how birds follow the food, plus best practices for bird-feeding, with aubudon’s eric lind
YOU PROBABLY ENJOYED brief recent visits from unexpected or even unfamiliar migrant birds, stopping by on their way to somewhere a little cozier and where the wintertime pantry’s better stocked. You’ve likely also already noticed a different mix of birds settling into your landscape for the duration of the offseason, birds we sometimes refer to as “feeder birds,” ones inclined to frequent whatever goodies we gardeners offer.
Birds follow the food supply, either staying put, or moving in one of several different styles of migration, including the unexpected occasional one called irruption. (Above, an irruptive pine siskin.)
I asked Eric Lind, Director of Audubon New York’s Constitution Marsh Center and Sanctuary in Garrison, New York, about how birds follow the food. We also talked about best practices for supplemental feeding, if you choose to offer seed and suet and such as they do in winter at the Marsh, a 270-acre tidal wetland on the east shore of the Hudson River. The site provides foraging, nesting and resting habitat to more than 200 species of birds and 30 species of fish, plus many other animals.
Read along while you listen in using the player below (or play it from this link). It’s the November 16, 2015 edition of my public-radio program.
my q&a with eric lind on migration, and feeding birds
Q. Before we talk birds specifically, Eric, can you tell us a little bit about Constitution Marsh?
A. It’s a brackish-water tidal marsh, right on the shore of the Hudson River, right on the edge of Putnam County. The marsh itself is identified as an important bird area, or IBA is the colloquial term that we use.
Q. I love it: an acronym!
A. And you notice I spell it out first, because acronyms can be kind of tricky.
It has been identified with more than 100 other locations in New York State that are very valuable habitats for wild birds. We also have a thriving and mature education program at our center, but we don’t keep this all to ourselves. We have an open door and the public that is interested in learning about and studying nature—our door’s open, and everybody’s invited to come down and experience the wonders of the natural world.
A. The boardwalk gets you right out over the surface of a small section of marsh, and the views of the valley here and the Hudson Highlands are really remarkable. The birding can be spectacular at times as well, but I think people who have already started bird-watching or observing birds also know that there are days when it is quite quiet, and the birds are small and brown and you really have to work hard to have them reveal themselves to you.
Q. In late October in my slightly more northern location in New York State from you, I was still seeing the occasional interesting temporary visitor: hermit thrushes, and vireos, moving through. It has definitely quieted down now. I know when I see things either very early or very late in the season, and I’m not quite sure what it is, I go to Ebird dot org–a joint project of Audubon and Cornell Lab of Ornithology. Do you use it yourself, too?
A. We do. When you work at a place like this, it’s really hard not to spend time outside—it’s irresistible. I know we should be in front of the computer more. [Laughter.] We’re sort of surrounded by this wildlife activity, so we do record interesting sightings.
We have a running list that all of us contribute to. We’ll write the bird we saw, whether it be something unusual, or something rare of a conservation concern, or just a new arrival for that particular season. We’ll write that down, and record it all on Ebird.
Q. Ebird.org—I love it, and it’s a way for someone like myself without the expertise, or without colleagues like you have, when I see something to look and see if anyone’s been reporting that kind of bird at this time, which is reassuring.
It also alerts me about possible birds I might be able to see—as you say sometimes, it’s like, “Uh-oh, what’s that little brown bird over there?” [Laughter.]
You say to yourself, “Some keen birder nearby has been listing three little brown birds, so maybe I should read up on those.”
A. And it goes beyond that, because you’re contributing to the continental-scale map of where birds are, and when. All of that information can be gathered and provides really important data for researchers to glean through, and figure out how birds are distributing themselves, either locally (as you and I are discussing) or even across much boarder landscapes.
Contributing to Ebird accomplishes two things: It helps reassure us that we’re seeing what we think we’re seeing, but it also contributes and provides this incredibly information about where birds are and how they’re moving and migrating across our landscape.
We’ve mentioned the word migrant multiple times already, but it’s not a one-size-fits-all generic label. Some that go shorter distances, and longer distances; some that migrate sometimes and not other times.
A. It’s a really fascinating topic. When I was a child, I grew up watching nature documentaries about migrations of large land animals, like wildebeests moving across the African plains. [Laughter.] Animal movements occur all the time. In our area, migratory birds accomplish an astonishing feat. Billions of birds move in all sorts of different directions. Sometimes seasonally.
