Ep. 693 - Ducks and Acorns: Red Oak Ecology and Management with Five Oaks

Jerad Henson: Hey everybody, welcome to the Ducks Unlimited podcast. I'm Dr. Jared Henson. I'm going to be your host today. We've got a great episode today. I think it's going to be something y'all are really going to enjoy, especially all y'all that like to travel down to the Mid-South, chase a duck around a tree. We're going to be talking about hunting ducks in the hardwoods. We're going to talk about acorns and ducks and some hardwood management and some aspects around waterfowl forage and acorns. So to do that, I couldn't think of any better guests than the folks over at Five Oaks. Ag Research and Education Center. So we've got the director, Dr. Ryan Askern, over here joining us. Ryan, thanks for being here. Hey, thanks for having me. And we've got Brandon Bennett, who is now the newest employee, I believe, at Five Oaks. Newbie. Newbie. What's your official title now?

Ryan Askern: I guess biologist, just to sum it up quick.

Jerad Henson: Yeah. Well, and so it's awesome to see some extra help around that. Love what y'all are doing. We've got to do some cool banding episodes down there, see some content and actually see what y'all are doing as far as the research aspect goes and the education. We've had some of your graduate certificate folks over on the podcast before, and that's always a fun, a fun time to talk to them and see them actually get excited about that stuff. Speaking of that, Brandon, you got a little experience with that? Oh, just a little bit. Just a little bit? Just a little bit. Do you mind giving us a little background on yourself and how you ended up at Five Oaks in the duck world?

Ryan Askern: Yeah, so it is crazy how it's all worked out for me, really. But I knew from a really, really young age that I wanted to be a biologist when I grew up. And sure enough, getting out of high school, I toured a couple colleges and found University of Arkansas Monticello and talked to the guys down there, and I realized this is where the stuff's happening. And so I wanted to do anything that had to do with ducks. And so that was the place to be, and I started college out there, and from day one, I wanted to be involved with everything I could get my hands on. And so that's what I did, whether I was paid or unpaid, it didn't matter, I was involved. And so quickly, I kind of moved up the leadership role, I guess, through the lab.

Jerad Henson: And you're working with Doug, right? Right. Dr. Doug Osborne.

Ryan Askern: Dr. Doug Osborne. I was in his lab, helped do a lot of different research topics there, and did a lot of the manual labor in the lab. The behind the scenes stuff. Seed sorting and digging through soil cores. A lot of stuff I don't even care to remember. Right. But all in all, helped me along the way for sure to get to where I am today. And then from there, it just worked out and just so happened that Five Oaks and Mr. George Dunklin there started a graduate certificate program. in what's the technical, I guess, title? Waterfowl and Land Management. Waterfowl and Land Management. So that, I mean, it fit right in exactly to what I wanted to do. And so just as soon as I graduated my undergrad, I went and interviewed there and happened to make part of the team, one of the four that started the inaugural class of the Five Oaks Ag Research and Education Center graduate certificate students.

Jerad Henson: So you stuck around now, though. Yeah, they couldn't get rid of me. I wouldn't want to leave either, I can be honest about that.

Ryan Askern: So after graduating with the certificate, I went and worked for Jody Pagan, who has restored more wetlands than most human beings that have ever walked the earth, probably.

Jerad Henson: Jody's a fun guy to be around. He's a wealth of knowledge in the topic.

Ryan Askern: Very, very knowledgeable human being, very high energy, and has just been really a fantastic mentor. That's awesome. And good knowledge base to lean on. And so it's, I've able to, I've tried to absorb everything I can. Sometimes he's got three different languages, he'll spit at you, and I'm multilingual in Jodi-isms, I guess.

Jerad Henson: But he's probably speak a little bit of soil science. Yeah. Because he likes his soil.

Ryan Askern: It's all over the place. Hydrogeomorphology. You may hear some of that come out and nobody else I think in the world speaks that language.

Jerad Henson: Oh yeah.

Ryan Askern: But no, I got to work for him for a couple two or three years and really did a lot of on-the-ground management, consultation through different parts of the country, a lot of wetland restoration, just duck stuff. That's awesome. In January, Five Oaks decided to hire me on full-time and now I've gone full circle really and now I help teach the graduate students and we do some research and land management and some grant writing and different things.

Jerad Henson: Yeah, getting a good well-rounded approach on it.

Ryan Askern: That's awesome. It's been great.

Jerad Henson: It's been great. No complaints here. I'm glad to see you as part of the team. And Ryan, you're no stranger to the podcast, so we're real glad to have you back. Thank you. And the reason we brought you all on is like, Five Oaks has the research aspect, and one of your primary focuses is bottom line hardwood research. Yeah. And so, we want to talk about that today. That's where we want to jump into this. So let's start real big. Let's talk waterfowl and red oaks or oaks in general. Let's just talk about oaks. And so when we talk about oak trees and acorns as duck food, right? Which oaks are we talking about?

Brandon Bennett: Yeah, we're mostly talking about the red oaks. I guess kind of take a step back, just talking about the geography, is a lot of times we think about timber just being important to ducks in Arkansas and the southern U.S. Really, especially historically, it was important. All the way up. All the way up, especially like Illinois, Iowa, Missouri. Unfortunately, because of a lot of the flooding, we've lost a lot of those oak forests where would have been historically really important stopover sites, but really red oaks. So those leaves that have little pointy things on the end of them, they're the ones that are producing the right size acorn. And that's really the main kind of key for what ducks eat is the size of the acorn. We haven't found a lot of differences. and kind of how much energy they get out of them. There doesn't seem to be a lot of differences. Most of the preference seems to be based on that size. So there are some white oaks. Those are the ones with the rounded leaves, not pointy leaves. The main white oak, Quercus alba, And then the Delta post oak is also kind of a bottomland species in these frequently flooded areas where ducks would be that produces an acorn that's small enough for a mallard or wood duck to eat.

