A new study indicates that Americans gained up to 15 IQ points after the addition of iodine to salt became mandatory. In an effort to prevent goiter related to iodine deficiency, authorities ruled that iodine be added to U.S. salt products in 1924. The iodine, in addition to eliminating goiter, appears to have had an unexpected result: smarter Americans.
At peak lactation a black bear cub consumes about 30 ounces of milk a day, and a brown bear cub takes about 45 ounces. Thatâs per cub, so a mom with a litter of two or three cubs could be producing three or four quarts per day â a difficult metabolic feat to sustain.
A big revelation to me was how reluctant black bear mothers are to defend their cubs against people, even when the family is cornered in a den and I'm trying to stick the mother with a needle to tranquilize her. Defense of cubs is more a grizzly bear trait. There is no record of anyone being killed by a mother black bear defending her cubs, and attacks are very rare. We routinely capture black bear cubs in the presence of mothers and have never been attacked.