BirdAnalyst
Guild · Iowa · BBS 2025 Release · 1966–2024

Waterfowl In Iowa

All statesIowa

5 species in this guild. As a group they are 13×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 1969.

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 →

No notable trend signals for waterfowl in Iowa. See the full index history below.

Forecast

If the recent trend holds, Waterfowl in Iowa is projected to rise about 22% by 2029 — from 3.9 in 2024 to a central estimate of 4.7 (95% range 2.9–6.5). A 5-year backtest shows a typical error of ±72.5%, with 60% of held-out values landing inside the 95% band.

+22%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 →
4.7Projected 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 →
2.9–6.595% 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 →
±72.5%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, Waterfowl in Iowa is projected to rise about 22% by 2029 — from 3.9 in 2024 to a central estimate of 4.7 (95% range 2.9–6.5). A 5-year backtest shows a typical error of ±72.5%, with 60% 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 →
20254.42.66.1
20264.42.76.2
20274.52.86.3
20284.62.86.4
20294.72.96.5

Member Species In Iowa

Waterfowl species in Iowa.
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 →
Blue-winged TealAnatidae+38%
Northern ShovelerAnatidae+73%
MallardAnatidae+195%
Wood DuckAnatidae+347%
Canada GooseAnatidae38×

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