Can we eat enough white-tailed deer to restore forest ecosystems?

Is it possible to eat enough white-tailed deer to keep their populations low enough to restore ecosystems? We posed this question to Bernd Blossey, professor at Cornell University who specializes in the management of invasive species and the restoration of disrupted ecological relationships.

In this episode, we look at the history of white-tailed deer in the eastern forests of the United States, how many we would need to harvest to keep the population in check, and whether the concept of ecosystem balance is scientific or a fantasy.

This is the third and final part of our series exploring whether we can eat our way out of the problems we’ve created. Let us know what you think by sending us an email or a voice memo to podcast@tablededebates.org.

For more info and resources, visit: https://tabledebates.org/podcast/episode58

Guests

• Bernd Blossey, Professor at Cornell University

Episode edited and produced by Matthew Kessler. Music by Blue dot sessions.

Transcript

Matthew

You’re walking in the woods. It’s pretty quiet. There’s a few birdsongs and the sound of your footsteps on dry leaves. Suddenly, a figure catches your eye—a mammal, roughly your size or slightly larger. It locks eyes with you for a moment, then vanishes into the thicket. Your instinct was right - it was a deer.

Do you stand in awe, thinking what a majestic animal? Or maybe you shrug your shoulders, since this is a pretty regular sighting - after all deer are common on most continents. Or, if you're a hunter, you’re patiently waiting, slowly raising your weapon, ready to take aim at your next meal. 

It might feel very natural to feel connected to this wild animal. But one of the reason they’re so abundant is because we’ve killed a lot of their natural predators. And now, with their populations thriving, they pose a significant threat to forest ecosystems.

Welcome back to the nature season of Feed, a food systems podcast presented by TABLE. I’m Matthew Kessler.

This is the third part of our mini-series exploring the question if we can eat our way out of a particular problem that we caused. This time we ask a conservation biologist if we can eat enough white-tailed deer in the forests of the eastern United States to keep the population in check.

To recap, In our last episode we heard Crayfish Bob talk about his business of trapping invasive Crayfish in London. He’d sell them either to restaurants or large gatherings. One time he was asked to bring invasive crayfish to a festival that served only vegan food.

Bob

The organizer of the festival, he stood up and I heard him say, “A lot of you are vegans, because they are invasive species, they’ve gotta be killed by law, you know, we need to get rid of them.”

Matthew

And in our first episode we spoke to Elena Lazos Chavero about eating grasshoppers in Mexico:

Elena

Well the harvest of grasshoppers is not at all sustainable, but it’s still sold as if it will be very sustainable.

Matthew

Of course I’d  recommend checking both those episodes out. But we are telling a different story here. So you don’t need to hear those first for this episode to make sense.

Bernd

Returning to a more natural landscape, the question always is what the hell is that? Right?

Matthew

Our guest this week:  Bernd Blossey at Cornell University. 

Bernd

At some point you shouldn't be living where you're sitting right now, because I don't know, it was a kilometer of ice there. It's not that long ago, 10,000 years, right? 12,000 15,000 years ago. 

I'm Bernd Blossey. I'm a professor in the Department of Natural Resources and the Environment. And my focus of work is on invasive species or introduced species and how to manage and control them. And another important aspect is deer management and understanding deer impacts. And I come at this entire piece from a perspective on how do we retain species in landscapes, fix relationships that we have disturbed, and so you can call that conservation if you want to. So that's my larger frame of mind when I'm thinking about it.

Matthew

In our conversation with Bernd Blossey, we talk about the different causes of the up and down fluctuations of deer population in North America, whether it is possible to eat enough deer to keep their populations low, and at the end, I ask this conservation biologist if the idea of eating our way into ecosystem balance is just  fantasy-thinking.

Matthew  01:28

You've conducted a lot of research on deer, what draws you to deer?

Bernd  01:32

Nothing draws me to deer particularly, other than I'm also a hunter, and I like to eat them. Wonderful table fare. I started out in my career really working on introduced plant species and how to control them. We looked at what are the impacts of these plants? And how can we really enhance forest understory plants, the beauty that we have in our forests here in the US. And it became clear to me. It was clear to many other people before I had that revelation is that without deer control and greatly reducing deer numbers, there's no future for conservation, there's no future of having climate change adaptations that nature is providing for us. So that's what's drawing me to deer as a scientist, right? Not just as a person who likes to consume some of the wonderful meat that they provide us. 

