BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Pygmy Nuthatch

SittidaeForest birdsSitta pygmaea

Pygmy Nuthatch has risen sharply: up 70% on the route-weighted index since 1970.

+70%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 →
271RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years 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 Pygmy Nuthatch

The Pygmy Nuthatch (Sitta pygmaea) is a North American member of the Nuthatches (Sittidae). In this analysis it is grouped with the forest birds.

Size
4–7 in long (10–18 cm) — a small tree-climbing songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 271 Breeding Bird Survey routes across 12 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Sittidae · Forest birds

Notable Pygmy Nuthatch TrendsNotable 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 →

Pygmy Nuthatch has risen sharply in surveyed states: up 70% on the route-weighted index since 1970.

Pygmy Nuthatch Population Forecast

If the recent trend holds, Pygmy Nuthatch is projected to rise about 51% by 2029 — from 0.15 in 2024 to a central estimate of 0.23 (95% range 0.14–0.33). A 5-year backtest shows a typical error of ±31.5%, with 80% of held-out values landing inside the 95% band.

+51%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 →
0.23Projected 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 →
0.14–0.3395% 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 →
±31.5%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, Pygmy Nuthatch is projected to rise about 51% by 2029 — from 0.15 in 2024 to a central estimate of 0.23 (95% range 0.14–0.33). A 5-year backtest shows a typical error of ±31.5%, with 80% 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 →
20250.230.130.32
20260.230.130.32
20270.230.140.32
20280.230.140.33
20290.230.140.33

Where the Pygmy Nuthatch Is Detected

BBS routes recording Pygmy Nuthatch, sized by most recent count.

Pygmy Nuthatch Population Trend by State

Pygmy Nuthatch 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 →
Arizona+74%197021
California-65%197080
Colorado-27%197142
Idaho-75%19896
Montana-78%198713
Nebraskainsufficient datan/a2
New Mexico+943%197122
Oregon+33%197040
South Dakotainsufficient datan/a5
Utah-71%19927
Washington+45%197026
Wyoming-49%19827

Pygmy Nuthatch Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Pygmy Nuthatch 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-63%197216
Great Basin+137%197151
Northern Rockies-53%197047
Sierra Nevada-72%197123
Southern Rockies / Colorado Plateau+94%197069
Shortgrass Prairie+360%19825
Coastal California-66%197029
Sierra Madre Occidental-0%197020
Chihuahuan Desert-72%19823

Pygmy Nuthatch Conservation Status

Our route-weighted index shows it up about 70% since 1970.

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