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

Loggerhead Shrike In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGrassland birds

Loggerhead Shrike in Tamaulipan Brushlands has surged: up 414% on the route-weighted index since 1976.

+414%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 →
16Routes 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 →
48YearsYears 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 →

Loggerhead Shrike has surged in Tamaulipan Brushlands: up 414% on the route-weighted index since 1976.

Loggerhead Shrike In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Loggerhead Shrike in Tamaulipan Brushlands is projected to stay roughly flat through 2030, near 0.80 (95% range 0.17–1.4). A 5-year backtest shows a typical error of ±176.9%, with 80% of held-out values landing inside the 95% band.

+10%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 →
0.80Projected 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 →
0.17–1.495% 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 →
±176.9%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, Loggerhead Shrike in Tamaulipan Brushlands is projected to stay roughly flat through 2030, near 0.80 (95% range 0.17–1.4). A 5-year backtest shows a typical error of ±176.9%, with 80% of held-out values landing inside the 95% band.19692030
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 →
20260.760.141.4
20270.770.141.4
20280.780.151.4
20290.790.171.4
20300.800.171.4

Routes In Tamaulipan Brushlands

Routes recording Loggerhead Shrike 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 →
KingsvilleTEXAS62024
RaymondvilleTEXAS62025
HeidelbergTEXAS42024
Mirando CityTEXAS22009
La PryorTEXAS22010
El SauzTEXAS22015
ProgresoTEXAS22011
RachalTEXAS12025
RandadoTEXAS12022
EncinalTEXAS11977
George WestTEXAS12024
CatarinaTEXAS12006
HondoTEXAS12025
Catarina 3TEXAS12018
SejitaTEXAS12024
MillettTEXAS11995

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