This site is not maintained. Click here for the new website of Richard Dawkins.

Comment

← Quest for Fire Began Earlier Than Thought

Helga Vieirch's Avatar Jump to comment 23 by Helga Vieirch

Comment 19 by Alan4discussion Comment 11 by Pete H

It would have only been a small step from this natural scavenging to deliberately triggering artificial bush fires, based on the observation that the charred vegetation opens up clearings in the bush and encourages new grass growth which attracts browsing megafauna while making them very much easier to catch. (Including catching them by starting a fresh bush fire and burning them to death.)

In Chaparral or savanna environments, dry combustible material simply builds up until some human or natural form of ignitions sets the wildfires away.

Most larger grazing animals in the African savannah actually will easily evade a fire, as in grassland, you can simply step or jump over the advancing line of burning material. A number of antelope species, notably the Sable antelope. actually calve on fresh burns.

Animals are also attracted to recently burned areas in order to lick ash and chew charred sticks, as a source of minerals and other nutrients.

The Kua used to set snares for ostriches around old campsites that had been burned down deliberately after someone had died and been buried there. There were enough odd bits of bone (of game previously consumed at the site) exposed by this process to attract the big birds. Ostriches are always on the lookout for such objects, since they need them to grind up food effectively in their gizzards. (This being the origin of the myth that ostriches will swallow tin cans and all kinds of other small bits of junk.)

Ash, of course, is a natural fertilizer. The productivity of certain wild nut bushes and bean fields in the Kalahari was enhanced by burning, sometimes remarkably so.

I was interested in your remark about how in certain environments like chaparral the dry material in deadwood builds up to the point where a lightning strike (or careless human) can set off a huge wildfire. We have witnessed a number of these in California every summer.

It was not so in before, when these areas were managed by the Amerindians. LIke foragers on every other continent, they kept wildfires from happening by setting up a schedule of smaller controlled burns annually that kept the amount of burnable debris down. Thus wildfires which might have threatened their own camps, as well as burning so out of control as to actually endanger the wildlife, were not allowed to happen.

The Kua, in fact, made explicit statements to this effect, when questioned about their management of veld fires in the Kalahari.

It is interesting to note that many kinds of valuable trees, like lodgepole pine, are in fact dependent upon fire for reproduction, and are highly adapted to thrive under conditions of light annual low-level grass fires.

Sun, 08 Apr 2012 14:55:58 UTC | #933076