BirdAnalyst
Species · New Jersey · BBS 2025 Release · 1966–2024

Bobolink Population Trend in New Jersey

All statesGrassland birds

Bobolink in New Jersey has increased: up 29% on the route-weighted index since 1970.

+29%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 →
13Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bobolink Trends in New JerseyNotable 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 Bobolink in New Jersey. See the full index history below.

Bobolink Population Forecast in New Jersey

If the recent trend holds, Bobolink in New Jersey is projected to rise about 507% by 2028 — from 0.10 in 2023 to a central estimate of 0.61 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±448%, with 100% of held-out values landing inside the 95% band.

+507%Change by 2028TrendPercent 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 →
0.61Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.695% 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 →
±448%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, Bobolink in New Jersey is projected to rise about 507% by 2028 — from 0.10 in 2023 to a central estimate of 0.61 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±448%, with 100% of held-out values landing inside the 95% band.19662028
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 →
20240.590.001.6
20250.600.001.6
20260.600.001.6
20270.600.001.6
20280.610.001.6

Bobolink Survey Routes in New Jersey

Routes recording Bobolink in New Jersey.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Gillette420151991
Clarksville319781978
Hope319931974
Masonville219661966
New Bedford219741971
Sandbrook120231983
Croton120071971
Robbinsville119781966
Bloomsbury119881970
High Point119871978
Ramseysburg120191995
Pottersville120231977
Roosevelt119951995

Bobolink Population Trend in Other States

californiacoloradoconnecticutidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.