BirdAnalyst
BBS Route · Pennsylvania · BCR 28

Warrens Mill Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 115 species recorded across 52 survey years, still active.

115Species 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 →
52Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1971–2024Span
3Observers

Bird Species Found on Pennsylvania Warrens Mill

Top 40 of 115 species by most recent count. Each links to its species trend.

Species recorded on the Warrens Mill 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
Red-eyed VireoVireonidae742024+49%1973
OvenbirdParulidae432024+186%1973
American RobinTurdidae432024+51%1973
Song SparrowPasserellidae292024+19%1973
American CrowCorvidae272024-34%1973
Eastern TowheePasserellidae222024-36%1973
Common YellowthroatParulidae212024+210%1973
Chipping SparrowPasserellidae192024-15%1973
European StarlingSturnidae152023-66%1973
Eastern Wood-PeweeTyrannidae132024-37%1973
Red-winged BlackbirdIcteridae132024-49%1973
Field SparrowPasserellidae132024-55%1973
Indigo BuntingCardinalidae132024-45%1973
Mourning DoveColumbidae122024+236%1973
Common GrackleIcteridae122024-96%1973
American GoldfinchFringillidae112024+35%1973
Scarlet TanagerCardinalidae112024-63%1973
Black-capped ChickadeeParidae112024+200%1973
Gray CatbirdMimidae92024+37%1973
Cedar WaxwingBombycillidae82024+250%1973
Canada GooseAnatidae82010n/an/a
Chimney SwiftApodidae72023+220%1976
Barn SwallowHirundinidae72024+21%1973
Acadian FlycatcherTyrannidae72024+69%1974
American RedstartParulidae62024+9%1973
Northern House WrenTroglodytidae62024+40%1973
Wood ThrushTurdidae62024-22%1973
Northern ParulaParulidae52024+125%1974
Blue-headed VireoVireonidae52024+350%1984
Black-throated Green WarblerParulidae52024+383%1975
Wild TurkeyPhasianidae42024+50%1984
Hairy WoodpeckerPicidae42024+133%1981
Downy WoodpeckerPicidae42024+83%1973
Pileated WoodpeckerPicidae42024+80%1974
Eastern PhoebeTyrannidae42024-44%1973
Grasshopper SparrowPasserellidae42019-73%1973
Northern CardinalCardinalidae42024+3%1973
Black-and-white WarblerParulidae42024-50%1973
House FinchFringillidae42022+20%1989
Turkey VultureCathartidae32024+0%1975

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