Forest Birds

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- Hi, Sanford Smith here with Penn State Extension.

Today I'm joined by Julian Avery.

He's a research professor of wildlife conservation in the College of Ag Sciences at Penn State.

Julian, we're gonna talk about forest birds today.

And the reason why I'm asking you about this is that you teach ornithology.

So can you tell us what that involves, and what's involved with forest birds, or what's so important about forest birds?

- Yeah, so I teach a class on the science of birds, so bird ecology.

Birds are an incredibly diverse group, more than 10,000 species spread around the globe.

And actually birds are most closely related to crocodilians.

So what we normally used to think of as a group that was quite distinct is distinct, but is actually nested within what we consider reptiles.

So they're basically just fancier reptiles that have evolved to take advantage of a lot of different habitats around the globe.

- And in the forest of Pennsylvania, which is the most common sort of dominant habitat here, we have lots of birds summer and winter, and can you talk a little bit about that life cycle?

- Yeah, so in Pennsylvania, we have lots of different bird communities throughout the year, and those communities kind of shift and change as the seasons change as well.

So in the winter, we have a nice subset of Pennsylvania birds that you could find year-round pretty reliably.

Within a given winter, you might expect between 30 and 40 species.

So when we run the Christmas bird count, there's a pileated woodpecker calling behind us, when we run the Christmas bird count, we might get around 30 species or 40 species within a given area.

As spring rolls around, however, on a good spring migration day, you can actually pretty easily get over 100 species if you travel across a range of habitats.

So to go from around 30 to over 100, and within the state of Pennsylvania, if you worked at it, you could easily get over 150 breeding bird species.

It's pretty cool how we have a community that goes from relatively few but abundant individuals, to one that's dominated by many more species and lots more individuals as they flood into our habitats from further south.

What's really neat is that some birds like to winter in the southern United States, others might winter in Central America or South America, or even in some of the Caribbean islands.

And as spring comes, they migrate back up to their breeding grounds.

A lot of them are choosing to stay in Pennsylvania, and then some are passing on through to more northern regions of North America.

- Yeah, you mentioned the birds that are here in the winter, we often call those residents, don't we?

- [Julian] Yeah.

- They're resident birds, and then they're sort of visited by their relatives in the spring and summer, and they stay here and raise their young, and so I do know some of the birds here that are here in the summer, and it's fascinating that some are up in the trees, like in cavities, small holes in trees, and then others are sometimes nesting on the ground.

Can you talk about that?

- Yeah, so when we're talking about Pennsylvania resident birds, we're talking about those that stay year round.

And what's kind of interesting too is that, in the winter, when we're looking at birds that we consider to be resident, some of those might actually be migratory individuals from further north.

A lot of species choose to come down to us in the winter because maybe it's a little bit more mild or maybe more food resources.

So our residents can actually be sort of augmented by more migrants from up north of the same kinds of species.

What's really fascinating is that in a forest like this is that you should think of a forest as having different types of structure, different elements within a forest.

Some birds have evolved to forage and nest within the canopy.

So having a well-established canopy, having older trees present in a forest is really important.

Then there's a group of birds that might use sort of the mid story, and you wanna have complexity of younger trees growing up within the more mature canopy.

And then some will actually use what we consider the understory or the shrub layer.

Lots of birds have evolved to build their nests in that denser layer.

So having a well-established shrub layer is really important.

And then some will also take advantage of the ground, nesting on the ground, foraging on the ground.

Having a nice complexity of structure within your forest means that you also have lots of opportunities for a very diverse community of birds.

- Yeah, right.

Gosh, there's so many things, fascinating things to know about birds, but I am curious to know a little bit about bird communities.

I hear that sometimes certain species like to hang around together, especially in the winter.

I'll see like chickadees, and the nuthatches, and the juncos are all in like little community groups.

- Yeah, so there's definitely a lot of social interactions between birds.

In the winter, some will forage and mix species flocks and they might follow each other around.

During migration, what's kind of cool is that as birds stream up from the south and maybe they're unfamiliar with the surroundings, they might actually pair up with a local chickadee or a titmouse and pay attention to where they're foraging.

And so you can have these mixed species flocks that are, you know, zipping around the canopy, looking for insects to eat, but they're all following one of our resident birds.

- Yeah, fascinating.

Julian, there's something else I'm sort of interested to ask you is what's so important about birds and what do people need to think about in regards to bird conservation?

- Yeah, first and foremost, birds are just, they're beautiful, they're so much fun to look at, and for me personally, I just get a lot of enjoyment bird watching on my free time.

And it's a hobby that allows me to never be bored wherever I go.

There's always something new to see, or see birds behaving differently in different habitats is fascinating.

But besides their beauty and how they bring us closer to nature and the happiness that they bring us, they also can tell you a lot about the quality of your habitat, of your surroundings.

If you have lots of species present and they're there reliably, that is an indicator that you have nice quality habitat and that you must have complexity in your habitat too, which is important.

So birds can tell us a lot about habitat quality, they bring us happiness, but they also do a ton of things in the environment, right?

They're eating invertebrates, they're helping control pest outbreaks, they're providing food for lots of other organisms, and they also provide opportunities for other animals, right?

So they might change the habitat in ways.

Woodpeckers are a good example of that.

- Well, thank you very much, Julian, and thank you, folks, for listening today.

These have been a few thoughts about forest birds in Pennsylvania and in the northeast.

(birds chirping)