Landscapes of fear and trophic cascade in Permaculture habitats.

I found a really interesting paper (1,2) on the effects of fear of carnivores on foraging activity, causing changes in abundance of both prey species and other organisms in an ecosystem (what us ecology geeks call trophic cascade).

I've spent some time considering what this means for ecosystem-based agriculture (most permaculture systems, and some sometimes covered by it). I was already aware of the implications of a human manager mimicking the activity of large and medium-sized herbivores in managing a forest garden, in terms of coppicing (eg beaver), water management (beaver again), pruning (browsers) and even root digging (eg wild boar) with their effects on succession.

I was also aware of some work done following the reintroduction of wolves to Yellowstone (3, 4), and the "landscape of fear" caused by it, but there has been controversy over this (5,6), so I was really interested to find some empirical research done in the wild.

Anyway, what this seems to show is that even the threat of the presence of predators is enough to change the behaviour of, in this case, medium-sized predators (raccoons) such that it has trophic cascade effects on the populations of other species in the ecosystem.

So, what does this mean for a permie managing a habitat? Given that the reintroduction of predators is often impractical and/or illegal, can we mimic their impact, possibly the same way these researchers did (1) by playing the sounds made by them? It would seem that a solar-powered player in the habitat would be enough to strike fear into browsing herbivores and encourage them to forage elsewhere.

In a permaculture world, where elsewhere would be someone else's plot, obviously this would present a different problem, emphasising the need for comparable wild space not, or at least not as intensively, used by humans.

The first thing that occurs to me is that the impacts might not be predictable. The Law of Unintended Consequences applies (for example, playing the sounds made by hawks or owls might protect fruit crops, but might also discourage activity by insectivores). Obviously, research might be needed.

That said, it also means we need to be cautious about making or accepting claims of ecosystem mimicry when engaging in land interventions (a forest garden would exclude deer, boar and others; mob stocking has no wolves). Our activities might be less damaging than monocultures, but we need to be careful not to overstate our cases.

There is also an ethical conversation to be had. From my perspective, a permaculture-based habitat would be based on principles of co-operation (mutualism) and commensalism (not just between humans but among the other animals we share the habitat with), not parasitism or predation, and scaring the living crap out of the local wildlife for our own benefit would seem to violate this principle.

What do others think?


1) Paper: http://www.nature.com/ncomms/2016/160223/ncomms10698/full/ncomms10698.html
2) Summary: https://www.newscientist.com/article/2078511-just-the-fear-of-big-predators-can-alter-an-entire-ecosystem/
3)Paper: https://www.researchgate.net/profile/William_Ripple/publication/30068786_Trophic_cascades_among_wolves_elk_and_aspen_on_Yellowstone_National_Park's_northern_range/links/0c960534e9511dff50000000.pdf
4) THAT video: https://www.youtube.com/watch?v=ysa5OBhXz-Q which also gives a summary of trophic cascade
5) http://onlinelibrary.wiley.com/doi/10.1890/11-1990.1/abstract (abstract only)
6) Popular summary: http://www.esa.org/esablog/ecology-in-the-news/yellowstone-wolves-take-a-blow-to-their-rep/

Neil Layton wrote:mob stocking has no wolves

Isn't there a style of traditional shepherding using dogs that keeps the livestock moving and contained in tight 'mob' style groups without fences under simulated predator pressure? Granted it's not something a modern permaculturalist would likely want to make a career out of, but pulsing the stock at the right times of year in this way might be a valuable thing.

Kyrt Ryder wrote:

Neil Layton wrote:mob stocking has no wolves

Isn't there a style of traditional shepherding using dogs that keeps the livestock moving and contained in tight 'mob' style groups without fences under simulated predator pressure? Granted it's not something a modern permaculturalist would likely want to make a career out of, but pulsing the stock at the right times of year in this way might be a valuable thing.

Not that I know of. I know of using dogs as guards against predators, and I know that dogs are used to gather sheep in (still a common practice in parts of Scotland, as elsewhere - the Border collie was bred for this sort of work), but not what you describe. I'd be interested to learn otherwise.

