Ivica Miskovic has an interesting list on the Amazing Nature blog. These lists are always open to argument, but Miskovic's effort is a good starting point.
A reader of that blog notes that humans are more dangerous to humans than anything on Miskovic's list. This is one of those claims that sounds intuitively true, but it really depends on what you count. If deaths caused by environmental damage, traffic, household accidents, and other more or less non-aggressive actions count, then we humans are definitely our own worst enemies.
But if you mean deaths caused by some direct action, it's a close race. As Miskovic notes, mosquitoes cause something like 2 million deaths a year by spreading malaria. Some estimates would put this number as high as 2.7 million. There are plenty of other mosquito-borne diseases to take into account, like Dengue fever and yellow fever, though admittedly these other diseases kill far fewer people than malaria does.
By comparison, the combined human mortality from war, crime, and police action in 2000 was "only" 1,659,000. So this accounting wins us a probable second place finish.
Of course there are many other ways to look at it. For example, do we count human-borne diseases in our total? It seems only fair, since the only serious problem mosquitoes cause is to spread disease. AIDS almost always comes to its victims from other people, and that disease, in itself, would add 2.9 million annual deaths to our total.
Saturday, May 31, 2008
Friday, May 30, 2008
The latest issue of Discover (July 2008) carries an article of mine on cedar apple rust, a spectacular parasite that invaded my backyard. It's a more personal piece than you usually find in science writing, and I'm very attached to it.
Coincidentally, I mentioned this fungal invader in passing a few posts back. See the article below on Mexican freetailed bats.
Tuesday, May 27, 2008
The wild boar, which is simply the untamed version of the domestic pig, is a formidable animal. Shakespeare described its dangers:
. . . thou know'st not what it is
With javelin's point a churlish swine to gore,Whose tushes never sheath'd he whetteth still,Like to a mortal butcher, bent to kill.
'On his bow-back he hath a battle setOf bristly pikes, that ever threat his foes;His eyes like glow-worms shine when he doth fret;His snout digs sepulchres where'er he goes;Being mov'd, he strikes whate'er is in his way,And whom he strikes his crooked tushes slay.
'His brawny sides, with hairy bristles arm'd,Are better proof than thy spear's point can enter;His short thick neck cannot be easily harm'd;Being ireful, on the lion he will venture:The thorny brambles and embracing bushes,As fearful of him, part, through whom he rushes.
I wrote about the perils of pigs—wild, domestic, and feral—in The Red Hourglass and Deadly Kingdom.
A woman I know was strolling in a zoo with her four-year-old son. There was no particular sound, just the usual chatter and the shoosh of traffic and children screaming at the monkeys on their moated island and mothers rebuking the children. She was walking in this world, and the next moment she knew she had been singled out. She knew, hackle and marrow, that someone was watching her. She turned and saw the sign that said leopard. In the cage was a cave. She couldn't see into the cave, but she knew the gaze emanated from that darkness. He couldn't hurt her. She knew that. She wasn't the dramatic type. But she looked to see where her child was, and kept him closer the rest of the afternoon.
Leopards are among the premier predators of human beings.
I wrote about them in Deadly Kingdom.
I inadvertently upset my seven-year-old nephew once by feeding a ladybug to a black widow spider. Ladybugs, he'd been told, were "good bugs." I tried to comfort him by pointing out that the ladybug didn't care about the human race, or about the good of the world, and was probably only eating aphids because it was hungry, not from any moral imperative. Furthermore, I said, the widow has at least as good a claim to sparing us the annoyances of a wide range of insects. My son, four at the time, assured him that one of the little orange creeps had bitten him and that he harbored a grudge against the entire race of them. In any event, the ladybug did some good that day by serving as a protein shake.
I wrote about ladybugs (a.k.a. lady beetles, ladybird beetles) in Deadly Kingdom.
I wrote about black widow spiders (Latrodectus spp.) in The Red Hourglass and Deadly Kingdom.
Monday, May 26, 2008
The predatory capacities of the great raptors have long suggested the harm they might do to human beings. The folklore of Europe, for example, is full of stories in which an eagle steals a human baby. Sometimes the child is rescued; other times his bones are found in the abandoned aerie years later.
I find no convincing documentation for any such story. It has been suggested, however, that large raptors like the harpy eagle might have made such use of our not-too-remote ancestors. Even today, there are cases of children attacked (but not carried off) by large raptors.
The eagle-hound of Zeus, red-ravening, fell
With greed, shall tatter piecemeal all thy flesh
To shreds and ragged vestiges of form--
Yea, an unbidden guest, a day-long bane,
That feeds, and feeds--yea, he shall gorge his fill
On blackened fragments, from thy vitals gnawed.
--Aeschylus, Prometheus Bound
Related Post: Golden Eagle Snatches Baby (a hoax, but interesting)