BirdAnalyst
Species · BCR 5 · BBS 2025 Release · 1966–2024

Tree Swallow In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestAerial insectivores

Tree Swallow in Northern Pacific Rainforest has declined: down 43% on the route-weighted index since 1970.

-43%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 →
149Routes 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 →
56YearsYears 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 rise about 15% by 2029 — from 3.1 in 2024 to a central estimate of 3.6 (95% range 1.5–5.7). A 5-year backtest shows a typical error of ±20.2%, with 100% of held-out values landing inside the 95% band.

+15%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 →
3.6Projected 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 →
1.5–5.795% 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 →
±20.2%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, Tree Swallow in Northern Pacific Rainforest is projected to rise about 15% by 2029 — from 3.1 in 2024 to a central estimate of 3.6 (95% range 1.5–5.7). A 5-year backtest shows a typical error of ±20.2%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20253.81.75.9
20263.81.75.9
20273.71.65.8
20283.71.65.8
20293.61.55.7

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
Moose PassALASKA391985
MolallaOREGON392005
CoquilleOREGON322024
CamasWASHINGTON282009
CougarWASHINGTON262023
DerbyOREGON251993
CordovaALASKA242024
RuchOREGON212023
Sitka (Short)ALASKA191992
Emigrant LkOREGON172001
IlwacoWASHINGTON172024
HoneydewCALIFORNIA162017
Orleans 2CALIFORNIA162014
RainierWASHINGTON162019
Bodega BayCALIFORNIA142011
WinberryOREGON132021
WedderburnOREGON132024
GlasgowOREGON132024
DeceptionWASHINGTON122018
Crescent CtyCALIFORNIA112024
AdairOREGON112023
DaytonOREGON112024
YrekaCALIFORNIA102019
Burnt RanchCALIFORNIA102016

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