BirdAnalyst
Species · BCR 36 · BBS 2025 Release · 1966–2024

Black-tailed Gnatcatcher In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsArid-land birds

Black-tailed Gnatcatcher in Tamaulipan Brushlands has surged: up 105% on the route-weighted index since 1993.

+105%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 →
9Routes 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 →
25YearsYears 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 →

Black-tailed Gnatcatcher has surged in Tamaulipan Brushlands: up 105% on the route-weighted index since 1993.

Forecast

If the recent trend holds, Black-tailed Gnatcatcher in Tamaulipan Brushlands is projected to rise about 519% by 2028 — from 0.06 in 2023 to a central estimate of 0.36 (95% range 0.09–0.64). A 5-year backtest shows a typical error of ±111.1%, with 60% of held-out values landing inside the 95% band.

+519%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 →
0.36Projected 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 →
0.09–0.6495% 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 →
±111.1%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, Black-tailed Gnatcatcher in Tamaulipan Brushlands is projected to rise about 519% by 2028 — from 0.06 in 2023 to a central estimate of 0.36 (95% range 0.09–0.64). A 5-year backtest shows a typical error of ±111.1%, with 60% of held-out values landing inside the 95% band.19712028
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 →
20240.340.070.62
20250.350.070.63
20260.350.080.63
20270.360.080.64
20280.360.090.64

Routes In Tamaulipan Brushlands

Routes recording Black-tailed Gnatcatcher 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 →
GuerraTEXAS42018
Agua NuevaTEXAS12019
EncinalTEXAS12006
CatarinaTEXAS11971
El IndioTEXAS12001
LaredoTEXAS12023
MillettTEXAS12003
Pedro CreekTEXAS12010
Cavasara Cr.TEXAS12013

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