Finding food in winter, here in northern portions of the Mississippi River watershed, can be a challenge for animals that don’t hibernate or migrate. Berries are important sources of nutrition for winter birds. As you walk along a woodland or prairie path in December, you will see many bright-colored fruits still clinging tenaciously to the plants that produced them. The names will sound familiar to you: bittersweet, poison ivy, hawthorn, grape, winterberry, sumac, highbush cranberry, mountain ash. It’s almost like the plant is advertising that it has luscious fruit for the plucking.
Well, it appears that the plants and the birds held a summit many, many years ago to explore ways that they can work together. The plants had a desire to find a way to move their children away from home and the birds are always looking for things to eat. So the plants agreed to bundle their seeds in tasty, nutritious and easily identifiable fruit and the birds agreed to eat the fruit and distribute the seeds over the landscape. While the fruit is digested, the seeds usually pass through the digestive system undamaged. Everyone is happy.
A great number of birds eat these fruit. For instance, 54 species of birds eat poison ivy fruit, 44 types of birds consume dogwood fruit, 38 birds eat sumac fruit, and 63 birds dine on grapes. In winter, these plants serve as important food sources for birds.
The type of food a bird eats has an impact on the color of its feathers. For instance, carotenoids help produce yellow, orange and red feathers. The cardinal and gold finch get their color from the food they eat. Pigments from their food are processed in the bird’s liver, find their way into the blood stream and are deposited in the feather follicles. An interesting article on this can be found in this Birder’s World magazine article.
As you walk along in the winter wonderland and you see the cardinal eating dogwood berries, marvel at how linked their lives truly are.