National Wildlife Research Center (NWRC)

PROJECT GOAL: Quantify the benefits and costs of NWRC products and Wildlife Services activities that aim to mitigate the impacts of wildlife diseases, wildlife damage to agriculture and natural resources, and wildlife risks to public health/safety.

Project Accomplishments 2008

The scope of wildlife damage management activities continues to expand as conflicts between humans and wildlife increase.  NWRC economists seek to quantify the potential savings (benefits) and costs derived from mitigating the impacts of wildlife diseases; wildlife damage to agriculture, proper, and natural resources; and wildlife risks to public health and safety.

Economic Analyses of Bird and Rodent Impacts to California Crops—California is the nation’s greatest agricultural producer.  In 2006, California’s gross value of agriculture production was nearly $38.9 billion.  The 20 top California crop and livestock commodities accounted for more than 80% percent of the state’s cash farm receipts, and eight of these commodities grossed over $1 billion in receipts.  The state ranks first in the nation for the production of dozens of crops, such as avocados, grapes, and processing tomatoes, and it is also the sole producer of many U.S. crops, such as almonds, artichokes, figs, olives, and walnuts. 

As part of a cooperative agreement with the California Vertebrate Pest Control Research and Advisory Committee, NWRC economists are evaluating the impacts of bird and rodent damage to selected county economies.  Bird and rodent pests of California agriculture include crows, ground squirrels, house sparrows, and cottontail rabbits.

To date, economists have used a three–step process to select 10 of 58 counties for input-output (IO) modeling:  (1) identify counties that led the State in total agricultural production, (2) identify those counties that had the highest valued cash receipts from a set of 25 key crops, and (3) identify those counties that had the highest percentage or concentration of targeted crops as compared to total agricultural cash receipts.  Based on this empirical scheme, the 10 counties receiving the greatest cumulative ranks in order are Monterey, Fresno, Ventura, Riverside, Kern, Tulare, San Joaquin, San Diego, Stanislaus, and Napa Counties. 

Estimating Economic Impacts of Vampire Bat-Transmitted Rabies in Mexico—Human population growth and movement into undeveloped areas of Mexico have created economically important interactions among agriculture, public health, and vampire bats.  Vampire bat-transmitted rabies is a major cause of cattle mortality and human exposure in Mexico. 

NWRC economists cooperated with scientists from APHIS’ International Services Program in Mexico City and Mexico’s Ministry of Agriculture, Livestock, Rural Development, Fisheries and Nutrition to examine the impacts of vampire bat-transmitted rabies to humans and cattle.  They quantified the costs of mitigating rabies impacts through bat control and cattle vaccination programs and derived potential savings from decreased rabies infections.  They then used this benefit-cost analysis to determine if the potential vaccination of cattle and control of bats in the vampire bat endemic region was economically efficient.

Results showed that producers benefited from vaccinating cattle for rabies, with benefit-cost ratios between three and 15 for many realistic scenarios.  Additionally, analyses showed that the regional Mexican economy was likely to gain an economic benefit of five to 25 pesos for every peso spent on vaccination and bat control. 

Bioeconomic Evaluation of Feral Hog Damage in Congaree National Park, North Carolina—NWRC provided consulting services to the Wildlife Conservation Society (WCS) on how bioeconomic analyses can benefit seabird and sea turtle conservation.  Of particular interest to the WCS was how to value endangered species and conduct benefit-cost analyses for control and eradication programs.  Successes for management actions are usually measured in resource improvement, but the costs to carry out the management are measured in dollars.  The WCS is involved in invasive species eradication efforts to protect the nests of sea turtles and shorebirds and would like to show the economic benefits of their efforts relative to the costs.  NWRC has used similar economic analyses to evaluate the results of predator control for protecting sea turtle nests on Florida beaches, and feral hog eradication and raccoon control on Cayo Costa Island, Florida, for protecting threatened and endangered sea turtles and shorebirds.

Economic Analysis of Invasive Monkey Damage to Commercial Farmers in Puerto Rico—Monkeys were introduced to supposedly secure locations in Puerto Rico beginning in late 1930s and continuing through the 1970s.  Almost immediately after the first introductions, monkeys began escaping into the wild on mainland Puerto Rico. Today, populations of two species, rhesus macaques and patas, are growing and have become threats to agriculture, human health and safety, and native wildlife.  In particular, the damage monkeys caused to agricultural crops has become so severe that some farmers have switched from growing fruit and vegetables to using their land as pasture for grazing.  Moreover, there is a high prevalence of herpes B virus among the rhesus macaques, which, while fairly benign in macaques, is approximately 70% fatal in humans.  Between 1996 and 2004, the monkey populations were estimated to have quadrupled.  NWRC and Florida WS  worked in a cooperative effort with the Puerto Rican Department of Agriculture (PRDA) to assess the annual economic damage to commercial farmers from 2002 to 2006.  During that period, the value of commercial farmers' losses to monkeys increased from more than $1.1 million to almost $1.5 million per year.  More telling, much of the losses increased through time and could be attributed to farmers’ giving up on growing fruit and vegetables due to monkey damage and switching to much less economically rewarding land uses, such as pasture land or growing hay.  The economic losses included only commercial farmers (over 90% of all commercial farmers) that sought any form of assistance from the PRDA.  Losses to small plot farmers and gardens were not part of the survey.  Other economic losses, such as the value of lost endangered species, medical costs, or property damage due to monkeys, also were not included.  The researchers predict that losses will continue to accelerate as the monkey populations continue to expand their range.

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