Pennsylvania’s state bird normally hides out in woodlands, away from people. But for a few weeks in the spring, a few of them are a bit bolder.
Ruffed grouse are wild birds hunted as game, and they like to live in young, dense forests. They’re brown, a little bigger than pigeons, and males have a band of dark feathers around their necks that puff up when they want to get a mate. But this time of year, a small subset of the birds display another behavior–they’re not afraid of humans, leading to the name “tame grouse.”
Reina Tyl, a wildlife biologist with the Pennsylvania Game Commission, says some people think that’s a misnomer.
“A lot of times they’ll run up to people, even show aggressive pecking at their pant legs,” Tyl said.
This spring the game commission is asking the public to report sightings of tame grouse as part of a larger study. The Allegheny Front’s Kara Holsopple recently spoke with Tyl about it.
LISTEN to the interview
[This interview has been lightly edited for content and readability.]
Kara Holsopple: What causes this “tame” behavior? What are some of the theories?
Reina Tyl: I will say we don’t know exactly what causes it. That’s part of what we’re hoping to investigate. Some of the theories in the past were that the birds were drunk. That they would eat old berries from the summer that had a chance to ferment, and maybe they were a little tipsy and so they were behaving abnormally.
Some of the other theories are that because it appears to be more common during the spring breeding season or sometimes in the fall when there are similar amounts of daylight to nighttime, people just thought maybe it was just a hyper-aggressive behavior during the breeding season. Male grouse this time of year become really territorial, defending their breeding territories, but also they drum to attract females. The thought was that maybe during that time of year, because their hormones start ramping up for breeding, they just are more likely to exhibit that behavior toward people.
Kara Holsopple: And is it just the males?
Reina Tyl: That’s something that’s really interesting. Every report that I’ve gotten so far, in photos and videos of grouse, and all the ones that I’ve captured so far or have encountered in the wild, have been males. We don’t necessarily think it means that it’s just males that can exhibit this behavior. We wonder if females maybe just exhibit this behavior differently.
Males are aggressive, as far as defending their territories and trying to find mates. It would make sense that they might care more about an intruder in their zone and be more physically aggressive towards a person.
But females might show this behavior differently as far as how they defend their nests and how they defend their brood. Maybe females exhibit aggressive behavior by more aggressively defending their nest from predators or more aggressively defending their broods from predators or other things.
Kara Holsopple: So you’re working on a ruffed grouse genetic study with Pennsylvania State University. What are you trying to find out?
Reina Tyl: The reason this study came about was to try to assess grouse genetic diversity across the state right now. A lot of folks are probably aware, especially if they’re grouse hunters or just invested in the resource, that the grouse population in Pennsylvania has declined over the long term, over several decades.
In the last couple of decades, those declines have been steeper due to a variety of factors: habitat loss and degradation and also the introduction of West Nile virus. That disease, we think, has been pretty detrimental to grouse numbers some years.
A lot of what we focus on with grouse habitat right now is maintaining connectivity between forest patches. Given that grouse numbers have declined in some areas and there might be isolated populations in portions of the state that might be a little less connected forest habitat-wise, we were just wondering if we were starting to see our grouse population diverge as distinct subpopulations.
So we are just trying to figure out if there are specific populations that are becoming isolated and if we can target habitat management in a way to maintain that connectivity, to make sure that the genetic diversity of our grouse population stays high so that they can be more resilient to future unknown changes, whether it’s weather changes or another disease change or anything that could happen on the landscape in the future.
Capturing these tame grouse could provide us with more samples for our genetic study. But potentially, we were just wondering, could this behavioral difference that we’re observing in grouse be explained by genetics as well? We figured while we’re looking into genetics, we might as well get some samples and see what’s going on here.
Kara Holsopple: So how do you collect the samples? You don’t keep the grouse?
Reina Tyl: No. That’s a good part about them being tame. We’ve had the greatest success where we have a grouse that’s hanging out on a landowner’s property pretty consistently. Someone will contact me and say, ‘There’s this grouse that every time I go back to the edge of my property with my ATV, it chases me down. I see them almost every day or several times a week.’
Then I’ll go out and visit with that landowner and we basically just mimic whatever activity that landowner normally does when they encounter that grouse. So usually we’ll go to where they see them with their ATV or their rotor tiller or whatever it is that seems to draw them in. Once that grouse shows up, we’ve just been netting them with a hand net because we can get within a few feet of the grouse. I have someone hold the grouse for me.
If you’ve ever done a 23andMe or an Ancestry genetics test, that’s essentially what we’re doing. I take a foam swab, swab the grouse’s mouth, and then let that grouse go. We’ve collected samples from four grouse so far, and I’ve got two visits lined up for tomorrow. And right now we are only planning to collect them this spring.
Kara Holsopple: You mentioned when someone reports a grouse, you have to flush them out or get close to them, and you have some techniques for that?
Reina Tyl: Yes. Grouse, during their mating display, do what we call drumming. They beat their wings back and forth really quickly. It actually creates a quick air vacuum under their wings and that creates a sound.
It’s a really low-frequency sound that sounds kind of like a basketball bouncing on a floor or something along those lines. Most times when you’re out, you actually kind of almost feel that sound before you hear it. We think that these tame grouse are attracted to that sort of vibration.
Landowners and people that have been giving me reports, if they’re running a chainsaw, the grouse will come out. Or if they’re rototilling up their garden in the backyard, you know, that kind of engine puttering, the grouse seem to be really attracted to that vibration. It’s almost like clockwork. If we have a UTV or an ATV and we can just drive that out into the area, a lot of times that grouse will show up within a few minutes.
Kara Holsopple: Sounds like it makes for some interesting wildlife interactions.
Reina Tyl: It does. It’s been fun. I’ve been having to take some folks out from the agency just to be my extra set of hands as I’m doing these captures, and some of them have never encountered this behavior before. So it’s really fun to watch people experience it for the first time. And the landowners that we’ve been working with, they’ve been really great. You can tell that they’re really excited to share their special tame grouse with us. So, yeah, it is a unique experience for sure.
Reina Tyl is a wildlife biologist with the Pennsylvania Game Commission.
The public can report “tame grouse” sightings to The Pennsylvania Game Commission at email@example.com. Please include:
- Phone number
- Date of the sighting
- Location of the encounter, including GPS coordinates if possible
- A description of the grouse’s behavior