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

Loggerhead Shrike In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Loggerhead Shrike in Tamaulipan Brushlands has surged: up 277% on the route-weighted index since 1976.

+277%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 →
47YearsYears 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 277% 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 fall about 32% by 2029 — from 1.2 in 2024 to a central estimate of 0.79 (95% range 0.16–1.4). A 5-year backtest shows a typical error of ±166.8%, with 60% of held-out values landing inside the 95% band.

-32%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 →
0.79Projected 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 →
0.16–1.495% 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 →
±166.8%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 fall about 32% by 2029 — from 1.2 in 2024 to a central estimate of 0.79 (95% range 0.16–1.4). A 5-year backtest shows a typical error of ±166.8%, with 60% of held-out values landing inside the 95% band.19692029
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 →
20250.750.121.4
20260.760.131.4
20270.770.141.4
20280.780.151.4
20290.790.161.4

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
HeidelbergTEXAS42024
Mirando CityTEXAS22009
La PryorTEXAS22010
RaymondvilleTEXAS22024
El SauzTEXAS22015
ProgresoTEXAS22011
RachalTEXAS12023
RandadoTEXAS12022
EncinalTEXAS11977
George WestTEXAS12024
CatarinaTEXAS12006
HondoTEXAS12019
Catarina 3TEXAS12018
SejitaTEXAS12024
MillettTEXAS11995

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