Forest Fridays: Chewing the fat
- by Guest Contributor
- September 13, 2024
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By Ryan Reed
For many of our migratory songbirds, the journey southward will commence soon or has already begun. Their arduous voyages consume vast amounts of energy that must be steadily replenished along the way. Of the most valuable food sources during this time are those that are high in fat content.
When it comes to native versus non-native berries, it’s no contest. Oft-eaten, non-native berries include those of the multiflora rose and various invasive honeysuckles, which contain less than one percent fat. For our feathered migrants, that just won’t cut it, and numerous studies have shown their clear preference for our native fall, soft mast producers.
Consider the chart below.
| Species | % Fat Content |
| Green briar | 50 |
| Winterberry holly | 50 |
| Northern bayberry | 50 |
| Arrow wood viburnum | 49 |
| Spice bush | 48 |
| Sassafras | 47 |
| Grey dogwood | 35 |
| Flowering dogwood | 24 |
| Red osier dogwood | 23 |
| Staghorn sumac | 19 |
Some general rules to follow are that the native dogwoods and viburnums are good to great sources of fat, with other native soft mast producers like fox grapes, Virginia creeper, hackberry, chokeberry, and poison ivy berries offering a quick fix of carbohydrates along the way.
Another interesting aspect of fall migration of songbirds for which some noteworthy evidence has arisen is their penchant for native berries that are darker in color. Examples include black chokeberry, poke berry, devil’s walking stick, and elderberry. Some ornithologists believe that this inclination is related to acquiring the abundant antioxidants present in the dark-skinned fruits, which helps the birds cope with the cellular oxidative stress of their long expeditions.
What’s more is that all the plants mentioned above are known to harbor many species of insects these birds require on their northward march, while later providing food for new broods of nestlings.
If you want to help our treasured avian travelers, especially during the fall, consider planting some of the species discussed here, and where possible, remove invasive species that essentially amount to the nutritional value of a fast-food diet in bird world.
Image: At about 48 percent fat content, spicebush berries are a valuable food for migrating songbirds in the fall.
About the Author: Ryan Reed
Ryan Reed is a Natural Resource Program Specialist in the Department of Conservation and Natural Resources, Bureau of Forestry. He possesses degrees in Wildlife and Fisheries Science and Wildlife Technology, while currently pursuing a master’s degree in Environmental Pollution Control. He has also worked for the Pennsylvania Game Commission, and taught high school sciences for 11 years. He is especially interested in biodiversity and ecology. A lifelong hunting and fishing enthusiast, Ryan resides in Annville, PA.
