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Observations by Gary Fewless for Green Bay WI (Lat.N 44.51° Long. W 88.02° ), except as noted. For flowers lacking conspicuous petals or sepals I define "anthesis" as release of pollen by mature anthers.

April 2003

Observations by Gary Fewless, except as noted


Observation (Click on links for photos)
April 30

Pennsylvania sedge (Carex pennsylvanica) in flower (anthesis), UWGB.

Plantain-leaved sedge (Carex plantaginea), Dutchman's breeches (Dicentra cucullaria), and bloodroot (Sanguinaria canadensis) all in flower, Elton, Langlade County (Steve Janke).

Spring-beauty (Claytonia virginica) in full flower; a few Dutchman's Breeches (Dicentra cucullaria) in full flower; an American Toad was seen during the rain showers, Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

Ringed-neck duck male in full breeding plumage, Sora (rails) calling, Brown County, Barkhausen Waterfowl Preserve (Matt Welter).

April 29

White trout-lily (Erythronium albidum) in flower, UWGB.

Tulip-tree (Liriodendron tulipifera) in flower, City of Green Bay. This is strictly a horticultural species in Wisconsin. This is an incidental sighting so I might be a day or two late for the earliest individuals (Gary Fewless).

Yellow-rumped warbler and Brown thrasher, near Mountain, Oconto County (Steve Janke).

Heard a Whip-poor-will early this morning, Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

April 28

Bloodroot (Sanguinaria canadensis) in flower. Also the weedy exotic species field pennycress (Thlaspi arvense) and creeping-Charlie (Glechoma hederacea) are in flower, and Ragwort (Senecio vulgaris) in flower in disturbed soil near buildings UWGB (Gary Fewless).

Palm Warblers and an Eastern Wood-Pewee showed up today, southern Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

Early buttercup (Ranunculus fascicularis) in flower, Brown County, Town of Scott (James P. Moore).

Be alert for new warbler species moving into our area. There are reports of new species in southern Wisconsin and a day like today will move them along quickly.

April 27

Shepherds purse (Capsella bursa-pastoris) in flower, Outagamie County (also 04/28 in Brown County). This species can flower much earlier in warmer, disturbed sites, but this is the first I have seen this year (Gary Fewless).

Dandelion (Taraxacum officinale) now beginning to flower in lawns, away from buildings, curbs, etc. The first flower were noted 04/11 (see below for 0411).

Red-bellied snake basking, Bairds Creek Parkway (Steve Price).

Eastern red cedar (Juniperus virginiana) in flower (anthesis), Brown County, Town of Scott (James P. Moore).

April 26

Long-stalk sedge (Carex pedunculata) in flower (anthesis) our earliest flowering sedge in this area, City of Green Bay (Gary Fewless).

Sweet gale (Myrica gale) in flower (anthesis); Red maple (Acer rubrum) also widely in flower in dry sandy upland forests; rock spike-moss (Selaginella rupestris) releasing spores, Marinette County, (Gary Fewless).

Lake Sturgeon are in the midst of their spring spawning run up the Wolf River. They are protected during the spawning season, because the number of sturgeon has declined and it takes a long time to rebuild the population. Females do not reproduce until the age of about 20 or more, and then they reproduce only at intervals of 4 - 5 years (Gary Fewless).

Visible greening of American currant (Ribes Americanum) and Tatarian Honeysuckle (Lonicera tatarica and hybrids). A careful observer would have noted green from the emerging leaves 12-14 days ago, but this is the point at which even casual observers will remark on the change (Gary Fewless).

April 25

Some of the earliest cottonwoods (Populus deltoides) are in flower (anthesis) City of Green Bay. These are planted trees, on definitely upland sites and probably from nursery stock from outside of the local area. Naturally occurring plants on wetter soils have not begun to flower yet, though, many are close and should start in a day or two (Gary Fewless).

Prairie willow (Salix humilis) in flower (anthesis), UWGB. Last year the same plant flowered 04/17. The average for 15 years is 04/20. The earliest plants of Box Elder (Acer negundo) in flower (anthesis), Allouez and elsewhere in Green Bay area--watch for an increase in "spring colds", that are often unrecognized allergies to spring tree pollen (Gary Fewless).

