BirdAnalyst
Species · Arkansas · BBS 2025 Release · 1966–2024

Anhinga Population Trend in Arkansas

All statesGeneralists

Anhinga in Arkansas has fallen sharply: down 66% on the route-weighted index since 1993.

-66%Since 1993TrendPercent 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 →
5Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Anhinga Trends in ArkansasNotable 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 →

Anhinga has fallen sharply in Arkansas: down 66% on the route-weighted index since 1993.

Anhinga Population Forecast in Arkansas

If the recent trend holds, Anhinga in Arkansas is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±28.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.01Projected 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 →
0.00–0.1095% 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 →
±28.1%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, Anhinga in Arkansas is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±28.1%, with 100% of held-out values landing inside the 95% band.19752029
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 →
20250.020.000.11
20260.020.000.11
20270.020.000.10
20280.010.000.10
20290.010.000.10

Anhinga Survey Routes in Arkansas

Routes recording Anhinga in Arkansas.
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 →
Hope320001975
Eudora219971996
Hughes120102009
South Bend120231997
Gillett120242010

Anhinga Population Trend in Other States

alabamafloridageorgialouisianamississippinorth-carolinaoklahomasouth-carolinatexasvirginia

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