Jerad Henson: Yeah, and those are some of the high preference. And they also favor, some of those red oaks favor those areas, right? That hydrology a little more. And so, which red oaks? Because it's not all red oaks. Y'all want to take us there? We can get species specific. Yeah, no, let's talk about the big ones.

Brandon Bennett: We talk about a lot of the ones that people call paint oaks. Down here, well, in Arkansas, it's mostly the nut-all and willow oak that are kind of the main species, but also cherry bark, which kind of occur at higher sites within these bottomland kind of wetlands. And then water oak, that's also kind of more of a ridge species, a little higher elevation.

Ryan Askern: And then if you get into some of the Gulf Coastal Plain, there's a shrubby oak called swamp laurel oak. It'll also be a food item at times. It's a little more rare, but… It looks a little like a willow oak though, right?

Brandon Bennett: Yeah, somewhat. Yeah, those are the main ones. And then a little further north, you know, pin oak. True pin oaks there.

Ryan Askern: Especially into Missouri, that whole forested wetland system is highly pin oak dominant.

Jerad Henson: I've even seen… some posts on social media and some other places talking about some hardwood hunting in Kansas. Yeah, it is lucrative. Eastern Texas, Oklahoma. Right, in that Central Valley area. So this does span out much further, right? Yeah, for sure. And I think there's some truisms and things we can talk about across all of those habitats. And when we're talking about ducks eating acorns, which type of ducks are we talking about?

Brandon Bennett: Mostly the wood ducks and the mallards. There's probably a few other species. Ringnecks is one that we've kind of been interested in that I would guess will probably eat some acorns occasionally. But that's study down the road maybe. I'm not sure if there's any literature to really support that. We certainly see them in the woods.

Jerad Henson: That's interesting. And that's something kind of cool. Wood ducks, like, and a lot of people, you know, they know that. Wood ducks get, like, to Arkansas in, like, October. And they are little hoover vacuum. They are. They are. They are. They are greedy little animals. You'll see them running across, like, you'll see them, like, waddling across dry ground across a flat. And, like, I'm a big bow hunter, and that's one of my favorite things. Like, you're like, oh, here comes a big old herd of, It sounds like elephants, but yeah, it's a sight to be seen.

Brandon Bennett: They're hungry, and you know, a lot of those acorns are just starting to drop, so it's not like there's a huge bounty of them. We even see along some of the ditches, like where there's a willow dropping acorns into a ditch. We'll see what ducks diving for them. Really? Especially early in the season. Yeah, we got some trail camera footage of that during banding.

Jerad Henson: Well, since you bring it up, some of that chronology of oak drops. Not all oaks drop at the same time.

Ryan Askern: Yeah, and not all of them are eaten at the same time by different animals. If we go past ducks, if you think about a white oak versus a red oak, where do you want a deer hunt at? It's at that white oak tree that's just dropping acorns. Well, a lot of that is due to tannin content within that acorn. And then sometimes you'll see a squirrel bury away a bunch of acorns. Well, some of that's for food storage and then other parts of that is for getting rid of some of those tannins in the red oak acorns just through percolation of the water. The tannins can inhibit some of the metabolic functions that that animal may incur. Okay.

Brandon Bennett: Inhibit digestion.

Ryan Askern: Yeah, it can inhibit digestion and mess with some of the proteins within that. But no, just a kind of rabbit hole you can go into if you want to.

Brandon Bennett: Oh, I imagine. But a lot of them, like, not all kind of meters their acorns out throughout the season. So you'll get some starting to drop in October. really be dropping throughout.

Ryan Askern: They're fairly marcescent, meaning they hold on to the stem for long periods of time. You get high wind events and it knocks down some of them, but it's more periodic rather than like a heavy drop of a white oak.

Jerad Henson: Gotcha. Yeah. Yeah, you get under a hot white oak tree and it's like walking on marbles. It's intense. And it seems like willow oaks drop, kind of temper that out a little bit. Are they heavy on the front end, back end? What would you say?

Ryan Askern: It's really all over the place and some of it depends on the amount of crop of that year. And I mean, a lot of that information can be anecdotal just because you'd see it that one year and it may be a heavy crop year. You think, my gosh, it's dropping a lot real early, but it could just be a heavy crop of acorns that year.

Jerad Henson: Okay. And yeah, that's kind of something that's like, I was talking about the wood ducks. They love some willow oaks. Oh, yeah. They do. But they are little bitty. That's their smallest acorn, right?

Brandon Bennett: Very small diameter. Really easy for them to handle. They're probably not expending as much energy to crush that up as it would take for a bigger acorn.

Jerad Henson: Yeah, and there's other birds and a bunch of other species that take advantage of that because they're small. Blue jays will crush them. Love them. They are a bully bird for an acorn. So, let's kind of jump down this row real quick. How much food is there? What's the food value, the forage value of an acorn to a duck?

Brandon Bennett: Yeah, so we focus a lot on really kilocalories, kind of the raw energy of that. Obviously, there's a lot more that goes into diets. We always go back to the cheeseburger example. If you're eating a cheeseburger every day, you're getting a lot of energy, but that's not healthy for you. That's not making you a better human being. So really, there's a lot of nutritional quality that goes into it. But from a strictly kind of energetic calorie standpoint, really low, really low compared to like unharvested crops, moist little wetlands, at least based on the literature. So on the high end, like, do you remember what 40% red oak, what the duck iron G days is?

Ryan Askern: Oh, so on the low end, you're looking at maybe 30 to 40 DEDs an acre, whereas on the high end, you could be upwards of 300 DEDs an acre.

Jerad Henson: Yeah, that's duck energy day is kind of what we're talking about. That's the forage value for a duck for a day for an acre kind of thing. To sustain a duck for a day. And so that's a huge kind of continuum you just put out there. And that's, I think that's something to talk about. So how do you get such a broad

Brandon Bennett: Well, you've got high variation between years. Right, so difference in mass production. Different in mass production, depending on kind of the canopy openness and the forest structure, you can have other food resources there. So moist soil seeds, these naturally occurring annual vegetation that produce lots of seeds, are one of the big ones we think about. Invertebrates, which we know is a really important part of their diets, more for the nutritional side, do really well in especially these healthy bottomland ecosystems. And healthier trees are going to produce more acorns.

