As winter approaches and temperatures start to drop, many hummingbird lovers worry about how to help hummingbirds survive the cold. Hummingbirds are resilient, amazing creatures, but they can face serious threats from freezing temperatures and winter storms. By understanding hummingbird biology and behavior in winter, and taking some simple steps to support them, you can help hummingbirds stay safe and healthy through the colder months.
Why do hummingbirds stay in cold climates in winter?
Hummingbirds are migratory birds that breed in North America and travel south to warmer climates like Mexico and Central America for the winter. However, more and more hummingbirds are stopping short of their traditional wintering grounds and overwintering in the southern United States instead. This is likely due to a few factors:
- Climate change – Warmer average winter temperatures may allow some hummingbirds to survive farther north than before.
- Backyard feeding – More people are setting up hummingbird feeders, providing a food source during winter.
- Habitat loss – Development and deforestation in Mexico may limit traditional overwintering habitat.
Research shows that up to thirty different hummingbird species have been documented overwintering in the U.S. Most common are Rufous Hummingbirds and Anna’s Hummingbirds on the Pacific Coast and in the Southwest, and Ruby-throated Hummingbirds and Black-chinned Hummingbirds across the Southeast.
How do hummingbirds survive cold weather?
Hummingbirds have adaptations that help them cope with hypothermia, frostbite and starvation during winter:
- Small size – Their tiny bodies (often under 5 inches and weighting less than a nickel) lose heat slowly compared to larger birds.
- Large brain – Their relatively enormous brain size for their body gives them problem-solving skills to seek food and shelter.
- Fast metabolism – Hummingbirds have the highest metabolism of any vertebrate which generates internal heat.
- Thick down feathers – Fluffy down feathers under their exterior feathers provide insulation.
- Torpor – They can enter a hibernation-like state where their heart rate and metabolism slows to conserve energy.
These adaptations allow hummingbirds to get through short cold snaps. However, when winter temperatures stay extremely low for long periods, it can still threaten their survival. Providing a few key habitat elements and supplemental food sources can go a long way in supporting wintering hummingbirds.
Leave natural food sources
In mild weather, hummingbirds rely on flowering plants and tree sap for food. Here are some steps you can take to ensure wintering hummingbirds have access to these critical natural food sources:
- Plant native species of shrubs, vines and trees that flower or produce sap in late fall and winter. Examples include coral honeysuckle, red buckeye, cypress, elm and pine trees.
- Leave seedheads and dead flowers intact on perennials like coneflowers, asters and sage so hummingbirds can access seeds and any remaining nectar.
- Place sap wells in holes drilled in trees to provide a natural high-energy food.
Taking steps to protect and maintain winter-blooming native plants will give hummingbirds the nutrition they need from their natural diet when possible.
Provide clean feeders
Artificial feeders are crucial for hummingbirds that linger into winter, especially during harsh weather when flowering plants are dormant. Follow these tips to give hummingbirds the best chance when using feeders:
- Use a simple 1 part white sugar to 4 parts water recipe. Do not add red dye which can be harmful.
- Change the nectar every 2-3 days (more often in hot weather) to prevent mold and bacteria.
- Clean feeders thoroughly once a week with a water-vinegar solution.
- Place feeders undercover to prevent water from diluting the nectar, but still allow hummingbirds to access it easily.
Feeders should be left up through early spring, removing them gradually to encourage hummingbirds to transition back to natural food sources as they become available again.
Provide extra calories
Hummingbirds need a tremendous amount of calories to survive cold weather. Here are some tips to ensure winter feeders provide maximum energy:
- Use feeders specifically designed to accommodate hummingbird beaks and tongues.
- Gradually increase the sugar concentration up to a 1:3 ratio as winter progresses.
- Try offering polyester fiber “batting” soaked in sugar water which they can eat for extra nutrition.
- Move feeders periodically to freshen the supply at new “territories”.
Making high calorie food easily available with these methods can help hummingbirds get the crucial energy they need.
Provide shelter
Hummingbirds burn up their energy reserves quickly in cold weather. Giving them places to roost in protected spots allows them to conserve energy between feeding. Ways to create shelter include:
- Allow dead leaves to accumulate under shrubs which hummingbirds use for shelter.
- Hang pine boughs near feeders to create an insulating microclimate.
- Fit feeders with side shields to block wind and rain so hummingbirds can feed without being exposed.
- Build enclosed nesting boxes with small entrance holes which hummingbirds may use to hide overnight.
Having numerous areas on your property that offer cover from the elements will give wintering hummingbirds refuge both day and night.
Avoid using pesticides
Insects are an important natural food source for hummingbirds. You can support that winter nutrition source by:
- Avoiding pesticide use which reduces insect populations.
- Providing shrubs like butterfly bushes that attract insects.
- Leaving dead leaves and organic matter where insects can shelter through winter.
Taking steps to build up insect populations will give hummingbirds a readily available protein source to balance their primarily sugar-based diet.
Monitor health and stress signs
Some signs that indicate a hummingbird is struggling in cold conditions include:
- Feathers puffed up for long periods to conserve body heat.
- Moving sluggishly or losing the ability to perch.
- Visiting feeders less often.
- Appearing thin or malnourished.
If you observe any of these warning signs, take steps like providing a warmer microclimate, keeping fresh nectar available 24/7, or capturing the hummingbird for rehabilitation if symptoms persist.
Know when to intervene
In extreme cold snaps, hummingbirds can reach life-threatening conditions. Look for these signs that they are in imminent danger and may need assisted intervention:
- Shivering or shaking.
- Lethargic or unable to fly.
- Little to no feather fluffing for warmth.
- Icicles forming on their beaks or feathers.
At this point, try capturing the hummingbird with a small towel and contact a wildlife rehabilitator. A rehabilitator can warm and hydrate the hummingbird, treat any frostbitten appendages, and release it when conditions improve.
Know your state laws
It’s important to know that under the Migratory Bird Treaty Act, it is illegal to keep wild hummingbirds as pets or rehabilitate them without proper permits. However, as long as you contact licensed rehabilitators and follow state wildlife regulations, you can still help hummingbirds survive periods of extreme cold if needed.
Conclusion
With their speedy metabolisms and tiny bodies, hummingbirds are prone to serious risks from freezing weather. But by improving the habitat around your home with winter-friendly flowers, maintaining fresh nectar in clean feeders, and monitoring hummingbird health, you can take simple steps to help hummingbirds stay safe through the toughest conditions nature throws at them. Getting involved in helping hummingbirds and observing them up-close is a rewarding activity that engages both hearts and minds.
