How to Keep Hummingbird Nectar From Freezing

Feeding Hummingbirds in Winter

Winter Hummingbird
Overwintering hummingbirds need unfrozen nectar to survive. Photo © Scazon/Flickr/CC by 2.0

Hummingbirds are some of the most desirable backyard birds, but what happens to hummingbirds in winter? While these birds are typically only found in northern backyards during the summer – with the exception of the Anna's hummingbird, a year-round Pacific Coast resident – the occasional hummingbird can overwinter in northern areas. This brings up the problem of how to keep hummingbird nectar from freezing so these tiny birds always have a reliable food source even when flowers may not be blooming.

The Dangers of Cold Weather

Hummingbirds have a high metabolism, and while they have ways to keep themselves warm, including going into a torpor at night to preserve energy, a sudden cold snap can be deadly. A reliable source of nectar is essential to replenish their energy. Low nighttime temperatures can freeze hummingbird sugar water, however, and night-starved birds may have to wait for hours for the nectar to thaw enough for drinking. Furthermore, frozen nectar can also crack or otherwise damage hummingbird feeders, making them less useful for feeding hummingbirds all year round.

How to Keep Hummingbird Nectar From Freezing

There are several tricks that can help keep hummingbird nectar from freezing even in the coldest weather.

  • Sweeter Nectar: The typical hummingbird nectar recipe is a solution of one part sugar to four parts water, and this solution begins to freeze at 27 degrees Fahrenheit (-2.8 Celsius). More sugar will lower the freezing point of the nectar, and a solution of one part sugar to only three parts water is more suitable for very cold weather. Not only will it stay unfrozen in slightly colder temperatures, but it will also provide a stronger source of energy for hungry hummingbirds. Do not, however, sweeten the nectar even further, as a very rich syrup can be difficult for hummingbirds to drink and digest properly. Be sure to return the nectar to the optimum one part sugar to four parts water ratio as soon as possible to minimize any dietary risks.
     
  • Protected Feeders: Chilly breezes can cool off nectar and freeze it more quickly. Placing a hummingbird feeder in a protected area, such as on a covered porch, next to a windbreak or under a deep eave, will keep it unfrozen for longer periods. This also keeps the feeder from getting covered with snow or ice that can clog feeding ports.
     
  • Heating the Feeder: Hanging an industrial work light or outdoor flood light near a hummingbird feeder can help heat the nectar to keep it liquid. Ideally, the light should be 8-12 inches from the feeder so the heat generated from the incandescent bulb can keep the nectar from freezing. Be sure all cords and outlets are protected from moisture and potential short circuits. Do not use LED or other low-heat bulbs, as they will not be able to heat the nectar sufficiently to keep it from freezing.
     
  • Use Window Feeders: Attaching hummingbird feeders to windows from a heated room can help transfer some of the heat to the feeder and keep the nectar from freezing. This works best on single-paned windows, but can be useful on any windows. This technique also helps bring the hummingbirds close to windows for superb views.
     
  • Bring Feeders Indoors: On the very coldest nights, it may be best to bring hummingbird feeders indoors where they will not be able to freeze. Hummingbirds need to feed very early in the morning, however, even before sunrise, and it is essential to replace the feeders outdoors as soon as the birds need them. On very cold days, keeping several feeders filled with nectar can be helpful, and the feeders can be rotated indoors and out so there is always a liquid supply of nectar available.
     
  • Insulate Feeders: Wrapping the reservoir of a nectar feeder with bubble wrap or other insulation can protect it from freezing. Cover as much of the bottle as possible but do not block the feeding ports, and take other steps as well to keep the feeder warm and unfrozen. Be sure the insulating wrap does not have any dangling strings or loose fibers that could be harmful to hummingbirds.
     
  • Lighted Feeders: Wrapping a strand of holiday lights (non-LED) around the bottle of a hummingbird feeder can generate enough warmth to keep the nectar from freezing. Using red or pink lights also adds a glowing welcome that can attract hungry winter hummingbirds. Be sure the light strand is in good condition before wrapping it around a feeder, however, and avoid using any lights with frayed cords or other damage. This technique is best with glass feeders, just in case the lights are up against the surface of the feeder, since plastic feeders may melt or warp if the lights are too warm.
     
  • Snow Baffles: Covering a hummingbird feeder keeps it from getting choked with freezing rain, ice and snow and will help keep the nectar itself from freezing. Choose a wide baffle, and preferably one with room for small perches underneath where the hummingbirds can rest while waiting for a chance to drink. A dark-colored baffle can also attract small amounts of heat that will help keep the area around the feeder warmer.

Tips for Feeding Winter Hummingbirds

While keeping nectar from freezing is essential for feeding hummingbirds in winter, there are other tips to keep in mind to ensure these birds are healthy even through the coldest season.

  • Always keep feeders clean to prevent mold and fungus that can be fatal to hummingbirds.
  • Refill feeders frequently so there is always an adequate supply of nectar for all overwintering hummingbirds.
  • Take care that any cords or lights used to warm feeders are not in danger of shorting out.

Hummingbirds can be a surprise in winter areas, but backyard birders who keeping hummingbird nectar from freezing can help these small flying jewels thrive even in the coldest temperatures.