April phenology

By Sylvia Marek

Baby great horned owl

Phenology is a science focused on observing and recording biological events from year to year and their relationships to the change of seasons and climate.

These are the “normal” phenology events we expect to see here and in the Madison area this month. We would love to hear about what you are seeing on the grounds of Holy Wisdom Monastery. Please comment on this post with what you are observing, where at Holy Wisdom and the date you observed the event.

No month ends or begins overnight. Events can be a few weeks early or late.

“For lo, the winter is past, the rain is over and gone; the flowers appear on the earth; the time of the singing of the bird is come…”    Song of Solomon

General

• Thirteen hours of daylight
• April showers, growing season, flowers bloom
• Possibility of snow

Birds

• Aerial skydance of woodcock continues at dawn and dusk
• Sandhill crane count
• Nesting season—many species build nests, lay eggs and raise young (sandhill crane, bald eagle, red-tailed hawk, Canada geese, mallard, wood duck, robin, cardinal, bluebird, mourning dove, house wren, chickadee and tree swallow)
• Look for great horned owl and barred owl babies in their nests. Screech owls lay eggs in cavities.
• Winter visitors depart—junco, tree sparrow, brown creeper, red-breasted nuthatch, pine siskin, purple finch, snowy owl, saw-whet owl and rough-legged hawk

Migrants arrive from the south—some of them include:

• Field, fox, white-throated, white-crowned, song and chipping sparrows
• Tree, barn, cliff, rough-wing and bank sparrows
• Purple Martin, house and winter wren
• Yellow-bellied sapsucker, ruby-crowned kinglet, Eastern townee, brown thrasher, catbird, hermit thrush, flicker, shorebirds, great blue heron, waterfowl
• Early warblers such as yellow-rumped, palm, black and white, orange-crowned, yellow and pine
• Some will stay others will go north to breed
• Many songbirds migrate during the night, listen for their “seep, cheep, chirp” call notes overhead

Mammals

• Arrival of little and big brown bat
• Chipmunk activity increases
• Coyote pups, mink kits, eastern cottontail rabbits and deer mice are born
• Male deer start growing antlers

Insects 

• Arrival of green darner dragonflies
• Black swallowtail butterflies emerge from chrysalids
• Other butterflies to look for include cabbage white, spring azure, mourning cloak, red admiral, painted lady, question mark and comma
• Many bee species are active
• Queen bumblebees make nursery nests
• Paper wasps active
• Spittle bugs on plants
• Water striders and aquatic insects are active
• Earthworms are active
• First biting mosquitoes
• Deer/bear/wood tick season (take precaution)

Plants

• Green grass
• Fern fiddleheads appear and unfurl
• Flowers bloom—dandelions, creeping Charlie and violets
• On prairies—pasque, prairie smoke, prairie buttercup, birdsfoot violet, puccoon, rock cress and pussy toes
• In woodlands—hepatica, spring beauty, Dutchman’s breeches, toothwort, bloodroot, trout lily, rue, false and wood anemone, bellwort, Virginia bluebell and trillium
• In wetlands—marsh marigold
• Trees and shrubs in bloom—chokecherry, American wild plum, serviceberry, red maple, oak, red bud, red-berried elderberry, hazelnut and pussy willow

Other events

• Frogs call—wood, chorus, spring peeper, northern leopard, and pickerel, tree and copes
• Toads start to call usually near the end of the month
• Turtles out in the sun
• Eastern garter snake active

Sylvia Marek is a highly trained and experienced naturalist. She works for the University of Wisconsin Arboretum and is a first rate birder.

Please share the biological events you notice while at Holy Wisdom Monastery below (remember to include what you see, where and when).