BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Mexican Jay In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Mexican Jay in Sierra Madre Occidental has fallen sharply: down 53% on the route-weighted index since 1970.

-53%Since 1970TrendPercent 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 →
56YearsYears 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 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 →

Mexican Jay has fallen sharply in Sierra Madre Occidental: down 53% on the route-weighted index since 1970.

Mexican Jay In Sierra Madre Occidental Population Forecast

If the recent trend holds, Mexican Jay in Sierra Madre Occidental is projected to fall about 36% by 2029 — from 3.7 in 2024 to a central estimate of 2.4 (95% range 0.00–12). A 5-year backtest shows a typical error of ±20.1%, with 100% of held-out values landing inside the 95% band.

-36%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 →
2.4Projected 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 →
0.00–1295% 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 →
±20.1%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, Mexican Jay in Sierra Madre Occidental is projected to fall about 36% by 2029 — from 3.7 in 2024 to a central estimate of 2.4 (95% range 0.00–12). A 5-year backtest shows a typical error of ±20.1%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20253.20.0013
20263.00.0013
20272.80.0012
20282.60.0012
20292.40.0012

Routes In Sierra Madre Occidental

Routes recording Mexican Jay in Sierra Madre Occidental.
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 →
RuckerARIZONA942009
DragoonARIZONA692009
PortalARIZONA322024
Tonto Vill.ARIZONA202021
PatagoniaARIZONA172024
SunizonaARIZONA141997
Peña BlancaARIZONA132024
Aztec PeakARIZONA81978
Carr MtnARIZONA82022
Forest LakesARIZONA62016
Sunizona 2ARIZONA52024
BlueARIZONA41989
SprucedaleARIZONA42023
Emory PassNEW-MEXICO41994
RedingtonARIZONA22023
Mt. GrahamARIZONA12022

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