Matthew  02:27

And can you walk through that mechanism for us? How are they affecting ecosystems?

Bernd  02:37

There’s one problem that we don't really know what our baseline is, right? So we have some historic records of how tree species abundance has shifted over time. Because people can go into swamps and lakes and bogs and look at pollen records and they can reconstruct for hundreds or thousands of years of history. We don't know in the understory, what was there when Native Americans arrived some 15,000 years ago or 500 years ago when Europeans came and settled in North America. 

At that time, we had deer, we had woodland caribou, we had elk. We had woodland bison, we had bears, we had wolves, we had mountain lions. All of these things live together with up and down fluctuations that we do not understand.

Matthew

The Europeans came, starting in the 16th century and for the few hundred years that followed, had devastating impacts on these larger mammal populations. The expansion of settlement westward caused a lot of deforestation and habitat loss. Settlers and market hunters killed what was estimated to be 10s of millions of bison. And diseases brought over from domesticated animals spread, which led to declines in native wildlife populations. 

This helps set the scene for the roller-coaster story of the white-tailed deer starting in the 19th century.

Bernd

Really with market hunting, white tailed deer almost disappeared off the landscape. They became endangered in the late 1800s throughout North America. And when people realize that, lobbying by wealthy hunters, helped to create pressure to establish state wildlife management agencies throughout the country that were charged with recovering deer populations and that worked exceptionally well. Deer are just large herbivores, they have high reproductive capacity. And with the elimination of their predators, and then reduction in the pursuit by human hunters, they just flourished within a few years, maybe a decade or so. They were expanding locally where there were remaining populations of deer, and then they were re-colonizing the areas where they had been eliminated. 

Part of that was also the recovery of the Eastern forests that had been clear cut and then were abandoned, and the forest regrow, providing super abundant food for the deer. So in the end deer by the 1920s and 30s were abundant in places that local foresters were complaining about the impact that they had on forest regeneration already in New York in the late 1930s and 40s. The foresters were the first to raise alarm. And then over time, the deer populations just kept on expanding, welcomed by the hunters that had an abundant target once again in their neighborhoods. And nobody really paid close attention to the forest understory plants other than the woody ones that were important for forest regeneration. And that changed probably in the 1970s, 1980s. There were conflicts with the abundance of elk in Yellowstone that was a high profile area. So ungulates forced themselves onto the research landscape, so to speak, right, where people were looking into that one further and further and further. And then over the last 20, 30, 40 years, the evidence of the disastrous long term impacts that the deer have on forest understory plants - the herbaceous ones, not just the woody ones, just can't be ignored anymore. 

Matthew

I want to pause on this distinction for a minute between woody and herbaceous plants in forest ecosystems. So Woody plants, trees and shrubs, are more noticeable to the everyday person than herbaceous plants, the ones with soft, green and flexible stems. Although  woody plants typically have higher economic value. Herbaceous plants however are really important for biodiversity - providing nectar, edible leaves and seeds, and helping facilitate pollination. And thousands of herbaceous plants can be used for food and medicine for humans. But the importance of these plants wasn’t well understood by scientists, industry and policymakers in the United States for most of the 20th century.

So now that the deer populations are thriving and inflicting harm on both the herbaceous and woody plants, an obvious move was to encourage hunters to help manage the population. But there’s an issue here. Most hunters typically only take one deer a season, and usually it’s a buck.

Bernd

One of my former students is the deer biologist for New York. And even though you can give them permits to shoot more Antler-less deer, the vast majority of people just shoot a buck that seems to be the thing of the day and it should be a big one. And less than 10% of people actually shoot a doe. And you need to shoot the does to actually get to population reductions. Over 60% of the doe herd needs to be shot annually to actually get into a decline. And we're not even close to that. Not just in New York, but throughout the US

Matthew  15:59

You run a lab on invasive plants and introduced species. And I wonder at what scale would we have to eat deer to control the population?