Neil Layton wrote:

Kyrt Ryder wrote:

Neil Layton wrote:mob stocking has no wolves

Isn't there a style of traditional shepherding using dogs that keeps the livestock moving and contained in tight 'mob' style groups without fences under simulated predator pressure? Granted it's not something a modern permaculturalist would likely want to make a career out of, but pulsing the stock at the right times of year in this way might be a valuable thing.

Not that I know of. I know of using dogs as guards against predators, and I know that dogs are used to gather sheep in (still a common practice in parts of Scotland, as elsewhere - the Border collie was bred for this sort of work), but not what you describe. I'd be interested to learn otherwise.

This guy is doing mob grazing with cattle without fencing by simulating predator pressure himself [on horseback], with limited help from a single herding dog.

Kyrt Ryder wrote:

Neil Layton wrote:

Kyrt Ryder wrote:

Neil Layton wrote:mob stocking has no wolves

Isn't there a style of traditional shepherding using dogs that keeps the livestock moving and contained in tight 'mob' style groups without fences under simulated predator pressure? Granted it's not something a modern permaculturalist would likely want to make a career out of, but pulsing the stock at the right times of year in this way might be a valuable thing.

Not that I know of. I know of using dogs as guards against predators, and I know that dogs are used to gather sheep in (still a common practice in parts of Scotland, as elsewhere - the Border collie was bred for this sort of work), but not what you describe. I'd be interested to learn otherwise.

This guy is doing mob grazing with cattle without fencing by simulating predator pressure himself [on horseback], with limited help from a single herding dog.

That doesn't look to me to be anything like the effect of predators in trophic cascade conditions. We do need to understand what is happening and why in mob stocking arrangements, but that's a separate discussion which we can't have because of a lack of good research, but it's off topic except in the most general of terms. I don't see you reintroducing wolves or trying to mimic their effects in these systems.

Can you more clearly state the effect of wolves you're talking about?

I was under the impression you were referring to keeping the animals moving and eating in tight groups, as happens when under predator pressure [which traditional mob grazing attempts to sort of simulate via tight fencing, but it still seals the animals in a given space for hours at a time.]

Kyrt Ryder wrote:Can you more clearly state the effect of wolves you're talking about?

I was under the impression you were referring to keeping the animals moving and eating in tight groups, as happens when under predator pressure [which traditional mob grazing attempts to sort of simulate via tight fencing, but it still seals the animals in a given space for hours at a time.]

That's actually a good question, because to find out what you would need to do is follow bison over a large area either restocked with wolves or where the bison had reason to think they could fear wolves. Modern domesticated cattle may well respond differently to wolves (although you might be able to ascertain that experimentally, at the expense of frightened, dead cattle, which as I've already indicated has ethical implications). What I'm saying is that habitat mimicry is more complicated than some people like to make out (and that goes as much for Toensmeier as it does for Savory). It is known that bison are not ecologically comparable to domestic cattle (http://www.bioone.org/doi/abs/10.2111/REM-D-12-00113.1) in any case. If what you are doing is ecological restoration, you need to reintroduce bison and wolves, not chase modern cattle around on a horse. If you are chasing cattle around on a horse, you need to be very careful about any claims of habitat restoration, even habitat mimicry.

@Neil L: "If what you are doing is ecological restoration, you need to reintroduce bison and wolves, not chase modern cattle around on a horse."

Sounds (literally) good to me....

This particular organization has done a good job of re-introducing wolves to N. Minnesota.....so much so (along with other centers) that the re-instated hunting season on them has been considered an indicator of that success. Without any permie consideration, however, the human population and it's trappings will continue to increase (or revert to its prior ethic) and increased interactions with the wolves will likely lead to pressure on politicians to do something. In general the larger predator populations are still reeling from the Euro-American carnage wreaked upon them from over 100 years ago....the coyote being one exception that's adapted quite well to an (sub)urban landscape. Our own farmstead saw a chicken flock plummet due to foxes, mink, and coyotes, then overshoot (rebound) with the intro of livestock guard dogs, and stabilize with the efforts of my pellet gun or .22 rifle and the chest freezer.

There is a way to live alongside of them, but you have to accept some losses. If they put selective pressure on your stock and you end up with more wiley chickens or Churras as a result, all the better.

