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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 2004

Observations by Gary Fewless, except as noted

Date Observation (Click on links for photos)
Apr 30

In spite of the cooler weather today there are several new species in flower: Ribes rubrum (cherry-currant), Ribes odoratum (golden currant, just a few open flowers), Fraxinus pennsylvanica (green ash), and one fully open flower of Trillium grandiflorum (big white trillium). I have annecdotal reports of a few trilliums in flower as early as April 28, but I did not see any until today. The 19 year average for first flowering date of this population of Trillium is May 3, UWGB (Gary Fewless).

Apr 29

Numerous yellow-rumped warblers following a heavy migration last night; saw our first white-crowned sparrows of the year, Baltimore Oriole, orchard oriole, rose-breasted grosbeak, palm warbler. Many flowers open on Erythronium americanum (yellow trout-lily) and Dentaria laciniata (cut-leaved toothwort), a few open flowers of Trillium grandiflorum (big white trillium). Many cabbage butterflies seen this afternoon as well. We had a great temperature drop following passage of the front today, going from 75 at 5:25 PM, to 51 at 6:00, and 45 by 7:00. Town of Cooperstown, Manitowoc County (Joel Trick).

Amelanchier arborea (juneberry) is in flower in the courtyard of MAC Hall, UWGB (Vicki Medland). Also flowering in the courtyard are Vaccinium angustifolium (blueberry) and Waldsteinia fragarioides (barren strawberry). I am not aware of any other individuals of these species flowering yet at other locations. The courtyard provides a warmer environment so the plants can develop earlier than others in natural habitats.

Betula papyrifera (paper birch) in flower (anthesis), UWGB.

Cabbage butterflies flying at UWGB, and elsewhere in Brown County.

Apr 28

New species in flower today: Ranunculus hispidus (swamp buttercup), Ribes cynosbati (gooseberry) and Veronica arvensis (corn speedwell), Lamium amplexicaule (henbit), UWGB.

Populus tremuloides (quaking aspen) leaves are now large enough to give the canopy a slightly green aspect from a distance, UWGB.

First Question Mark butterfly seen on UWGB campus.

First gray treefrogs calling this evening; also many American toads, Town of Cooperstown, Manitowoc County (Joel Trick).

Green heron near the East River, Village of Allouez, Brown County (Joel Trick).

Bumblebees (Apidae: Bombus sp.) flying. Also, I'm pretty sure I saw a six spotted tiger beetle (Cicindelidae:Cicindela sexguttata) on a pile of soil near the language house on campus. I didn't get a second look, though, Cofrin Arboretum UWGB, (Mike Draney).

Apr 27

Thlaspi arvense (field penny-cress) in flower, UWGB.

Gypsy moths hatching in DePere, Brown Co.

This morning's low temperature was 29°F in Green Bay.

Apr 26 Light rain and a little hail in the morning at UWGB.
Apr 25

Acer platanoides (Norway maple, cultivated individual) began flowering on UWGB today on a tree that has been monitored for 19 years. The average for 19 years is April 30, the earliest was April 18 and the latest was May 15. Some individuals in the City of Green Bay were in flower a day or two before, I think.

Anemone Quinquefolia, Dentaria diphylla, Erythronium americanum in flower, UWGB.

Apr 23 American robin nest with 2 eggs, Town of Cooperstown, Manitowoc County (Joel Trick).
Apr 20 Larix decidua (European Larch, cultivated) in flower (anthesis), Viola conspersa (Dog violet), Erythronium albidum (White trout-lily), Euphorbia cyparissias (Cypress spurge) in flower, UWGB. These flowering dates are within 3-4 days of the earliest dates recorded in the last 19 years.
Apr 19

Glechoma hederacea (gill-over-the-ground ), Dentaria laciniata (cut-leaved toothwort) in flower, UWGB. The dates of the last few days are about 10 days earlier than last year for the same items--even more for some.

First day for toads "singing" on UWGB, Prairie Pond. In most years they don't start this breeding period until early May on this pond.

Acer negundo (box elder) and Populus deltoides (cottonwood) widely in flower in city of Green Bay.

Apr 18

Capsella bursa-pastoris (shepherd's purse), Sanguinaria canadensis (bloodroot), Carex pedunculata (long-stalk sedge ), Carex pensylvanica (Pennsylvania sedge), Cardamine douglassii (purple spring-cress, only one plant in flower) all in flower, UWGB.

Acer negundo (box elder) and Forsythia sp. (Forsythia, cultivated) in flower, Allouez, Brown County.

Lemna minor (common duckweed) growing vigorously on stagnant pools, Brown County.

