BirdAnalyst
BBS Route · Pennsylvania · BCR 28

Mawr Glen Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 135 species recorded across 53 survey years, still active.

135Species 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 →
1966–2024Span
2Observers

Bird Species Found on Pennsylvania Mawr Glen

Top 40 of 135 species by most recent count. Each links to its species trend.

Species recorded on the Mawr Glen 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 VireoVireonidae852024+462%1968
American RobinTurdidae642024+20%1968
OvenbirdParulidae422024+197%1983
Song SparrowPasserellidae322024+186%1968
Gray CatbirdMimidae322024+538%1968
VeeryTurdidae272024+208%1984
American CrowCorvidae252024-56%1968
Red-winged BlackbirdIcteridae252024-58%1968
Common YellowthroatParulidae22202414×1975
Mourning DoveColumbidae212024+293%1968
Cedar WaxwingBombycillidae172024+433%1968
Tufted TitmouseParidae162024+246%1984
Yellow-bellied SapsuckerPicidae15202416×1983
Northern CardinalCardinalidae152024-13%1968
Blue-headed VireoVireonidae152024+78%1984
American RedstartParulidae152024-4%1984
Common GrackleIcteridae142024-48%1968
American GoldfinchFringillidae142024+9%1968
Scarlet TanagerCardinalidae142024+875%1969
Wood ThrushTurdidae142024-64%1968
Canada GooseAnatidae142024+200%1996
Chipping SparrowPasserellidae132024+8%1968
Eastern PhoebeTyrannidae122024+329%1968
Northern House WrenTroglodytidae122024+144%1968
Yellow-billed CuckooCuculidae122024+300%1989
Barn SwallowHirundinidae112024-79%1968
European StarlingSturnidae102024-88%1968
Magnolia WarblerParulidae92024+425%1984
Blue JayCorvidae82024+6%1968
Indigo BuntingCardinalidae82024+471%1968
Black-capped ChickadeeParidae82024+300%1971
Rock PigeonColumbidae82006+175%1973
Black-throated Green WarblerParulidae82024-29%1984
Wood DuckAnatidae82024+100%1992
Baltimore OrioleIcteridae72024+200%1969
Eastern TowheePasserellidae72024+367%1982
House FinchFringillidae72024+63%1985
Chestnut-sided WarblerParulidae72024+500%1987
BobolinkIcteridae62024+10%1969
Eastern BluebirdTurdidae62024+57%1970

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