Large Midge (Chironomidae) swarms present today. 100s of Swallows feeding over fields and prairie, mostly Tree and Barn Swallows though some Cliff Swallows were present. Impressive timing with the Chironomid hatch. Many Tree Swallows quarreling over nest boxes, southern Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler) .

White-throated Sparrows and Slate-colored Juncos are conspicuously absent from the feeders today, and have apparently moved on, Town of Cooperstown, Manitowoc County (Joel Trick).

Yellow-headed blackbirds reported for Oconto County, David Marks.

April 24

Common horsetail (Equisetum arvense) releasing spores, UWGB, Brown County. The average over the last 18 years has been 4/18, the earliest 4/3 and the latest 4/30. (Gary Fewless).

Common Suckers in Mahon Creek to spawn (just a few so far), UWGB (Gary Fewless). 4/19 is average for 12 years of data.

First flowers open on marsh marigold (Caltha palustris).
Also first flowers open on bloodroot (Sanguinaria canadensis), on a
semi-shaded southwest-facing slope. Most other bloodroot plants are
barely emerged in typical locations, Town of Cooperstown, Manitowoc Co (Joel Trick).

A few Bonapart's Gulls present far out on Lake Michigan. Thought I glimpsed a Milbert's Tortoiseshell Butterfly fly by but could not relocate for a confirming ID.
Some Tree Swallows noticed... about 10 to 20, southern Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

Centipede noted at UWGB's Cofrin Arboretum (Matt Welter).

April 23

Wisconsin DNR reports that there is still some ice on lakes in extreme northern Wisconsin, though most of the state now has open water.

Western rock-jasmine (Androsace occidentalis) in flower, Brown County, UWGB. This little plant may be less than an inch tall and still flower. The main part of its range is west of Wisconsin and it favors very dry, unproductive, often sandy sites in full sun. The petals are white and are shorter than the sepals so they are difficult to see without dissecting a flower.

Tamarack (Larix laricina) in flower (anthesis), probably beginning yesterday, Brown County, Barkhausen Waterfowl Preserve (Matt Welter). [These are planted trees on mostly upland sites, so this may be a little earlier than tamarack trees in bogs or swamps. The horticultural species, European Larch (Larix decidua), also began to flower yesterday, City of Green Bay, GF]

Leatherwood (Dirca palustris) in flower (anthesis), Elton, Langlade County (Steve Janke).

This was the last day we saw Tree Sparrows at our feeders, Allouez (Gary Fewless).

Spotted and Blue-spotted salamanders in ponds, wood frogs going strong,
Western Marinette County (Steve Price).

April 22

First flower for Red Maple (Acer rubrum), Town of Hobart, Brown County and Forsythia (Forsythia sp.), City of Green Bay (Gary Fewless).

White-throated sparrow, Lakewood, Oconto County (Steve Janke).

First Brown Thrasher and Ruddy Duck, Barkhausen Waterfowl Preserve, Brown County (Matt Welter).

Blue-gray Gnatcatchers have arrived along with many more Yellow-rumped Warblers. Common Garter Snakes copulating, southern Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

White Pelican's have returned to Green Bay, though I'm not sure when they first arrived --they have been in southern WI since at least the 18th (Gary Fewless).

Pine cones snapping and popping as they open, Veterans Park, near Broadway District, City of Green Bay (Matt Welter).

April 20

Sharp-lobed hepatica (Anemone acutiloba, previously Hepatica acutiloba) in flower, City of Green Bay (Gary Fewless).

A large group of Northern Flickers moved through. There was also an increase in Hermit Thrushes and Brown Creepers. Less abundant were Winter Wrens, White-throated Sparrows, Yellow-rumped Warblers and a single Swamp Sparrow. Also a Canada Goose sitting on eggs, southern Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

A Caspian Tern hunting over the harbor. Also noticed a blooming Dandelion. City of Manitowoc (Rhonda Reisenbuechler).

Galerina autumnalis (fungus) cluster on stump. First Tree Swallows, Northern Shovelers, Hermit Thrushes, Heckrodt Nature Center, Appleton (Matt Welter).

April 19

Eastern Towhee, Rock County (Andy Paulios).

