BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Cliff Swallow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieAerial insectivores

Cliff Swallow in Eastern Tallgrass Prairie has surged: up 126× on the route-weighted index since 1968.

126×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 →
220Routes 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 →
58YearsYears 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 increasecomputed 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 →

Cliff Swallow has surged in Eastern Tallgrass Prairie: up 126× on the route-weighted index since 1968.

Cliff Swallow In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Cliff Swallow in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 17 (95% range 12–21). A 5-year backtest shows a typical error of ±10.1%, with 100% of held-out values landing inside the 95% band.

-5%Change by 2029TrendPercent 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 →
17Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
12–2195% 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 →
±10.1%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, Cliff Swallow in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 17 (95% range 12–21). A 5-year backtest shows a typical error of ±10.1%, with 100% of held-out values landing inside the 95% band.19662029
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 →
2025151120
2026161120
2027161121
2028161121
2029171221

Routes In Eastern Tallgrass Prairie

Routes recording Cliff Swallow in Eastern Tallgrass Prairie.
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 →
GreenviewILLINOIS2302024
Queen CityMISSOURI1802022
GretnaNEBRASKA1642018
EldredILLINOIS1572021
MillwoodMISSOURI1212024
BarnardMISSOURI1182019
New PointMISSOURI1042024
TrentonMISSOURI1032024
FilleyMISSOURI1022024
ChandlervillILLINOIS962024
SheffieldILLINOIS892024
AliceIOWA791999
WrefordKANSAS772024
FairdaleILLINOIS742024
HolcombILLINOIS712024
West LibertyIOWA692024
LucerneMISSOURI652021
BelleviewILLINOIS612024
ReeceKANSAS612024
Terre HauteILLINOIS602024
Deer CreekILLINOIS552024
GeneseoILLINOIS522021
Duncan MillsILLINOIS512024
GalesburgKANSAS502024
GeraldMISSOURI502024

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