A POST-MORTEM … OCCAM’S RAZOR AND A CONTRADICTING PRINCIPLE

This relates to the following observation submitted by @vynbos:

https://www.inaturalist.org/observations/32933634

Let’s use the “spanner” to fix things.

This observation and my own responses to it provide some insights into this challenging business of identifying droppings. I don’t really want to turn this journal facility into a blog, but I think others may benefit from the thoughts below. I have.

MY FIRST MISTAKE

I looked at the pics initially and couldn’t immediately decide whether this was a cat or not (which is why I said initially “while I give this one some thought”). I studied my own published and unpublished cat pics and thought, “well, they could be”.

I saw, and wondered about the substrate, the flattened dry vegetation. “Would a cat do its thing on that?”. It didn’t look right. (This business is a lot about inconclusive feelings, I’m afraid.) A canis species would use such a substrate, I felt.

Then it occurred to me that it was a multiple deposit. A cat producing a multiple deposit?! But the general “rule” is: “they don’t use latrines”. Wow, that’s interesting. And it is just possible, and I gave the (rarely observed) reasons.

What rule did I break you ask? The principle of Occam’s Razor. https://simple.wikipedia.org/wiki/Occam%27s_razor

The principle: If there are two explanations for something, the simplest one is usually correct.

Two possible explanations are:

(1) The multiple deposits (on what seemed an unusual substrate) were possibly a black-footed cat (which is quite scarce) near a den or a wildcat (which rarely does this).
(2) It’s not a cat, but some other carnivore.

Explanation (2) is the simplest.

MY SECOND MISTAKE

I had looked at the map and zoomed in to the best resolution it could give. I even did it in my Google Earth (although the map is the same, GE is more flexible). I noticed the buildings to the south east but made the mistake of not measuring the distance to those buildings. I see now they are only about 500 m away. That should have been at least a red light that a domestic animal could not necessarily be ruled out (whether canis or felis).

I’m still in a bit of that mode in which I have to remind myself frequently that domestic animals are important to consider in this business. (To this end, I included some of them recently in my database of quantitative data, so they appear automatically now. But some refinement is necessary.)
Domestic dogs and especially cats even appear in species lists for some protected areas or are known to have been present but are not recorded in lists.

IN MY DEFENCE (he adds timidly)

Another principle (long used in various other contexts, I see from Google) that I still frequently remind myself of, is this:

“When it concerns animal behaviour, always remember never to use the words always and never.”

[ In the above case, this conveniently negates Occam’s Razor! But let’s not go there. :-) ]

Don’t underestimate this principle. I have seen examples of this over the years. (Just one: Once, and only once, a single unquestionable aardwolf dropping, unburied, on the edge of a dirt road. The “rule” is: They bury them in middens. The lack of adherence to the rule might be easily explained, of course: when you gotta go, you gotta go.)

But, generally speaking, the problem with animals is they don’t read the guidebooks we write about them. If only they would. They might then follow the rules more closely. Our lives would be much simpler.

The only relevance this has to the above-mentioned observation is that one shouldn’t ignore the unusual in this business.

However, I hasten to add, maybe Occam’s Razor should have more prominence than it’s been getting.

Kevin

Publicado por kevinatbrakputs kevinatbrakputs, 20 de septiembre de 2019

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