The objective of this analysis was to estimate the net benefits of controlling bird and rodent pests in California production of wine grapes and avocados. These two crops were chosen because of the expected differences in types and extent of pest damage and methods of pest control used by growers, as well as their importance in California agriculture. A web-based survey was designed to capture grower experiences with current levels of pest damage and their expectations about damage levels without control. Information on the methods of pest control and associated costs was also solicited from growers. We obtained 83 responses from avocado growers and 84 responses from wine grape growers. Results indicate that rodenticide use and trapping are the predominant methods of rodent control in both crops, while netting and visual scare devices are the most common methods used to control birds. The net benefits of bird and rodent control were measured on a per-acre basis and accounted for crop savings, avoided property damage, and control costs. In avocado production, the net benefit of bird control was estimated to be $60 to $196 per acre, and the net benefit of rodent control was estimated to be $574 to $1,117 per acre. In wine grape production, the net benefit of bird control was $956 to $1,600 per acre and the estimate for rodent control was $390 to $832 per acre.

California is the nation’s greatest agricultural producer. In 2006, California’s gross value of agriculture production was more than $38.3 billion, almost double the value of production for the second most important agriculture state, Texas. The agricultural sector is a fundamental segment of any economy because it not only contributes substantially to the general economy and employment of the region, but it is additionally linked to almost all other sectors in the economy (i.e., manufacturing, retail trade, and accommodation and food service) as a source of inputs. Damage to crops by birds and rodents can reduce total crop yield and increase pest control costs. This ultimately reduces the production output of the agricultural sector and all other linked sectors and could potentially have significant total economic impacts. One method to estimate the total impact to the California economy of a decrease in agricultural yields and increase in pest control costs as a result of bird and rodent damage is an input-output (IO) model. To capture the sub-regional effects of economic changes, IO modeling is done at the county level. For the initial phases of this project, a deductive process was used to systematically rank California counties according to gross value agricultural production, value of production of targeted crops, and concentration of targeted crops. This process was used to identify the 10 leading agricultural counties, out of California’s 58, that will be processed for IO modeling to measure economic impact of bird and rodent damage on employment and revenue in each of these counties.

This paper presents a general summary of an economic assessment of the United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Wildlife Services (WS) Program in California (CA). Detailed analyses quantified WS economic benefits to each of the 38 counties that contributed cooperative funds in 2004, with an aggregate report of county results used to form an overall statewide estimate of the Program’s value. Four general categories of wildlife damage management activities were: Agriculture, Health and Human Safety, Natural Resources, and Property. Two general methods of determining economic valuation were employed to quantify benefits: replacement-cost method, and damage-avoided method. Results showed that the protection of livestock, particularly sheep, cattle, and goats, from predation was a main activity of WS–CA personnel in each of the cooperating counties. Annual estimated replacement costs for WS–CA operations for Year 1 and Year 2 of the analysis (i.e., approximately equivalent to fiscal years 2003 and 2004, respectively) totaled $6,605,234 and $8,602,590 for the combined counties, respectively. Mean replacement costs for WS operations in the cooperating counties in Year 1 and Year 2 equaled $173,821.95 and $226,373.13, respectively. Given that the counties paid an average $51,798.10 share to WS–CA in 2003, the counties would have incurred averaged net increased expenses of $122,023.85 and $174,575.03 for similar services offered by commercial wildlife damage management companies.

Mexican gray wolves were reintroduced into New Mexico and Arizona in 1998. When wolves kill a producing cow, ranchers in the region are eligible to receive an indemnity payment equal to the market value of the lost animal. We developed a model that allows estimation of the present value of the revenue stream that a cow or herd provides and find that if a producing cow is killed, the decrease in the present value of the rancher’s revenue stream is about $1,230. Mean indemnity payments are currently $1,000, implying ranchers are not being sufficiently compensated.

The economic impact of wildlife-caused damage and associated management is one of the many factors that arguably play a role in the decision-making process of wildlife managers. Often the role of an economist is to value the damage created by wildlife, or to assess programmatic efficiency to determine if changes can be made to increase return per dollar invested in management efforts. Frequently, the results of economic analyses of wildlife-caused damage are used to justify program efforts in the pursuit or maintenance of funding. The complexity of determining the economic impact of wildlife-caused damage requires that there is a clear understanding of the methodological approach used to determine impacts. Examining specific methodological approaches used in actual case studies provides a systematic replicable approach to valuing damage. This study outlines the methodology for determining the economic impact of cormorant damage to natural resources in a local economy: the Oneida Lake Region of central New York.