Monday, August 26, 2013

Berries and Birds

Fall is in the air. The leaves are just beginning to change color and the bittersweet berries are turning from green to yellow.  Soon they’ll burst out of their golden pods and the bright reddish orange berries will be very eye catching, attracting some hungry birds as well as some humans who don’t realize how dangerous those little colorful berries from the choking vines can be to the environment.

Not only do the bittersweet vines kill trees, but they also displace native plants and ground covers that are much more nutritious for birds. By removing the many bittersweet vines during our Work Day at Riverfront Park we’ll be allowing the native plants to begin regrowth.  One of the park’s native plants is Elderberry. Another is Chokeberry. Both have lots of antioxidants and are very nutritious for our avian friends.
If you have not yet signed up for the Work Day please go to and pre-register. The event will be on September 28, 2013 at Riverfront Park.

Do birds need to depend on bittersweet berries as a food source?  Usually not unless it’s an extraordinarily cold winter and the birds can’t find other more nutritious berries to eat. Most birds instinctively look for berries that are high in fat content as well as antioxidants. Bayberry is one of their favorites; it’s like the Big Mac of plants with 50% fat. Bittersweet berries have very little fat and practically no antioxidants.

Also, bittersweet berries are solid and not easy for birds to digest. In fact most of the bittersweet berry is still intact when it’s excreted from a bird so it re-sprouts elsewhere in the spring.  Sadly for the native birds, when it’s very cold they don’t want to expend a lot of energy foraging for food. So, if they see that bright red berry they’ll eat it but it’s like us eating a stick of celery. It doesn’t go far to keep them warm. 

It now appears that more and more song birds that rely on berries and bugs are staying north for the winter. Since most do not frequent bird feeders, such as the robin, mocking bird, catbird and bluebird, they constantly search for berries so you might see them eating the bittersweet berries in desperation. 
If it were not for the bittersweet invasion birds would have a far greater variety of much more nutritious food so get rid of the bittersweet and grow plants such as bayberry, elderberry, chokeberry, high bush blueberry, dogwood, winterberry, viburnum and many others (see link on "Other Resouces" page)..
Interestingly, the 2 most common birds to eat the invasive bittersweet berries are the European Starling and the English House Sparrow. Both are invasive birds eating invasive berries!

Thanks to bird lover Ann P for authoring this excellent post!

Oriental bittersweet berries are a last resort for bluebirds and other winter song birds
since the berries have very little nutritional value.