Information provided by CZS/Brookfield Zoo, an EcoMyths Alliance Partner.
If you’re an animal at CZS/Brookfield Zoo, trees might be what you eat for dinner. More specifically, “browse” is the name for the trimmings taken from about 800,000 to one million trees—and that’s just a small percentage of the approximately 9,000 miles of trees ComEd prunes to keep its power lines flowing each year.
Believe it or not, these trimmings are gourmet stuff to many of the animals at the zoo. The electric company donates two truckloads of the leaves and branches a week to the Zoo from May to October, and zookeepers freeze it to keep a supply for animals all winter. They can also save twigs and some leaves to create silage, a special fermented browse that is enjoyed by hoofed animals during the winter.
While the trimmings are largely recycled into mulch, feeding browse to the animals is an even more eco-efficient use of the greens, according to an ABC News video. The animals digest the food and turn it into manure, which serves as a fertilizer for new plants. The twigs and sticks also provide a mental challenge for the animals, who also play with it (like the wild African dogs pictured above are doing) or strip the bark before they eat it, as you can see in this Brookfield Zoo video.
The 40-50 cubic yards of browse delivered to the zoo each week goes to feed a variety of different animals including gorillas and other primates, giraffes, grizzly bears, rhinos, kangaroos, and Rodrigues fruit bats. There are lots of varieties of trees that can be eaten as well, including sugar and silver maple, willow, grapevine, mulberry, box elder, honey locust, and alder. In this Chicago Sun-Times article, zoo nutritionist Jennifer Watts tells us sugar maple is a favorite because it’s sweet. Turns out animals need dessert, too!