Following up on last month’s article about creating a winter garden for birds, a friend forwarded me an article about the link between the northward spread of red birds (namely, robins and cardinals) who dine on red berries. Evidently, the red berries help keep the red pigment in feathers for these birds.

Cardinals at winter feeder

When growing up, most of us never saw a robin or a cardinal in winter.  Those birds used to migrate south in the fall and stay there until mid March, returning to our area as a harbinger of spring.  Today, however, robins and cardinals are plentiful at our feeders and in our yards.  The robins regularly visit my winterberry shrubs in February to tank up on the red berries that have been through several freezing and thawing cycles and are now more palatable.  And cardinals lurk at woods edge all year long.

What happened?

We now have warmer and longer falls, have experienced an increase in the global warming pattern, and have the ready availability of red berries from invasive plants such as Oriental bittersweet, multiflora rose, Japanese barberry, and burning bush (not only my native winterberry).  These berries pass through a bird’s digestive system with the seeds intact, ready to germinate where the bird left them.  Thus, more habitat and food supply is created, and the birds do not need to migrate south.  However, studies by the entomologist and author Doug Tallamy and others show that the invasive plants do not provide nutritious food for the birds but simply “junk food.”

Another drawback is that the invasive plants can form a combined dense thicket three to nine feet tall.  Birds, of course, like such habitat as it protects them from predators.  Males especially will remain here in order to be close to claim spring breeding territory early.

What can you do?  Replace any invasive shrubs lurking around your property with natives that bear nutritious fruit for birds in winter, such as Viburnum, Winterberry, and (carefully placed) Sumac.  It is important to have a plan to replant in place before an outright removal project gets underway.  Disturbed soil left bare exposes the invasive seed bank to light and quick germination.  Many times, the removal/replanting activity can be phased in over time.

Viburnum trilobum, Cranberry Viburnum

Contact Priscilla at to arrange an appointment to discuss options for your property.

About the author