There is a reason that mulberries and blackberries are so attractive to birds. In whatever stage of their development, whether red and unripe or black and ready to pick, mulberries and blackberries stir up avian appetites in a big way. The reason? Birds are most enticed by fruit that is either red or black in color. In one university study, several species of birds were exposed to artificial fruits of every color. The birds showed most interest in those that were either red or black. Such research helps to explain why the fruit of most plants — not just mulberry trees or blackberry brambles — appear in one of these two colors.
Red and black, as well as blue and deep purple colors, whether found in fruits, flowers, or leaves, are attributable to the presence of plant pigments known as anthocyanins. There are more than 500 different anythocyanins and they are beneficial to plants in a variety of ways. In flowers, anthocyanins attract pollinators such as bees and hummingbirds while, in leaves, they deter insect pests and fungi.
Ultimately, though, plants benefit most by the anthocyanins that give fruits their color. Fruit consumption by frugivorous (fruit eating) birds, magnetically attracted to both red and black fruits, is responsible for distribution of the fruits’ seeds. As a seed passes through a bird’s gut, it may be primed for germination by the action of acidic digestive juices, whether by softening the seed coat or neutralizing chemicals that inhibit germination. Some seeds, in fact, can only germinate after undergoing avian digestion.
Even where the bird’s biochemistry does not affect germination, the fact that the seeds are taken a distance away from the mother plant makes an important contribution to perpetuation of the plant species involved. Excretion of seeds in habitats that may be drier or colder or with soil that is different from where the mother plant is found may give the species, over time, the advantage of adapting to more extreme environmental conditions than those to which it was previously exposed.
Interestingly, it has been suggested that one of the reasons birds are attracted to anthocyanin pigments has to do with their nutritional value. Birds instinctively know what is good for them and anythocyanins meet this criterion since they are rich in antioxidants. It should be noted that fruit with high anthocyanin content will not only be more salubrious than conventional varieties, but will have a longer shelf life due to anthocyanin resistance to fungi, including mold. Tomato breeders have successfully prolonged tomato shelf life by increasing anthocyanin concentration in hybrid fruit. (Yes, the tomato definitely meets botany’s definition of a fruit.)
Mexican elderberry (Sambucus mexicana) is a California native with especially high concentrations of anthocyanin in its fruit. Elderberries are not only favorites of birds but can be enjoyed by people, too, who use them for making jam, syrup, and wine or as cobbler, pie, or pudding ingredients. Since elderberries are low in pectin, however, you will have to add lemon juice or jam sugar to give them bonding strength.
Elderberry extract has won acclaim as an anti-viral agent, especially as it has been shown in clinical trials to reduce the duration of typical bouts of flu from six to three days. Marketed as Sambucol in both liquid and tablet form, it is one of the most popular herbal remedies for flu and is sold over the counter in most drug stores.
Consider Mexican elederberry to be a giantic shrub or small tree. It grows rapidly to a height of around thirty feet with a twenty foot spread. Although it is deciduous, its period of leaflessness is brief and it is one of the first plants to leaf out in the spring. While capable of surviving a drought, it will look better and stay leafy deep into the fall when it is soaked once every two weeks during the growing season. Flowers are creamy parasols that give way to the navy blue fruit. When handling the fruit, take care to wear old clothes since the stains created by its inky juice are permanent.
Birdscape is a term that refers to a garden designed to attract — you guessed it — birds. This can be achieved by planting flowers such such as abutilons, salvias, as well as trumpet vines (Tecomas and Tecomarias) with tubular blooms, since they are all candidates for hummingbirds’ attention. Cotoneaster, pyracantha, and toyon (Heteromeles arbutifolia), on the other hand, are ornamentals that yield small, spherical red fruit that serve as delectable snacks for birds of every kinds. Of course, you may want to think twice about birdscaping if you are growing crops such as blueberries, unless you have impregnable netting or cages covering your plants. Other common ornamentals whose fruit brings birds into the garden would include heavenly bamboo (Nandina spp.), Viburnum species, holly (Ilex spp.), and ornamental cherries such as Catalina cherry (Prunus ilicifolia lyonii) and Carolina laurel cherry (Prunus caroliniana).
And to make sure you maximize avian interest in visiting your garden, it would be worth thinking about addition of a bird bath, a bird house, and two bird feeders — one with sugar water for hummingbirds and one with seeds for every other kind of bird.
Tip of the Week: Sedum telephium goes to the top of the plants-I-should-grow list when it blooms this time of year be white or pink. The cultivar ‘Autumn Joy,’ a related hybrid species, has flowers that turn a dark rosy pink before giving way to bronze. Flower stalks also fade to bronze and will remain on the plant throughout winter even after flowers have gone away. Evergreen leaves are pleasantly scalloped and light to medium green. Sedums are members of the orpine or stonecrop family (Crassulaceae) and, like most of their cousins, including jade plants, echeverias, and kalanchoes, demonstrate considerable drought tolerance. Sedums are usually frost resistant, too, and this particular species is as cold hardy as they come, suitable for growing anywhere in the West.