Spring has not come in northern hemisphere, and we need warmth to survive the chill. We have warm house and blankets keep us warm while we are sleeping. But wild animals can only rely on their survivability to survive cold winter wind, especially at night.
The nests and furs are the only place they have to keep themselves warm. But it doesn’t apply to birds, because they don’t rely on the warmth of their nests. Yes, surprisingly snuggling inside is not the way birds keep themselves warm, unlike other animals.
You may wonder how birds keep themselves warm during cold winter nights. Well, it is pretty unique and maybe birds are the only ones that can use this simple yet effective method to keep themselves warm in cold winter nights.
Here in this article we will tell you how birds survive cold winter nights.
Mass Migration
Birds are warm blooded, in which their bodies maintain constant temperature unlike cold blooded animals. That’s why they cannot easily regulate their body temperature to suit surrounding temperature. If the weather is too hot or too cold, they have to rely on their ability to survive.
Migrating is the first option that birds do. Instead of staying in their homes, they choose to go far away from the cold. Geese are known species of birds commonly recognized to fly far away from their homes to seek for warm places with their V formation.
Arctic Terns even fly 25,000 miles away from their homes. Before migrating, most of the birds are feeding themselves extra food to build up fat reserve. The fat reserve is useful for extra energy and overcoming cold weather while they are flying.
“Big birds, like geese and grouse, do what we do. They put on insulation,” said physiologist David Swanson at the University of South Dakota. However, migrating birds cannot build up too much fat in their body. Not only too much fat means too much weigh to be carried while flying, but also because too bulky body means less aerodynamics.
But migrating is not the unique thing we are talking about. Some birds indeed migrate, but some others prefer to protect their homes, or in this case territories and torture themselves in freezing winter nights. Again, we should tell you that snuggling in their nests is not the best thing to do to protect territory.
The Territorial Insight
Black-capped Chickadees are one of the most territorial birds. The urge to protect their territories makes them to not leave their areas unprotected, even in the coldest winters. While geese fly to warmer areas, the chickadees don’t.
But how they keep themselves warm during winter? They eat. Yes, just as what we do when fall comes and air is getting colder, we crave for more food. However, instead of eating a lot when fall comes, the chickadees are collecting that much food.
Chickadees collect as much food as they can, and store it in between splinter woods or tree barks. They don’t collect it in one spot to prevent losing the entire stock, instead they place it in separate places and memorize those places.
The places where they keep the food stock can be miles away, as long as it is in their territory. This is how their territorial instinct has even developed into their biological feature: they can shrink their brain and grow it back as they will.
To memorize the places, they grow their brain up to 30% bigger to add more neurons and makes memorizing those places easier. When the time comes to collect the seeds, they shrink down the brain because they no longer need those extra neurons to memorize the places.
Natural Blanket
Another species of bird, the Golden-Crowned Kinglets choose another way to survive winter. They prefer to enjoy the freezing night breeze in their ‘natural jacket’. Yes, they also have ‘jackets’, but not like what we have in our cupboards.
The ‘jacket’ is made of their own feathers. In cold winter night, the tiny birds (even tinier than Chickadee) huddle in groups and puff their feathers to make it thicker. The feather ‘jacket’ can even grow into an inch thick, providing warmth to the group.
Not only the thickness of the ‘jacket’, but they also have additional insulator to prevent cold breeze sips into their body. To overcome the cold breeze, the oil produced by their uropygial glands that coats their feather provides better insulation.
So that’s how they keep themselves warm in the night, but how do they make themselves warm during the day? They cannot collect seeds like Chickadee because they only eat insect. And the problem is, what kind of insect wandering around in a cold winter day?
Well, indeed there is not any grasshopper or butterfly wandering around during cold winter day. Moth caterpillars are the only insect that can survive the winter wind, thus they don’t really care about the weather. This way, kinglets can still have food supply by eating moth caterpillars on trees.
Meditating
Some birds are even able to overcome cold winter nights by ‘meditating’. Many birds are able to enter ‘torpor’ state in which their metabolism rate is reduced. This way, their body temperature is lowered and requires lower calories to maintain proper heat. Hummingbirds are known to be able to enter this state.
Some birds are also able to control heat circulation in their bodies. They only concentrate the heat around important areas in their bodies and let the extremities become colder. This way, they are able to minimize the total surface area and minimize heat loss in winter.
Those birds mentioned above are not the only ones that can survive cold winter nights. There are many other birds with their own unique ways to survive the chilling breeze.
In addition, some birds are able to overcome the coldest winters by their own, but if you care about them, you can also help them. Putting tube feeder outside your house filled with mixed seeds will help those birds find food easier.
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