The thing is they’re not like thundering herds of wildebeests. They’re very small, and a lot of them fly at night and they’re also silent, so it’s not as dramatic. Here in North America there are astounding movements of billions of animals in the form of birds that occur across the year.
Each one is different: It depends on what species of birds, or what group or family of birds, you’re talking about. There are forest-breeding birds, like wood thrushes and scarlet tanagers and all these beautiful treasures, that breed in our Northeastern forests that have these astounding migrations south to Central America or South America.
Hawks migrate, often using ridgelines that deflect air currents and rising thermals so they can move down across the landscape. Even hummingbirds undergo these incredible migrations.
Q. And not everybody moves the same distance. For instance, a reader recently said she was seeing a lot of turkey vultures [above], and asked me whether they migrate—and where they go. That’s a bird that might be resident in some areas where it’s more favorable conditions, or it might be a long-distance migrant, if it’s from a more Northern population.
A. Yes. That’s one species, the turkey vulture, that might be termed a partial migration. If a bird lives in the Southeast and there isn’t a huge range in temperature, and it has enough to eat, it might be a resident bird. But turkey vultures that live further North will migrate farther South, so the whole population doesn’t move—only portions of it. I think that’s captured with the term “partial migration.”
Q. Another example is with bluebirds. I start to get emails about bluebirds as the cold weather comes on, sometimes with photos, saying, “My bluebirds stayed; they’re still here.” Of course it might not be the same birds.
A. It might not be the same individual birds that you saw over the summer. You actually might be seeing bluebirds that nested north of us, and are overwintering here—so this would be south to them.
A. If it were easy, everybody would know the answers, but it depends what species captures your imagination. We may sort of think somebody out there knows everything about birds. [Laughter.]
That’s not the case—there are still so many mysteries, and things to discover about how a wild animal like a bird has evolved and figured out ways of surviving. The thing is: They fly. They can move long distances. In some ways they make our world really small, because an animal you can hold in the palm of your hand can move thousands of miles a year.
Q. Impressive. And then there are the most dramatic times. I get excited and perhaps selfish, and hope it’s going to happen in a given winter, the extreme example of birds following the food and looking for a winter supply when there is not enough in their summering grounds—even ones that don’t do it most years, but only in an irruptive year.
I confess I sneaked a peek at the Winter Finch Forecast already online out of Canada. Do you look at it ahead of time?
A. I don’t want to reveal—to give away—the surprise.
Q. You like the surprise.
A. I want to show up one day and be like, “Oh my gosh, there it is.”
Q. “Who’s that, who’s that?” [Laughter.]
A. Yes. And you’re right, that’s called irruptive behavior. Just to put it in more formal sense: That would be an irregular migration, where the animals don’t move in a consistent, regular pattern. So some years there isn’t that push southward; other years there is.
Snowy owls are another example of that, beyond the winter finches. For the past couple of winters there has been a big push of snowy owls moving south, and they find their way to either beaches or golf courses or salt marshes—places that to their eye look like the tundra. But they’re pushed way, way south, mostly likely in the quest for something to eat.
The downside of it is, though they’re spectacular animals, you are seeing an animal that is potentially under a lot of stress and maybe even starving because it has to spend so much energy moving outside of its normal range. It’s desperate to find food to eat.
Q. In a recent Ebird email—ebird.org also has an e-newsletter—there was a photo of one on a car hood in a parking lot in Sheboygan County, Wisconsin, kind of looking around. Speaking or irrupting to a place where you wouldn’t normally see a snowy owl.
A. I saw one a couple of years ago on top of a Wal-Mart type building—a big flat-roofed building covered in snow. There was a gentleman in the parking lot of the shopping center feeding pigeons breadcrumbs, and of course I think the owl was eyeballing the pigeons.
Q. Uh-oh, not the breadcrumbs. [Laughter.]
A. There was kind of a weird little food chain that had developed there for that particular bird.
Q. Not unlike when we say, “my bluebirds,” as I mentioned before, and refer to things informally, we also refer to a certain familiar group of birds as our “feeder birds.” It’s not really a taxonomic order or anything, but rather these are the birds I expect to see if I have a feeder, especially in the wintertime. Do you feed at Constitution Marsh?
