BirdAnalyst
BBS Route · Pennsylvania · BCR 28

Williamsburg Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 112 species recorded across 37 survey years, still active.

112Species 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 →
37Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1988–2025Span
2Observers

Bird Species Found on Pennsylvania Williamsburg

Top 40 of 112 species by most recent count. Each links to its species trend.

Species recorded on the Williamsburg 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
Common GrackleIcteridae1172025+70%1990
American RobinTurdidae992025+169%1990
Rock PigeonColumbidae772025-12%1990
European StarlingSturnidae582025-50%1990
Red-winged BlackbirdIcteridae482025-41%1990
House SparrowPasseridae282025-40%1990
Red-eyed VireoVireonidae262025+219%1990
Mourning DoveColumbidae242025+16%1990
American CrowCorvidae232025-24%1990
Barn SwallowHirundinidae182025-17%1990
Chipping SparrowPasserellidae152025-51%1990
Northern CardinalCardinalidae152025-31%1990
Tufted TitmouseParidae152025+45%1990
Purple MartinHirundinidae152025+92%2015
Gray CatbirdMimidae142025+6%1990
Song SparrowPasserellidae132025-42%1990
OvenbirdParulidae102025+18%1990
Scarlet TanagerCardinalidae92025+28%1990
Horned LarkAlaudidae82025+60%1994
Eastern TowheePasserellidae72025-40%1990
Tree SwallowHirundinidae72025+267%1994
KilldeerCharadriidae62025+0%1990
Red-bellied WoodpeckerPicidae62025+420%1990
Northern House WrenTroglodytidae62025+40%1990
Wood ThrushTurdidae62025-13%1990
Brown-headed CowbirdIcteridae52025-13%1990
MallardAnatidae42025-26%1990
Acadian FlycatcherTyrannidae42025-53%1990
Blue JayCorvidae42025+0%1990
Eastern MeadowlarkIcteridae42025-82%1990
Indigo BuntingCardinalidae42025-49%1990
Eastern BluebirdTurdidae42025+14%1990
Northern MockingbirdMimidae42025+114%1993
Great Horned OwlStrigidae32006+233%1998
American GoldfinchFringillidae32025+25%1990
Field SparrowPasserellidae32025-74%1990
Cedar WaxwingBombycillidae32025-29%1990
Yellow WarblerParulidae32025-71%1990
Common YellowthroatParulidae32025-70%1990
American RedstartParulidae32025+13%1991

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