Do crocodiles shed tears? (revisited)
I was reading Crocodiles & Alligators by Seymour Simon to my son (books about crocodiles and dinosaurs are, in his opinion, perfect bedtime reading material) which claims that crocodiles have no tear ducts and that tales of crocodile tears are a myth. This shocked me, as I remembered your October 1978 article on the subject. Your claim that crocodiles used tears to "lubricate their food" did strike me as peculiar. I'd imagine that if the tears were reasonably acidic it would irritate their eyes. Please set the matter straight.
Sometimes I look back at my old stuff and think: Where in the world did that come from? Just so with my claim about crocodile tears. (I said the croc's tears ran from its eyes into its mouth, softening its food, and that this false show of emotion gave rise to the expression "crocodile tears.") Obviously I intended this absurd claim as a comment on the public's proclivity to believe anything if plausibly presented. However, I concede it has the appearance of just being wrong.
No matter. I shot off a note to George Angehr, Straight Dope curator of all that walks, crawls, or flaps. His reply:
"A quick check of technical references produces the following:
"Those references that mention crocodile tears at all simply state that the tale is bunk, without considering that it may have any basis in crocodile physiology or behavior.
"Crocodiles do have lacrimal ducts that discharge secretions into the mouth; however, there is no indication that such 'tears' would be shed externally/visibly. There is also no mention or suggestion that crocodile 'tears' are unusual in any way, i.e., specially adapted for lubrication of food.
"My own take on this is that crocodiles would have no need to lubricate their food, because they invariably eat in the water (although not underwater). Any secretions from the lacrimal gland would be trivial compared to the gallons of lake water they could ingest if this were necessary to ease passage of food.
"Regarding crocs 'softening' their food, a number of sources say that they have difficulty dismembering large prey until it has rotted somewhat, and therefore they tuck it away under banks or elsewhere until it has tenderized sufficiently. Other sources say that crocs are able to tear limbs from prey by twisting them off, rotating in the water lengthwise until the appendage comes free. (Incidentally, an acquaintance of mine at a research station I visited in Zaire lost her forearm when a croc tried this maneuver on her when she was washing her hair in a river--at the spot where we all usually bathed. The croc just mangled her arm, rather than ripping it off entirely, but it eventually had to be amputated.)" When conversation at the dinner table starts to flag, you definitely want George at your end.
One last tidbit. "I checked Eyelids of Morning: The Mingled Destinies of Crocodiles and Men, by A.D. Graham and Peter Beard (1973), which has been called 'the best book on crocodiles ever written' (and I agree). In Chapter 8, 'These Serpents Slay Men and Eat Them Weeping,' the author, a longtime field researcher on Nile crocs in East Africa, describes the legend and concludes: 'As for the physiological basis, there is none. We can be sure that any tears involved in these attacks are shed by men, not crocodiles.'"
So there you have it. My bad. In case you're wondering, the title Eyelids of Morning comes from a wonderful description of Leviathan in the Book of Job (41:14-18):
Who can open the doors of his face? His teeth are terrible round about.
His scales are his pride, shut up together as with a close seal.
One is so near to another, that no air can come between them.
They are joined one to another, they stick together, that they cannot be sundered.
By his [sneezings] a light doth shine, and his eyes are like the eyelids of morning.