Bernd  16:10

So the easy answer would be in terms of population dynamics, right, we need to eat every year at least 60% of the does, or remove them from the landscape, that will start a decline in the population. We don't get there at the present time with recreational hunting in the US.  We don't get there with market hunting let's say in Germany, or in the UK, or in Sweden, where you sit right? So roe deer are expanding in southern Sweden, going further north, doing all kinds of crop damage, and how many we would need to shoot. It's not just the numeric thing, but also is depending on the health and quality of the forest understory. So what I mean by that is here in the US, in the Northeast, where I'm sitting, deer have been in super high abundance for many decades. If we want to recover some of the species that we have almost lost, they're still there, they are hanging on and some places where the deer have difficulties to get to in gorges, or on boulders or so. These heavily impacted forests need to have extremely low deer populations, let's say for a decade or more to allow the recovery of the native species. They're being a little bit hampered by their biology because they're very long lived plants with low seed output. So they have a very different life history. They're not breeding like flies, so to speak, right, but they take a long time, it may take them 6, 7, 8 years to grow from a seed to a flowering individual. So they're made for slow, long life. That's a lot of the typical understory plants that we have. And if deer eat them, it takes them decades to recover their populations. They will over time. But it takes a while. So at that time, we need to have deer populations that are really, really low. Once there is abundant food back in the woods, the deer populations can be higher, right? So we really need to measure how well are these other species doing that we would like to recover? And with that we need to adjust the deer populations. Can we do this all by eating them? Yes, we could, if we would have the tools at our disposal so that we are able to reduce deer populations at a landscape level. And we don't have the tools at the present time. That's the difficult thing, right? Even if you and I and everybody in society decides that we should be eating more deer and have fewer pigs in factory farms and fewer cattle in feeding operations and eat more deer. We don't really know how to get there as of yet. So that's important work that needs to be done.

Matthew  19:12

You said we need certain tools. What sort of tools or infrastructure would we need to set up a system like that? And maybe if you could draw any examples of smaller scale versions of this happening in other parts of the world? 

Bernd  19:26

So some of the more sophisticated examples are coming from South Africa, where there is a market for what is called game meat, whether these are antelopes or something else. And they often are on private ranches or farms that are typically fenced and they measure the health of the vegetation and if they have too many impalas or kudos or whatever you have on the landscape, they can come in and shoot a number of them to restore lower populations of the particular ungulates. And they come in with mobile slaughterhouses. And then, as I said, they have a market for wild meat, where they can be selling it. And so that's one approach. But that is an open landscape, not necessarily a forested landscape. It's privatized, and they can make money out of it. That approach you wouldn't be able to do all across the US, or even the Northeast, where you have urban areas where there's plenty of deer, or you have lots of small individual pieces of land that are owned by individuals, and you just can't go onto their property, and just shoot the deer until they say this is enough. Now, we have some resemblance of recovery in the forest. So there are property rights. How do you get to the deer where the deer are hiding out? How do you pay for it? Who would be doing it? Can we do it with government appointed hunters? Or Should this be privatized? And how do you get the meat to market? And can it be sold? And does it need to be inspected? So there's lots of aspects to it, too, to think about? What would be an approach where we get the venison to market and people can buy it instead of buying a chunk of beef somewhere?

Matthew  21:32

Not to mention the regulation around slaughterhouses? It's a difficult landscape in the US for a variety reasons.

Bernd  21:40

So there is no safety problem with deer. So human health problem in terms of eating venison, there is none. There's no diseases that would jump. People talk sometimes about chronic wasting disease, but there's no transmission path that we know of right now from a deer into a human. So it's not a health issue.

Matthew

Maybe we can’t eat our way into ecosystem balance in the near future. At least not with hunters preferring to shoot bucks rather than female does, and we don’t have supportive infrastructure in place. Still, Bernd still sees hunting deer as playing a role in reducing hunger.

Bernd  40:41

At the present time, the way that we're trying to work with a lot of the deer reduction programs that we have implemented in local municipalities around Ithaca is donate a lot of the venison that we have. Our individual hunters, they are shooting not just one deer, but they may be shooting five or 10 or 20, or even more, the really dedicated ones. We are trying to get it to people that are food insecure or in need. And very often that goes to food banks, we also work with local non for profit here called Reach that services folks that are homeless, and very often also drug addicts, and they are providing medical services for them. And so we're providing venison for them that then gets out to them as burger meat or so because they can then utilize that.

Matthew

But, it’s worth pointing out that deer is not always such a reliable source of food.

Bernd

So sometimes the food bank centers ask “when are we getting more?” Well, we've reduced the numbers down so instead of you getting 50, you only getting five this year, they would always love to have more. And so, you know, if you put it out to scale, having an entire landscape reducing the deer numbers there, that gets you to the problem that something that was super abundant at some point needs to become less abundant, but then you also need to switch where your protein comes from. You get that Matthew, because I know this section is involved with harvesting crayfish and nd other abundant introduced species right? 

