BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Red Crossbill

FringillidaeForest birdsLoxia curvirostra

Red Crossbill has surged: up 215% on the route-weighted index since 1969.

+215%Since 1969TrendPercent 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 →
790RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57Years 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 Red Crossbill

The Red Crossbill (Loxia curvirostra) is a North American member of the Finches (Fringillidae). In this analysis it is grouped with the forest birds.

Size
4.5–6.5 in long (11–16 cm) — a small 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 790 Breeding Bird Survey routes across 34 states, most concentrated in the Northern Rockies.
Family
Fringillidae · Forest birds

Notable Red Crossbill 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 →

Red Crossbill has surged in surveyed states: up 215% on the route-weighted index since 1969.

Red Crossbill Population Forecast

If the recent trend holds, Red Crossbill is projected to rise about 36% by 2029 — from 0.61 in 2024 to a central estimate of 0.83 (95% range 0.33–1.3). A 5-year backtest shows a typical error of ±46.8%, with 100% of held-out values landing inside the 95% band.

+36%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 →
0.83Projected 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 →
0.33–1.395% 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 →
±46.8%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, Red Crossbill is projected to rise about 36% by 2029 — from 0.61 in 2024 to a central estimate of 0.83 (95% range 0.33–1.3). A 5-year backtest shows a typical error of ±46.8%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.800.301.3
20260.810.311.3
20270.810.321.3
20280.820.331.3
20290.830.331.3

Where the Red Crossbill Is Detected

BBS routes recording Red Crossbill, sized by most recent count.

Red Crossbill Population Trend by State

Red Crossbill 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/a2
Alaska-79%198730
Arizona-17%197420
Arkansasinsufficient datan/a4
California+126%197183
Colorado+161%197174
Georgiainsufficient datan/a1
Idaho+352%197633
Illinoisinsufficient datan/a1
Maine+243%197521
Marylandinsufficient datan/a1
Massachusettsinsufficient datan/a4
Michigan+51%197334
Minnesota-82%197421
Montana+207%197158
Nebraska-83%198411
Nevadainsufficient datan/a2
New Hampshire+146%197115
New Mexico-82%197725
New York-4%197427
North Carolinainsufficient datan/a5
North Dakotainsufficient datan/a3
Oregon+19%197092
Pennsylvaniainsufficient datan/a1
South Carolinainsufficient datan/a1
South Dakota-5%197019
Tennessee+338%20064
Utah-3%198926
Vermontinsufficient datan/a4
Virginiainsufficient datan/a3
Washington+62%197078
West Virginiainsufficient datan/a4
Wisconsin+62%197038
Wyoming+11%197045

Red Crossbill Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Red Crossbill 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+80%1971131
Great Basin-25%197076
Northern Rockies+94%1970136
Boreal Hardwood Transition+90%197079
Atlantic Northern Forest+309%197053
Sierra Nevada-9%197126
Southern Rockies / Colorado Plateau+380%1971127
Badlands and Prairies-28%197050
Shortgrass Prairie-62%19817
Prairie Hardwood Transition-82%197412
Appalachian Mountains+468%198525
Coastal California-42%197611
Sierra Madre Occidental-48%197417
Chihuahuan Desert-91%19823

Red Crossbill Conservation Status

Our route-weighted index shows it up about 215% since 1969.

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