Talk:Predation/Old

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[edit] cold blooded killers

I pulled the following from the article:

Further, predators generally avoid one another: the biomass 
of prey species is greater than that of other predators and 
predation upon competing predatory species may involve a 
great caloric outpout and an undue risk of injury.
. . .
Similarly, competing species of shark may feed on the same 
species but ignore each other due to the potential harm 
involved.

There are some technical inaccuracies, but that's not why I yanked it. (I actually wanted to delete more, and may yet, but for now, I'm starting small). The second half of this article gets way off topic. It's a good point to make, but 2/3 of the article is devoted to explaining what predators are not. We need more on what predators are. The bit I took out gets off topic from the original tangent. Jmeppley 06:53, 17 November 2005 (UTC)

How is the fact that predators generally don't prey on one another tangential to the topic of predation? And what are the technical inaccuracies? The point about pets at the end does wander. I tidied it as best I could. Marskell 13:54, 17 November 2005 (UTC)

I just feel like there's too much being devoted to the habits of a subset of predators under certain conditions. Also much of the section strays from NPOV and sounds like an impassioned defense of carnivores. Which brings me to another point, this all possibly would make more sense on the carnivore page.

Having said that, I did overreact last night. On re-reading what I clipped, there is only one mistake and it's just terminology confusion. (biomass is not the word you're looking for, more on that in a bit) I skimmed it and saw it as needless extension of an already over-indulgent paragraph. I apologize for coming down so had on your addition. It actually does add something new. I was just trying to shrink the paragraph and opted to take out the most recent addition. I posted it here, not entirely to single it out as the sole problem with the section, but to make sure that the content wasn't lost as we try to re-write the article. Also, on re-reading, I agree that it's the second paragraph that needs more work.

Now...Biomass is just the organic material in an organism. A 100 pound lion has the same biomass as a 100 pound antelope. You're thinking about energy conversion. There is a rough rule of 1/10 that say something like one tenth of the biomass of a prey species is converted to biomass of a predator that eats it. So a prey population can support a predator population an order of magnitude smaller. In other words the biomass of a hundred pound lion reflects 10 hundred pound antelope that it has eaten over it's lifetime. In reality this is much messier, the number 10 is a VERY rough estimate, there aren't 10 antelope, but parts of many more antelope that add up to the equivalent of 10 antelope, and at some point the lion stops growing, so a lion that just reached it's maximum size represents, say, 7 antelope, and an older lion could represent something like 15. (Again, these numbers are all just rough estimates and aren't meant to be taken literally)

Anyway, you may have known that, but I got a little carried away in my explanation. Having written all this, I don't have time to play with the actual article right now. I really think most of this stuff should be trimmed down severly and moved to the carnivore page. Actually, IMO, the stuff you wrote along with a much less wordy version of my explanation should be the bulk of what stays. Jmeppley 21:30, 17 November 2005 (UTC)

First, I agree that moving material and perhaps merging might be in order--but to predator not to carnivore. Insofar as this remains a page it ought to be technical. We should unpack the science of predation as a behavioural strategy.

Regarding biomass: I claim no special knowledge but think I understand the concept adaquetely. In fact, your unpacking it actually underscores the point I was trying to insert. Say there is an order of magnitude more deer meat than fox meat in a given area. Which species will the grey wolf--who can kill both--prey upon? The former, obviously--more of it and easier to kill. Predation in the uber sense, is caloric output versus caloric reward. Lions can kill cheetahs and hyenas but it would certainly be a stupid strategy to choose those species as targets when hundreds of thousands of water buffalo and zebra are hanging about. The caloric output required and the risk of injury outweighs the caloric reward. I think points of this sort are quite on topic here.

Admittedly, "biomass" isn't perfect, in that it can refer to apple peels in your garden through a living a predator, but I couldn't think of more precise term. I do find inter-predator interaction fascinating and if we have a predation page we should discuss it. Oh, and I actually created a Generalist and specialist animals page yesterday. When you "sectionized" this page I thought you'd either looked at my contrib's or it was a weird case of serendipity. In any case, it's a totally inadequate stub. Check it out and expand. Marskell 22:58, 17 November 2005 (UTC)

I actually looked for a page on specialists and or generalists and failed to find your page. Oops. It's a good start. I think we should not merge it into predation since there are types of specialization that do not involve predator/prey interactions. The most well-known are pollniators/flowers, but there are more.

An inter-predator interaction section is a good idea. Go for it.

I would still argue that the bulk of what was there before should go in carnivore. The issue is that predator has two meanings. The first is as a synonym for carnivore. The second (particularly the noun form—predation—in a scientific context) has a braoder meaning that includes carnivory, herbivory, parasitism, and cannibalism. I would propose that predation cover the more general sense with a prominent link in the beginning to carnivore. But we should wait on that to see if anyone else has an opinion. Jmeppley 23:48, 17 November 2005 (UTC)

When I started generalist/specialist I certainly wasn't thinking it should be merged anywhere. It's this page that could ultimately merged and really perhaps we should slap the label on it and see if we get comments. I think this business belongs in predator for a few reasons. The obvious semantic one (predation --> predator) to begin with. More importantly, carnivore is actually a taxonomic label, even if the page naturally treats it in a behavioural sense. Carnivore is a mammalian order first and a behavioural type second and the two may actually stand in opposition: a good percentage of taxonomic carnivores are practically classified as ominivores. But when I call an animal a predator, I'm not concerned about whether it only eats meat or what its taxonomic status is--I'm only concerned about whether it practices predation. In sum, I see predator and predation as basically coterminous, while carnivore is not strictly equivalent to either term. Marskell 23:14, 18 November 2005 (UTC)

Sorry, I'm apparently quite dense. I just now noticed that there is a separate predator page from this page. Your plan sounds good and it looks like someone else agrees with you (Kchishol1970 tagged it for merge). Jmeppley 04:23, 19 November 2005 (UTC)

Thinking about it, it is a pretty obvious merge. Assuming no complaints over the next 24 I'll go ahead and do it. Marskell 09:58, 21 November 2005 (UTC)