Ryan Askern: And even within an individual, you can be talking some crazy variability among mast crops, among years. And some oaks will, some of them will never grow an acorn their entire life, which is, this is part of kind of that management side we'll probably go into later. If you have especially smaller acreage, understanding the individual trees and their history of mass crop can really go into your management styles.

Jerad Henson: That's something that I didn't really put a whole lot of thought into, right, is understanding that. And I think that's going to be really important going forward here in a minute. And so when we talk about that variance and the health of those trees and things like that, that's something that's been talked about a lot right now. It's a hot topic is forest management health. And I don't want to jump down too big of a wormhole here, but note, I do want to make a point that high quality forests can produce a lot of forage, right? and low quality, little to none. I think 30 DEDs, is that what you said? 40, 30 to 40. What's the give up rate for a duck?

null: 40.

Jerad Henson: Right, so anything below 40, a lot of times the science has shown that ducks will give up on that habitat. They'll go find some other food source. Especially if you add in any kind of pressure at all among that variable. Right, right. And that could be a whole other episode in itself. Lord, let's not go into that. And so you mentioned a little bit of those other resources. And so before we jump into that stuff, I kind of want to get a little bit more into that red oak ecology or that oak ecology, since we did mention a little bit of white oaks. So what are some of the key biology and the key ecology of those oak species?

Brandon Bennett: Yeah, so differences in kind of mass production, how often they're producing acorns. One of the things we talk a lot about in oncology is predator-prey relationships, and a lot of how these oaks evolved is really based on those predator-prey interactions. It's funny to think about it this way, but acorns have predators. They've got mice, squirrels, blue jays. So that's really influencing how often they produce acorns, kind of how they drop. That's probably the differences between red oaks and white oaks is a lot of these bombland kind of species that evolved in floodwaters evolved to drop acorns into the water. So they're not as exposed to predators as, say, a white oak. So that white oak's probably dumping a bunch of those acorns at once to hope that the predators can't get all of them. And that at least a few of them make to be seedlings and pass on to their genes.

Jerad Henson: Squirrel forgets a few of them and went ahead and planned for it.

Brandon Bennett: They will. Yeah. So red oaks produce acorns every two years. Two years. So right now we've got the acorn bud for the acorn that's kind of growing and filling out the summer that's going to be dropped this fall and winter. But we also have buds that are starting to emerge that are actually going to be acorns for next year.

Ryan Askern: So oak, just to kind of get into some reproduction, I don't want to go too far in the weeds here. I can spend days talking about it, but I don't want to bore everyone to sleep. So oak trees are dioecious, meaning they have both male and female parts. You see the catkins generally drooping down. That's when everybody's sneezing everywhere.

Jerad Henson: The pollening, the yellowing of the Mid-South, yeah.

Ryan Askern: And so when we talk about the fertilization of these flowers, what do you think would be the best time for that to occur? Well, it's generally when everybody's sneezing. Everybody's praying for a rain, but it's just the opposite for me when I'm a tree nerd and I'm really wanting high mass production and I see a lot of flowers on these on these oak trees. I'm hoping it's dry and it's windy because there's a level of humidity that these pollen sacks on the end of these catkins have that they need to be able to break open and disperse. And then they're wind dispersed and then it's caught, if you look, at the new section of stem growing on the end of an oak tree twig, you will see at the base of the leaf, there'll be a little flower.

Jerad Henson: Yeah, they're teeny tiny.

Ryan Askern: They are little bitty. You really need to know what you're looking for. Sometimes there'll be multiple flowers, which is even better. That pollen gets blown in the air, and then it's caught on the stigma of that flower. It's just a little sticky portion of the flower. And that's kind of the beginning of the fertilization process. So dry and windy would be fantastic.

Jerad Henson: And those flowers are teeny tiny, right, because it's wind pollinated. They're not trying to attract a bee or a butterfly or anything like that. They're very small. Yeah. And out of each flower, you would get one acorn. So dry and windy. So you're looking for a dry and windy. at least a couple weeks in a spring at least.

Ryan Askern: I mean there's not a lot of literature that goes into it, but that's when fertilization seems to be great. As long as the flower abundance is present to be able to catch the pollen. Now flower abundance can differ among years just as mass crop will.

Jerad Henson: Well and that's going to differ on the tree itself.

Ryan Askern: It can be individually highly variable.

Jerad Henson: And that kind of leads into, I guess before we jump into that, but So it's every two years for red oaks, every year for white oaks, which y'all just mentioned, but that doesn't mean that there will be no red oak production one year, right? It's just, there'll be some years that have much higher, because more trees are on that two-year cycle.

Ryan Askern: If you look on that, if you look behind this year's growth on the twig and look at last year's growth on the twig, that's where you'll find This year's acorns. If you look on the new growth on the twig, that's where you'll find this year's flowers, which will hopefully grow into next year's acorns.

Jerad Henson: But a lot can happen between now and then. That kind of brings into that next question is, what are those factors that do impact? mass production that we know of, like nutrients.

Ryan Askern: Right. That's a million dollar question, really. I mean, you can get really chemically heavy, but it's all over the place, really, as far as the literature is concerned.

Brandon Bennett: Yeah, I mean, from the literature, a lot doesn't really support that fertilization or really kind of that nutritional quality that's available to that tree is driving it as much as climatic, just kind of random stochastic factors that are influencing that. And that's probably a big part of why it's highly variable. So obviously, things that stress trees. Flood stress is one of the big ones we're talking about right now. We currently have a lot of water on woods that doesn't need to be on woods. It's probably hurting the aerobic respiration that those trees need during this growing season. And then later in the summer, especially the last two years seem like have been really rough in Arkansas, is drought conditions. So going from flood stress to drought stress probably has, you know,

Jerad Henson: And that's going to mess with the root system of the tree. For sure.

