Impacts of domesticated ferrets upon wildlife, agriculture, and human health in the USA, compiled from state agency surveys and literature review, with special emphasis upon California.

The pet ferret (Mustela putorius furo) is at the center of a controversy over how domesticated carnivores should be regulated and managed, and in general, how the impacts of introduced mammals can be minimized. California is presented as a case study because it contains the largest state population of pet ferrets, is subject to repeated petitions to repeal the ownership ban, and has diverse wildlife communities vulnerable to exotic animal introductions. The impacts of ferrets upon native wildlife and ecosystems, agribusiness, and human health and safety were compiled from a thorough review of the published literature and the analysis of four surveys of U.S. state agencies, including our unpublished survey data. Results highlight two primary concerns: the ferret can easily escape confinement, and could impact native bird populations, as do feral cats; and human safety concerns, especially with infants, because of the proclivity of the ferret to bite. The requirements for introduction and establishment of an exotic animal are discussed in relation to the case studies of feral ferret populations and applicable life history traits. While the pet ferret may lack the genetic rigor and instincts to be an effective predator and invader, the European polecat (M. p. putorius) and ferret-polecat hybrids can and do exploit vulnerable ecosystems such as islands. Regulatory strategies and environmental impact mitigation measures are presented: methods for minimizing the risk of release and for quantifying risk/benefits in general; addressing gaps in regulation, enforcement, funding, and information sharing; mitigating human health and safety concerns by mandatory sterilization /vaccination and pet owner education; and improving monitoring of invasive species and adequacy of emergency response and eradication measures. [ABSTRACT FROM AUTHOR]