Winter is a challenging season for most of us, and birds are no exception, as their natural food sources diminish. Berries and other winter fruits are a lifeline, sustaining populations when insects and seeds are scarce. These fruits not only help birds survive but also play a crucial role in broader ecosystems, creating a cycle of interdependence between plants, animals, and their environment.
Berry-bearing plants are more than food sources—they are cornerstones of thriving ecosystems. Plants have evolved to attract birds seeking out nutritious and hydrating foods, and in being consumed, birds offer a forestry service by dispersing seeds; in fact, studies have shown that 25% of all seed-producing plants and 50% of all plants are regenerated by birds either caching or dropping berry stones and seeds or passing them through fecal matter.
Berries are a high-energy food source that provides carbohydrates, essential for birds enduring cold temperatures. Species like the American robin are known for their love of fruit, often seen foraging on berries during the colder months. Similarly, waxwings—renowned for their social flocks—flock to berry-laden trees to fuel their long winter flights.
The bright colors of winter berries—vivid reds, oranges, blues and purples— are an evolutionary adaptation by plants to attract birds, which, in turn, aid in seed dispersal. The varying colors act as beacons for birds, signaling ripeness and nutrition. Birds can detect when berries are ripe by using their remarkable ability to see in ultraviolet. Berries with more sugar—and therefore more energy—are darker with shades of purple, blue, and black, and these reflect more UV light. Fatty berries, where the sugar has yet to form, tend to be brighter red and yellow, and are not as reflective, but the birds will know they are there, and can be left to help them get through another day.
However, it’s not just during the wintertime where these plants serve a purpose. The presence of berry-producing plants in gardens, parks, and wild areas offers immense ecological benefits throughout the year. While winter fruits will sustain birds and other animals, the flowers of berry-producing plants such as snowberry, cotoneaster and chokeberry attract pollinators like bees, wasps, and butterflies earlier in the year, enhancing overall ecosystem health. As well as their vital pollination work, these insects provide a secondary food source for birds in spring and summer, helping control pest populations. Many berry plants like serviceberries and elderberries also prevent soil erosion and improve water retention, contributing to a healthier environment.
Helping birds survive the dark days of winter, or birds like this red-eyed vireo passing through on their long journeys to their South American wintering grounds, is one of the many simple acts of citizen conservation that we can take part in. Check which plants are native in your area, but ones like dogwood and winterberry holly are ideal for thrush species and cardinals, and many birds also enjoy juniper, three types of berry-bearing plant that are common to many parts of the US.
By providing these vital food sources, resident and migrant bird populations will also be contributing to seed dispersal, which leads to greater ecological stability—a variety of self-sustaining flora brings greater diversity of fauna. Planting these shrubs and trees in your garden or community not only creates a winter haven for wildlife but also helps maintain the intricate balance of nature; you will be investing in a healthier, more vibrant environment for all species.
