BirdAnalyst
Guild · New Hampshire · BBS 2026 Release · 1966–2025

Grassland Birds In New Hampshire

All statesNew Hampshire

4 species in this guild. As a group they are -58%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Grassland birds as a group have fallen sharply in New Hampshire, down 57% since 1968.

Grassland Birds In New Hampshire Population Forecast

If the recent trend holds, Grassland birds in New Hampshire is projected to rise about 39% by 2030 — from 0.91 in 2025 to a central estimate of 1.3 (95% range 0.17–2.4). A 5-year backtest shows a typical error of ±20.5%, with 100% of held-out values landing inside the 95% band.

+39%Change by 2030TrendPercent 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 →
1.3Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.17–2.495% 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 →
±20.5%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, Grassland birds in New Hampshire is projected to rise about 39% by 2030 — from 0.91 in 2025 to a central estimate of 1.3 (95% range 0.17–2.4). A 5-year backtest shows a typical error of ±20.5%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20261.40.342.5
20271.40.302.5
20281.40.262.5
20291.30.212.4
20301.30.172.4

Member Species In New Hampshire

Grassland birds species in New Hampshire.
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 →
Eastern MeadowlarkIcteridae-99%
Vesper SparrowPasserellidae-86%
BobolinkIcteridae-68%
Savannah SparrowPasserellidae-64%

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.