A large group of White-throated Sparrows first appeared at our feeders today. Only a few Fox Sparrows still evident, after having been quite common for the past 2 weeks, Town of Cooperstown, Manitowoc County (Joel Trick).

April 18

Wild leek (Allium tricoccum), Virginia Waterleaf (Hydrophyllum virginianum) and Spring Beauty (Claytonia virginica) have all emerged in woods, seemingly overnight. Largest leeks ~4" tall, Town of Cooperstown, Manitowoc County (Joel Trick).

White Pelican, Bonaparte's Gull, Sora all returned to Rock
County (Andy Paulios).

April 17 Another ice storm in Green Bay over the last 2 days leaves everything coated in ice, UWGB . The impact on some wildlife could be severe (Gary Fewless). In spite of the cold and ice, there are some very green lawns in the City of Green Bay.
April 16

At least 19 whooping cranes have returned to Wisconsin from their winter grounds in Florida (the first returned March 25). The cranes were reintroduced into the wild in 2001 and 2002 in a large project designed to re-establish this very rare species in the eastern United States. Whooping cranes were saved from extinction by captive breeding programs and these released birds were escorted to Florida by ultralight aircraft in each of the last two Falls to establish their migration patterns. The success of this program rests in years of meticulous work by many people and the combined efforts of many organizations including the Wisconsin-based International Crane Foundation, U.S. Fish and Wildlife Service, the Wisconsin Department of Natural Resources and others, under the banner of Whooping Crane Eastern Partnership. More information can be found at:

Yellow-rumped Warblers, Blue-gray Gnatcatchers return, Rock County (Andy Paulios).

First sightings for Northern Rough-winged Swallow, Barn Swallow, and
White-throated Sparrow, Rock County (Andy Paulios).

April 15

Another hot day in Green Bay. The high temperature reached 82F before beginning to fall later in the day (Gary Fewless).

First flower (anthesis) American Elm (Ulmus americana), UWGB The average first flowering date for this tree over the last 18 years is April 13, the earliest date was March 25 (2000) and the latest April 24 (1993) (Gary Fewless).

First flower (anthesis) Pussy Willow (Salix discolor), UWGB. The average date of first flower over the last 18 years is April 14, the earliest was March 28 (2000) and the latest was April 27 (1993) (Gary Fewless).

Common Snipe, Pt au Sauble, Brown County (Amy Wolf).

Hepatica in bloom, Louisiana Waterthrushes are back, Baxter's Hollow, Sauk County (Andy Paulios).

Garter Snakes , Juneau County (Andy Paulios) .

Garter Snakes and Northern Leopard Frogs out and about (Leopard
frogs not calling yet though) Peshtigo Harbor, Marinette Co., WI (Steve Price).

Green Darners ovipositing eggs, Juneau County (Andy Paulios)

April 14

Green Bay reached a high temperature of 81 F today, Stevens Point 86 and Clintonville 88F! All were record highs for the date, along with many others in the 80's . Green Bay's previous record high for this date was 77F in 1941 (Gary Fewless).

First flower (anthesis) Siberian Elm (Ulmus pumila), and Big-tooth Aspen (Populus grandidentata) UWGB (Gary Fewless).

Yellow-rumped Warbler, City Green Bay (Amy Wolf).

First Flicker, Pied-billed Grebe and Fox sparrow, Pike's Creek, Bayfield County (Matt Welter).

Chorus frog in full chorus, the Buffalo Ranch north of Merrill, Lincoln County (Matt Welter).

Green Darners flying, UWGB's Cofrin Arboretum (Ron Eichhorn).

April 13 First water beetles, Bayfield County (Matt Welter).
April 12

Trembling aspen (Populus tremuloides) has begun to flower (first anthesis--release of pollen), UWGB and several other locations in Brown County.

The first male blue-spotted salamanders (Ambystoma laterale)
have entered breeding ponds, Peshtigo Harbor Area, Marinette Co., WI (Steve Price).

April 11

First open flower of dandelion (Taraxacum officinale) and chickweed (Stellaria media), UWGB. These are extreme sites on a south facing slope, at the base of a brick wall. They flower much earlier than the average lawn dandelion because the soil warms up earlier due to extra heat reflected from the wall and perhaps even some heat transmitted from the inside of the building . The next early site for dandelions is often a few scattered plants right at the edge of curbs along lawns--again benefitting from extra heat from the adjacent concrete (Gary Fewless).