A. We’ll be putting them up in the next couple of days [taped November 5]. We have what we call a feeding station of a couple of different feeders, and we use an assortment of seed. We put that up every winter and usually take it down in the spring, for a couple of different reasons. But yes, it’s something we do and look forward to doing every winter.
Q. You say “a couple of different reasons.” My reason is bear—I have black bear in my yard (not everyday, but regularly if I have feeders up when they are not hibernating). What are your reasons?
A. Part of it is expense—bird food can be expensive. And come spring a lot of the winter birds we feed head to the north country to breed. And there is lots of wild foods that are emerging in the spring, insects and so on—natural foods that are emerging in the spring for birds. You certainly can feed throughout the year; it’s a personal choice. We sort of establish for ourselves the winter feeding only, with the assumption that there is plenty of food available for the wild birds that come here to breed in the summer.
Q. You just said insects, and I guess it would be safe to say that most birds are at least partly insectivorous. When there are insects about, most songbirds would like to eat them. In our dormant season, there are not insects being hatched out, right?
A. Some birds can select different types of foods, but some are quite specific to eating insects. The cardinal, for example, has a beak that has evolved for cracking seeds or eating seeds. It’s not to say that it wouldn’t eat a luscious caterpillar or something like that. But the birds that almost exclusively eat insects—those are the ones that typically will leave. If you think about it, they’re migrating south to the tropics essentially, where they can find their preferred food sources.
Even the hummingbird—we think of it as a feeder bird, if you put up a hummingbird feeder. But it nectars on wildflowers and natural sources of food and will also catch insects, and eat them, too.
A. So some are a little more adaptable in finding the right food and the right nutrition for themselves.
A. We use a lot of black-oil sunflower seed. It’s easy for the birds to open the husk. It’s high in protein. And it’s very attractive for a suite of feeder birds. We also use mixes of seed, and the important thing to remember is that you want to get the highest-quality seed you can, that isn’t full of filler.
The black oil satisfies a lot of birds. The mixes satisfies sparrows, and ground feeders. We also put up suet for woodpeckers, and another protein source for other birds. We use thistle seed, which is really selective for goldfinches and pine siskins [photo, top of page], which are always a treat to see, too.
We have a mix of feeder styles—tube feeders and platform feeders—but we also like to mix up the type of seed we’re using.
Q. You said tube feeders, and it’s interesting: There are even subtle differences in those. The styles that have the perches above the hole—above the feeding port—are for birds that can fed hanging upside-down, like goldfinches or chickadees. Some other birds like starlings can’t do that—so it’s also down to like, “Who are you wanting to include and exclude?”—and let’s not even go into the squirrel thing. [More on choosing the right feeder.]
A. A lot of the feeders are designed for smaller perching birds. You do have to be careful about where you place them. The birds do need cover. If they’re too exposed, the birds themselves are open to predation from hawks that might come and hunt, or cats are a big problem for wild birds. If you’re ground feeding birds you need to keep your cats inside.
Birds need a relatively close area of cover, so that they feel safe—but not too close so a squirrel can’t jump off the shrub cover you’re providing onto the feeder. It’s also really important to keep your feeders, because you are artificially drawing in birds in close proximity to each other. If the seed gets wet or your feeders are soiled, you have to keep them clean so the birds aren’t transmitting possible diseases to each other.
There are two other things, beyond Ebird, I wanted to mention: There are some fantastic other forums for people interested in feeding birds.
One is called Project Feederwatch. Do you do that?
Q. Yes, I do.
A. And that’s starting quite soon. And then in February there is the Great Backyard Bird Count.
Q. Yes, the GBBC.
A. Both are amazing ways of sharing what you’re seeing and finding out what other people are seeing—and again, you’re contributing information to researchers who are using your sighting and observations to figure out where these birds are and how long they stay.
more from audubon
- About Audubon’s IBAs or Important Bird Areas nationwide
- “To feed or not to feed?”
- Attracting birds: seed chart of what birds like what seed
- Selecting a bird feeder
- Monthly list of tips for having a healthy backyard for birds
- Bird habitat necessities
- Start your own Ebird account starting at this link, or learn more about Ebird
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