DU Podcast Transcript: Ep. 21 – DU Chief Scientist Explains Hunting Pressure and the Impacts on Wintering Distribution (3 of 3)

Dr. Tom Moorman gets into detail about hunting pressure impacting wintering distribution of waterfowl

© Michael Furtman

Clay Baird: Welcome to the Ducks Unlimited podcast, the only podcast about all things waterfowl from hunting insights to science based discussions about ducks, geese, and issues affecting waterfowl and wetlands conservation in North America. We bring the resource to you, the DU podcast with your host, Chris Jennings.

Chris Jennings: We have been talking, where are the ducks? Basically wintering and migration waterfowl distribution. We've, we're gone through whether, we've gone through different habitat landscapes, annual rainfall. Onto the next topic, we're going to talk about hunting pressure and how hunting pressure impacts waterfowl distribution across the entire continent. I've got Dr. Tom Moorman here, DU's chief scientist. He's going to bring to light some very interesting points about hunting pressure. Tom, thanks for joining me today.

Tom Moorman: Thanks Chris. Glad to be here.

Chris Jennings: So tell us a little bit about hunting pressure and how... I think everyone knows that, you know, if you shoot at a duck it's going to fly away. But landscape wide, I think people have a little bit of a misunderstanding of, you know, when there's just consistent pressure on a certain population. And maybe it's just a... Let's just as an example, in southeast Missouri when there's just so many hunters and and such limited habitat in some cases, what are ducks doing? How much will they put up with? I'm sure if we could all answer that question, we'd figure it out. But there is some science behind it, right?

Tom Moorman: There is some. It's actually one of the more poorly studied elements of waterfowl management. I mean we're, the Fish and Wildlife Services is really good in doing databased harvest management. So our regulations on harvest are pretty clear and the populations are well managed in that regard. But harvest and hunting pressure are different animals. So the way to think about this is for your personal duck hole, if you overshoot it, the response of the bird is going to be to quit using it on a consistent basis.

Tom Moorman: Now scale that up. If all around you say in a circumference or radius, let's just say, I don't know, five, 10, 15 miles, what have you. If there's not refuge where birds can go and be undisturbed and that doesn't necessarily mean they have to have food on it, they just need to be there undisturbed and we'll get to what they probably do in the absence of food. If they don't have that, then you can also blow them out or at least thin out the density of birds because of disturbance.

Chris Jennings: Yeah.

Tom Moorman: And it's not just necessarily shotgun shells going off either.

Chris Jennings: Absolutely.

Tom Moorman: It's hunters accessing places via all kinds of relatively new technology for them. ATVs weren't real common until say the late 80s maybe early 90s. We now have surface drive boats. All those things that hunters get to places where ducks maybe were harder to get at or maybe they had some refuge benefits. So there's that kind of disturbance. There's shooting disturbance and there can be other forms too, but those are probably the two big ones. And as I often tell people, ducks, of all things they don't like, they don't like to get shot.

Chris Jennings: Yeah.

Tom Moorman: I mean this goes without saying. It's not necessarily bad that any do, but the survivors learn.

Chris Jennings: Yeah.

Tom Moorman: And you can bank on them learning. And so the more shooting that's going on, the more missing that's going on, or taking birds out of big flocks, there's a reinforcement of man. What's going on? What's going on? Disturbance, disturbance.

Chris Jennings: They're learning now.

Tom Moorman: And so they take avoidance behaviors. And so people get nervous, you know, or hunters sometimes get upset about seeing a bunch of birds sitting on a refuge. Well, there's a reason for that. They've been disturbed and, and access to those other habitats is precluded and they're hedging their risk, right? If I fly off this place, something's going to go boom. I may not die, but it scares me. So I go back.

Chris Jennings: Yeah.

Tom Moorman: Now they still have to feed, right? So they have to feed every day. A mallard's going to need somewhere on a neighborhood of fistful or two of some kind of food, native plant seeds or agricultural waste grain or something. And so we also see birds in the face of heavy hunting pressure become nocturnal.

Chris Jennings: Yep.

Tom Moorman: And I know probably lots of hunters have seen that, but that is a response to hunting pressure that often we kind of overlook. Birds have access to your habitat as soon as legal shooting hours are over until they begin the next day. And in the right conditions they'll sure enough make use of it. Sometimes all night.

Chris Jennings: Yeah.

Tom Moorman: And then they'll leave before shooting starts and you can watch them, but you can't shoot him. Frustrates hunters a lot.

Chris Jennings: Absolutely.