Ryan Askern: Shallow rooting is a huge problem, especially in forested, flooded areas.

Jerad Henson: And I think one of the things that's going to be really interesting about that as well, or that we need to talk about, is the difference between what type of flood stress. Water is not just water. I do know that from hanging around some of y'all a little too long. Moving water seems to be Little less detrimental.

Brandon Bennett: Yep. And we're, there's still so much we still need to learn on that side of things is we don't have a lot of hard data for anything I'm about to say. But yeah, it seems like dissolved oxygen, water moving across the woods. And when you think about how these systems evolve, they evolved to be flood stressed and we've altered the hydrology, we're draining water off the landscape faster, we've destroyed most of the wetlands that would have held that water and kind of, you know, tempered the flow of water into these river systems. So it's coming at different times, it's coming at kind of more greater intensity, greater depth. For longer periods. But they were, historically, they were exposed to that flooding, even during the growing season at times. So when the water kind of comes up and there's current going through, and then it sucks back down in the matter of a week or two, and that's probably not having a huge effect. When we put stagnant water on them, so when we artificially impound them and leave it flooded for several months, water source is another thing we've started talking a lot about is well water versus surface water.

Jerad Henson: I heard y'all talking about this one day and I thought that was like, and y'all even talked about it too as far as how that impacts your ag fields and duck use, which is bizarre.

Brandon Bennett: Yeah, and that's a lot of harebrained kind of pontificating, but things that we really think need to be examined and better understood to kind of guide our management and conservation efforts.

Jerad Henson: And so on that, so you did mention a little bit, and the Mid-South, the past Arkansas, Mississippi, there was not an acorn to be found in those bottoms. No doubt. And I hunt in the White River bottoms, I deer hunt down there a bunch as well. I walked over 40 miles, and I don't think I found a feed tree for… You're not alone. And so, like, that blew my mind, because that's generally fantastic habitat, even some of the higher places, and a combination of… And do y'all have any ideas? Like you said, the drought cycle is probably a big part of that. Maybe the drought and flood cycle is kind of double-teaming it? I don't know.

Ryan Askern: So just based on kind of looking at the trees, just general observations over time, I've noticed it affected both White and Red Oaks from what it seemed, at least in every area I've been in, which is pretty vast in the MAV. But from what it seems, because White Oaks are a one-year producer and Red Oaks are a two-year producer, and we didn't get anything this last year. It seems that the high drought period that was a pretty substantial amount of time last year. Oh, yeah. It was dry. Really, really put in effect. And I'm sure the heavy freeze that we had that spring before didn't help anything. So you're talking about a highly stressed environment from the very beginning at the growing season. falling right into a heavy drought-y period, and I found many, very many, aborted acorns.

Jerad Henson: Meaning that… That tree's going into survival mode.

Ryan Askern: Right.

Jerad Henson: Right. They're going to forego reproduction.

Ryan Askern: The tree just broke them off and gave no more energy into that. It's going straight into survival.

Brandon Bennett: Yeah.

Ryan Askern: Yeah.

Brandon Bennett: Sucking all that energy back into the trunk and not trying to reproduce.

Ryan Askern: That makes me think that this drought, followed by that freeze possibly, really put a damper on the acorn production.

Brandon Bennett: What are your thoughts on the ice storm we had two years ago? How could ice storms kind of impact?

Ryan Askern: Let me backtrack and go into some of the processes of how this acorn forms. So once pollen's caught on the end of that flower, it's not fertilized at that point. And a red oak. It's not fertilized at that point. It's more of, I'll say, stored. And then further from, I'll say, end of July through April-ish, that flower is then covered by capule material, which is going to become the cap of the acorn. It covers it, and it's protected. at that point, but if there was an event that was to occur that damages that capule material and then goes into the flower, you could see damages that could have repercussive effects in the future. And that could be part of that freeze problem, as well as limbs breaking. That could be a big deal. You don't have the whole limb, you're not going to have an acorn on the end of that limb.

Jerad Henson: Right, yeah. Pruned a bunch of trees.

Brandon Bennett: Right. One of the other things that, hopefully this isn't getting too controversial, but pesticide use during, especially that flowering period, we really don't know the effects. We know we've got some pesticides that are really driftable, that just means they They get up in the air and can travel kind of off-site. And we see effects of that. We see leaf curling. We see physiological signs of that.

Jerad Henson: I've noticed that. I've noticed in edge-of-field effects and things like that when you're driving around some well-established oaks after they do a herbicide application, you can tell, man, that burned those oaks pretty good. They're older oaks, right? So they've seen pesticide before.

Ryan Askern: If you have a flower that's trying to catch airborne materials, it's going to catch an airborne pesticide or herbicide.

Brandon Bennett: So that's just an area that, you know, we're interested in. Yeah, absolutely.

Jerad Henson: We need to understand those effects. That sounds good. Well, I think this is a really good spot for us to take a quick break. We're going to come back onto this in just a second. We're going to go with more suggestions on habitat management, some suggestions for you as a duck hunter to better understand these habitats to actually take advantage of these resources. And so we will catch y'all in just a second. Hey y'all, welcome back to the Ducks Unlimited podcast. We've got the crew here from Five Oaks and we've been talking about acorns and ducks and kind of, we talked a lot about the biology, the ecology. Now we're going to jump into a little bit more on the management side. And I know enough about this stuff to know depth, duration, and timing of water is kind of a big aspect for managing for this on the Southern end or in that stopover site. So can y'all speak to that a little bit? talk about, so let's start with depth first.

Brandon Bennett: Yeah, so I guess, again, taking a step back, all these trees evolved for different water conditions.

Jerad Henson: Right.

Brandon Bennett: So they evolved to be at different, what we call niches, different kind of elevations within these forests. And that's why we've got some that are really more water tolerant, some that are much less water tolerant. So really, I mean, the depth, duration, timing influences species differentially.