To really control the populations you can build early on when they are abundant, you can build a market economy around it, but can you eat yourself to reduction of the impact? Probably not so much because you will then create a dependency for the people that are doing it using market forces.  If they lose their livelihood because they need to drive the populations down that's not a good way of dealing with it either. Right? So, what if deer abundance should become lower and with its lower abundance can't provide that protein for as large of a customer base as it used to be? So you bite yourself in the tail a little bit there. But it's a necessary thing if the reduction is the important thing that you are after.

[music]

Matthew

When we come back - I chat with Bernd Blossey not just about deer, but how a conservation biologist thinks about the resilience of nature, whether there is such a thing as “ecosystem balance”, and whether it’s harmful to use non-natural materials like plastic in order to allow ecosystems to thrive.

Bernd  08:03

It's an interesting thing. Very often we think nature is weak, or landscapes are weak. And there is an incredible power in terms of native species dealing with challenges that we throw at them, or climate throws at them or other disturbance, wind storms, fires or whatever. Typically, they can respond well over time.

Matthew

Bernd takes the example he mentioned before. From the late 1800s to the early 1900s, 80% of the forests across the eastern United States were logged. While this was a massive disturbance - we also saw that nature could and did recover.

Bernd

So as the forest regrew, you know, the birds, the salamanders, the insects, the plants, they all return. Sometimes it takes quite a while, we know from Europe, and also here from North America, that if you allow that return, and you don't have forces that prohibit that, it may take 100, 150 years.

Nature is powerful in its willingness to live right. So even though we have lost some of the major tree species to diseases like American chestnut, it hasn't really resulted in something that were widespread extinctions, except when human persecution of some species were part of that. Like there used to be a parakeet here in North America, the Carolina parakeet that was wiped out by hunting. People may know, even across the world about the passenger pigeon, right one of the most abundant animals in North America. By the millions, they were shot and shipped to the markets in the East. And we lost the passenger pigeon as well, that was human persecution. And then biology plays a role, right that needed large flocks to breed and be safe in that. And then the last individual died in a zoo in Cincinnati, I think, about 100 years ago, maybe even less than that.

Matthew  10:23

And it wasn't even that long before that I read an old settler account that said, “you can throw a rock up into the sky and hit a passenger pigeon,” they would black out the sky during their migration patterns, just to think of the kind of the vast scale of their population numbers.

Bernd  10:40

Yeah, millions of birds in a flock, right? It's unimaginable. And so what would they do to a landscape, right. So just imagine the amount of feces that rains off the trees, the amount of beech nuts or acorns, or whatever they need to eat. And so that's just not there anymore. And think about all the hawks and predators that would have an abundant food resource. And it's just, again, it's unimaginable, right? What that would have done to the forests of the Northeast. 

Matthew  11:16

I’ve lived in southern Appalachia, and in western North Carolina, and there, I would talk to some old timers who said, our soils, the geology of our soils, make them deficient in phosphorus. But one of their hypothesis the passenger pigeon would go to the Gulf of Mexico, they would eat a bunch of the phosphate rock, and their manure would deposits on the fields when flying back. Because of the abundance of their populations would help make some of those phosphorus deficiencies, you know, not as extreme. 

Bernd  12:04

And so obviously, if you have a million birds poop out of the sky that’s going to be a lot of nutrients deposited into landscape, right? And so, of course, and the meat that sits on the passenger pigeon fed a lot of different animals, right, including birds and mammals and Native Americans, and then sometime, Europeans, and they just overdid it. So that's the danger, right? And it wasn't recognized early enough. And they lost a food resource, too, right. So with clear cutting off the woods, the passenger pigeons lost their home and their food resources. And then the shooting was done with guns, not with rocks.

Matthew  12:55

So, this episode is exploring this question around, can we eat our way into ecosystem balance and ecosystem balance is kind of a funny, vague term. But you've already kind of alluded to what sort of the resilience of nature can do if left alone for some time.

Bernd  13:15

I don't think there is a balance, there is even a book if I were to turn around here. It may be called the balance of nature or so. And there's no such thing. We always assume that's there. If you look from the moon onto the earth, it's a blue planet. And you would think everything is peaceful, and the clouds, just covering some blue thing. And then once you look a little closer, there's storms and hurricanes and winter and summer, and whatever. And so it's the same with ecosystems, they're constantly changing. They may look stable over time, just because we see a forest doesn't mean that the forest is made up of the same number of individuals all the time, and the insects and birds are not changing. They respond to changes in climates and changes in whatever food availability, so there's constant oscillations in terms of abundance. 