Tom Moorman: That's simply a response to hunting disturbance.

Clay Baird: [ADVERTISEMENT] Be the first to know when ducks are on the move. Sign up for DU's waterfowl migration email alerts and receive ongoing in depth updates on the latest habitat conditions, weather changes, and hunting reports for your flyaway. Visit ducks.org/migrationalerts.

Tom Moorman: There are other things that come into play here relative to hunting pressure and hunting success. Annual production's a pretty big deal. The number of immature birds or young birds in the fall flight. In years where there's good production of waterfowl in the prairies in the boreal forest, the riches are spread far and wide across latitudes. So even in the deep south, there's still young birds and hunter success goes up. In years like, unfortunately, I think this one's going to be, you know, it was pretty dry across Canada this year. So production is probably not going to be great. That's going to mean a population dominated a bit more by adults. Those young birds that are produced, you know, they're vulnerable. And so at northern latitude, hunters get first crack at them and they're going to sit them out.

Chris Jennings: Yeah.

Tom Moorman: And so by the time folks sit mid and southern latitudes, you know, birds start to arrive, you're going to have a lot more adults. And remember these birds have learned once or more.

Chris Jennings: They've seen a few decoys.

Tom Moorman: And if you don't believe that, think about snow geese.

Chris Jennings: I was going to say, that's the example that most people use.

Tom Moorman: When's the last time you saw snow geese flying about 40 yards high?

Chris Jennings: Yeah, exactly.

Tom Moorman: They hardly ever do it unless conditions are just really horrible, windy, foggy. That's a learned behavior and it's probably getting reinforced genetically now. And so it's, it gets, they get to be harder and harder to kill.

Chris Jennings: And I think that's something that people will reference regularly, you know, talking about the, you know, you see the juvie population of light geese and that's a very, it's very indicative of how that next season is going to be. But people don't necessarily relate that with even mallard, you know? The common hunter doesn't really relate that, but it may, it's a key factor in the fact that these mallards are learning the same way that the snow geese are. That's a great point.

Tom Moorman: Yeah, and you know, the other caution I throw out for folks is usually sometime in August, the Fish and Wildlife Service publishes their breeding population survey. Well, that's a survey of adult birds in May.

Chris Jennings: Yep.

Tom Moorman: And it does not necessarily translate to the fall flight. The juvenile production could be much higher than anticipated if wetlands are good, but much lower than you might think of just looking at the number of breeding mallards, you might think the population is going to be great.

Chris Jennings: Yeah.

Tom Moorman: But it might actually get worse and it'll decline if it's really dry. And so you got to be able to temper that with an understanding of what happens from say late May through about the 1st of August.

Chris Jennings: Yeah.

Tom Moorman: If conditions are good, things will be good. If conditions are not good, set your expectations accordingly because there's probably going to be fewer immature birds in the fall flight, which means you're going to be working on adult birds and we all know they're harder to kill.

Chris Jennings: Yep.

Tom Moorman: You better get your game on. You better get hid, better get your call tuned. Better not blow a bad note, all that stuff, right?

Chris Jennings: Yeah, they'll figure it out.

Tom Moorman: Yeah.

Chris Jennings: No, and that's a very good point of tempering those expectations. I know just based off of last year, me personally, I've decided to go into this waterfowl season with absolutely no expectations and just go in to say, "Hey, I'm going over to duck camp to have a good time one way or the other." So, and I recommend everyone do that. That's always a very, a very strong move. So if you go in with low expectations, you can't be upset.

Tom Moorman: That's right.

Chris Jennings: Well Tom, I appreciate you joining me. This has been great. I think what everyone has to do now is kind of check those weather apps, keep your eyes peeled for that next big front, and hope for some real winter weather. And if the weather cooperates, I hope everyone has a great duck season.

Tom Moorman: Yep, be an optimist, but balance your expectations with weather and think about production.

Chris Jennings: Absolutely. Thanks Tom.

Tom Moorman: You bet.

Chris Jennings: Appreciate it. Special thanks to Dr. Tom Moorman, our guest today, and a special thanks to Clay Baird, Ducks Unlimited podcast producer. He does a great job putting this show together. I'm your host, Chris Jennings. Thanks for joining us and thanks for supporting wellness conservation.

Clay Baird: Thank you for listening to this episode of the DU podcast. Be sure to rate, review, and subscribe to the show and visit www.ducks.org/dupodcast for resources based on today's topics, as well as access to more episodes. Opinions expressed by guests do not necessarily reflect those of Ducks Unlimited. Until next time, stay tuned to the ducks.