Sportsmanship in Hunting Act of 2008 - Amends the federal criminal code to prohibit anyone, in or substantially affecting interstate or foreign commerce, from knowingly transferring, transporting, or possessing a confined exotic animal for purposes of allowing the killing or injuring of such animal for entertainment or for the collection of a trophy. Exempts the killing or injuring of an exotic animal in a state or federal natural area reserve undertaking habitat restoration from such prohibition.
Defines "confined exotic animal" as a mammal of a species not historically indigenous to the United States that has been held in captivity for the majority of its life or for a period of one year.
Allows persons authorized by the Secretary of the Interior to make arrests, execute warrants, and search for and seize animals to enforce the provisions of this Act.