Of Holly Berries And Robins

When we moved into our little house in Hyannis 40 years ago, there were three large holly trees in the backyard. Two were full of berries, the third berry-less but no doubt proud of his assistance in the berry production. The American holly is dioecious, meaning it has flowers on separate plants that have separate jobs. The male plants produce the pollen that fertilizes the female flowers that produce the berries. This is true of winterberry as well.

Each year varies a bit in the production of berries, but this year seems to have been a banner year. Our pollinator garden is within feet of these hollies so there are lots of bees doing their good work throughout the blooming season. Each year I watch for the robins to show up in force to eat the berries, and they never disappoint. Their dates of arrival vary with the arrival of extreme cold, but often they show up in January. The latest date I’ve seen them flock to our yard was mid-February, and that was last year.

Holly berries don’t seem to be the favorites on any bird’s list of yummy foods, but they are full of calories and give the birds that eat them a welcome energy boost when the temperatures drop.

In the fall you may see robins and cedar waxwings gorging on cedar or juniper berries. Both species eat worms and other invertebrates all spring and summer, and when they can find them in fall and winter they will remain the first choice. As insects and worms become dormant, the birds must turn to other sources of nutrients, and fruits and berries are their choices.

If you grow any berries such as blueberries or raspberries, you are probably well aware of their popularity with your backyard birds. Catbirds, mockingbirds, cardinals, bluebirds, robins and cedar waxwings will all happily help themselves to your berry crop. 

As the summer winds down, the birds will go after late berries. Red cedars or junipers are a favorite choice in late summer and early fall, and it is not unusual to come upon flocks of dozens, even hundreds, of birds feasting if you’re out walking in areas where these trees are common.

Rose hips and winter berries are also popular choices, and in some areas you may find birds claiming whole tracts of shrubs as their personal territory. Although several species may do this, northern mockingbirds seem to bring a special level of intensity to their attempts. This often works for them until a flock of birds discovers their stash. Then no amount of frantic clamoring or threatening matters, often leaving the defending bird puffy and perhaps huffy.

Other berries that birds enjoy include pokeberries, elderberries, viburnum berries, native privet, honeysuckle and bittersweet berries. There are invasive berries as well that are not as nutritious though may be equally popular. Think junk food for birds. 

Depending on how cold the late fall and early winter are, the supply of berries will often last at least into the first months of the year. This helps enormously when other food supplies become limited by the cold weather.

Robins are migratory and for many years were considered harbingers of spring. Rather than migrating huge distances, however, robins often don’t go that far. Our breeding robins have gone farther south but the robins from up north, from areas in Canada but also northern Maine, Vermont and New Hampshire, have discovered that here on Cape Cod the weather is a bit more moderate than other areas. Huge roosts of these visiting robins number in the tens of thousands on the mid-Cape, and watching the steady arrival of thousands of robins arriving at their roost at dusk is a humbling, amazing experience.

When the robins are out looking for food, there seem to be a few scouts that arrive first. If their search has been successful, a few more will arrive, and within an hour dozens or more will join the others. Do robins return to the same areas year after year? I don’t know and can’t find anything to substantiate that thought, but over the years I’ve definitely seen robins return to the same spots every year, just as the tree swallows seem to flock in the same dune areas every fall to eat up the bayberries before flying south.

The cold snap that hit us brought many birds back to my yard. I gave up my bird feeders a few years ago due to finding a rat helping itself to seed, but my little yard has many plants, both native and invasive, that are full of seeds, cherries, berries and acorns in the latter part of the year. I knew from perusing my nature journals that January and February were the best times to watch for the robin extravaganza in the hollies, and after a few days of peeking out the window about 50 times a day, I saw the first robins arrive.

Winter robins have a drab, almost gray plumage compared to their brighter spring and summer plumage. They are able to blend into the background and gobble up their preferred food quickly and without ceremony.

Over the next few hours more and more robins arrived until the two berry-bearing trees were alive with the chatter and movements of gorging birds. I stood, sketching and watching, and suddenly the birds went silent and disappeared into the deeper, darker parts of the trees. A Cooper’s hawk had been alerted to their presence. Crows drove it off and the robins eventually began feeding again, at least that time.

It only takes a few days for the birds to eat all the berries and then they move on. It’s a moment in time, but one I look forward to every year. It’s good to know some things occur no matter what else is going on, that nature can soothe and inspire us with simple delights.