Lonicera xbella, (showy bush honeysuckle) and Ribes americanum (American black currant) are both beginning to leaf-out, giving a light green cast to woods where they are common. Lonicera xbella is an invasive species that displaces native plants. Ribes americanum is native.

Our first chipping sparrow seen today; many open flowers on
(Claytonia virginica) spring beauties and (Sanguinaria canadensis) bloodroot, Town of Cooperstown, Manitowoc County (Joel Trick).

Barbarea verna (

Apr 17

Populus deltoides (cottonwood), Salix humilis (prairie willow), Juniperus chinensis (Chinese juniper, anthesis, cultivated) in flower, UWGB.

Hepatica acutiloba (sharp-lobed hepatica) in flower, several locations in Brown County; Draba verna (spring whitlow-grass) in flower, probably for several days by the time I noticed it, Brown County, Town of Green Bay.

Dicentra cucullaria (Dutchman's-breeches) in flower, Brown County, Town of Scott (Kathey Groves).

Isopyrum biternatum (false rue-anemone) in flower, Calumet County (Katie Hemauer).

Suckers (fish) in Mahon Creek to spawn, UWGB.

Lake Sturgeon are spawning in the Wolf River, Shiocton. They began during the last week, I think, since we saw none there last Saturday (Apr 10).

First broad-winged hawk seen; many migrating turkey vultures
today, City of Green Bay, Brown County (Joel Trick)

Apr 16

Equisetum arvense (Common horsetail) dispersing spores; Acer rubrum (red maple) in flower (anthesis), UWGB.

Sanguinaria canadensis (bloodroot) in flower, Shawano (Joel Whitehouse)

Dragonfly (large, blue) flying, UWGB (Katie Hemauer).

Winter Wrens, Baird's Creek Parkway, Brown Co., WI (Steve Price).

Apr 15

Yellow-headed Blackbird males, Barn Swallows, Belted Kingfisher, Sensiba Wildlife Area, Brown County (Heather Gentry).

Eastern Pheobe, Field Sparrow and Eastern Meadowlark heard
singing on the Cofrin Arboretum,UWGB Campus, Brown Co (Steve Price)

Apr 14

Populus grandidentata (big-tooth aspen), Ulmus americana (American elm) and the earliest individuals of Caltha palustris (marsh marigold) in flower today, UWGB. The Caltha plants are in areas with springs and usually flower at least a week before plants in other sites. Ulmus americana flowers have been swollen for two weeks or more and the anthers had been exserted for 4-5 days, but today is the first day that pollen was released (anthesis).

Field Sparrow, Town of Cooperstown, Manitowoc County (Joel Trick).

Apr 13

First few flowering plants of Claytonia virginica (spring beauty), on open, south-facing slope, Brown County.

Garter Snake, Brown County.

Apr 11

Several northern Leopard Frogs (Rana pipiens)calling at Bayshore Pond,
UWGB Cofrin Arboretum (Steve Price).

Light snow in Green Bay.

Two Great Egrets, East River, Brown County.

Purple Martins, Calumet County (Katie Hemauer).

Apr 10

Light snow in Green Bay (0.6 inches at the NOAA weather station) enough to make roofs white very early in the morning.

Ulmus pumila (Siberian elm) in flower (anthesis), UWGB.

Apr 09 Salix discolor (Pussy Willow) in flower (anthesis); new leaves of Ribes americanum (American black currant) are beginning to emerge, UWGB.
Apr 08

Androsace occidentalis (Rock-jasmine) in flower, UWGB.

Apr 07

Senecio vulgaris (common groundsel) in flower, UWGB. This is a fairly common weed in the City of Green Bay.

WIS DNR reports there is still ice on some northern lakes and there are still people ice fishing, although the ice is deteriorating quickly. There is also some snow left in northern forests, especially where shaded.

There is still snow in Door County, Bailey's Harbor, in forested areas and where it had drifted or been piled deeply during the winter.

Dry conditions have led to several grass fires in northern Wisconsin.

Apr 06 Wood frogs and Spring Peepers calling, Pensaukee (Tom Erdman)
Apr 04

Male Bluebird, UW-Green Bay's Cofrin Arboretum (Paul Sager).

First tiger salamanders seen; two adult males in shallow water, Point Pond, near Iola, Waupaca County (Peter Lembcke).

Wood frogs calling, Kewaunee County, (Pete Wolter).

Apr 01

Stellaria media (chickweed) and Taraxacum officinale (dandelion) in flower--earliest plants, on south facing lawn next to brick wall; the first open flowers (anthesis) of Populus tremuloides (quaking aspen), UWGB.

First northern flicker calling in our woods. Town of Cooperstown, Manitowoc County (Joel Trick).

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Last updated on May 20, 2015