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The concepts of “integrated control” and “integrated pest management” (IPM) were devised by entomologists, but they proved relevant to the monitoring and control of virtually any agricultural pest (i.e., weeds, fungi, vertebrates). Within IPM, economic threshold characterized pest densities that would have negative impacts and economic injury level characterized amounts of predicted crop injury (destruction) that would allow recovery of potential pest-control costs. Approximately 150 species or groups of vertebrates have been documented to pose human health/safety risks or to cause agricultural, natural resource, and property losses in North America. Rodent (e.g., mice, rats, ground squirrels) and bird (e.g., blackbirds, gulls, cormorants) populations are the most frequently cited species/groups of vertebrates linked with IPM. Uncertainty characterizes IPM applications to control damage by these species/groups. Uncertainty is a measure of variance, which occurs due to the myriad of biological, crop, economic, meteorological, pesticide, production, seasonal, and soil unknowns that impact IPM programs. Six uncertainty-reduction techniques are commonly used by economists: 1) worst-/best-case scenario, 2) contrived scenarios, 3) decision tree analysis, 4) sensitivity analysis, 5) Monte Carlo simulation, and 6) systematic projections. This paper reviews key IPM literature, especially economic literature, and discusses techniques that can reduce the economic uncertainty of using IPM programs with vertebrates.

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.

This paper describes issues and concepts relevant to economic modeling of oral rabies vaccination (ORV) campaigns for managing wildlife rabies. Economic models of ORV are mathematical expressions used to predict and draw inferences about the costs and savings likely to be recouped by these rabies management efforts. Costs that are prevented due to ORV campaigns convert to savings. Comparison of campaign duration, bait cost, bait density, and bait distribution data for North American ORV campaigns showed that: 1) campaigns are lengthy, 2) those involving raccoons entail greater bait densities (i.e., related bait costs) and per unit area bait-distribution costs than those involving foxes and coyotes, and 3) all entail “enhanced” surveillance and establishment of maintenance barriers (i.e., deter translocation or reintroduction of new cases) upon completion. Key modeling issues were: model parameterization, ORV cost variables (i.e., bait costs, bait densities, and unit area distribution costs), time horizon, contingency costs, and ORV host specificity.

A comprehensive cost model of wildlife rabies is presented. A total of 11 factors were viewed to comprise the diverse agricultural, insurance, medical, and veterinary expenses associated with rabies (i.e., pet vaccinations, livestock vaccinations, pet replacements, livestock replacements, pre-exposure prophylaxis for humans, post-exposure prophylaxis for humans, adverse medical reactions, animal control activities, public health charges, quarantine costs, and human death settlements). These factor costs form the basis of potential savings to be gained from rabies control activities. Irrespective of incidence, per unit costs and ranges were found to be greatest for livestock replacement, post-exposure prophylaxis, adverse medical reactions, and human death settlements, with substantial costs of adverse medical reactions and human deaths occurring infrequently but due to potential insurance or litigation claims. Empirical studies are needed to document the incidence of these factors during pre-epizootic, epizootic, and post-epizootic phases of wildlife rabies.

Benefit-cost analysis (BCA) involves comparing all of the gains and losses from a given wildlife damage management action or management technique over time in similar units, thereby providing a total picture of potential gains and losses to society. This technique is at the core of justifications for wildlife damage management efforts. BCA has been noticeably absent from the study of vertebrate pest management problems, and in the few studies where a BCA has been included, the analysis is incomplete. This paper provides an overview of the steps in a BCA, using specific wildlife damage examples to highlight and expand the technique for researchers interested in documenting these effects.

This paper describes several unexpected benefits of rodenticide-registration research funded by the California Bait Surcharge Program. An enclosure-type study was conducted to determine efficacy of single, pre- and test-bait broadcasts (10 lb./ac.) of 0% and 2% zinc phosphide (Zn3P2, CAS #1314-84-7) steam-rolled-oat (SRO) groats to control voles (Microtus spp.) in alfalfa (Medicago sativa). Unexpected research spinoffs resulted from the use of: 1) eight randomly-located, sieved-dirt plots per enclosure to monitor bait distribution, bait removal, and rodent/avian (non-target) activity; 2) a bait-weathering plot and bait-sample analyses to monitor Zn3P2 biodeterioration; and 3) a C++- language program to derive theoretical benefit-cost ratios associated with Zn3P2-bait broadcasts

Abstract: Rabies is a fatal zoonotic disease of mammals; it exacerbates the uncertainty of conserving populations of some threatened mammals (TM). Modelling affords an inexpensive, a priori way of studying key parameters of wildlife rabies transmission, rabies management economics, and TM conservation. Numerous models of rabies transmission have been published. Linear density dependent models predicted that a threshold density (K T ⩽1.0), possibly attained by culling or contraception, would eliminate an epizootic through reduced contacts among host animals. Density independent models predicted less advantage of culling and contraception in rabies control due to limited contacts among territorial host animals. Recent stochastic, mixed models offer novel predictions about the role of culling, fertility control, and oral rabies vaccination (ORV) in disease management. Use of a “threshold successful contact” rate (C T) as a parameter in these models predicts that density reduction of host animals will enhance ORV campaigns in non-TM contexts via more efficient bait delivery and vaccination. Economic analyses of medical, public health, and veterinary costs have shown post-exposure prophylaxis (PEP) and increased pet vaccinations (PV) to be major rabies-caused expenses during and after epizootics in North America. No modelling efforts have examined either the benefits-costs of rabies management strategies to conserve TM or the use of ORV, per se, to conserve TM – an omission due in part to the lack of methodologies for properly valuing TM (potential savings) and the expense or lower priority of using ORV for TM protection. This paper: (1) describes key aspects of rabies-transmission models in wildlife, (2) posits the use of C T to predict disease persistence, (3) reviews selected ORV strategies, economic studies, and benefit–cost models associated with the use of ORV as a means of rabies control in non-TM situations, (4) discusses implications of these models to the conservation of TM, and (5) recommends five steps to improve modelling of rabies transmission (wildlife disease in general), rabies-control economics, and TM conservation. [Copyright &y& Elsevier]

Abstract: Important nest sites for the endangered California least tern remain at the U.S. Marine Corps Base, Camp Pendleton, CA; these terns comprise approximately 17% of the state''s breeding population. This paper presents an empirical analysis of annual, fixed-cost budgets expended for reproduction-monitoring and predator-removal activities to protect this shorebird. The ex post study covered the inclusive 7-year period between 1995 and 2001. Separate regression analyses were computed using 15 biological (X B), economic (X E), and meteorological (X M) variables. In separate analyses, 14 of these variables served as independent variables to predict each of four dependent tern observation variables (i.e., Y nests, Y eggs, Y fledglings, and Y adults), with certain variables “lagged” (i.e., regressed after fixed intervals) to compensate for delayed effects of predator management. Mean net current annual reproduction-monitoring and predator-removal budgets were US$80,115 and US$78,178, respectively; annual fiscal data were converted to “proxy” variables of personnel time (h) for analysis of economic effects. Mean time spent in reproduction-monitoring (3.12 h/day) and predator-removal activities (6.96 h/day) differed greatly. Expenditures for both reproduction-monitoring and predator-removal staff hours were associated with greater counts of tern eggs and adults, with increased monitoring hours predictive of finding more tern nests and fledglings and increased predator-removal hours linked with fewer fledgling counts. No meteorological variables predicted any dependent variable. Economic issues involved in recovery of threatened and endangered species (TS/ES) are discussed. [Copyright &y& Elsevier]