Lake Michigan Lacustrine Clay Plain

Monarch butterflies were observed on 2026-10-14 at two locations in the Milwaukee area during their fall migration. The species is proposed for federal Threatened status, adding regulatory weight to sightings that document the migratory population passing through the Lake Michigan Plain during peak southbound movement in mid-October.

Eastern redbud showed ripe fruits and recent fruit drop on 2026-10-13 in the region, with observations continuing through early October in Franklin. This native tree planted as an ornamental enters late-season fruit maturation in early October, providing seed resources for songbirds during fall migration.

Common buckthorn was recorded at Minooka Park and W Huntington Dr in Mequon on 2026-10-18, continuing its presence through mid-October as fruit enters peak ripeness when birds consume and disperse the black berries. The introduced species persists widely distributed across the Milwaukee region during this critical dispersal window.

New England aster was recorded in flower at Minooka Park on 2026-10-18, well into mid-October across multiple Milwaukee area locations. This native perennial normally peaks bloom in early October; its extended flowering may be sustained by mean temperatures 3.3°F above normal for highs and 5.6°F above normal for lows over the past month, which lengthens the fall season.

A mayfly species, Red Speckled Dun (Callibaetis ferrugineus), was recorded on 2026-09-08 in Wauwatosa. Mayfly larvae are pollution-sensitive indicators requiring clean, well-oxygenated water.

Caddisflies (Trichoptera) including Great Autumn Brown Sedges (Pycnopsyche) were observed on 2026-09-12 in Grafton. These aquatic insect larvae are bioindicators of clean flow conditions.

Chinook Salmon were recorded moving into the Milwaukee River on 2026-10-02 and 2026-09-30 during the fall spawning run. Chinook migration into Milwaukee-area tributaries peaks in September and October, with water temperature at 16.2°C on 2026-10-05, within the suitable range for migration.

Golden Northern Bumble Bee was observed on 2026-10-02 in Milwaukee, a federally Threatened species and increasingly rare forager. Its October presence reflects late-season resource use or possible nesting activity in urban habitat. With no written profile available, this sighting documents the species' occurrence and phenology in the Lake Michigan Plain region.

New England aster was recorded in flower 12 times in the past week across the Milwaukee area, with the most recent sighting on 2026-10-03. This native fall-flowering perennial reaches peak bloom in early October, providing critical late-season nectar and seed resources for migrating wildlife as temperatures cool.

Common buckthorn was recorded 6 times in the past week, with the most recent sighting on 2026-10-04 in Hales Corners. This introduced shrub enters peak fruit ripeness in early fall, when birds consume and disperse the black berries that enable its continued spread across the region.