Efficacy of Predator Management

[omicron1792]

I think there is some truth to this but it’s all highly dependent on where you are.
There are plenty of studies as well as anecdotal evidence that shows how predators affect prey populations.
You can say something like “bears mostly eat grass/berries” and that would be true but it doesn’t discredit the fact that a bear in a calving ground eating 20 calves in a week is not having a dramatic effect on the population in that area, which is how statements like that are often presented.
“It’s not doing what you think it’s doing” is the purpose of this thread, for people to share their anecdotal experiences with Predator management of all types.
“They just come back” is the logical equivalent of saying that cutting the grass is not effective because the grass grows back. The goal here isn’t to vilify predators but rather for people to share their experiences that often contradict some of the more famous and dubiously funded studies, some that I think you are basing your conclusions from.

Great post and alMost my thoughts exactly.

The answer isn’t to let a predator without any natural predators for it to go unchecked.

 

[Superx3]

Timing and persistence is everything. If you kill 10 coyotes before or during calving/fawning season, that’s 10 less that are eating any kind of prey. Yes they will be replaced, but that takes time. Calving season will be over. Coyote numbers also plays a key role in preying on calves or fawns. If you mainly see single coyotes they are usually not much of a problem. On the other hand, if you have a pack of 3 or more running together they are much more likely to kill fawns/calves or even adults. Just like anything there is strength in numbers. This is not rocket science, the few predators there are, the fewer prey animals will be eaten. I’m not saying you have to completely wipe them out, but killing predators before and during the calving season WILL save calves.

 

[Q_Sertorius]

The whole “they will just have more pups” argument is a bit absurd. Predator populations expand to carrying capacity. There’s no internal regulator for “have more pups or have less pups.” There’s just “did mom get enough calories to go into estrus, bring the pups to term, and keep them alive after birth.” If there’s not enough prey for mom to eat, the pups won’t be born or won’t make it.

Killing predators is always going to be good for the prey population. There’s no situation where more predators is good for overall numbers of prey species. The prey species will also expand until it meets carrying capacity for its environment. Adding predators may keep a few prey animals from dying of lack of food in the winter, but that is just putting a different source for the limit on the prey population.

The points I find interesting in the thread are the coyote population’s possible effect on other predators and nest raiders like raccoons, etc. It seems to be that removing those smaller predators might be very efficacious for helping turkeys and other birds, while also removing potential food for the coyotes.

But my understanding - gained from my ecologist ex-girlfriend - is that better habitat, particularly native plant species and their associated native insects, is more important for bird populations than most people think. We tend to think in terms of “what fruit or seeds does this plant produce for the birds to eat?” Her books say that the insects that eat those plants are critically important for the birds when they are nesting in late spring or early summer or for young birds growing. And, whether it makes sense or not, a lot of birds are specialist predators, not generalists. Just as a lot of insects specialize in a particular plant and are often dependent upon it (like those horrible spotted lantern flies and the equally horrid Tree of Heaven). But this is something I rarely see mentioned when people talk about planting food plots or other landscape development.

And the timing of killing seems pretty interesting to me too. Killing an adult coyote in the late winter or early spring probably makes more difference on controlling numbers than it would in the late summer or fall.

 

[omicron1792]

The whole “they will just have more pups” argument is a bit absurd. Predator populations expand to carrying capacity. There’s no internal regulator for “have more pups or have less pups.” There’s just “did mom get enough calories to go into estrus, bring the pups to term, and keep them alive after birth.” If there’s not enough prey for mom to eat, the pups won’t be born or won’t make it.

Killing predators is always going to be good for the prey population. There’s no situation where more predators is good for overall numbers of prey species. The prey species will also expand until it meets carrying capacity for its environment. Adding predators may keep a few prey animals from dying of lack of food in the winter, but that is just putting a different source for the limit on the prey population.

The points I find interesting in the thread are the coyote population’s possible effect on other predators and nest raiders like raccoons, etc. It seems to be that removing those smaller predators might be very efficacious for helping turkeys and other birds, while also removing potential food for the coyotes.

