What in the world does this tongue twisting term mean?
The combination of red berries and rapidly color changing foliage in early fall has an important wildlife function. Called “fall foliar fruit flagging”, the bold color difference acts as a colorful signal, or “flag”, that helps migrant birds notice the trees and find the fruits so they can fuel themselves during the journey south.*
Plants producing early colorful fall foliage and fruits include spicebush, dogwood, sassafras, virginia creeper, and black gum. The fruits these plants bear are called drupes. Drupes are stone fruits that have a thin outer skin, a pulpy middle and a stony center enclosing a seed, like a peach. The fleshy part of these drupes is full of fat, just the kind of thing that hungry migrating birds are looking for! **
Many of the early drupes are red, and easy for birds to see, but others, like virginia creeper and sassafras, are dark colored and easy to miss. That makes the brightly colored leaves ranging from yellows and oranges through deep reds, that serve as the “flags” on these plants doubly important to fall migrants.***
Once the birds eat the drupes, the seeds are ‘scarified’ as they go through their digestive systems. This weakens the tough outer coats of the seeds inside the drupes and makes it easier for them to germinate. The birds deposit the seeds along their migratory route, away from the original plant and thus ensuring the future perpetuation of the plants.***
Other plants produce fall fruits that are lower in fat but still nutritious such as staghorn sumac, chokecherry, mapleleaf viburnum, and poison ivy. These plants tend to keep their fruits for a longer time, thus making them a great food source for wildlife when less is available.
So, next time you are out walking or hiking in Rugby and see the early colorfully changing leaves and fruits think about the great system that nature has devised to signal migrating birds to the ripened fruits that will provide nourishment for them on their long migrations!
For more information about fall foliar fruit flagging check out these great articles:
* “Falling for Dogwood” By Natalie Brewer
University of Maryland Extension Howard County Master Gardener