These studies conclude that GM animals may have either positive or negative effects on the environment depending on the particular animal, trait and production environment in which it is introduced. The main environmental concerns associated with animals involve: (a) the possibility that transgenic animals could escape with resultant negative effects on wild relatives or ecosystems, and (b) potential changes in production practices that may lead to varying degrees of environmental stress. These reports recommend that GM animals should be evaluated in relation to their conventional counterparts.