Table of Contents
TL:DR
- Ducks and geese stay warm through countercurrent heat exchange in their legs, waterproof feathers, fat stores, and group huddling that also prevents ice formation.
- Small birds survive winter by trapping air in puffed-up down feathers, rapidly building fat stores before storms (they can sense barometric pressure changes), and entering energy-saving "mini-hibernation" during extreme cold.
- Winter food sources include stored seeds (chickadees cache up to 80,000!), persistent berries, insect larvae/pupae, and ground seeds that birds forage for even in snow.
- Birds shelter in pine trees (blue jays, cardinals), tree cavities (woodpeckers, nuthatches), dense bushes, and even park barns during storms and cold nights.
Here's a great example of a white-breasted nuthatch puffing itself up to keep warm on a cold and windy day
Thursday, December 4th, 2025, was a cold day at Rockefeller State Park Preserve in Pleasantville, NY. Temperatures were in the high 20s and low 30s while I was hiking in the park. As I hiked around Swan Lake, I watched Buffleheads, Hooded Mergansers, Mallards, and Canada Geese swimming and diving in the lake. At the shallow end of the lake, ice has started to form, and that made me wonder: “How can these water birds keep swimming and diving when the water temperatures are close to freezing?
As I hiked up the Overlook Trail, I saw small flocks of Dark-Eyed Juncos, White Throated Sparrows, a Tufted Titmouse, Northern Cardinals, and some House Finches. I began wondering how these birds keep going during the cold winter months. Where do they go during high winds and snowfall? What are they eating once the berries and other “fall foods” are gone? How can they stay warm when temperatures fall into the teens, or even lower?
I decided to research these questions because, after photographing birds at Rockefeller State Park Preserve for almost 3 years, I wanted to better understand my photo subjects.
Canada Geese and Mallard Ducks on a cold day on Swan Lake
How Water Birds Handle Freezing Temperatures
First, let’s talk about the ducks. How have these birds developed to handle the cold? When I see them standing on ice, I wonder if they even feel cold. My research found that ducks have arteries very close together in their legs. This allows warm blood to heat the cold blood returning to the body’s core. This lets them better handle cold surfaces. Also, in winter, you often see ducks on the shore of Swan Lake standing on one foot. This enables them to conserve heat while standing on frozen sections of Swan Lake.
Water birds have dense waterproof feathers that keep heat close to their bodies. Something I didn’t know about the preening these birds do is that it helps them maintain the waterproofing of their feathers by distributing oils as they preen.
Ducks and geese burn a lot of fat to keep warm. Their larger body mass compared to other birds means they need to increase their food intake to build the fat stores needed to survive cold winters.
These birds often congregate in groups during the winter. As a group, they will swim and move together to maintain heat, and their motion helps keep ice from forming on Swan Lake so they can continue feeding. Last winter (2024/2025), Swan Lake was completely frozen over at times, and during these periods, the ducks and geese moved to other open bodies of water.
Small Birds' Winter Survival Strategies
Next, I’ll let you know what I found out researching how smaller birds like northern cardinals, blue jays, dark-eyed juncos, nuthatches, and chickadees survive the cold winters at Rockefeller State Park Preserve. When walking up the Overlook Trail or along the Farm Meadow Trail, I’ll see small flocks of birds in the brush or hear them scratching around in the leaves.
These birds have dense down feathers near their bodies to trap heat. They will preen their feathers to trap more air for insulation. They may even puff up their feathers to capture more air, which they warm with their bodies to insulate themselves.
Like water birds, small birds work to maintain their fat stores, which they burn to keep warm. One interesting thing I found is that birds can sense barometric pressure changes as storms approach. When this happens, they work before the storm to rapidly build the fat stores they need to keep warm.
A House Finch loads-up on berries December 04, 2025
What Birds Eat When "Fall Food" Runs Out
I’ve wondered what the birds at Rockefeller State Park eat during winter. Last week, while taking pictures in the park, I captured a group of house finches devouring berries. I also saw a group of goldfinches hanging off tree branches, eating seeds. What happens once those are gone?
