers

Bird Species Found on Pennsylvania Doubling Gap

Top 40 of 89 species by most recent count. Each links to its species trend.

Species recorded on the Doubling Gap 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
House SparrowPasseridae961977-32%1968
Red-winged BlackbirdIcteridae811977+15%1968
European StarlingSturnidae771977-30%1968
Common GrackleIcteridae691977-68%1968
American RobinTurdidae601977-37%1968
Rock PigeonColumbidae531977-41%1968
Barn SwallowHirundinidae421977+190%1968
American CrowCorvidae401977+68%1968
Song SparrowPasserellidae321977+187%1968
Mourning DoveColumbidae301977+69%1968
Indigo BuntingCardinalidae271977+116%1968
Gray CatbirdMimidae241977-17%1968
Field SparrowPasserellidae221977+124%1968
Chipping SparrowPasserellidae191977+47%1968
Eastern MeadowlarkIcteridae181977-43%1968
Northern CardinalCardinalidae161977+38%1968
KilldeerCharadriidae151977+333%1968
American GoldfinchFringillidae151977+27%1968
Wood ThrushTurdidae151977+50%1968
Ring-necked PheasantPhasianidae141977+46%1968
Common YellowthroatParulidae131977+143%1968
MallardAnatidae111977+186%1969
Chimney SwiftApodidae101977-6%1968
Purple MartinHirundinidae101977+3%1970
Northern House WrenTroglodytidae81977-16%1968
Brown-headed CowbirdIcteridae61977-70%1968
Baltimore OrioleIcteridae61977-29%1968
Northern Rough-winged SwallowHirundinidae61976+75%1972
Northern MockingbirdMimidae51977+80%1968
Northern BobwhiteOdontophoridae41977-65%1968
Eastern PhoebeTyrannidae41977+18%1970
Blue JayCorvidae41977-7%1968
Scarlet TanagerCardinalidae41976+60%1968
Northern ParulaParulidae31967+50%1966
Yellow WarblerParulidae31977+75%1968
Brown ThrasherMimidae31976-75%1968
Carolina WrenTroglodytidae31976+150%1967
Tufted TitmouseParidae31977-65%1968
Great Horned OwlStrigidae21966n/an/a
Belted KingfisherAlcedinidae21977+233%1972

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. A route is a sample, not a census.