1996-97 NATIONWIDE FERRET SURVEY OF STATE WILDLIFE AGENCIES
From the California Department of Fish and Wildlife Website:
SUMMARY. In October 1996, the California Department of Fish and Wildlife mailed a survey questionnaire to each state wildlife agency in the nation to obtain legal and natural history information regarding domestic ferrets (Mustela putorius furo). All state wildlife agencies, including California, were polled. The goal was to determine the concerns of each state wildlife agency and to clarify what authority and role each state wildlife agency had regarding ferrets. This was undertaken to obtain information for use by California Department of Fish and Wildlife in assessing environmental concerns relating to proposed legalization of ferrets as pets in California. All states responded. A database was developed and survey results were tabulated to summarize the wide array of responses state agencies provided on agency authority and other legal background, ferret classification and terminology, status of ferrets owned or wild, and environmental concerns.
Appendix B is at the bottom of the survey.
Their survey failed to find any detriments caused by ferrets so they buried the study.