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

Bonaparte's Gull In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestWetland birds

Bonaparte's Gull in Northern Pacific Rainforest has surged: up 619% on the route-weighted index since 1984.

+619%Since 1984TrendPercent 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 →
18Routes 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 →
33YearsYears 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 →

Bonaparte's Gull has surged in Northern Pacific Rainforest: up 619% on the route-weighted index since 1984.

Forecast

If the recent trend holds, Bonaparte's Gull in Northern Pacific Rainforest is projected to stay roughly flat through 2023, near 0.00 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±247.5%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2023TrendPercent 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 2023 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2.595% 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 →
±247.5%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, Bonaparte's Gull in Northern Pacific Rainforest is projected to stay roughly flat through 2023, near 0.00 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±247.5%, with 100% of held-out values landing inside the 95% band.19712023
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 →
20190.000.002.5
20200.000.002.5
20210.000.002.5
20220.000.002.5
20230.000.002.5

Routes In Northern Pacific Rainforest

Routes recording Bonaparte's Gull 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 →
Juneau AltALASKA3351985
KetchikanALASKA552017
PetersburgALASKA241987
ZaremboALASKA202001
Zimovia StrtALASKA42017
Warm BeachWASHINGTON41986
YakutatALASKA32018
Mitkof IsleALASKA32010
HainesALASKA21997
Sheep MtnALASKA22017
SkagwayALASKA22011
Kuiu IslandALASKA22010
HoneydewCALIFORNIA21973
WedderburnOREGON21985
Elmendorf (Short)ALASKA11984
Sitka (Short)ALASKA11986
HullvilleCALIFORNIA11971
Port AngelesWASHINGTON12012

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