While the diets of different bird species differ, some birds, like chickadees, store seeds they eat during winter. One study found that chickadees store up to 80,000 seeds before winter and remember where they put them all! Seeing chickadees foraging at the park during October and early November makes sense. They were building up their winter food stores. I sometimes forget where I put my car keys; how can they remember where they put 80,000 seeds!
Other birds that eat insects will eat insect larvae and pupae during winter, and during brief warm spells, they’ll eat insects close to the surface. Birds like dark-eyed juncos and sparrows will forage on the ground for small seeds. I’ve observed this in most sections of the park during the winter, even while there’s snow on the ground. During snowy periods, they seem to congregate around the bases of bushes or trees where there is less snow.
A Blue Jay hiding out in a pine tree on a cold day
Where Birds Take Shelter During Storms and Cold Nights
So, where do the birds go in the evening and during snowstorms? The blue jays and northern cardinals in the park often roost in large pine trees like the ones found on the Stone Barn trail. When walking by these trees in the winter, I’ll frequently hear blue jays making noise that is coming from branches deep in the trees.
Woodpeckers, tufted titmice, and nuthatches will stay in tree cavities to protect themselves from bad weather. Other birds roost or stay in groups near the bases of trees or in dense bushes to keep warm. I’ve seen groups of birds early on winter mornings huddling in the barns on the Farm Meadow Trail near the Barnyard Hill Trail.
Energy Conservation: Why You See Fewer Birds on the Coldest Days
During cold weather and storms, birds can enter an energy lockdown, minimizing movement to conserve the energy needed to stay warm. Some even go into a “mini-hibernation.” I know when hiking in the park, as temperatures are in the low teens, that I don’t see as many birds on the trails. This is especially true when it’s windy.
The next time you’re hiking at Rockefeller State Park Preserve during the winter months, keep the information above in mind. When you’re along Swan Lake, watch for the ducks and geese huddling together on cold days. See if these water birds are standing on one leg to conserve heat. When hiking on the Overlook Trail or Ash Tree Loop, watch for dark-eyed juncos, white throated sparrows, and other birds foraging along the ground to find food. When you’re walking by pine trees in the park, listen for blue jays and northern cardinals.
Even though winter can be very windy, cold, and snowy, birds have adapted to this environment. Certainly better than me. As I get older, it seems the winter gets more and more unbearable!
FAQs
Q: How do ducks keep their feet from freezing when standing on ice?
A: Ducks have a specialized circulatory system called countercurrent heat exchange, where arteries in their legs are positioned very close together. This allows warm blood to flow down to their feet, warming the cold blood returning to their body's core. You'll also often see ducks standing on one foot in winter—this helps them conserve heat by keeping one foot tucked up in their warm feathers.
Q: What do birds eat during winter when berries and insects are scarce?
A: Winter bird diets vary by species. Chickadees are remarkable food planners—they can store up to 80,000 seeds before winter and remember where they cached them all. Insect-eating birds switch to eating insect larvae and pupae, and will catch active insects during brief warm spells. Ground-foraging birds like dark-eyed juncos and sparrows search for small seeds, often congregating around the bases of bushes and trees where there's less snow.
Q: Where do birds go during snowstorms and at night?
A: Different species have different strategies. Blue jays and northern cardinals roost deep within large pine trees for protection. Woodpeckers, tufted titmice, and nuthatches shelter in tree cavities. Other birds huddle together in groups near the bases of trees, in dense bushes, or even in park structures like the barns along the Farm Meadow Trail.
Q: Can birds really predict when a storm is coming?
A: Yes! Birds can sense barometric pressure changes as storms approach. When they detect an incoming storm, they work quickly to build up their fat stores by eating more food. This gives them the energy reserves they need to stay warm and survive the storm period when they may not be able to forage.
Q: Why do I see fewer birds on really cold or windy days?
A: Birds enter what's called an "energy lockdown" during extreme cold and storms. They minimize movement to conserve the energy they need to stay warm, and some species even go into a "mini-hibernation" state. This survival strategy means they're tucked away in their shelters rather than actively moving around the trails where you'd normally see them.