Male grizzly bears basically have two courting
styles: find a female and guard her from other males; or, find one
that is mating, chase the male away and take over. Those are the
conclusions of “Do Big Mean Studs Get All the Action?” and “Why Are
Deadbeat Dads Often Abusive?” two chapter titles Lance Craighead
employed in his doctoral thesis on grizzly bears. Craighead, son of
bear scientist Frank Craighead Jr., also showed with DNA testing
that more than one male can sire a litter of cubs, reports the
Billings Gazette. The tests were part of a six-year pedigree study
of a bear population in northwest Alaska that he says is “virtually
undisturbed and not hunted. It’s probably been there since the
bears first came to the New World.” The study, which identified 256
bears and 53 different family groups, showed that 44 percent of the
males successfully bred and that breeding success was not
age-related. The oldest male in the study, 32, was still fathering
cubs last year. But aggression seems to play a major part in
successful breeding. When males kill the cubs of other sires, the
mother goes back into estrus. Aggression is also important between
competing males. Craighead says one male had a softball-size chunk
taken out of his back, “and he was the winner.”
This article appeared in the print edition of the magazine with the headline It ain’t Antioch.
Republish our articles for free, online or in print, under a Creative Commons license.