Jerad Henson: They're all connected.

Brandon Bennett: Two, but they're all connected and those things, yeah, are tied to where these trees are kind of occurring in these woods. And that's why we're really interested in red oak health is because a lot of those trees are less water-tolerant than St. Overcup Oak, the species of oak that produces a huge acorn with a big cap on it that we know isn't a super important diet item for mallards and wood ducks.

Jerad Henson: Just from a physical standpoint, that's a big acorn. Yes. It is. It'd be.

Brandon Bennett: A huge cap. They're not snakes. They can't unhinge their jaws. It's amazing what they can get down that gullet. Exactly. They're not that big.

Ryan Askern: And if you think historically, I mean, from the beginning of GTRs, that DDT, depth, duration, and timing changed completely across every impounded area. It went from depth is whatever I can get my boat into. Yes. Duration is at least all the duck season, let's catch the rice water on the front end, and so we don't have to spend any money on water. So you're getting super early water, and then timing is, well, just as soon as we can catch the water till the ducks leave.

Jerad Henson: Or till I need that water later for rice. Right, right. And I think if you look at, was the first GTR, was the Tyndall Reservoir? Tyndall, yeah. It doesn't have many trees in it left anymore, but they were flooding. It was brought in for rice agriculture, that was the purpose.

Ryan Askern: The name would have been one of the first detriments to the trees. It's a green tree reservoir. They were first used as reservoirs.

Jerad Henson: So when you look at those species, the most water tolerant is? As far as oaks go, it would be overcup oak. the preferred. Beneficial oaks. Yeah.

Ryan Askern: Oh, beneficial. It'd be, uh, you'd be drifting more into the nut all and some willow oaks.

Jerad Henson: Right there. But I mean, how many months can they handle water? How many weeks, weeks, months? What's the thought? Some nut all. After, and I will say this, I do know that that's, after they've gone dormant, right? Leaves are falling off. If you start flooding green trees, green leaves, that's really, that can be detrimental.

Brandon Bennett: Yeah, and we'll even say, so now, and then this is a lot of work that Dr. Babs at UAM is doing, they're really not ever going completely dormant. They're kind of going into senescence, so they're slowing way down, but there's still… The word dormancy is probably one of the most detrimental words to ever happen to a tree, especially in the MAV. So that flooding, I mean, anytime there's water over those trees, when they have to go into anaerobic respiration, that's to the detriment of that tree. So flooding, except in the drought for irrigation, is pretty much always having some negative effect on those trees.

Ryan Askern: So I don't know, in terms of weeks, that… I mean, if you've got like… I mean, some of these trees are the same species and different elevations have physiologically adapted to different durations of flooding. I mean, if you go into a very, very low area and find a nut all acorn, it's going to be much more physiologically adapted to higher frequency and longer duration flooding as to one that you find more on a ridgetop. Right. That elevation occurrence is highly variable as far as being able to handle different durations, but in general, you want to flood as late as you can and pull it off as early as you can. It's for tree health.

Jerad Henson: For a willow oak, though, I mean, a couple months, maybe eight weeks, maybe. I was going to say, even four weeks is probably about max.

Ryan Askern: I like to, when I talk about this Delta floodplain, I like to, people don't like this sometimes, but I compare it to a toilet bowl. Yeah. So if we were to look at where the water sits, think of that as your water system, whatever that may be. Where would these oaks occur? Well, it would be not too far above that water line, but far enough it's not setting in the water.

Jerad Henson: Right.

Ryan Askern: And what happens when you flush the toilet? Well, same thing as a flood, a natural flood would occur. It would come up, reach up into those trees, and then come right back down. Right. It's a pulse. Right. Very pulsating, low duration, the frequency would depend on year, but that long duration has really, really done a lot of trees in.

Jerad Henson: And so that, so that's what, so nut-alls, willow oaks are probably your most tolerant of that? In general, yeah. Cherry bark and water oak.

Ryan Askern: They're a little further up the hill. In those bottomland hardwood systems. They're much more highly intolerant. Now all these red oaks that we've talked about are classified as no more than mildly intolerant. And some of them are water intolerant. Whereas an overcup is fairly water tolerant.

Jerad Henson: They handle it and that's what a lot of systems are moving towards is that because they do tolerate the prolonged flooding for 60, 70, 80 years, right?

Ryan Askern: And that's why we've seen in a lot of forested systems a species composition shift. towards much more water tolerant species such as overcup water hickory.

Jerad Henson: Well, and I think that brings up a really important point that you just talked about when you're going into forest management or reforestation. Seed source, right? If you go pull oak trees from a nursery and that's growing trees in high ground or collected acorns on a real high elevation area, they're not going to do well if you put them in wet areas.

Brandon Bennett: It goes back to that different physiological adaptations based on elevation. Yeah, and that's one of the things. We've got a little greenhouse that we're just kind of moving to use for experiments in red oak physiology and growth type stuff. We collected acorns from one of our really low sites, this block of woods that gets flooded by the bayou pretty much every spring. We collected some from a high site, probably 10-year flood plain historically. I mean, really, the bayou almost never backs all the way up into those woods, so much higher kind of elevation than those low ones. We saw huge differences in even just how those trees emerged. Really, the timing of germination was wildly different. We had those high sites, even though they were in a greenhouse in the same medium and pots, those high sites were emerging early and just kind of gradually growing. I thought all the other ones were dead, and all of a sudden they shot out and just surpassed. I mean, shot way up. And that's probably a flood adaptation within that specific, you know, genetic.

Jerad Henson: They got to get tall enough to get out of the water for between a post or something.

Brandon Bennett: So again, that's just kind of anecdotal stuff, but stuff we're really interested in using that to inform how we are reforesting, where we're collecting these acorns from, and making sure we have kind of, I guess, a phenotype to the genetic or the ancestry of those that best fits or best sets up that acorn to survive in a given site. Yeah.

