BirdAnalyst
BBS Route · Wisconsin · BCR 12

Union Twp Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 143 species recorded across 56 survey years, still active.

143Species RecordedSpecies recordedDistinct species detected on standard-protocol BBS runs here across all years on record — a measure of survey breadth, not a complete checklist.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1966–2024Span
5Observers

Bird Species Found on Wisconsin Union Twp

Top 40 of 143 species by most recent count. Each links to its species trend.

Species recorded on the Union Twp route.
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 →TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →History
Red-eyed VireoVireonidae992024+800%1969
Eastern TowheePasserellidae612024+85%1968
OvenbirdParulidae482024+97%1968
Canada GooseAnatidae422024+190%1973
American RobinTurdidae392024+325%1968
VeeryTurdidae39202423×1970
American CrowCorvidae352024-33%1968
Blue JayCorvidae322024+5%1968
Chestnut-sided WarblerParulidae322024+111%1977
Mourning DoveColumbidae282024+76%1968
Chipping SparrowPasserellidae272024+327%1968
Scarlet TanagerCardinalidae262024+71%1968
Gray CatbirdMimidae252024+141%1968
Black-capped ChickadeeParidae242024+135%1968
Brown-headed CowbirdIcteridae232024+35%1968
Field SparrowPasserellidae152024-37%1969
American RedstartParulidae152024+920%1978
Eastern Wood-PeweeTyrannidae142024-14%1968
Common GrackleIcteridae14202412×1977
Indigo BuntingCardinalidae142024+50%1968
Cedar WaxwingBombycillidae142024+108%1970
Blue-winged TealAnatidae121987n/an/a
Common RavenCorvidae112024+467%1979
Least FlycatcherTyrannidae102024+100%1968
Red-winged BlackbirdIcteridae102024+86%1968
Common YellowthroatParulidae102024-6%1968
White-breasted NuthatchSittidae10202411×1973
Eastern BluebirdTurdidae102024-30%1968
Pine WarblerParulidae102024+380%1977
Hermit ThrushTurdidae102024+35%1977
White-winged CrossbillFringillidae102008+400%1977
American GoldfinchFringillidae82024+233%1968
Song SparrowPasserellidae82024+171%1968
Tree SwallowHirundinidae82024+329%1970
Red-breasted NuthatchSittidae82024+700%1982
Eastern PhoebeTyrannidae72024+220%1968
Black-and-white WarblerParulidae72024+280%1989
Ruby-throated HummingbirdTrochilidae72024+300%1982
Vesper SparrowPasserellidae62024+17%1974
Rose-breasted GrosbeakCardinalidae62024-31%1968

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. A route is a sample, not a census.