BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Bewick's Wren

TroglodytidaeForest birdsThryomanes bewickii

Bewick's Wren has risen sharply: up 62% on the route-weighted index since 1968.

+62%Since 1968TrendPercent 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 →
1,058RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years 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 Bewick's Wren

The Bewick's Wren (Thryomanes bewickii) is a North American member of the Wrens (Troglodytidae). In this analysis it is grouped with the forest birds.

Size
4–8.5 in long (10–22 cm) — a small, energetic 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 1,058 Breeding Bird Survey routes across 29 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Troglodytidae · Forest birds

Notable Bewick's Wren 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 →

Bewick's Wren has risen sharply in surveyed states: up 62% on the route-weighted index since 1968.

Bewick's Wren Population Forecast

If the recent trend holds, Bewick's Wren is projected to stay roughly flat through 2029, near 0.97 (95% range 0.61–1.3). A 5-year backtest shows a typical error of ±33.3%, with 80% of held-out values landing inside the 95% band.

-4%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 →
0.97Projected 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 →
0.61–1.395% 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 →
±33.3%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, Bewick's Wren is projected to stay roughly flat through 2029, near 0.97 (95% range 0.61–1.3). A 5-year backtest shows a typical error of ±33.3%, with 80% of held-out values landing inside the 95% band.19662029
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 →
20250.970.601.3
20260.970.601.3
20270.970.601.3
20280.970.611.3
20290.970.611.3

Where the Bewick's Wren Is Detected

BBS routes recording Bewick's Wren, sized by most recent count.

Bewick's Wren Population Trend by State

Bewick's Wren 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 →
Alabamainsufficient datan/a6
Arizona-51%197064
Arkansas-70%196912
California+14%1970222
Colorado+92%197357
Idahoinsufficient datan/a2
Illinoisinsufficient datan/a6
Indianainsufficient datan/a1
Iowainsufficient datan/a1
Kansas-23%196924
Kentucky-97%196829
Marylandinsufficient datan/a1
Mississippi-73%196810
Missouri-93%196951
Nevada+890%197128
New Mexico+210%197155
North Carolinainsufficient datan/a1
Ohio-66%19688
Oklahoma-54%196963
Oregon+72%197057
Pennsylvaniainsufficient datan/a2
Tennessee-95%196831
Texas-9%1969180
Utah-8%198156
Virginia-90%19688
Washington+35%197061
West Virginia-81%197015
Wisconsininsufficient datan/a1
Wyoming-86%19926

Bewick's Wren Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Bewick's Wren 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+43%1970102
Great Basin+340%197096
Northern Rockies-39%197619
Sierra Nevada-72%197033
Southern Rockies / Colorado Plateau-5%1970129
Shortgrass Prairie-28%196941
Central Mixed Grass Prairie+9%196964
Edwards Plateau+31%196919
Oaks and Prairies-22%196961
Eastern Tallgrass Prairie-55%196842
Central Hardwoods-97%196884
West Gulf Coastal Plain / Ouachitas-71%196922
Southeastern Coastal Plain-96%196824
Appalachian Mountains-97%196843
Coastal California+25%1970114
Sonoran and Mojave Deserts+68%197046
Sierra Madre Occidental-62%197036
Chihuahuan Desert+26%196943
Tamaulipan Brushlands+12%196927
Gulf Coastal Prairie+226%199110

Bewick's Wren Conservation Status

Our route-weighted index shows it up about 62% since 1968.

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