One effect I saw in an online magazine earlier this year (it may be in one of the links, I didn't read them) was that with wolves being reintroduced, the river bottoms got a lot more growth and the rivers flow a lot different.

The deer quit feeding on the river flats constantly and started living in more secluded, shaded and less visible places, meaning the rivers had less silting due to short grass being unable to hold back the soil in rains.
As well as some other conclusions I forget. for me the change in the rivers due to the reintroduction of wolves was the interesting bit. You don't think of deer, land dwelling grass and brushy browse eaters, having an effect on the river flows. But they actually do.



As to areas where predators such as wolves have been removed, leaving no natural check on population limits, there is an ethical requirement there for human hunting, culling by another name, to keep the populations under control and low enough the do not eat their food supply into non-existence due to overbreeding, causing a slow cruel death from starvation for a large proportion of the population as feeders outstrip feed.

Like it or not, Humans are a predator, Opportunistic rather than obligate, but still a successful predator with a prey drive.

Neil Layton wrote:
So, what does this mean for a permie managing a habitat? Given that the reintroduction of predators is often impractical and/or illegal, can we mimic their impact, possibly the same way these researchers did (1) by playing the sounds made by them? It would seem that a solar-powered player in the habitat would be enough to strike fear into browsing herbivores and encourage them to forage elsewhere.

I haven't had a chance to read the article, just the summary, and I need to be in bed now. But, I thought I would put down a few thoughts, in case they are helpful...

Perhaps another idea for introducing that predator pressure would be the use of bone salve and/or predator urine (human could possibly work, but supposedly works better if one eats a lot of meat)? We have a lot of predator pressure here (coyotes, bobcat, bear, possibly cougar, too). But, we also have a lot of deer. Bone salve does a pretty reasonable job for me of keeping the deer out of an area. I don't see them nearly as often in my garden, and they rarely browse on the trees. Neither bunnies nor ducks seem affected by it, though. It doesn't seem to scare the deer so much as deter them, as they don't want to eat much in that area. As bone salve reaks of death, they might avoid the areas where the salve is not only because it's not appetizing, but also because predators tend to be where death and decay are?

One could also use urine from the local predators, but that presents ethical problems all of it's own (how do they harvest that urine, anyway?).

If course, if one avoids eating meat, finding bones to make salve presents ethical problems of its own unless one tends animals and one dies naturally, or a dead animal is found on the property...

Nicole Alderman wrote: As bone salve reaks of death, they might avoid the areas where the salve is not only because it's not appetizing, but also because predators tend to be where death and decay are?

In my locale it could be made from the bones of road kill, but if it reeks of death, I don't want it in my garden or anywhere else I want to be. I want my garden to not smell like roadkill. And another thing I wonder, if I drive the deer away from "my" territory, they just go to the neighbors' and kill the plants over there, so it doesn't seem to solve the problem of too many deer, just moves the problem to someone else's yard.

Our big problem is these huge exotic deer whose natural predators are leopards and tigers. They are deforesting the locale by killing all the young trees. Is there a solution which does not involve killing?

http://www.ultimateungulate.com/Artiodactyla/Axis_axis.html

This morning we saw a herd of about 15 Axis Deer on the neighbors' place to the north. Below is a photo I took this morning of the browse line on our woods (note the lack of any undergrowth), and also an example of a tree damaged by the deer and the only solution I've come up with so far - surround each young tree with a ring of brush. Putting brush rings around every small tree on a mostly-wooded 20 acres is going to be a tough job for one person. High fencing is another - but expensive - option, and I've done a little of that around the house area, but I don't know how appropriate it would be throughout the rest of the land. The idea of that much fencing bugs me.

I looked at that and thought "Chital (the name I know them by) in Texas? Seriously??" I'm really surprised to find them there. How on earth did they become naturalised in Texas?

I think you are probably looking at a different solution, perhaps stock-proof hedging, which itself provides habitat, windbreak and useful plants as well as herbivore exclusion, which is very much a permie solution. You could also look at bee fences such as those used in parts of Africa to exclude megafauna: http://elephantsandbees.com/beehive-fence/ These are mostly being used to exclude elephants, but may work for other herbivores.

