Outdoor Ontario
Discussion => Behaviour => Topic started by: Axeman on August 12, 2013, 10:57:25 PM
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Having grown up with the image of robins being first birds to return in the spring...and the Mage of them picking off worms on rainy days...I was shocked a few years ago to discover overwintering robins...but I've always wondered what they ate in the winter...I mean the worms are stuck in the frozen ground...well the other day I observed a robin foraging for berries in a tree...omg ! They eat more than worms !
Go ahead...you can laugh at me...I have.
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Interesting - a few days ago I got this photo as I had not noticed Robins eating berries before - no idea what the berries are and if they last into the winter.
(http://i1304.photobucket.com/albums/s539/bronco1941/2013-08-11-6120aaa_zpsbf452ce5.jpg)
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The berries might be some species of dogwood--the leaves look appropriate, but a botanist might know.
I have a handy reference, a Peterson Field Guide to Eastern Forests, from which I've taken the following:
Major fruit-consuming birds include cedar waxwing, catbird, & all the thrushes, including robins. There is also a list of Other fruit-consuming birds, presumably not major.
Fruits can be grouped into 3 categories: summer fruits, fall high-quality and fall low-quality.
Summer fruits are high in carbohydrates (think of summer berries), fall high-quality fruits are high in lipids (fats), and fall low-quality fruit are low in lipids.
Two dogwoods are listed in this source as having high-quality fruit--grey and flowering dogwoods. The list in not comprehensive and it is possible that other dogwoods such as alternate also have high-quality fruit.
Birds generally eat all the high-quality fruit quickly, which is just as well, since it rots if left uneaten.
Low-quality fruit (examples hawthorn, sumac, chokecherry, mountain-ash, roses, poison ivy, winterberry, red cedar, juniper) is the stuff that hangs around all winter & is still there when the birds come back in the spring. Kind of like leftovers...
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Looked at some references, namely Shrubs of Ontario (publisher-ROM).
Alternate-leaved dogwood Cornus alternifolia (page 345): "Fruit a stalked cluster of round, dark blue, berrylike drupes with a bloom, each drupe about 6 mm in diameter and on a red stalk; July and August."
Just like in the picture.
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Thanks Leslie - great information.
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I'm glad you found it helpful.
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When my Manitoba Maple was removed in early July I discovered a hackberry tree I never knew existed! Well, the young robins really did a cleanup job on it in just a few days, but it's been good for hummingbird photography because they wait there when I'm (deliberately!) too close to the feeder! I also have a flowering cherry tree in front and those berries usually attract robins and waxwings starting late in the fall.
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Thanks...some really good info here !