Afton State Park phenology, October 13 to 19

View of St. Croix River from Afton State Park (Iain Campbell/Flickr)

Astronomy

On Saturday the 14th there will be an annular solar eclipse, also called a “ring of fire”
eclipse. In this kind of eclipse the disk of the sun is not fully covered by the moon, so that a ring of light remains visible around the darkened center. Totality will be visible from parts of Oregon, Nevada, Utah, and Texas; here in Minnesota we will see the spectacle as a partial eclipse. Use eye protection or an indirect viewing method. One nifty way to “see” eclipses is to use a kitchen colander. Hold the colander up so that sunlight shines through the holes, and watch shadows creep across all the little
circles of light. The eclipse will start at about 10:30 a.m. Central time, and last until about 1:00 p.m, reaching maximum at about noon.

Birds

Migration continues. Late-flying warblers trickle through heading south, including Yellow-rumped Warblers and American redstarts. Ducks and Geese follow the St. Croix flyway, and many will linger in this area as long as there is open water. Robins have formed flocks – some will travel farther south, while others will stay in this area through the winter. Watch for them moving through the trees like ghosts when you hike. The Robins who stay all winter will shift from eating insects to eating fruit, like crab apples and mountain ash berries.

Mammals

Rabbits are plentiful at Afton, and they remain active all winter long. They are most active at dawn and dusk, when the temperatures tend to be milder and when they can move about without attracting too much attention from predators. For much of the day and night they shelter in brush piles, under evergreen trees or in hollow stumps. In the winter their diet switches from grasses, which are often buried by snow, to tree bark, twigs, and . . . their own poop! Rabbits have inefficient digestive tracts so they can extract more calories from their droppings by eating them. The practice of eating poop is called “coprophagy”.

Insects

Mourning Cloak and Eastern Comma butterflies both overwinter as adults, hiding under leaves or tree bark and becoming active on mild days. What about Red Admirals? Red Admirals to the north of our area migrate south for the winter. Red Admirals to our south overwinter locally as adults. It’s likely that some of the Red Admirals at Afton overwinter here, while others go south. Have you seen any Red Admirals at Afton on mild fall or winter days?

Plants

In the woods look for the fruits of early-blooming wildflowers. Jack-in-the-Pulpit and False Solomon’s Seal both have bright red berries, Upright Carrion Flower has deep blue berries, and Early Horse Gentian has tiny orange fruits next to its stem that look like tiny pumpkins or persimmons.

Trees

This week’s featured oak is the Northern Pin Oak. It is in the red oak group, with pointed lobes on its leaves. The spaces between the lobes, which are called “sinuses”, are very deep. The Pin Oak’s acorns take two years to mature, with nubby caps that cover the top third of the nut.

Another deciduous tree to look for is the American Basswood, also called the Linden. It grows to be 50 to 70 feet tall, and has large heart-shaped leaves that turn yellow or sometimes orange in the fall. The small white flowers of the Basswood mature into small round nut-like fruit about the size of a BB. The inner bark is used by Native Americans to make rope and baskets, and Basswoods are sometimes called “rope trees.” Gray Squirrels often strip the outer bark off of small branches and use the ropy
inner bark to line their leafy nests.

Weather observations

Here are some weather observations for this week from past years.

Friday, October 13	2019: alternating sunshine and flurries, with high in the 40s
Saturday, October 14	2022: dusting of snow in the morning; 2011: Overcast and breezy, high in the 50s
Sunday, October 15	2021: dark clouds and sprinkles, temperature in the 50s; 2010: sunny and high in the 60s
Monday, October 16	2020: snow flurries in the morning, with a high in the 40s; 2014: sunny with a high of 72°
Tuesday, October 17	2004 and 2002: trace of snow
Wednesday, October 18	2021: temperature in the 70s; 2011: temperature in the 40s through the day
Thursday, October 19	2000: record high of 84°