Hummingbirds possess one of the highest metabolic rates in the animal kingdom, requiring them to consume vast amounts of fuel daily. This high-energy demand does not lessen during the colder months, making their winter food sources particularly important. When natural resources become scarce, these tiny birds must rely on a specialized and often supplemented diet to maintain the energy necessary to regulate body temperature.
Wintering Species and Geographic Context
The question of a hummingbird’s winter diet depends on its geographic location and species. While many North American species migrate south, several species are resident or overwinter in specific regions. For example, Anna’s Hummingbirds are commonly found year-round along the Pacific coast, from California up into British Columbia.
Rufous Hummingbirds, traditionally highly migratory, have also been observed overwintering in increasing numbers along the Gulf Coast and southeastern states. These overwintering populations actively seek sustenance during the cold season, necessitating a consistent food supply that differs from the abundant nectar sources available in summer.
Natural Food Sources During Cold Months
When traditional summer flowers disappear, overwintering hummingbirds turn to less obvious natural resources for energy. One significant source is tree sap, often accessed through small holes created by sapsuckers. The sugary fluid weeping from these “sap wells” provides a quick energy boost when flower nectar is unavailable. They also opportunistically feed on residual nectar found in late-blooming or evergreen shrubs, such as certain salvias or fuchsias.
The most significant difference in their winter diet is the increased reliance on arthropods, which provide necessary protein and fats. Tiny insects and spiders, often found clinging to tree bark or caught in spiderwebs, become a much larger proportion of the winter menu. This insect protein is necessary for building muscle and maintaining body condition during periods of cold stress.
Providing and Preparing Sugar Water
To supplement scarce natural resources, many people offer a simple sugar water solution in feeders. The correct mixture is a ratio of one part refined white granulated sugar to four parts water (1:4). This concentration closely mimics the sugar content found in natural flower nectar, providing the necessary energy.
It is important to use only plain white granulated sugar, as other sweeteners pose health risks. Brown sugar, organic sugars, honey, and artificial sweeteners contain components or bacteria that can be difficult for the hummingbirds to digest or can even be toxic. Furthermore, adding red dye is unnecessary and potentially harmful.
Maintaining the cleanliness of the feeder is just as important as preparation. The solution should be changed and the feeder thoroughly cleaned every few days, even if the liquid appears clear. In warmer winter temperatures, the sugar solution can ferment or grow mold rapidly, which can cause illness.
Keeping Feeders Accessible in Freezing Weather
The greatest challenge to providing winter sustenance is ensuring the sugar solution remains liquid and accessible during freezing temperatures. Hummingbirds rely heavily on a high-calorie intake first thing in the morning to exit torpor and begin warming their bodies. If the feeder is frozen solid at dawn, they may not be able to find the immediate fuel they require.
A common strategy involves using multiple small feeders and rotating them indoors overnight, placing a fresh, room-temperature feeder outside before sunrise. For continuous access, several commercial solutions are available, including small heating elements or light bulbs designed to keep the feeder ports warm enough to prevent freezing.
For less severe cold, wrapping the feeder with insulation, such as bubble wrap or a sock, can sometimes prevent the solution from freezing quickly. Maintaining a constant liquid supply is often a matter of survival during intense cold snaps.