New Hampshire Audubon has a new study on the status of the many migratory and local bird species that are commonly found across the state’s varied habitats.
It shows conservation measures that have been effective to improve some species’ populations, as well as the pressures from climate change and human development that threaten others.
Since the last version of this report 10 years ago, Audubon has gotten more data on species that weren't well studied before. Of the species with useful data, the new report says 46% are stable or increasing, and about 39% of species are in decline. (Click here or scroll down to read the full report.)
NHPR’s Peter Biello spoke with Pamela Hunt, the study's author and senior biologist with New Hampshire Audubon, to learn more.
Peter Biello: So why is it important to pay attention to the state of New Hampshire's birds?
Pamela Hunt: A couple of reasons. The ones we usually give are, A, birds are often really good environmental indicators. There's the overused canary in a coal mine thing. People still understand Silent Spring, the book that launched the DDT ban, additionally. So, you know, things that happen in the environment, birds are often things we can easily see respond. People notice them respond because they're common and visible, things like that. So as good environmental indicators, birds are up there.
The other reason we should care is because, why not? That's a line I often give, that they're just part of what we've got here and they're part of our natural ecosystems, and we should just appreciate them and recognize their right to be here along with us. And thirdly is the fact that people just like birds - we relate to them. We watch them. We spend millions of dollars every year looking for them. They're an economic driver in that regard as well.
Peter Biello: And what did this study attempt to measure about birds?
Pamela Hunt: So what the State of the Birds is, is a compilation of population trend data for all the species that occur in New Hampshire with some regularity -- 280, 290 species. A hundred and ninety of those breed here. We've got usually some pretty good data on breeding bird population trends. We collected all the trends - are they increasing, decreasing, by how much, that sort of thing -- and then grouped those into categories, whether it's based on habitat, based on migration strategy, based on some sort of other grouping like birds of prey or waterfowl.
And oftentimes, if you're looking at groups of birds like that, you'll see some groups are disproportionately more likely to be increasing or decreasing than other groups. And in those cases, that's when you might say, OK, something's going on that's affecting this group of birds more than some other group, and that allows us to identify common threats, which then we can actually try to take action to maybe mitigate what's going on.
Peter Biello: Year-over-year fluctuations in bird populations, birds like migratory birds, birds that live here year round, those are important to measure. But long-term trends, as you point out in this report, are really important. What kind of long-term trends did you find?
Pamela Hunt: The good news theme is that species that we've actually invested conservation efforts into, things like birds of prey and waterfowl, have been increasing over the last 50 years or more. We banned DDT, we protected habitat, things like that. So things like eagles are now all over the place. Waterfowl are doing quite well. So the message there is if you put conservation effort into something, it actually has benefits.
Another broad increasing trend are several sort of common species that are adapted to live near people, things like cardinals that we see at our feeders. A lot of these are southern species that are probably actually partially moving north because of things like climate change. So they're able to adapt to both disturbed landscape, lots of houses, plus a warmer climate that makes it easier for them to survive.
Peter Biello: And how much do environments in other parts of the world affect birds that migrate to and from New Hampshire?
Pamela Hunt: Yes, that is the key question. And it's excellent that you asked it because, you know, most of our birds actually leave the state at some point in their lives -- there are only 20, 30 or so species that don't migrate at all. And the farther away a bird migrates, the more likely it is to be declining. So that tells us that the stress of migration is important and also anything that might affect them during migration or during the winter when they're in South America or Mexico or Cuba or wherever they go, are going to be big factors.
And we do know that things that happen in the winter can affect the birds' not only survival there, but also could affect its chances of being successful at migrating north again. If it doesn't get enough the food or is stressed somehow in the winter, it might not survive migration. It might get here late and therefore not be as likely to breed. And so does this whole annual cycle of things that happen in one season affect the next season and on and on and on and on. So it's really critical for most of our birds to think about what's happening south of the border, as it were, because it does affect what happens back here in the summer.
Peter Biello: And which habitats are doing well in New Hampshire and which seem to be under the most threat?
Pamela Hunt: The good news part is that bird that nest in our forests - we're a largely forested state - those species tend to be increasing at least as much as decreasing. So there's not this disproportionate, declining number of species in our forested habitats. And that's partially because we've done a fairly good job of protecting a lot of our forests, White Mountain National Forest, lots of other chunks here and there. On the flip side, species that use early successional habitats, grasslands and shrubby habitats, pine barrens, tend to be declining disproportionately. And that's usually, again, because those habitats are ephemeral. If you don't manage them in some way, they will turn into forest.
Peter Biello: You write here that there are some things ordinary people, not necessarily people who study birds, can do to help protect birds here in New Hampshire. What would you recommend for ordinary people if they want to preserve the birds that are here and the birds that that come and go?
Pamela Hunt: Cats kill billions of birds a year in North America. So that's a really big take-home message. And you can't really keep them from killing things except by keeping them inside. So that's that's number one.
Number two is to minimize bird window strikes. You know, half a billion birds or more get killed by running at the buildings during the year because they don't see glass like we do. They just see reflections in it and try to fly into the next piece of woods that they see there. And there's all sorts of things you can do, expensive and inexpensive, to minimize that if you've got windows that are that are likely to be a problem. Basically, you just need to have something on the outside of the window at regular intervals like four inches apart. Vertical strips is what they usually do to break up that reflection. Then you can still see out the window and it looks a little funny right away, but the birds will see it and not fly into the window. Or screens are the best answer, actually. If you've got screens, leave them up.
Another good one is just sort of what kind of habitat you've got in your yard, in your neighborhood. Minimize pesticide use, minimize non-native plants -- actually eliminate non-native plants, which often are less suitable for food. Birds don't like the berries as much in many cases, but more importantly, non-native plants tend to support fewer insects and the birds that eat insects won't be foraging on them as often. Let your lawn grow into a weedy field and sparrows will love it. Neighbors might not, but (laughs).
Read the full State of the Birds report below.