How songbirds are surviving climate change

Scientists in North Carolina’s Great Smokey Mountains National Park are studying how Carolina Chickadees build their nests in different climates. They hope to use this research to understand how songbirds will adapt to climate change in the future.

TRANSCRIPT

Scientists in North Carolina's Great Smoky Mountains National Park are studying Carolina chickadees build their nests in different climates.

They hope to use this research to understand how songbirds will adapt to climate change in the future.

Let's take a look.

[ Birds chirping ]

The Great Smoky Mountains and even a larger region of the southern Appalachian Mountains are a treasure trove of biodiversity.

Forests and streams, as well as the mountains and valleys, are filled with a seemingly endless variety of life, both large and small.

And all of these things fit together and help tell the story of the Smokies and what we're trying to protect.

[ Insects chirping ]

20,000 different species counted so far in Great Smoky Mountains National Park alone, but this is the story of just one tiny creature filling one tiny spot in that web of life.

Meet the Carolina chickadee.

Most all songbirds in North America, most of our breeding birds are in decline.

And so, if we know more about them, it might enable us to be able to better protect and conserve them.

Scientists know some things about this little bird.

It weighs about .4 ounces.

That's about the same as a half-slice of bread.

The Carolina chickadee is about 5 inches tall.

The wingspan is about 8 inches across.

Carolina chickadees, they do a single brood in a season.

So, that means they have one shot at it every year.

And if they fail, then they have to wait till the following year.

Like most songbirds, the female Carolina chickadee builds the nest.

Once the nest is ready, the female lays one egg per day Once there is a full clutch, the female begins incubating the eggs.

And that is a really critical time for both themselves and the nestlings.

So, they need to keep the temperature of the eggs above a certain threshold in order for them to develop properly.

And it turns out nest building is critically important to the survival of Carolina chickadees.

The better the female builds the nest, the better she'll be able to take care of her little ones because she will be healthier.

So, being on the eggs and keeping them warm means they're not out foraging and taking care of themselves.

So, they have to balance their activity to take care of the eggs and keep them at an optimal temperature for development and taking care of themselves so that they can survive to reproduce again in the following year.

And it seemed like a good opportunity for us to ask what is really critical about female behavior that's going to lead them to have a lot of reproductive success.

But to study nesting behavior, researchers need to observe nests.

Nest boxes were placed at varying elevations.

That meant different temperatures, and that translated into different times for nesting.

Temperature sensors were placed outside and inside the boxes, as well as inside the nests for comparison.

These are just a quick example of some of the variations that we found.

This is a smaller nest.

So, you can see that they typically will build a layer of moss, and then they'll build the cup on top.

You can see they'll use a little grass or fur that they find.

And you can see how this one of course is so much taller and deeper and a little more insulated than this one.

Researchers found the female Carolina chickadee didn't build one standard type of nest.

The style depended on where the nest box was located.

So, the females want to try to reach about 100 degrees Fahrenheit in the nest, temperature.

If the eggs are not kept at a proper temperature, then the embryos won't develop correctly, so they won't hatch.

And as far as the nestlings, when they're first born, they're unable to regulate their body temperature for three to four days.

So, they really depend on warmth from their mother and from the nest to regulate their temperature.

Different types of insulation and different types of nest construction were used to adapt the nest to the climate.

That allowed the female to stay stronger and take better care of her nestlings.

This is an investment that they're making that might help them when they're incubating.

So, it might alleviate some of the pressure of being on the nest so often to keep the temperature of the eggs up, because if there's a lot of insulation in the nest, then the temperature of the eggs might fall more slowly when she leaves the nest.

So, she can be off for a little bit longer.

That means the female can forage longer and be stronger and healthier.

The question -- what happens as the climate changes?

There's probably a lot of factors that are involved with decline of songbirds in North America, but the fact that these birds have one shot at a reproductive in a season is probably gonna be a big factor for chickadees.