BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Northern Saw-whet Owl

StrigidaeBirds of preyAegolius acadicus

Northern Saw-whet Owl has fallen sharply: down 52% on the route-weighted index since 1973.

-52%Since 1973TrendPercent 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 →
96RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
48Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Northern Saw-whet Owl

The Northern Saw-whet Owl (Aegolius acadicus) is a North American member of the Owls (Strigidae). In this analysis it is grouped with the birds of prey.

Size
5–27.5 in long (13–70 cm) — a nocturnal raptor (typical for the family)
Habitat
Open country, woodlands, cliffs and wetlands, hunting from the air or a high perch.
Diet
Live prey — small mammals, birds, reptiles, fish and large insects (carrion for vultures).
Range
Recorded on 96 Breeding Bird Survey routes across 19 states, most concentrated in the Northern Pacific Rainforest.
Family
Strigidae · Birds of prey

Notable Northern Saw-whet Owl TrendsNotable 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 Northern Saw-whet Owl. See the full index history below.

Northern Saw-whet Owl Population Forecast

If the recent trend holds, Northern Saw-whet Owl is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.00). A 5-year backtest shows a typical error of ±93.9%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.0095% 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 →
±93.9%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, Northern Saw-whet Owl is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.00). A 5-year backtest shows a typical error of ±93.9%, with 100% of held-out values landing inside the 95% band.19702029
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 →
20250.000.000.00
20260.000.000.00
20270.000.000.00
20280.000.000.00
20290.000.000.00

Where the Northern Saw-whet Owl Is Detected

BBS routes recording Northern Saw-whet Owl, sized by most recent count.

Northern Saw-whet Owl Population Trend by State

Northern Saw-whet Owl population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alaska-18%199413
Arizonainsufficient datan/a2
Californiainsufficient datan/a9
Coloradoinsufficient datan/a6
Idahoinsufficient datan/a3
Maineinsufficient datan/a12
Michiganinsufficient datan/a2
Minnesotainsufficient datan/a5
Montanainsufficient datan/a3
New Hampshireinsufficient datan/a1
New Yorkinsufficient datan/a3
Oregon-40%197711
Pennsylvaniainsufficient datan/a5
Vermontinsufficient datan/a1
Virginiainsufficient datan/a3
Washingtoninsufficient datan/a7
West Virginiainsufficient datan/a1
Wisconsininsufficient datan/a7
Wyominginsufficient datan/a2

Northern Saw-whet Owl Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Northern Saw-whet Owl population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-22%197723
Northern Rockies-30%198411
Atlantic Northern Forest-17%199117

Northern Saw-whet Owl Conservation Status

Our route-weighted index shows it down about 52% since 1973.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.