Goin' Nuts in the Neighborhood!
Photo of Bur Oak acorns (Albion College); Black Walnuts (Johnson's Nursery)

Do you feel the need to "duck and cover" as you walk through your neighborhood or through the campus Environmental Study Area? “You’re not alone," says Bert Cregg, a professor in the department of horticulture at Michigan State University. "It's sort of a perfect storm, if you will,” Cregg said of the factors leading to this season’s “copious” mast—not a “crop”—of nuts dropping on our heads.

Biologists call the overproduction of acorns and other nuts, like walnuts and hickory nuts, masting. Mast is the botanical name for the nuts, seeds, buds, or fruits of trees and shrubs that are eaten by wildlife. 

There are two main types of mast: hard mast includes nuts and seeds with tough shells such as acorns, hickory nuts, and walnuts. Soft mast includes berries and fruits such as crabapples, blueberries, and serviceberries.

The definition of mast can be expanded to include the winged seeds (nicknamed “helicopters”) of trees such as maple and elm, as well as pine seeds and nuts, and even rose hips, the fruits of roses (right). Both types of mast are important year-round food sources for wildlife.  

What causes a mast year? The reasons are unclear, but one theory suggests that since acorns are a major food source for many animals, mast years make up for the intense predation: the overabundance of acorns make it impossible for animals to eat them all. That way, the leftover acorns can take root to replenish oak sapling populations. 
During non-mast years, acorn predators such as birds, mice, squirrels and chipmunks decline because the harvest is nominal. This reduces the number of nut predators storing acorns during the mast years. Some scientists have suggested that the interval between mast years may also be necessary for trees to recover their energy and mineral reserves from the last high-output year and to accumulate enough energy for the next one. (Blue Jay photo by Douglas Tallamy)


A second hypothesis is that masting trees are trying to maximize pollination efficiency. New evidence suggests that deciduous trees flower and release pollen at the same time in order to increase their chances of reproduction. It is an economy of scale, favoring large, occasional outputs of seed rather than frequent, small ones.

Temperature and moisture are likely factors in the cycle, and oaks might even communicate with one another, sending chemical signals so they can coordinate their production. Research has shown that trees are linked by mycorrhizal fungi networks (left) that allow them to exchange carbohydrates.
Mycorrhizal fungi form a symbiotic relationship with trees. They colonize the tree roots and receive carbohydrates while providing nutrients and water from the soil. Michorrhizal fungi extend much farther than a tree's roots. 
Red Fox photo by Janis Gascoigne
Mast years occur in irregular cycles of two to five years. State and federal wildlife agencies do acorn surveys annually because hunters know their “target species,” like deer and turkey, will likely be where the acorns are. USDA Forest Service scientist Katie Greenberg reports, “Big acorn crops can help to increase reproduction and survival of deer, grouse, turkeys, and other game species that eat acorns. In fact, acorns are considered a keystone species because mice and squirrels also benefit from big acorn crops, and so do other animals – like hawks, foxes, and bobcats – that in turn eat them. Foresters are also interested, since acorns are the seeds for future baby oak trees.”


Jeremiah Sandler, 28, is a certified arborist in Royal Oak and owns a company called Tree First. Sandler said he gets a lot of calls this time of year about the extra tree nuts. "I like mast years," Sandler said. "It gets more people looking at trees. Nature is doing just what it's supposed to be doing!"
Congratulations to Griffin Bray!!
The Michigan Alliance for Environmental and Outdoor Education (MAEOE) has presented the brand new Rising Star Award to EIC staff member and UM-Dearborn graduate Griffin Bray! 
“This award recognizes an early career professional who is new to the fields of environmental and outdoor education. The nominee has demonstrated leadership, innovation, as well as exhibited best practices in environmental and/or outdoor education.” Nominated by both EIC full-time staff as well as his supervisors and co-workers at Oakland County Parks, Griffin was a perfect first-time recipient of this new award!
Did You Know...?
October 17-23 is Wolf Awareness Week!
In 1987, only eighteen wolves were estimated to live in Wisconsin and fewer in Upper Michigan, which led the Sigurd Olson Environmental Institute, based at Northland College in Ashland, Wisconsin, to form the Timber Wolf Alliance (TWA). To recognize Wolf Awareness Week, the Timber Wolf Alliance creates an annual poster featuring an award-winning artist’s rendering of a wolf or wolves in their natural habitat. Check out TWA's educational resources for formal and nonformal educators!
Tales from the Trails
Male (left) and female (right) Golden-crowned Kinglet (Jim Simek)
"Little Kings" 
Natural Areas Manager Rick Simek reports a recent overnight breeze from the north turned the page to a new chapter in this year's fall bird migration stopovers in the Environmental Study Area. Enjoy his reflections...

Golden-crowned kinglets ("little kings") have arrived, and when that happens you know that the latter half of the fall migration season has begun. Listen for their quiet, rather thin and buzzy calls, and you might find yourself in the company of several kinglets, as they like to forage in rather close proximity to one another. Stand still a bit, and if the little kings are foraging near the ground they may come so close to you that you won't need binoculars to see their field marks.

Golden-crowned kinglets can be found in the Environmental Study Area (and our neighborhoods) through mid-to-late November. You'll see them out and active in some of the coldest, wettest, windiest late fall weather we can expect to encounter in our region. A few even spend the winter there, but most will have headed south by December. Spend some time watching a bunch of "little kings" and you'll likely be reminded of how some of the toughest birds come in really small packages. 
Thank you all for your
Pollinator Photo Contest submissions!
We'll be reviewing the entries shortly and will publish the results in an upcoming issue.
Keep an eye out for the "show!"
Resources
In this unusual time, venturing outdoors and encountering nature is even more important. 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.