How do you know a restaurant is good? If the parking lot is full of cars, that’s a pretty good indication. If it’s empty, you probably won’t bother stopping.
In this case, the restaurant is a newly restored wetland in Michigan and the customers are rails. The birds migrate at night, so if they don’t hear other rail calls in an area, they’re not likely to stop. Researcher Dustin Brewer is broadcasting recorded rail calls to try to bring the secretive birds to prime habitat – to feed and mate.
Rails are declining, mostly due to habitat loss. Experts say if rails are influenced by these recordings, it could help increase the bird's population. Find out what preliminary research shows.
Credits:
Host/Producer: Dan Wanschura
Editor: Morgan Springer
Additional Editing: Patrick Shea
Music: Axletree and Independent Music Licensing Collective
Photography: George Terrizzi
Transcript:
DAN WANSCHURA, BYLINE: Hey guys, Dan Wanschura here with a question for ya. Have you ever heard of the phrase “thin as a rail”? I don’t know about you, but I thought rail referred to like a guard rail on the side of a mountain road, or the rail on train tracks – something like that. But I was wrong. Here’s researcher Dustin Brewer.
DUSTIN BREWER: I think it’s been lost. A lot of us don’t even know that that term refers to actual rails anymore.
WANSCHURA: This is what an “actual rail” is.
(Sora rail bird call)
WANSCHURA: That’s a Sora rail. A small bird about the size of a robin. It’s one of many different kinds of rails. They range from about the size of a sparrow, to close to the size of a chicken. They’ve got long, skinny feet good for walking around marshy areas. And for food, they forage around looking for bugs and plants. But if you forget all that, just remember this:
BREWER: They are laterally compressed, they have to walk through very dense vegetation.
WANSCHURA: What do you mean, laterally compressed? What does that mean?
BREWER: So, their body is very thin from one leg to the other, like across their body, so that they can fit in tight spaces like between vegetation and the marsh. These are very secretive…marsh birds that are able to survive by staying concealed from predators.
WANSCHURA: This is Points North, a show about the land, water, and inhabitants of the Upper Great Lakes. Today’s episode, “Thin as a rail.” These secretive marsh birds are in decline mostly because of habitat loss. But recorded bird calls are being used to try to help bring rails back.
(wind and ambient wetland noise)
WANSCHURA: On a windy April day, Dustin Brewer and I are listening for rails. We’re at the Shiawassee River State Game Area in Michigan. Brewer is working towards his PhD at Central Michigan University. He’s interested in wildlife conservation, and he’s focusing on rails.
BREWER: Alright, so we’re ready to go in?
WANSCHURA: Let’s do it.
(sloshing through the marsh sounds)
WANSCHURA: We’ve got waders on, and we head out into muddy, knee-high water to the middle of a cattail marsh. Wetland habitats have been disappearing for a long time in the Great Lakes basin. According to research published in 2016, over 50% of original wetlands here have been drained for agriculture and other developments. And for rails, that means less quality habitat for them to live, survive and reproduce. But some of these areas are getting converted back to wetlands again.
Is that a beaver dam over there?
BREWER: It’s a muskrat hut. There’s a Canada goose nest on top of it, but a muskrat made that.
WANSCHURA: This area we’re in today has been converted back from farmland. But that doesn’t solve the problem for rails. In the spring, they migrate north from southern states. And they do it at night. This means they might not see the restored habitat.
Mike Ward is an avian ecologist at the University of Illinois.
MIKE WARD: I like to use the…analogy of humans and restaurants. Alright so if you go by a restaurant and there’s no one there, then the thought is it’s not very good, right? So you don’t have any information to use other than the fact that no one’s at that restaurant, but you assume there is something wrong with it. You go by another restaurant, there’s a bunch of cars there, you think, ‘Well, that must be the place to go.’ You stop and you eat there.
WANSCHURA: Ward says the same can be true for birds. If they don’t hear any other bird calls of their species, they might continue their migration. The habitat is missing what Ward calls a “social cue.” So, to try to trick the birds, Dustin Brewer sets up audio playback stations in and around this restored wetland area. That’s where we’re headed now.
(sloshing through the marsh sounds)
BREWER: Coming upon the playback station.
WANSCHURA: There’s a platform with a speaker on top of it. It’s attached to an audio device loaded with rail calls. And it’s jerry-rigged to a car battery for power.
(Yellow rail call)
BREWER: It plays on a loop. So I’ve got a variety of different instances of rail calls here so it’s not monotonous for the rails, hopefully. But it’s on a loop set to turn on an hour and a half after sunset, and it’s supposed to turn off an hour and a half before sunrise.
WANSCHURA: He’s targeting the Yellow rail, Sora rail, Virginia rail and the King rail heard here.
(King rail call)
WANSCHURA: Brewer says he plays the recorded calls as loud as 95 decibels, which is about the volume of a motorcycle engine. The King rail is the largest in North America and pretty rare in this region, according to Brewer.
BREWER: But if we could bring them to our playback sites, that would probably be some pretty good evidence that this does influence habitat choice by these birds.
WANSCHURA: Using audio playback like this has been tried before with other birds. And depending on the species, it’s worked. Mike Ward, the avian ecologist you heard earlier has done it with about 12 species of birds, including the Kirtland’s warbler in Wisconsin.
Broadcasting bird calls not only signals to them, “Yeah there’s a restaurant here, and it’s good!” It could also help increase the rail population. Ward says it’s like matchmaking.
WARD: It’s kind of like eHarmony, right?! So, just trying to get, in this case, birds together at the same place at the same time and so they can interact. We destroyed a lot of habitat, some bird populations are pretty low, and so the chances of them finding each other are kind of slim, right? And so all we’re trying to do is provide a cue … and then they start mating, pairing, raising young – those kind of things.”
WANSCHURA: Once a bird discovers good habitat, Ward says they’ll generally return to that spot every year.
Dustin Brewer is doing research both at control sites where there is no audio playback and at his experimental sites where there is.
BREWER: So, if it so happens that there’s more birds at the experimental sites when we average them all together, that would be good evidence that we are drawing them in.
(plucky violin music)
WANSCHURA: That was back in April. I recently caught up with Brewer to see if the audio of the rail calls was actually drawing in the birds during their nighttime migration. He says preliminary data points to, yes — the audio did influence where rails settled and the number of rails in a location.
BREWER: 5:49 A.M. May 25th, 2022…there’s a King rail kecking. Unquestionably a King rail calling here at Shiawassee National Wildlife Refuge.
WANSCHURA: Brewer detected that rare King rail near one of his audio playback sites — pretty clear evidence it drew the bird to that spot.
BREWER: A moment like that is really an example of the reason I’m in this line of research. Given that there are relatively few moments where I can see a very clear example of success, those moments are really special.
WANSCHURA: He says other birdwatchers likely spotted that same bird breeding.
Brewer says he hopes the results of his experiments lead to audio playback of rails across the Great Lakes region. And that that might lead to more people knowing what “thin as a rail” actually means.
