In response to nutria-linked degradation of much of its coastal wetlands, Louisiana established the Coastwide Nutria Control Program (CNCP) in January 2002. CNCP instituted, among other things, an "economic incentive payment” of $4.00 per delivered nutria tail from registered participants in the program. To examine whether this bounty has had an impact on nutria harvest and whether alternative bounty levels can, in general, generate additional harvesting activities, we developed a bioeconomic supply model that relates Louisiana's annual nutria harvests to a suite of economic and environmental factors. Results suggested that the annual nutria harvest is responsive to both the price received per animal and costs. Results also suggested that the nutria harvest has increased as a result of the bounty, but that the initial bounty of $4.00 per tail may be insufficient to achieve the state's goal of harvesting 400,000 animals per year but that a bounty equal to $5.00 per tail would likely achieve the stated goal.

The coypu (Myocastor coypus) is an aquatic rodent usually bred for fur production. Fluctuations in fur prices have led to coypu meat being considered as a genuine resource in commercial farms, which contribute to the diversification of agro-ecosystems. To characterize coypus as a meat resource, maternal and heterotic effects on birth weight, weaning weight, slaughter weight, number of days required to attain a weaning weight of l kg, and on two parameters of the Gompertz growth curve (asymptotic weight and maturing rate) were studied. Eight males and eight females of Standard (S) and Cognac (C) genotypes and of their reciprocal crosses (C × S) and (S × C), where the first letter denotes the paternal genotype, were used. Significant genotype, sex and (genotype × sex) interaction effects were evident for most traits. S animals were lighter than С at all ages. Hybrids with С mothers were heavier than their reciprocals. Maternal effects on the parameters of the growth curve were observed only in females. Heterotic effects were extremely significant. Favourable heterotic effects in immature animals were explained by a change in the F1 growth pattern. Males showed a dominant deviation toward low asymptotic weights and overdominance for high maturing rate. Females showed partial dominance of high asymptotic weight and over dominance for high maturing rate. This association of genetic effects would justify a productive system based on a terminal cross using С females and S males because of the higher maturing rate of both hybrids and the maternal effect of С genotype, a combination that allows higher weights at the usual slaughter age (6 months) or butchering of animals at earlier ages.