BirdAnalyst
BBS Route · Pennsylvania · BCR 28

Warrens Mill Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 115 species recorded across 53 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 →
53Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1971–2025Span
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
European StarlingSturnidae832025-15%1973
Red-eyed VireoVireonidae542025+26%1973
American RobinTurdidae392025+37%1973
OvenbirdParulidae372025+247%1973
Red-winged BlackbirdIcteridae262025-32%1973
American CrowCorvidae232025-41%1973
Indigo BuntingCardinalidae222025-62%1973
Song SparrowPasserellidae172025-10%1973
Common YellowthroatParulidae162025+114%1973
Eastern TowheePasserellidae122025-58%1973
Scarlet TanagerCardinalidae122025-53%1973
Black-capped ChickadeeParidae122025+100%1973
Chipping SparrowPasserellidae112025-36%1973
Yellow WarblerParulidae112025-9%1973
Blue JayCorvidae102025+13%1973
Mourning DoveColumbidae92025+118%1973
Field SparrowPasserellidae92025-70%1973
American RedstartParulidae92025+82%1973
American GoldfinchFringillidae82025-25%1973
Northern CardinalCardinalidae82025-53%1973
Acadian FlycatcherTyrannidae82025+54%1974
Canada GooseAnatidae82010n/an/a
Gray CatbirdMimidae72025-40%1973
Yellow-billed CuckooCuculidae62025+42%1973
Eastern Wood-PeweeTyrannidae62025-46%1973
Barn SwallowHirundinidae62025-23%1973
Northern House WrenTroglodytidae62025-7%1973
Northern ParulaParulidae62025+100%1974
Black-and-white WarblerParulidae52025-29%1973
Louisiana WaterthrushParulidae52025+175%1974
Wood ThrushTurdidae52025-71%1973
Black-throated Green WarblerParulidae52025+183%1975
Black-billed CuckooCuculidae42025+100%1976
Hairy WoodpeckerPicidae42024+133%1981
Eastern PhoebeTyrannidae42025-25%1973
Grasshopper SparrowPasserellidae42019-73%1973
Carolina WrenTroglodytidae42025+100%1975
Tufted TitmouseParidae42025+20%1973
Eastern KingbirdTyrannidae32021-38%1973
Brown-headed CowbirdIcteridae32025-84%1973

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