BirdAnalyst
Species · New Jersey · BBS 2025 Release · 1966–2024

Carolina Wren Population Trend in New Jersey

All statesForest birds

Carolina Wren in New Jersey has surged: up 54× on the route-weighted index since 1968.

54×Since 1968TrendPercent 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 →
42Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Carolina Wren Trends in New JerseyNotable 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 New Jersey: up 54× on the route-weighted index since 1968.

Carolina Wren Population Forecast in New Jersey

If the recent trend holds, Carolina Wren in New Jersey is projected to fall about 19% by 2029 — from 16 in 2024 to a central estimate of 13 (95% range 8.7–18). A 5-year backtest shows a typical error of ±31.3%, with 20% of held-out values landing inside the 95% band.

-19%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 →
13Projected 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 →
8.7–1895% 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 →
±31.3%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 New Jersey is projected to fall about 19% by 2029 — from 16 in 2024 to a central estimate of 13 (95% range 8.7–18). A 5-year backtest shows a typical error of ±31.3%, with 20% of held-out values landing inside the 95% band.19662029
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 →
2025127.717
2026138.017
2027138.218
2028138.518
2029138.718

Carolina Wren Survey Routes in New Jersey

Routes recording Carolina Wren in New Jersey.
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 →
Cape May Ch6220131992
Woodbury Hgt3720241968
Pedricktown 23420242013
Six Points3220241980
Croton 23120242008
Pedricktown2920121991
Ramseysburg2720241995
Sandbrook2420241974
Kemah Lake2320241986
Bennett Mill 22120242016
Del Haven1919911991
New Bedford1920241969
Greenwich1820241968
Dover1620231990
Winslow1620241989
Gillette1420241991
Roosevelt1420221986
Pomona1420241978
Croton1320071975
Albion1220221966
Holmansville1120091971
Bloomsbury1120241976
Ocean City1020221995
Keyport920221990
Deepwater619761969

Carolina Wren Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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