BirdAnalyst
Species · BCR 36 · BBS 2026 Release · 1966–2025

Carolina Wren In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsForest birds

Carolina Wren in Tamaulipan Brushlands has surged: up 621% on the route-weighted index since 1976.

+621%Since 1976TrendPercent 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 →
10Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
27YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 increasecomputed 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 →

Carolina Wren has surged in Tamaulipan Brushlands: up 621% on the route-weighted index since 1976.

Carolina Wren In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Carolina Wren in Tamaulipan Brushlands is projected to fall about 79% by 2030 — from 1.7 in 2025 to a central estimate of 0.37 (95% range 0.00–0.96). A 5-year backtest shows a typical error of ±111.2%, with 40% of held-out values landing inside the 95% band.

-79%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 →
0.37Projected 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 →
0.00–0.9695% 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 →
±111.2%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, Carolina Wren in Tamaulipan Brushlands is projected to fall about 79% by 2030 — from 1.7 in 2025 to a central estimate of 0.37 (95% range 0.00–0.96). A 5-year backtest shows a typical error of ±111.2%, with 40% of held-out values landing inside the 95% band.19712030
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 →
20260.350.000.94
20270.350.000.94
20280.360.000.95
20290.360.000.96
20300.370.000.96

Routes In Tamaulipan Brushlands

Routes recording Carolina Wren in Tamaulipan Brushlands.
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 →
Catarina 3TEXAS162025
George WestTEXAS22025
RachalTEXAS11996
ZapataTEXAS11976
KingsvilleTEXAS11993
La PryorTEXAS11971
HondoTEXAS12025
Catarina 2TEXAS12017
Encinal 2TEXAS12014
Millett 2TEXAS12015

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