An amazing 3.19 inches of rain have fallen here in the Linnaeus Arboretum since last Thursday 7/22. High temperatures coupled with high humidity levels have again pushed the heat index past 100 degrees Fahrenheit on several recent days, creating conditions for severe storms as both warmer and cooler fronts pushed through the state. Luckily for us, these storms brought with them heavy but brief rainfall, a much appreciated bonus for all our greenery. The first week of August appears to be more pleasant according to the next ten days’ forecast, with just a couple chances of storms and temperatures in the comfortable high 70’s and low 80’s.
Many observers are already seeing signs of fall throughout the state, which is probably due to this past spring’s unusually early and rapid progression of phenological events. While it is true that some birds begin migrating back south from their northern breeding grounds as early as late June, such as some shorebird species, fall migration begins in mid- to late August for the majority of migrating birds. We haven’t seen any early migrants in the Arb yet, but several observers have seen small flocks of migrating warblers as far south as the Twin Cities in the past few days; these warbler “waves” aren’t usually seen in southern Minnesota until mid-August. There is one very noticeable hint of an early fall here in the Arb, however: crabapples. Most of the crabapple trees in front of the Interpretive Center, as well as others around campus, are sporting fruits with the diameters of a dime, and still some others have fruits with penny diameters. These crabapple sizes are more characteristic of late August than late July, and thus they are perhaps indicative of more early fall events yet to come.
Here are some other highlights from this week in the Arb:
– Field Sparrow still singing territorial song near Uhler Prairie 7/28
– Male American Goldfinch and House Finch visiting nyjer thistle feeders in Bird and Butterfly Garden behind Interpretive Center 7/28
– White Monarda, or Bee-Balm, in full bloom in Bird and Butterfly Garden behind Interpretive Center 7/28
– Hydrangea ‘Limelight’ blooming in Thornberg Garden on east side of Interpretive Center 7/28
– Red-spotted Purple nectaring on Purple Coneflowers in Bird and Butterfly Garden behind Interpretive Center 7/26-27
Red-spotted Purple nectaring on Purple Coneflower in Bird and Butterfly Garden behind Interpretive Center, 7/27/10.