Here in Minnesota we finally got a hard frost. This means those summer stragglers have finally been silenced into hibernation or oblivion. Insects in particular don’t do well with the frost. It is a part of their life cycle. The adults have spent all summer breeding and laying eggs that will stay stashed away until the sun warms the soil with the return of spring.
The first hard frost eliminates all but a few lucky insects from my house lights at night. Yesterday I saw a lone moth flitting across my yard at a temperature in the high thirties (F). Not all insects die in the fall. Some, like Monarch butterflies, migrate to warmer climates to wait out their return to the frozen tundra of the north. Others like ants, wasps, bees and the Morning Cloak butterfly spend their winters hibernating here in the north.
I found this bumble bee lethargically tromping through the grass in the shade of my house. I brought it into the sun and watched it recharge it’s batteries until its body temperature was within operating parameters. Bumble bee queens overwinter under logs, leave litter and mouse holes. Here she will wait to start a new colony in the spring. All of the workers in her brood are destine to freeze with the first hard frost. This worker may very well be making it’s final flight of its life.
Grasshoppers are a group of insects that do not overwinter. They lay eggs underground that overwinter until the following spring. These insects do not go through complete metamorphosis like moths and butterflies (egg-caterpillar-cocoon-moth) but instead go through incomplete metamorphosis. This means that in the spring when the eggs hatch, what comes out looks like a miniature grasshopper. These mini-hoppers then shed their skin, developing wings and sex organs, until they reach the adult stage. The large grasshoppers we see at the end of summer started life as tiny versions of their adult selves several months before.
When the frosts come the adults freeze and return their borrowed molecule to the earth.
The migration is almost over, the most northern breeding birds are passing through or setting up winter residence.
Last weekend I had the honor to see a Northern Shrike pursue, capture and consume a local Gold Finch in my backyard. Shrikes are northern birds that are usually found north of the arctic circle, they come south to Minnesota to spend their winters (that’s one hardcore bird!). Unlike true birds of prey Shrikes do not have talons. They only have a hooked bill. Even without those adaptations the Shrike I saw made quick work of the hatch-year Gold Finch it was pursuing.
Thousands of birds BONK into windows, antenna, and other obstacles on their migration south. Help them out by turning off your outdoor lights at night. Put stickers on your windows to give contrast. Little things like that will ensure we have these beautiful birds for generations to come.