Spring Peepers and Wood Frogs calling, Pensaukee, Oconto County (Tom Erdman).

First Spring Peepers and Wood Frogs calling,Town of Cooperstown, Manitowoc Co (Joel Trick).

Spring Peepers and Wood Frogs calling, Peshtigo Harbor, Marinette County (Steve Price).

First midge hatch, first Yellow-bellied Sapsucker, DePere,
Brown County (Matt Welter).

April 10

First Belted Kingfisher, UWGB (Amy Wolf).

First Theridion sp. spider (small cobweb spider--4 mm long), DePere, Brown County (Matt Welter).

First wood frogs calling, Barkhausen (Matt Welter).

April 9

Prairie Pond is still frozen over at 11 am, UWGB, as are all ponds on UWGB. Temperatures are expected to rise into the 50's so this should be near the end of the ice cover. There is still conspicuous snow cover over much of our area (G. Fewless) and the soil is still frozen.

First Winter Wren, Pike's Creek, Bayfield County (Matt Welter).

April 8

Vesper Sparrow, Rock County (Andy Paulios).

Prairie Pond in UWGB's Cofrin Arboretum is still frozen over (Gary Fewless).

April 6

Double-crested Cormorant, Hermit Thrush, Common Loon,
Ruby-crowned Kinglet arrivals, Rock County (Andy Paulios).

Green Bay's low temperature of 12 F this morning should be a new record for this date. The average low for this time of year is about 32 F. This is the third consecutive day for which the low temperatures have been below 20 F. Prairie Pond in UWGB's Cofrin Arboretum is frozen (Gary Fewless).

April 5

Green Bay received a total of 5 inches of snow, last night and today. Rhinelander received 7 inches and the TV weather reported some sites as high as 10 inches in NE Wisconsin.

The Army Corps of Engineers reports the water level in Lake Michigan is down 10.3 inches compared to this time last year. This is the lowest water level in Lake Michigan since March of 1965, and is only about 6 inches above the lowest level previously recorded, in March of 1964. The low water has exposed a broad zone of lakebed along southern and western shores of Green Bay. The fluctuating water levels cause problems for commercial shipping and recreational boaters. Fluctuations in water level result from the balance between precipitation and evaporation over the area of the lake basin. Precipitation in the Lake Michigan basin during the last 12 months was about 84% of the long term average, and mild winters have led to increased evaporation. Fluctuating water levels are an important component of retaining biodiversity in the Green Bay ecosystem (Gary Fewless).

First Great Blue Heron. Waxy paper thin covers of tamarack buds have blown off revealing fresh green of needles soon to grow. Coots walking on ice, unable to submerge in the refrozen ice. Crows pestering a Red-tailed Hawk for a vole. The ice covering from the recent storm has made food scarce, Barkhausen Waterfowl Preserve, Brown County (Matt Welter).

April 4

Sleet, freezing rain and a little snow overnight and continuing into the morning. The forecast includes the possibility of 4-8 inches of snow later today. Ah, springtime. Secondary roads are extremely slippery and there is a thick coating of ice on just about everything, including these plants at UWGB: a red pine, white oak, and even the grass, which crunches like broken glass when walked upon (Gary Fewless).

The ice and snow has brought numerous birds to our feeders
throughout the day, including our first Yellow-bellied Sapsuckers, and
first female Red-winged Blackbirds of the year. Juncos are abundant
today, with at least 60 seen at one time, Town of Cooperstown, Manitowoc Co (Joel Trick).

April 3

Osprey, Red-breasted Merganser, Western Chorus Frog, Spring
, and Leopard Frogs all singing, Rock County, Gibbs Lake ( Andy Paulios).

There have been several reports of conspicuous mortality of frogs this spring, perhaps due to the low water levels and the very cold late winter/early spring weather.

Sleet and freezing rain throughout northeastern Wisconsin today with an ice storm warning through tonight. Noon temperatures ranged from 24 - 27 F for much of NEWIS, to 29 at Green Bay (Gary Fewless).

April 2

First turkey vulture observed, Town of Cooperstown, Manitowoc County (Joel Trick).

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Last updated on May 20, 2015