The only birds I've seen eating the bittersweet berries along my back fence are bluebirds, when they hang around late enough in the year. Others berry-eaters like robins & catbirds seem to ingnore them. I have seen the local squirrels eat them, though, when times are tough!

We have Asian bittersweet vines (Celastrus orbiculata) growing along the fence and up into the trees behind my house. The birds don't seem to touch the berries, and unfortunately, all of those seeds will germinate next season.
Celastrus orbiculata is a non-native invasive liana which has actually been listed as a noxious weed in some states. I've been trying to get rid of mine for years. And not only do the birds avoid the berries, but the plants can also choke out other bushes and shrubs that do attract wildlife.

The seeds don't germinate and spread does that mean it is native? It has been hear for many years and grows on the kennel fence.

Well low and behold The Henry Field's catalog arrived today and as bold as can be they have the advert for American Bittersweet,beautiful orange and yellow color in fall and winter and the birds love it!Perhaps this is a case of false or ignorant advertising.
Peter

Peter,
There is a native bittersweet vine as well as a non-native asiatic bittersweet. The two vines are apparently rather similar in appearance and have similar fruit. They can be separated by the location of the fruit on the vine, but you'll have to look up the difference in your field guide because right now I can't recall exactly what the difference between them is.

I do know that American Bittersweet is far less common than asiatic bittersweet in all of the places I have looked. In fact, I have never seen a wild American Bittersweet, whereas Asiatic Bittersweet is quite common and in fact a very dominant invasive plant in many areas. I have seen areas of many acres of land almost completely covered by Asiatic Bittersweet and supporting little other vegetation.

It may be that American Bittersweet fruit is more readily eaten by birds than the fruit of ASiatic Bittersweet, or it might be false advertising. A think that a lot of what you read in many seed and plant catalogs is copied from another catalog or simply made up - read catalogs with a grain of salt.