Santa Catalina island has an over-population of bison, an this year they’re trying a new way to manage it, call it bison birth control.

It was one of several herding operations that will culminate today with the inoculation of female bison older than 2 years, part of an experimental program designed to limit the population through contraception. The goal: reduce herd size — which increases by 15% or more each calving season — to a manageable, healthier, less environmentally damaging and constant 150 or so.

The vaccine is non-hormonal and will not harm the animals or change their social structures, said Carlos de la Rosa, the conservancy’s chief conservation and education officer. It is also reversible after about a year.

“Bison will continue to be bison,” De la Rosa said. “Males will continue to compete for females, and females will continue to go into heat. The only difference is that we can control how many calves they have.

“For bison in love,” he added with a laugh, “this means romance without responsibilities.”

Oh-oh, too much of that last talk and some right-wing legislator will start demanding that there be an alternative bison abstinence program.