Jerad Henson: Well, so once you get them up and we get a forest established or you're trying to manage a forest, I think there's some guidance y'all can give as far as that goes as well as about what a forest should look like. Water management and thinning.

Ryan Askern: Right. If it doesn't look like a nuke went off in the woods after a thinning, you've probably done it wrong. So, to make it attractive to a duck.

Jerad Henson: Or is it better for the trees, too?

Ryan Askern: I mean, just overall holistic management. I mean, you want a super diverse structure, and it's gonna, even if you cut some oaks, you gotta understand, if you had a stand, let's say hypothetically, of 100% oak trees, and you cut, half of those trees, if it was a closed canopy system, and you cut half those trees, you could have up to twice as many acorns in that system just from canopy expansion. And then that comes back to where we talked about knowing those individual trees and their history of mass production can really come in handy if you're working on a smaller system. Because if you're releasing those high mass producers, then you're hitting a home run on a good year, especially.

Jerad Henson: That's really cool to think about. And you talked about opening that up, and that also opens up canopy floor, the forest floor for regeneration. Regeneration, moist soil seed production. But in the time until that canopy closes back, Yeah, you get the best of both worlds. You've got a ton of food in that system through those.

Ryan Askern: Right. Yeah, moist soil production. And then there's going to be just high soil disturbance just from equipment moving in and out of it, which is going to propagate those moist soil seeds. And it's altogether just unreal the benefits you can see from a good thinning.

Brandon Bennett: Yeah. We really, so I'm working with one of Doug Osborne's students at UAM, Mackenzie Weirich, who is also in our graduate certificate program. Working with a bunch of these GPS transmitters that we've had out, using LiDAR data to really kind of map out the forest, the structure. And yeah, we're seeing these transmitter mallards use areas of more open canopy. So about 50 to 60% canopy seems to be kind of the highest selection for those areas. And you know, we haven't disentangled kind of the moist soil seed production, the food that's available there.

Jerad Henson: But something about those sites is more attractive to a duck. You can say that from the data so far.

Brandon Bennett: Yeah, something's more attractive. And that goes back to basal area too, is they're selecting a lot for those more open, kind of older growth trees, I guess probably 50 to 70%.

Jerad Henson: But with canopy openings too, right? Yes.

Brandon Bennett: Not big, open, closed canopy, right?

Jerad Henson: That's a different system there.

Brandon Bennett: And that's not to say, I mean, we want to be thinking about the whole ecosystem all the time. There's all sorts of other things that go into how we should be managing these forests and how to benefit ducks. But just from kind of that raw kind of use availability data from those transmitters, it seems like those kind of middle-of-the-road canopy openness and stem densities are really important.

Jerad Henson: What about like, oh, five to six, seven, eight years past disturbance? when you start to get enough, the canopy's not closed yet, but you're starting to get some regeneration and some thickets.

Ryan Askern: Hopefully by that time with correct water management, you've got good advanced regeneration coming back up.

Jerad Henson: And so, but those thickets, do y'all see use of that? I know on the public land side where I hunt, and this could be a pressure question, not a food resource, but those ducks hole up in thickets. They stay in there, whether it's trying to avoid the weather or people or aerial predators.

Brandon Bennett: We haven't seen as much of that. I think specifically on five oaks is what I'm speaking to. And I think some of that has to do with kind of the other areas they're using. So they're spending a lot of the day in scrub shrub wetlands. bunbush, and then some younger actual oak plantations that are in CRP. So I think they're using those habitats more so for kind of those courtship behaviors, getting away from predators, getting out of sight from other ducks when they're paired up. So that's kind of one of my hypotheses about why we're maybe not seeing as strong of a signal for that is we're not seeing a huge change through the season, like they're not using those thicket areas a bunch later in the season. But I think that just has to do with what else is kind of available for them. in our specific geography, whereas if you're big blocks of woods, yeah, those areas within the woods are probably really important for those kind of behaviors. Habitat variability. Right.

Ryan Askern: Habitat complex. High diversity among the complex. Yeah, that's key. That the duck is using.

Jerad Henson: Yes, they can't live on one type of habitat. We had a podcast the other day I was talking to, and one of the questions was asked was, You know, if you've got a small property, what would you do to manage it most effectively to be, you know, the best duck hunting spot? I quickly said, I want to know what all my neighbors are doing, and I want to do something different.

Ryan Askern: If you can find the limiting factor in the area, you control the limiting factor, You can, you control the ducks.

Jerad Henson: Right. You're going to have something they want in that habitat, you know, and so that's kind of same thing, that diversity, right? They're going to seek out those other habitats. Okay. Well, I want to come back really quick because we kind of hit at it a little bit. So, we kind of mentioned duration a little bit. So, a pulse of water, you don't need to flood your trees October to, you know, March. Yeah. Right? Definitely not. How long do y'all try and hold water on trees?

Ryan Askern: Well, it's highly variable among stands, so we're fortunate enough to have multiple impounded areas, so we can kind of stagger those off, and we may pull water off earlier than different areas. If we have a higher site, then we may try to inundate that area for a much lower point in time.

Jerad Henson: We have some… You stair-step them up. Right. The water levels up.

Ryan Askern: We don't want to flood at 100% full pool in day one. I mean, we've got some points in the GTR where it's only flooded the last week of season.

Jerad Henson: When's your flood date, your first flood date?

Ryan Askern: In November. Yeah, middle towards the end of November. Right, and some of that's weather.

Jerad Henson: Are y'all reading trees? Or like, looking at the trees, looking for that?

Brandon Bennett: A lot of it's where we're flooding, so a lot of times we're flooding areas that are natural sloughs, where they might have some red oaks on the edge, but most of the time they're, you know, hickories and overcup. Which naturally may have been standing water at one point in time. Yeah. Whereas, you know, those higher sites, especially the higher elevations that we know were less frequently flooded are the ones that we'll usually hold back, and then also try to palter those three years, not have the same water management schedule for an individual GGR ever.

