Wildlife contraceptive

Wildlife contraceptives of various kinds are under development. Contraceptives such as these are intended to control population growth among both tame and wild animals.

White-tailed deer may be controlled with contraceptives in suburban areas, where they are sometimes a nuisance. In parts of the United States, does are shot with darts containing a contraceptive vaccine, rendering them temporarily infertile.[1] The Humane Society of the United States runs a deer birth control program, but it is experimental; it may not be cost-effective in the long run.[1][2] It may cost $300[2] to $1000[1] per deer.

One contraceptive vaccine used is porcine zona pellucida (PZP), or derivatives. This form of immunocontraception prevents sperm from accessing an ovum.[3] Another form of deer contraception, called GonaCon, produces antibodies to sex drive hormones in the deer, causing them to lose interest in mating.[4]

Similar forms of injectable contraceptive are being studied for use in elk[5] and gray squirrels.[6]

Oral contraceptives may also be developed for population control among a variety of animals, including deer, feral pigs, coyotes, cougars, dogs and cats.[7] One product that has success in mice, rats, and dogs originally went by the name Mouseopause, but was approved for commercial use under the name ContraPest.[8]

Pigeons have been a target for experimental contraceptives for decades.[9] An oral contraceptive is in use for the control of Canada geese.[5]

A slow-release hormonal contraceptive implant for female Tasmanian devils is under development. While it may seem counter-intuitive to develop contraceptives for an endangered animal, their use is intended to promote the wild behaviour of mating freely, but without certain females over-contributing to the next generation, which "can have long-term genetic consequences for the insurance population". Contraceptive trials in male devils showed that their testosterone increased, instead of decreasing as other male mammals' testosterone does.[10]