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Species · BCR 5 · BBS 2026 Release · 1966–2025

Tree Swallow In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestAerial insectivores

Tree Swallow in Northern Pacific Rainforest has declined: down 40% on the route-weighted index since 1970.

-40%Since 1970TrendPercent 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 →
150Routes 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 →
57YearsYears 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 →

No notable trend signals for Tree Swallow in Northern Pacific Rainforest. See the full index history below.

Tree Swallow In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Tree Swallow in Northern Pacific Rainforest is projected to stay roughly flat through 2030, near 3.5 (95% range 1.5–5.6). A 5-year backtest shows a typical error of ±20.9%, with 100% of held-out values landing inside the 95% band.

+2%Change by 2030TrendPercent 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 →
3.5Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
1.5–5.695% 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 →
±20.9%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, Tree Swallow in Northern Pacific Rainforest is projected to stay roughly flat through 2030, near 3.5 (95% range 1.5–5.6). A 5-year backtest shows a typical error of ±20.9%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.71.75.8
20273.71.65.8
20283.61.65.7
20293.61.55.7
20303.51.55.6

Routes In Northern Pacific Rainforest

Routes recording Tree Swallow in Northern Pacific Rainforest.
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 →
Horse CreekCALIFORNIA702019
WedderburnOREGON472025
Moose PassALASKA391985
MolallaOREGON392005
Nicolai Mtn.OREGON332025
CamasWASHINGTON282009
CougarWASHINGTON262023
DerbyOREGON251993
CordovaALASKA242024
DaytonOREGON212025
Sitka (Short)ALASKA191992
Emigrant LkOREGON172001
HoneydewCALIFORNIA162017
Orleans 2CALIFORNIA162014
RainierWASHINGTON162019
Bodega BayCALIFORNIA142011
WinberryOREGON132021
GlasgowOREGON132025
Mendota 3WASHINGTON122025
DeceptionWASHINGTON122018
YrekaCALIFORNIA102019
Burnt RanchCALIFORNIA102016
SvensenOREGON101992
IlwacoWASHINGTON92025
CarnationWASHINGTON92025

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.