Jerad Henson: That's a Heitmeyer thing. That was something he found, and he, you know, like the four impoundment rotation, and one year was no flood. And his, which is not real desirable for some people in the duck club, but those, that soil does need to dry out, and those trees need to be able to run those tap roots back down. Okay, so that's kind of the window, and the other thing we didn't really get at that we kind of mentioned was depth. How deep are you flooding most of these trees, maximum?

Ryan Askern: Well, we're hunting it about shin deep. So I mean, it depends on what stage of the flood and what point in that forest you're at. So if you're in our first flooded area at the end of season, then it's going to be deeper than where we're flooding at the very end of season. But in general, we're flooding up to shin deep around that.

Brandon Bennett: Well, we're going shin deep or shallower for those ducks to be able to forage, for them to get those acorns, moist soil seeds, and those invertebrates. Sometimes the invertebrates will be suspended, attach things. But for the most part, that kind of leading edge of water, that new water, is where those ducks are feeding, where they're focusing their energy. You want to follow the water line.

Jerad Henson: That's it.

Brandon Bennett: Rising flood, you want to be on that. that kind of leading edge of the water.

Jerad Henson: On the edge, so there's a lot of resources in that leaf litter that are only available for two to three days. And so they're super attractive to a duck.

Ryan Askern: And if you have a thin forested system, then you also have those moist soil stems that It's just a much higher diversity of invertebrates that can occur within that same system.

Jerad Henson: So that's that depth duration timing. Timing. Right. You want water off by when? Well, best case scenario.

Brandon Bennett: Historically, these trees were probably more adapted to these spring floods. We know those are often the wetter time of year. But, I mean, kind of reading the trees, and oftentimes we've got the water pretty much off all of our woods by the middle of February, towards the end of February. And, you know, still some slough areas that we might let it stay in there. We want to make sure we're not just ripping all the habitat off the landscape for these ducks before they go back. Some of our transmitting data has shown that a lot of these stay into March. So, obviously, you don't want to just, you know… remove all the habitat off the landscape. They need that energy, especially right before they go back. So spring floods are much less detrimental.

Jerad Henson: I wouldn't necessarily say that. Because then an early fall flood?

Ryan Askern: As we leave out of dormancy as well, and we start to have a lot of heavy leaf on, the root systems also have a surge in respiration. So you could go out in an area that's super saturated right now, drill a hole in the tree and there's water. You're liable to get shot with water shooting back out of the tree just because of that heavy root respiration that's going on.

Jerad Henson: So having water on trees through April, May, and June, probably not good. Let's avoid that. Yeah, less than desirable. Sometimes out of our control, unfortunately. Right, and some of those natural systems now. So that's kind of one of the things I want to talk about. And then or we wanted to mention. Let's kind of go quickly, basal area. You said open, but like basal area or stems per acre, what's y'all's recommendation?

Ryan Askern: Well, most, a lot of systems that are ready for a cut are beyond ready for a cut. So they're at 110 basal area, and that's just the square footage per acre of space that they're taking up. So they're around 110, 120 plus basal area, that's including the mid-storage trees. So we want to cut that way down to, it could be 60, 70, let it start filling back in, and it may be multi-stage. We may not go straight from 120 to 60 just because wind throw can be such an issue. So we may go from 120 down to… 80, 90, and then in a couple years, we may come back in and do another thinning, and through this thinning, we're kind of doing the opposite of what foresters have always done. We're not high-grading the area, we're low-grading. We're leaving the best and taking the rest.

Jerad Henson: Yeah, okay. And again, that's like you mentioned on those smaller areas, and on those trees and where you've got the most production. Right. And even if it's not super small areas, if you've got an area where you know where this ridge or this little high spot always produces well, you may not know those individual trees, but you know that something's going right there, right?

Brandon Bennett: What if you're seeing, you know, any sort of regeneration, advanced regeneration, you know, saplings that are getting to shoulder high, you know that's probably a good area. And these red oaks are really light loving, they need this sunlight, so that's where the canopy openness That's really what you need to regenerate these forests. And that's we're seeing a lot of state, I mean, federal and private ground where we just don't really have this advanced regeneration yet. We've got all these trees that are aging out and getting sick from the flood stress and we don't have red oaks to replace those. And that's that's really one of our biggest concerns. That's I mean, a big part of why we're here is to to better understand that and figure out how to kind of rectify fix that.

Ryan Askern: Right.

Brandon Bennett: You take us to our core.

Ryan Askern: We're just sunlight managers. So that's all we're doing. We're trying to flooded as little as we can to have a high productive duck season, and then manage the sunlight. Because we want a new forest coming in underneath our currently one.

Jerad Henson: You're looking to tomorrow, not just today. Right.

Ryan Askern: We want to look a hundred plus years down the road.

Jerad Henson: Well, and peak acorn production is how old? Roughly for red oak, what the literature says?

Ryan Askern: Yeah, as far as peak goes, it's pretty variable depending on canopy openness, but you may start to see acorn production at year 12 on a really good tree on a lot of these red oaks, but yeah, peak production really depends on how open and spread your canopy is. 30, 40 years old is pretty good.

Jerad Henson: And then pass, and then once they get, you know, 60, 70, they might not produce as well.

Ryan Askern: And in an area where I see just crazy, stupid acorn production, and then I look at the canopies and it's not doing very well, I'm extremely concerned at that point because they will go into a fight-or-flight mode where reproduction is their number one goal. I'm dying. I'm dying. I want to put out as many seeds as I can. I've noticed that. And get my genetics out there. And when I see that, then that becomes a big concern. I think we've seen a lot of that in some of these areas because of that. Mass production may seem like a great thing, but if you look at all the variables and put it together… If the leaves are coming out off the trunk… Right. We've got large dead branches, some basal swelling, some shallow rooting. It's not a good thing. Not a good thing.

Jerad Henson: Well, let's shift gears just a second. What tips could y'all give hunters? better use these resources and better understand these resources to have a more successful duck hunt on public, private, whatever land.