But my understanding - gained from my ecologist ex-girlfriend - is that better habitat, particularly native plant species and their associated native insects, is more important for bird populations than most people think. We tend to think in terms of “what fruit or seeds does this plant produce for the birds to eat?” Her books say that the insects that eat those plants are critically important for the birds when they are nesting in late spring or early summer or for young birds growing. And, whether it makes sense or not, a lot of birds are specialist predators, not generalists. Just as a lot of insects specialize in a particular plant and are often dependent upon it (like those horrible spotted lantern flies and the equally horrid Tree of Heaven). But this is something I rarely see mentioned when people talk about planting food plots or other landscape development.

And the timing of killing seems pretty interesting to me too. Killing an adult coyote in the late winter or early spring probably makes more difference on controlling numbers than it would in the late summer or fall.

I’ve had multiple wildlife biologists to my farm developing plans for wildlife. Every one puts habitat at the top of the list for improving deer, turkey, and quail. Predator control is on the list but well behind habitat.

 

[Q_Sertorius]

I’ve had multiple wildlife biologists to my farm developing plans for wildlife. Every one puts habitat at the top of the list for improving deer, turkey, and quail. Predator control is on the list but well behind habitat.

Agreed. It seems like you have consulted with proper experts.

My point about the food sources - especially for birds - is that most of the people I know who are into developing habitat seem to focus on providing extra food in fall or winter. A grain plot is all well and good, but if the poults or chicks needed bugs in June, it’s of limited value.

A lot of the hunters I have met basically don’t think of the animals outside of hunting season. They want food sources that attract the animals to their hunting spot during hunting season. Or they want to provide extra food in winter to keep more adults alive (which is probably good if your goal is growing big trophy deer).

It’s just something I have been looking into a lot since I started wondering why the quail, grouse, and turkey numbers are way down on the farm (quail are non-existent these days). And that’s lead me to developing some long term plans to address habitat issues specifically for those birds. I don’t plan on ever hunting quail, but I would love to see and hear them. And maybe my grandkids can…

 

[omicron1792]

Agreed. It seems like you have consulted with proper experts.

My point about the food sources - especially for birds - is that most of the people I know who are into developing habitat seem to focus on providing extra food in fall or winter. A grain plot is all well and good, but if the poults or chicks needed bugs in June, it’s of limited value.

A lot of the hunters I have met basically don’t think of the animals outside of hunting season. They want food sources that attract the animals to their hunting spot during hunting season. Or they want to provide extra food in winter to keep more adults alive (which is probably good if your goal is growing big trophy deer).

It’s just something I have been looking into a lot since I started wondering why the quail, grouse, and turkey numbers are way down on the farm (quail are non-existent these days). And that’s lead me to developing some long term plans to address habitat issues specifically for those birds. I don’t plan on ever hunting quail, but I would love to see and hear them. And maybe my grandkids can…

Yeah. Food plots play a role, but behind overall habitat. I do yearly burns and TSI, which is of more importance.

 

[RockAndSage]

The whole “they will just have more pups” argument is a bit absurd.

This is also the kind of thing you see with politicized "science" - arguments that killing coyotes actually just makes them breed even more coyotes, or that killing terrorists just makes more terrorists. It's the same kind of sophomoric attempt at being clever and understanding that leads to paralysis by those unwilling to employ basic reasoning. You might get some females having more pups, or a dead terrorist's brother becoming a terrorist in response, but on the whole, the math is in favor of those willing to exchange bullets for biologic timelines.

Your points about the seeds, insects, and smaller segments of the food-web and ecology are really great, btw. It works all the way down to the soil, too - forests that get clear-cut have their fungal/mycological systems hammered pretty hard, and don't grow back as quickly or robustly as a system. When replanting is done with mycological treatments mixed in, all the things thrive better, from microbes to trees, insects, birds, etc.