Peak Saw-whet Owl Migration

Wisconsin's smallest owl is a mere 7 inches long and weighs less than a bar of new soap. These nocturnal forest dwellers hunt from perches for their favorite food... mice. A smaller part of their diet is made up of small birds and insects. Saw-whets will lengthen their tiny bodies to look like branches, which helps camouflage them from predators such as larger owls and hawks.

This week, saw-whet owls are making their nocturnal journeys south (some as far as Tennessee) in search of more abundant food. They are one of the few owls to leave Wisconsin for the winter.

Did you know? As with most birds of prey, female owls are larger than the males. This is called reverse sexual dimorphism. One possible reason for this is that larger females produce more body heat for their eggs. Also, the difference in size between the sexes may encourage them to hunt for different sized prey and avoid competing with one another for food.

Learn more: Cornell Lab of Ornithology

Lady Beetles Mass

This is the time of year when lady beetles appear to be everywhere, even in our homes! The multi-colored Asian lady beetles seem to especially enjoy creeping into our houses through small cracks and openings. These little creatures are in search of a cozy place in which to overwinter. A good clue for identifying Asian lady beetles is to look for a thick black M or W near their heads.

Asian lady beetles were introduced to the US to control aphids, and were found in WI by 1994. When the little critters get scared or annoyed, they secrete a stinky yellow liquid to ward off predators.

Lady beetles begin life as eggs, emerge as larvae, pupate (somewhat like a butterfly's chrysalis), and then emerge as adults that can live 2-3 years. Most lady beetles and their larvae feed on tiny insects like aphids who can damage crops.

A lady beetle larva hunting for aphids

The Red Squirrel: Master of Middens

With the coming cold, these forest alarm calls are caching large stores of food by burying them near the base of trees. They will return to these caches when winter food is scarce. In the meantime, these chattering creatures defend the territory in which they have hidden their food by chirping, scolding, and chattering at other animals. They can also be seen flicking their tails and jumping from perch to perch when irritated.

Red squirrels especially love pinecone seeds, and large piles of shredded cones are evidence of their favorite eating spots. Such piles of food are called middens. Red squirrels will also eat buds, fruit, nuts, mushrooms, insects, and even bird eggs and nestlings. When spring comes, red squirrels have been known to use their sharp front teeth to pierce little holes in sap-filled trees. They then return to nibble on the sweet leaks.

Did you know? Red squirrels remain active during winter and escape the cold by hiding in dreys and tree cavities. While searching for winter caches, red squirrels are not quite as adept at finding their buried food as grey squirrels.

Learn more: Natureworks

The Original Velcro

As you’ve walked through the woods at CWES, you’ve most likely come across the sticky seeds of common burdock. The plant is native to Europe and considered an invasive species in America. This member of the aster family was originally introduced to New England by early settlers and has since moved its way across the US. The leaves of this biennial plant are sometimes mistaken for rhubarb. One hint to help tell the difference is feeling the leaves: burdock leaves are hairy. The plant's leaves also have a bitter taste and are avoided by most animals.

Common burdock has purple flowers that bloom from July until the first frost. From these blooms, a single plant can produce over 10,000 hitchhiking seeds which are dispersed throughout winter. The seed pods are so good at clinging to animals that hummingbirds have been known to get stuck on them. Burdock has been used for a wide range of medicinal uses from treating swollen joints and fevers to coughs and gout. It also has potentially dangerous diuretic effects.

Learn more: Robert W. Freckmann Herbarium