Ryan Askern: A lot of what I did was I would follow the cutter man. Wherever they're cutting trees, that's where I wanted to hunt.

Jerad Henson: that area, the canopy's open, it's got that regeneration.

Ryan Askern: If I could find a stand with some great moist soil in it underneath a freshly cut area, man, that's where I'm going. That's what the ducks like.

Jerad Henson: And water depth, right?

Ryan Askern: Right, yeah.

Brandon Bennett: That's dependent on the water depth and the flooding of that area. Yeah, and for private landowners, I mean, pressure management is key. Big part of why ducks are in these woods is to avoid disturbance, avoid predators. When we're coming in, scaring them out of there, hunting, I mean, we're that predation risk for them. So being as careful as you can to, you know, just get your few and get out of there makes a huge difference for kind of the quality of hunts that you'll have throughout the season over just having a few really bang up hunts.

Jerad Henson: When you're hunting in that habitat, what's your favorite tip or trick?

Brandon Bennett: I'm a terrible duck hunter, so I'll let the Arkansas native answer this.

Ryan Askern: Don't hunt where the massive ducks are. Just hunt the edge. You don't want to bust them all out at once. You want to get several good hunts out of the deal. So don't just go busting up in just a big mass of ducks you find. Let's kill the stupid ones on the edge and let the rest of them go, and you'll have much more prolonged success.

Jerad Henson: What's your decoy spread look like?

Ryan Askern: Oh, it's all over the place.

Jerad Henson: A bunch of decoys. Motion, motion, motion.

Ryan Askern: Yeah, if you're on the X, let's take a handful and keep the water splashing.

Jerad Henson: Yeah. Ripples.

Ryan Askern: That's my favorite setup.

Jerad Henson: Yeah, and if you're like me, in an archie, you're hammering down on a duck call. Early season, at least. Late season, you gotta get quiet and talk to them.

Brandon Bennett: Yeah. No, that water movement's key, and seeing it flying from an airplane, from the drone, you almost never see the duck before you see the ripples, especially in the woods.

Jerad Henson: And the light kicks off of it and reflects it, so it does glow.

Ryan Askern: Studying these overhead has really changed the game as far as my concern for motion in the water versus number of decoys present. That water movement is so critical.

Jerad Henson: And I'm not going to jump into this too much, but do y'all use spinning wings in the woods? Nope. I don't either. I was just curious.

Ryan Askern: I like moving the water. A lot of motion decoys on water movement, not necessarily image flashing.

Brandon Bennett: We're fortunate, even outside of season, to get to spend a lot of time in the woods and around ducks. It's amazing how how often a duck will flare out of a spot because a lot of motionless decoys, spinning wing decoys, versus having a group come in, pitch into the hole, and just stay there. Especially on a low wind day.

Ryan Askern: Yes. If you're already fighting that variable, then you're just kicking yourself in the butt by not having motion in the water.

Jerad Henson: What's your favorite kind of weather to hunt in the woods? I already know the answer to this. Oh, man. Clear, cold, and a mild wind. Yeah, that blue bird. Gotta have shadows, Todd.

Ryan Askern: Real cold with some good wind.

Jerad Henson: It doesn't need to be like 20 to 30 where I'm worried about tree limbs hitting me in the head, but I want a 10-plus mile wind. There is a point. Right, yeah. Which we had some of those the past couple years. I'd get out there in the woods like, huh, there's stuff crashing around. I should probably get out of here.

Brandon Bennett: There was. Yeah. And they just seem so much more nervous when those treetops are whipping around.

Jerad Henson: They do.

Brandon Bennett: They do. The ducks don't finish.

Ryan Askern: And if you're fortunate enough to have an area to yourself, then you're And you have wind and the forecast and those kind of conditions, you may be better off just letting them rest, let those low wind days just be their comfort days, and then go in there and bust them.

Jerad Henson: Conditions are, I can tell you, I've been into a lot of forests on a nasty overcast day, and I'd have been better sitting at home. It's tough. Ducks, even if there's ducks around, They, you know, line it up, get ready to come through the hole, and they're like, oh, there's six Pie Faces down there smiling at me. Like, nope. Yeah. So, so that was kind of tips and tactics for that. And last thing I want to do, what's your best advice you would give someone listening to this podcast on management for these systems? Like, if you had to give them One to two piece of advice, what would that be?

Brandon Bennett: Mine's think about the ecosystem. I mean, think about how these systems naturally functioned and, you know, the hydrology and how all that came into play. And when you have a healthy ecosystem, you're going to have more critters in there and it's going to be better for ducks.

Ryan Askern: That point, along with, don't be afraid of the thinning. It's going to look nasty the first year, but let it do its job. And you'll see the benefits on the back end.

Brandon Bennett: And that's really, I mean, that's mimicking a natural process as straight line winds or a tornado or something.

Ryan Askern: As far as the eastern United States, We can't hardly thin enough. From bottomlands to uplands, it doesn't matter. We cannot hardly thin enough.

Jerad Henson: We've controlled all the disturbance at this point.

Ryan Askern: Right. Historically, this was a highly, highly disturbed landscape.

Jerad Henson: If it wasn't flooded, it was burned.

Ryan Askern: Right. One disturbance level or another, something was happening. It was not sitting stale.

Jerad Henson: Exactly. So, dynamic systems, keep that in mind. Well, Ryan, Brandon, I want to thank y'all for joining me today. Appreciate it. Thank you for having us. Driving over from Five Oaks. Always enjoy y'all in the studio and getting to kind of soak up some of that knowledge y'all have on these topics. So thanks again. I gotta thank Chris and Rachel over here, the podcast production crew. They always do a fantastic job. And we gotta thank you, the listener. Thank y'all for joining in. Hope you enjoyed this episode of the Ducks Unlimited podcast.

Creators and Guests

Jerad Henson
Host
Jerad Henson
DUPodcast Conservation Host
Ep. 693 - Ducks and Acorns: Red Oak Ecology and Management with Five Oaks