But over time, there would always be let's say, it would be wolves and mountain lions until Europeans arrived in North America. Or until glaciers pushed them south or so. Right. So big disturbances will wreak havoc in the oscillations that are there, but typically, that that's what's happening. 

So there's not a balance. so predators don't always keep the deer in check. And most of the time, it would be food availability. That gets us to your question, can we eat ourselves into ecosystem? I don't know resiliency or stability. None of these words really capture what we are after really?

Matthew  33:21

Moving towards wrapping up. A thread here throughout our conversation. Is what do you care about the most here? Like you personally ,Bernd? Where do you kind of draw your attention to first to then unravel the system behind it?

Bernd  33:36

So I would say that I care about relationships and attitudes, I don't necessarily want to determine and say, this landscape - I'm looking out my window now at the snow covered hills here and said, there shouldn't be that many deer on that hillside. And that many understory plants of this or that variety, I don't care about that. I think I care about the respect that we have for all the organisms that want to live with us, around us. Sometimes they kill us, sometimes they cause diseases, we need to find some kind of a right relationship with that. But they all have a right to exist. And we shouldn't be determining how they exist. So instead of us forcing ourselves and our way of life onto everything, I think we should be looking at a landscape and say, “Well, how can I live within this landscape without being the major disrupter of it all?” That doesn't mean I want to live in a barrel on the hillside right? So that's, I'm not arguing that. But a recalibration of the way that we work with the landscapes and the species around us is a major important thing.   

I'm gonna give you an example. Maybe that helps. I love water. So I couldn't live in a desert. I like to go and visit. But I always would go to the waterfalls or oases or whatever, I need water. So one of the things that I did, when we bought this piece of land that we have, I created a bunch of ponds, because I also like amphibians and turtles and we have them in abundance. But sometimes the land doesn't hold upon just because you dig a hole, it just drains. So I put plastic underneath some of them, right because I couldn't line them. And my wife says, “Oh, you just put all this plastic in the landscape.” But ask the frogs and turtles and the insects and the dragonflies and everybody else who lives there, they don't care why there's water. The plants just grow there. So there's a compromise that I made, yes, there's plastic as PVC under a line of muck and other stuff that's built there. But it creates a new opportunity for species to live and thrive. And we enjoy the salamander and turtles and frogs that come in and sing all summer. And migrate over our driveway, and we need to veer around them. 

So there is a relationship where I'm trying to give something back because obviously our house has a footprint here, but provide some opportunities for other things to thrive as well. So it's a little bit of giving back. And it's the same thing with plants that we have here by taking a whole bunch of deer off the landscape, I allow some other organisms to flourish. It's not because I don't like the deer, I really appreciate their existence. But I need to reduce and thin them a little bit. So other things can thrive as well. So it's a reforming of relationships. It's not a total hands off approach, but doing something beneficial at the same time. That's where I tried to come from.

Matthew  38:02

Yeah, and I think that fits into - this is part of the calculation. So plastic is not a natural solution. But the use of it here builds habitat. 

Bernd

Isn’t that interesting?

Matthew

I mean, I also I can testify. I spent the summer in Ithaca on a farm in Tompkins County called Shelterbelt farm. 

Bernd  38:25

Shelterbelt. You know, Erica and Craig.

Matthew  38:28

Yeah, I set up I worked with him in the construction and I worked with her on the farm for a bit.

Bernd  38:34

You’re kidding me. Erica was an undergrad with me. She's good friends with us. That's funny.

Matthew  38:40

That's such a great coincidence. But yeah, I was sleeping in a tent near one of their ponds. This was kind of in the early days. This was you know, eight years ago or so.

Bernd  38:50

Plenty of the deer that I've shot because Craig comes and takes the carcasses over there. What a connection.

Matthew  38:57

Yeah. So but I mean, my anecdote is here, though, like, I could barely sleep because of how lively the pond was. I mean, all the different types of frogs and amphibians and

Bernd  39:08

Yeah, wonderful spring peepers, and green frogs and everything else. Yeah, exactly.

Matthew  43:49

Bernd thank you so much for speaking with us today.

Bernd  43:53

Thank you so much for having me, Matthew. Pleasure.