Birds Have Cavities?!
Photos by Jim Simek (above) and
Ellen Kenny (below)
How can birds have cavities? They don’t even have teeth! 

In this case, the reference is nesting cavities. Quite a few birds choose to nest in holes in trees, such as woodpeckers and chickadees, screech owls, and even turkey vultures. But did you know that some ducks prefer tree cavities for their nests? Among the species of cavity nesting ducks is the shy, skittish Wood Duck (Aix sponsa), sometimes regionally called the Carolina duck.
Once referred to as a “glowing gem” by Henry David Thoreau, the male (drake) is intricately decorated with deep green, shimmering feathers on his head, a bright red eye, and a delicately speckled rich chestnut colored breast. The female (hen) is more subtly colored. Cornell's All About Birds describes the hen: “warm brown plumage, with grayer slightly crested head. White teardrop around the eye; white also along the edge of dark blue “speculum” patch in the wings.” 
It’s an unusual sight to see ducks in a tree. Even more so when the duck slips into a hole to investigate its suitability as a home. The North Carolina Wildlife Resource Commission writes, “Early in the morning, the drake follows the hen as she flies to various cavities, inspecting each to determine if it is acceptable. Unless the hen returns to the cavity occupied the previous year, she may search for several days before finding a suitable one.” Pair formation begins as early as late October, continues through the fall and winter, and is usually complete by late February. (Photo by Kris Petersen)

The pair typically choose a tree more than 1 foot and often 2 feet in diameter, with a cavity anywhere from 2–60 feet high (higher sites seem to be preferred). These cavities are typically places where a branch has broken off and the tree's heartwood has subsequently rotted. When tree cavities are scarce, nesting boxes are also used. A typical clutch size is between 6-16 eggs and, unlike many duck species, wood ducks sometimes have two broods (families) in a nesting season. (Photo by Steve Bly)
Wood duck ducklings are precocial, meaning they crack out of their eggs, usually in June, fully feathered and ready to go. Good thing, too, because upon hatching, the young use their sharp claws to climb up the inside of the nesting cavity to its entrance, then jump and flutter to the ground. Leaving the nest is a real leap of faith (just watch!). When leaving the nest, the hen positions herself on the ground, under the cavity or nest box, and softly calls to the young. The young peep back, climb from the nest and then leap to the leaf litter or water. Even when dropping from long distances, the young land, generally uninjured, and immediately follow the hen to the nearest cover.  
Their mother guides them to the nearest water, where they will spend the next eight to nine weeks hunting for food together. Ducklings will stick close to their mother for the first three or four weeks. Mom provides a valuable service by watching for and alerting her young to nearby predators. (Photo by Roseann Smith)
Even so, predation during this period is quite high. Nearly 50 percent of ducklings are lost between the time they leave the nest and go their separate ways in migration 8-10 weeks later. Canadian Wildlife Federation
Look and listen for these elegant couples, like the pair on Fair Lane Lake, and their families in bottomland forests (like the Rouge River floodplain), swamps, freshwater marshes, and beaver ponds. They are also common along streams of all sizes, from creeks to rivers. 

Wood duck families thrive in habitat that alternates between open water and shelter from plant cover, including downed trees, shrubs such as alder, willow, and buttonbush, as well as emergent herbaceous plants such as arrowhead and smartweeds. If you are lucky to see them in open water, take a good look--once they see you, they will likely take cover in all those beneficial plants!
The blogger/photographer Neighborhood Nature reveals, "The mother Wood Duck watches me while five of her young hide in leafy branches around her (you can't really see them). The other four ducklings seem to have wandered off."
Please Try Again!
The Michigan community once again came through for all three campuses on Giving Blueday: for our students, life-changing research, and much more.
However, the outpouring of support on March 16 overwhelmed the website!

If you were unable to make your gift on Giving Blueday, you can still support the great things that happen here at the EIC.
Did You Know?
The University of Michigan-Dearborn will be hosting the State of the Strait Conference on our campus in May!

The State of the Strait is a binational (Canada-United States) collaboration that hosts a meeting every two years to bring together government managers, researchers, students, environmental and conservation organizations, and concerned citizens.

This year's focus is on the remediation of contaminated sediment in the Detroit and Rouge Rivers. The public is encouraged to attend.
Tales from the Trails
Hazelnut “Kittens” of Early Spring
Friend and EIC volunteer Joe Turek recently took this photo of male catkins, or flowers, of the American Hazelnut (Corylus americana) in the Environmental Study Area (ESA). The word “catkin” comes from the Old Dutch word katteken meaning “kitten.” The association with cats is said to come from how some catkins resemble a kitten’s long tail. To me, they resemble very relaxed yellow caterpillars stretched out vertically from the hazelnut twigs. Caterpillarkins??

In early spring, the hazelnut catkins elongate and begin to produce yellowish pollen, which is sent out from the catkin by wind. The female hazelnut flowers, which occur on the same plant as the male flowers and are tiny, red, and very showy, receive the pollen and produce the hazelnuts. A dense clump of hazelnut shrubs can result in the female flowers from separate plants getting pollinated.

American hazelnut shrubs are uncommon in the ESA. I have never seen hazelnuts on any of the plants out there. Maybe the squirrels get to them before I can spot any. Though edible to people, we do not encourage anyone to harvest hazelnuts from the ESA. We like to leave them for the wildlife, and also to potentially disperse and grow into new hazelnut shrubs. American hazelnuts also have many other benefits. This makes them wonderful and attractive native shrub choice for backyard plantings.
Enjoy!
Rick Simek
Resources


Venturing outdoors and encountering nature is good for your physical and mental health! Our trails are accessible, so please visit our Environmental Study Area. Check out our Remote Learning Activities & Resources page for ideas to create a “Neighborhood Nature Journal” and “Family Nature Walk” activities!
Please stay safe, stay tuned, and stay engaged in learning activities while we eagerly wait for the opportunities to share experiences together. In the meantime, watch for our new online activities to satisfy your curiosity about the natural world.