Afton State Park Phenology, March 26, 2021

Birds on the move, flowers ready to bloom, maple trees budding, and a full moon.




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St. Croix River view from Afton State Park, March 31, 2012 (Brett Whaley/Flickr)

Note: Nina Manzi is a long-time volunteer at Afton State Park who has long recorded and shared seasonal observations at the visitor’s center. Due to COVID closures, St. Croix 360 is publishing her updates when possible. Thank you, Nina!


Sunday, March 28 is the Full Worm Moon, marking the time of year where saturating rains drive worms to the surface of the soil in search of oxygen. In the morning before sunrise look for Jupiter and Saturn in the eastern sky.


As days get longer and warmer, more and more species of birds make their way north to Afton for the summer. Watch for turkey vultures gliding high overhead, and on the prairie look for meadowlarks, song sparrows, and tree swallows. Tree swallows often use bluebird boxes, which is one reason bluebird boxes are often set out in pairs. Tree swallows are very territorial. Once they occupy one of a pair of bluebird boxes, they won’t tolerate another tree swallow couple taking up residence next door, leaving the second bluebird box available for . . . bluebirds!

Many species of birds move north as the ice goes out on rivers and lakes. Loons, pelicans and sandpipers are all likely to continue farther north, though some may stay in the general area of Afton. Loons are more likely to summer on lakes, but as they move north you may see them on the St. Croix River. Look for sandpipers along the edges of Trout Brook near where it meets the St.Croix. And watch overhead for pelicans! The American White Pelican is one of the largest birds in North America, with a wingspan of up to nine feet. When you see flocks of pelicans overhead they are easy to identify – very large white birds with black on their wings. Watch them for a while and sometimes the flock will turn sideways and all the birds seem to disappear!

Amphibians and Reptiles

Snakes have spent the winter curled up together in their hibernaculae, and turtles have burrowed into the mud at the bottom of ponds and along riverbanks. As the weather warms up look for snakes and turtles basking in the sun. Two kinds of snakes you might see at Afton are Bull Snakes and Garter Snakes. Two kinds of turtles are Painted Turtles and Snapping Turtles.


Hepatica leaves are poking up from under the leaf litter, and should produce blossoms soon. Hepaticas are usually the first of the spring ephemeral wildflowers to bloom. They are called “hepaticas” because their three-lobed leaves are shaped like a liver – “hepar” means “liver” in Greek. Bloodroots also bloom very early. Bloodroot takes its name from its reddish orange stems that extend underground. These two “spring ephemerals” and others live in the hardwood forests and bloom before the trees have leafed out, when sunlight reaches the forest floor. Look for them in the woods at Afton.


Maples trees have bloomed, marking an end to maple syrup season. The flowers are very small, and blow down in the wind and rain. Look for them on the ground. Maple trees drop their leaves in fall, but you may find some around them on the ground.

Weather observations

Here are some weather observations for this time period from past years.

Friday, March 262007: record high of 81°
Saturday, March 272016: light rain
Sunday, March 282020: thunder and lightning in evening
Monday, March 292010: breezy with high in the 60s
Tuesday, March 302014: high of 60°, first 60° reading since previous October
Wednesday, March 312008: wet heavy snowfall, 5.5 inches at the airport.
Thursday, April 12002: record snowfall of 4.6 inches; 2015: record high of 84°

Photo credits: All photos copyright Nina Manzi, except:

  • Dean Lokken: Meadowlark, Snapping Turtle, Turkey Vulture
  • Gary Sater: Common Loon, Song Sparrow


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Afton State Park Phenology, March 26, 2021