EVIDENCE ON THE ACCURACY OF EXPENDITURES REPORTED IN RECREATIONAL SURVEYS

This article discusses the results of four experiments to test the accuracy of recreational expenditures reported in survey relative to expenditures reported in dairies. We found few situations in which the reported expenditures in the surveys and diaries differ significantly. In general, we conclude that individuals are able to accurately report recreational expenditures in ex post mail surveys. Given the wide usage of survey expenditure data by economists, we find this results encouraging.Resource /Energy Economics and Policy,

Waterfowl Lead Poisoning Studies at Forney\u27s Lake, Iowa

Forney\u27s Lake in Fremont County is a popular waterfowl concentration area along the Missouri River with a history of lead poisoning of mallards. About 1,500 mallards died from lead poisoning in 1960 and about 2,500 in the winter of 1965 and 1966. A total of 143 bottom samples taken in 1966 and 1967 indicated an average of 1.6 pellets per square foot were available to waterfowl. Lead poisoning losses on this area can be minimized by regulating water levels after the hunting season to move the birds elsewhere

Iowa\u27s Wetlands

The Wisconsin glacier created a 7.6 million acre prairie-marsh-pothole complex in north-central and northwest Iowa. Prairie marshes, valuable for wildlife habitat and water retention, have been relentlessly drained. In 1938, only about 50,000 acres of prairie marshland remained and in 1980 this had been reduced to 26,470 acres of natural marsh. Meandering rivers have been straightened, eliminating miles of river course. Only 1,637 miles are officially designated as meandered streams. While natural marshes and unchannelized streams are threatened aquatic habitats, other wetlands have actually increased. Artificial reservoirs provide 47,562 water acres and 47,700 farm ponds have been constructed. Proper public attitude could increase the acreage of marshland as well as reservoirs. Approximately 5,000 acres of prairie marsh and pothole habitat remains in private ownership. To protect these threatened wetlands, additional money and public support is needed

A Comparison of Approaches to Mitigate Hypothetical Bias

We compare two approaches to mitigating hypothetical bias. The study design includes three treatments: an actual payment treatment, a contingent valuation (CV) treatment with a follow-up certainty question, and a CV treatment with a cheap talk script. Our results suggest that both the follow-up certainty treatment and the cheap talk treatment produce willingness-to-pay (WTP) estimates consistent with the actual payment treatment. However, the follow-up certainty treatment provides response distributions at all offer amounts that are statistically similar to the actual payment treatment, while the cheap talk treatment provides similar responses only at some offer amounts. Furthermore, the cheap talk treatment is effective only for inexperienced individuals. We conclude that the follow-up certainty approach is more consistent than the cheap talk approach for eliminating hypothetical bias.contingent valuation, hypothetical bias, follow-up certainty, cheap talk, nonmarket valuation, Environmental Economics and Policy, Public Economics, Research Methods/ Statistical Methods,

Lake Michigan Salmonid Stocking Costs in Wisconsin

The costs of stocking salmonids in the Wisconsin waters of Lake Michigan are estimated for 1985. Estimation procedures and costs per stocked and captured fish are presented. Fingerlings of a species were found in most cases to cost more per captured fish than yearlings. However chinook salmon fingerlings were least expensive at an average cost of only $0.35 per captured fish. Most expensive were brook yearlings and fingerlings at$12.67 and $10.14 respectively. While a full policy evaluation awaits additional research on species specific benefits, three tentative conclusions can be drawn for the Wisconsin fishery. First, the role of brook trout in the fishery should be reviewed. Second, despite difficulties with lake trout rehabilitation, the role of lake trout in the sport fishery is encouraging and may justify continued stocking. Finally, increased stocking of the popular chinook salmon may be justified if the recent problems of low capture-per-release rates can be solved.restocking costs, benefit-cost methodology, sport fisheries, salmonids, Lake Michigan, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Re-Establishment of the Giant Canada Goose in Iowa

Giant Canada geese (Branta canadensis maxima) were common nesters in Iowa before 1900 but were exterminated through overexploitation about that time. Recent efforts by the Iowa Conservation Commission to re-establish these birds have been successful. By providing protection and nesting areas this flock has been increased from a few pair in 1964 to 800-1,000 birds in 1970. The birds have adapted to the surrounding habitat and established a migration tradition. The goal is to increase the flock to 7,000 birds

Absolute quantification of the host-to-parasite DNA ratio in Theileria parva-infected lymphocyte cell lines

Theileria parva is a tick-transmitted intracellular apicomplexan pathogen of cattle in sub-Saharan Africa that causes East Coast fever (ECF). ECF is an acute fatal disease that kills over one million cattle annually, imposing a tremendous burden on African small-holder cattle farmers. The pathology and level of T. parva infections in its wildlife host, African buffalo (Syncerus caffer), and in cattle are distinct. We have developed an absolute quantification method based on quantitative PCR (qPCR) in which recombinant plasmids containing single copy genes specific to the parasite (apical membrane antigen 1 gene, ama1) or the host (hypoxanthine phosphoribosyltransferase 1, hprt1) are used as the quantification reference standards. Our study shows that T. parva and bovine cells are present in similar numbers in T. parva-infected lymphocyte cell lines and that consequently, due to its much smaller genome size, T. parva DNA comprises between 0.9% and 3% of the total DNA samples extracted from these lines. This absolute quantification assay of parasite and host genome copy number in a sample provides a simple and reliable method of assessing T. parva load in infected bovine lymphocytes, and is accurate over a wide range of host-to-parasite DNA ratios. Knowledge of the proportion of target DNA in a sample, as enabled by this method, is essential for efficient high-throughput genome sequencing applications for a variety of intracellular pathogens. This assay will also be very useful in future studies of interactions of distinct host-T. parva stocks and to fully characterize the dynamics of ECF infection in the field

The Point System Approach for the Harvesting of Ducks in Iowa

Under this system, different species and sexes of ducks were assigned various point values. The daily bag limit was reached when the point value of the last duck taken, added to the sum of the point values of the other birds already bagged during that day, reached or exceeded 100 points. The point system differs from past conventional regulations by freeing the hunter from the necessity of correctly identifying each duck before shooting in order to remain legal. This system was first tested in Colorado in 1968 and since has been tried on an experimental basis in several states. Hunter opinion was highly favorable and hunter observation data indicated major compliance with the regulations. Hunters tended to select mallard drakes and avoided shooting at hen mallards and wood ducks. The point system regulations were more restrictive than the conventional regulations permitted elsewhere in the flyway. Seasons operating under point system regulations had fewer problems associated with them than were experienced under conventional species oriented regulations and offered more flexibility and enjoyment to the hunter

Marsh Management and Its Relationship to Vegetation, Waterfowl, and Muskrats

Management of Iowa marshes is primarily aimed at waterfowl production with secondary considerations for furbearing animals and non-game wildlife. Difficulty in maintaining the hemi-marsh, which is considered optimum for avian production, prompted this study to examine the interrelationships between duck breeding populations, muskrat (Ondatra zibethicus) population densities, and emergent vegetation. Blue-winged teal (Anas discors) populations responded more closely to changes in percent of the area that contained emergent vegetation than mallards (Anas platyrhynchos). Waterfowl populations were not totally dependent on vegetative conditions of the marsh. Muskrat populations were directly related to habitat quality but fall water levels were influential m regulating the number of muskrat houses and number of muskrats caught by trappers. The most beneficial management program for waterfowl production on glaciated marshes requires revegetation by man-induced droughts and maintenance of water levels until the open stage occurs, then the procedure should be repeated. Marshes are best managed individually by utilizing results from past management procedures