BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Savannah Sparrow

PasserellidaeGrassland birdsPasserculus sandwichensis

Savannah Sparrow has fallen sharply: down 51% on the route-weighted index since 1968.

-51%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 →
1,874RoutesSurvey 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 Savannah Sparrow

The Savannah Sparrow (Passerculus sandwichensis) is a North American member of the New World Sparrows (Passerellidae). In this analysis it is grouped with the grassland birds.

Size
4.5–7.5 in long (12–19 cm) — a small songbird (typical for the family)
Habitat
Open grasslands, prairie, pasture and hayfields.
Diet
Seeds and insects gathered from grasses and the ground.
Range
Recorded on 1,874 Breeding Bird Survey routes across 40 states, most concentrated in the Great Basin.
Family
Passerellidae · Grassland birds

Notable Savannah Sparrow 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 declinecomputed 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 →

Savannah Sparrow has fallen sharply in surveyed states: down 51% on the route-weighted index since 1968.

Savannah Sparrow Population Forecast

If the recent trend holds, Savannah Sparrow is projected to rise about 14% by 2029 — from 2.1 in 2024 to a central estimate of 2.4 (95% range 1.6–3.2). A 5-year backtest shows a typical error of ±41.6%, with 20% of held-out values landing inside the 95% band.

+14%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 →
2.4Projected 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 →
1.6–3.295% 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 →
±41.6%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, Savannah Sparrow is projected to rise about 14% by 2029 — from 2.1 in 2024 to a central estimate of 2.4 (95% range 1.6–3.2). A 5-year backtest shows a typical error of ±41.6%, with 20% 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 →
20252.51.73.3
20262.51.73.2
20272.51.73.2
20282.41.73.2
20292.41.63.2

Where the Savannah Sparrow Is Detected

BBS routes recording Savannah Sparrow, sized by most recent count.

Savannah Sparrow Population Trend by State

Savannah Sparrow 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+365%1975113
Arizonainsufficient datan/a5
California+65%197077
Colorado+49%197086
Connecticut-12%19759
Delawareinsufficient datan/a1
Idaho-23%197051
Illinois-86%196875
Indiana-77%196859
Iowa-38%196932
Kansasinsufficient datan/a1
Kentucky-43%196812
Maine-48%196857
Maryland+86%196821
Massachusetts-26%196920
Michigan-85%196897
Minnesota-39%196985
Missouriinsufficient datan/a8
Montana+313%197098
Nebraska-46%19778
Nevada+35%197330
New Hampshire-59%196823
New Jersey+44%19967
New Mexico-66%199210
New York-50%1968107
North Carolina-22%20103
North Dakota-16%196951
Ohio-53%196870
Oregon+22%1970100
Pennsylvania-70%1968107
Rhode Islandinsufficient datan/a3
South Dakota-21%196937
Tennesseeinsufficient datan/a1
Utah+128%197060
Vermont-5%196825
Virginia-59%198211
Washington+24%197093
West Virginia-83%196826
Wisconsin-83%196893
Wyoming+509%1970102

Savannah Sparrow Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Savannah Sparrow 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 →
BCR 2-26%198522
BCR 3+194%19955
BCR 4-66%197763
Northern Pacific Rainforest-6%1970100
Great Basin+92%1970200
Northern Rockies+132%1970171
Prairie Potholes+15%1969114
Boreal Hardwood Transition-66%1968106
Lower Great Lakes / St. Lawrence Plain-50%196883
Atlantic Northern Forest-29%1968124
Sierra Nevada-12%197510
Southern Rockies / Colorado Plateau+157%1970110
Badlands and Prairies+42%196993
Shortgrass Prairie-88%198025
Eastern Tallgrass Prairie-79%1968172
Prairie Hardwood Transition-85%1968158
Central Hardwoods-27%196830
Appalachian Mountains-78%1968181
Piedmont+42%196825
New England / Mid-Atlantic Coast-33%196837
Coastal California-44%197233
Sonoran and Mojave Deserts-48%19904

Savannah Sparrow Conservation Status

Our route-weighted index shows it down about 51% since 1968. Grassland birds are North America's steepest-declining group, down roughly 50% since 1970 as prairie and pasture were lost.

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