Apart from their nutritional value (and availability after insects disappear for the year), the berries have an additional role to play...
The fruits of fall are especially important to birds that were hatched this summer. Many youngsters, including cardinals and house finches, are initially quite drab. Their summer diet of high-protein insects allows them to develop quickly but doesn't contribute much to feather color. They don't begin to resemble their parents until late fall, when they eat berries rich in carotenoids. These pigments provide the dye that colors feathers as young birds molt into their adult plumage.Photo credit Ryan Brennecke, Associated Press
I'll bet the plants don't care at all about what color bird is eating their berries. They make desirable berries so that their seeds are propagated. Isn't evolution grand!
ReplyDeleteI used to work at a public aquarium which featured black oystercatchers, a large black shorebird with a long, brilliant red bill. That bill color could only be maintained in captivity by injecting the birds' food with regular doses of carotenoids. There's actually a commercial product made for this. Any aquarium or zoo that exhibits flamingos will also be a customer.
ReplyDeleteI'm sorry but the article that this is linked is complete bullshit! I don't other birds but I have watched watched SCORES of cardinals growing from fledgling to adult plumage over the last three summers. Last summer the cardinals in my yard had three full hatchings (it was a very good year for them here in Mississippi). And when they drop their baby feathers and put out their adult plumage they are fully adult coloring and in fact extremely BRIGHTLY colored. There is no coloring added from berries; that is total and complete bullshit.
ReplyDeleteIf you go to Google Image search, and type in "baby cardinal" you see lots of pictures of brown and grey baby birds.
ReplyDeleteFortunately that evidence is completely overturned by your observations outside your kitchen window.