I think we are drawing the wrong conclusions from this research. On reflection, given that both the predators and many of the herbivores are either extirpated or extinct, or need to be excluded, it's not going to be a case of mimicking an ecosystem down to the last detail, but about not making overblown claims about how closely the ecosystem mimics one without any human interference. I'm thinking about land ethics - "a thing is right when it A thing is right when it tends to preserve or enhance the diversity, integrity, stability and beauty of the biotic community. It is wrong when it tends otherwise" (modification to the original mine).

Scaring some of the wildlife will have trophic cascade effects, but prediction what those effects will be is going to be a lot more complicated, and may only become clear on monitoring or direct comparison.

I think there is a difference between observing that humans are predators, drawing too many parallels between the ecological implications of human hunting and hunting by other predators such as wolves and tigers, and using it as an excuse. Herbivores will respond differently to a human on horseback, or a human with a rifle, than they will to a pack of wolves in the area. Humans do not need to be predators, but some of us are socially conditioned to be, and some other animals (and some humans) will respond accordingly.

Personally, I treat them as a threat just as other animals do, because if they will harm other animals they seem more likely to be a threat to me too. It goes back to one of my initial comments above: is it ethical? I don't want to live in a landscape of fear any more than any other animal.

I know it's a bit of a fine line, but this is about how I respond to what I perceive as a threat, not about what others should and should not be doing.

Neil Layton wrote:I looked at that and thought "Chital (the name I know them by) in Texas? Seriously??" I'm really surprised to find them there. How on earth did they become naturalised in Texas?

I think they were released from a ranch some time in the past. They seem to thrive here because of the lack of large predators, and a climate very similar to that of India.

To your idea of a "landscape of fear" - that is what I do not want to create on our place. Most of our 20 acres is Zone 4 and once our sheep pass on, the plan is that only one acre will be for primarily human use, with the rest devoted to wildlife. I don't think we can ever have real Zone 5 "unmanaged wild natural ecosystem, such as bushland, forest or similar natural area, free of human intervention, interference or control" because there isn't a stable ecosystem developed here since the destruction of the previous one (prairie) over the past 150 years or so. But I want to try to restore as much habitat as possible for the native plants and critters. The Axis deer are seriously thwarting my plans. Anything that will scare them away will scare everyone else also, which is not acceptable.

Tyler Ludens wrote: Anything that will scare them away will scare everyone else also, which is not acceptable.

Indeed. I think there is a strong argument that it's not a great idea ecologically, and also a strong one that it ain't right. I think we might do a lot better working on our mutualistic relationships than on causing chaos through fear. The paper has implications, but not those I thought of initially.

FWIW, I thought it interesting that this link from Sri Lanka [ http://goviya.com/testing-indigenous-techniques.htm ] and a separate site regarding the Mandan in the northern Plains of the US have a history of using a combination of song, prayer, and astrology to protect their crops in a non-hostile way from damage and grazing by wild fauna. So much of this valuable information dwindling away....

"There are three categories of traditional practices to protect crops from wild animal damage. The first group is based on astrology, the second on the powers of the spirits and Gods, and the third involves the chanting of verses and the use of specific symbols. Often these different practices are combined."

And another thing - non-human animals aren't stupid. They quickly figure out if there's really a threat or not, and they are very observant. We sometimes feed the sheep near where there is a deer blind. When we put out the oats for the sheep, the Whitetail Deer come up to eat the oats with the sheep, while we are standing there. These deer are nearly as tame as the sheep. But when we (my husband, myself, and Izzie the Border Collie) hid behind the blind, the deer got very nervous and wouldn't eat. They associated the blind with something dangerous, or suspicious, anyway. I think they would quickly determine that "threat noises" without a real threat were fake, and not anything to really worry about, as they figured out Izzie may bark at them, but she will not seriously chase them - we've seen her slow down as she approaches them, as if she and the deer are playing a game. They know she is not a real threat, as they know we aren't a real threat - although we might be one when we're acting like a hunter hiding in the blind.

Tyler Ludens wrote:I want my garden to smell of life, not death.

To me, they are the same smell: Both are the smell of living things.

Common farming saying: "Everywhere you have livestock, you have deadstock"