BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Henslow's Sparrow In Appalachian Mountains

All regionsAppalachian MountainsGrassland birds

Henslow's Sparrow in Appalachian Mountains has collapsed: down 95% on the route-weighted index since 1968.

-95%Since 1968TrendPercent 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 →
69Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Henslow's Sparrow has collapsed in Appalachian Mountains: down 95% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Henslow's Sparrow in Appalachian Mountains is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±322.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.00Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0595% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±322.2%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Henslow's Sparrow in Appalachian Mountains is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±322.2%, with 100% of held-out values landing inside the 95% band.19662028
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20240.000.000.05
20250.000.000.05
20260.000.000.05
20270.000.000.05
20280.000.000.05

Routes In Appalachian Mountains

Routes recording Henslow's Sparrow in Appalachian Mountains.
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 →
LisleNEW-YORK72003
RasselasPENNSYLVANIA52004
WakenaPENNSYLVANIA42000
MeadowbrookOHIO32016
Coal RunOHIO31990
SigelPENNSYLVANIA31999
BebeeWEST-VIRGINIA31975
MedusaNEW-YORK21969
Phillips CrNEW-YORK22006
SwainNEW-YORK21983
NewcomerstwnOHIO21984
RayOHIO21998
OmegaOHIO22023
CumberlandOHIO21998
SheloctaPENNSYLVANIA21995
MunsonPENNSYLVANIA22001
FinzelMARYLAND12021
AccidentMARYLAND11994
SomersNEW-YORK11975
DurhamNEW-YORK11969
LaurensNEW-YORK11981
Whitney PtNEW-YORK11972
CoventryvileNEW-YORK11978
CorbettsvileNEW-YORK11986
E NewarkNEW-YORK11993

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.