The great biologist Dr. Valerius Geist observed in his book, 'Deer of the World' (on page 34, with figure 2-12 on the opposite page), that large mammals which are known to typically confront and defend against predators have a strong tendency to have darkly colored bodies.Geist gives nine examples: the sambar, moose, guar, okapi, water buffalo, musk ox, wild boar, and black bear, and gorilla. I would also add the cape buffalo.
What Geist does not address is why this tendency towards dark coloration should be the case. As a hunter, I have a perspective on this that may be useful.
I believe that these animals all benefit from the dark colorations of their species as juveniles. An animal that is of a mostly uniform dark shade is especially difficult to judge in terms of size unless it is very close. Its not easy to tell a lone, young cape buffalo from a lone, older one at a distance. I won't say that this is impossible to do - just that its difficult. You can't always tell the difference between size versus depth perception.
If you are a predator that can kill and eat a smaller pig but expects to be injured in a fight with a larger pig then you can't go running after any given pig until you have determined how big and potentially dangerous it is. If there is an easier meal somewhere else then you'd probably take it.
This doesn't need to work every time against every predator every time in order to be useful to the species overall. If dark coloration confuses predators and causes them to move on, say, in 10% of approaches then that ought to be enough to justify the trait.
Observe the photo included above. I took this picture at around dusk in Texas a few months ago. It isn't great photography but it illustrates the exact thing that I'm talking about. I took this picture and then stood there with a knife on my belt for a few minutes trying to figure out whether to pursue this particular animal. This was while I was hunting on foot armed only with a knife and I wasn't stupid enough to go charging after some 300 pound boar with tusks like tent pegs that could rip me to shreds. I was deliberately seeking out smaller, isolated pigs of roughly 100 pounds or less that looked like something I could handle without a trip to the hospital.
With its uniform black color I could not tell how big a pig I was looking at. All I get when I look at these wild pigs at more than around 50 yards distance is a silhouette, even in better light than this. On this occasion I stalked in towards them with the wind in my favor until I could tell that one of the others in the field was a good target. Other times I ended up hesitating for too long and finding that they would scent me or see me while I was still trying to make up my mind.
In the field as an actual predator armed only with what amounts to a single big fang (my knife), I discovered that being darkly colored provides a very real advantage to large animals that frequently fight back against predators. I have to hesitate or pass up juveniles because I can't tell if they are actually larger, dangerous specimens. This is the sort of thing that I just don't tend to notice while hunting with firearms.
Geist's book, by the way, is excellent.
[Photo copyright 2011 and 2012 by Jackson Landers.]
0 comments:
Post a Comment