One good decision here: http://www.returntofreedom.org/murderers-creek-wild-horses/
Interesting article (part of which is below) on the use of PZP on wild horses, if you can ignore the title, that is. Read past the mention of one mare being darted and not having a foal for 10 years. She was actually darted at least 5 times.
http://www.eenews.net/stories/1059985227
WILD HORSES:
Taking back the West -- one contraceptive dart at a time
GRAND JUNCTION, Colo. -- Josie, a buckskinned mare that roams the Book Cliffs here, had given birth every year from 1996 to 2003.
First, there was Joker. And then came Classy, Teardrop, Jolene, Gunshy, Jolie, Haywire and an unnamed colt. All but one were removed from the range -- with federal taxpayers picking up the tab.
And Josie? She was spared the ravages of having that ninth foal by a retired teacher named Marty Felix.
A volunteer with the nonprofit Friends of the Mustangs, Felix crawled on hands and knees through sagebrush and around juniper pines to sneak within 40 yards of Josie and shot her with a 4-inch fertility dart. That was in April 2003.
"It's been 10 years since she's had a foal," Felix, 65, said during a recent visit to the range northeast of Grand Junction. "She's 22 years old and she looks like she's 10. She looks fantastic!"
