THE ECONOMIC IMPACT OF WILDLIFE DAMAGE ON HUDSON VALLEY ORCHARDS
The impact of wildlife damage on the profitability of apple farming in New York's Hudson Valley was determined by vise of a Standard Net Present Value (NPV) analysis as a means to measure long-term impact. Data were gathered through questionnaire and interview of a stratified random sample of 39 growers that represented 17% of the regional growers. Data concerning species causing damage, extent of wildlife damage and types of controls used were combined with current and long-range costs including revenue lost through damage and control costs. Limitations of the analysis are discussed along with results that indicate an annual equivalent cost flow for all wildlife damage between $3.8 and $3.85 million or $184 to $188 per acre. This study shows that a typical grower experienced combined revenue losses and control costs of $12,500 during 1986. Fifty-two percent of this was associated with wildlife controls, 40% with revenue losses and the remainder with tree replacement costs. Over a 25-year period beginning in 1985, the NEV of control costs and revenue losses is projected to total between $53 and $62 million depending upon whether a 3.5% or 5.0% discount rate is used. I/Research Associate, Dept. of Agricultural Economics, Cornell Univ. 2/Professor, Dept. of Pomology, Hudson Valley Lab., Cornell Univ. 3/ Associate Professor, Dept. of Agricultural Economics, Cornell Univ. 4/Associate Professor, Dept. of Natural Resources, and Leader, NY Cooperative Fish & Wildlife Research Unit, Cornell Univ. INTRODUCTION Wildlife damage a variety of crops produced in the United States such as grains, orchards, vegetables, and ornamentals (Byers, 1984: Caslick and Decker, 1977; Katsma and Rusch, 1979; Tobin, 1986; McDowell and Pillsbury, 1959). The extent of the damage varies by region due to differences in climate terrain, crops, and wildlife. Despite the implementation of numerous control strategies, wildlife continue to be a severe problem in some parts of the country. This is because wildlife are extremely adaptable and in some cases thrive in areas where man has significantly altered the original habitat. For example, deer populations in New York are much larger than in the past because of the creation of fields and meadows while orchards are an ideal habitat for voles (Sauer, 1984; Byers, 1984). Hudson Valley apple orchards are particulary susceptible to damage caused by pine and meadow voles, deer, woodchucks, and a variety of birds. The primary objective of this study was to estimate the impact of wildlife damage on the profitability of producing apples in four counties of the Hudson Valley, New York. These counties were: Ulster, Columbia, Dutchess, and Orange. The first objective is important for several reasons. First, apple production is an integral part of the agricultural sector of the region. In 1985, 234 farms produced apples which had a total gross revenue ranging between $35-$45 million. Second, most fruit growers obtain most of their revenue from the sale of apples since half of the regional fruit farm acreage in the Hudson Valley is planted with apple trees (New York Crop Reporting Service, 1986; see Table 1). This implies that if wildlife cause extensive
Evaluation of Deer Damage in Mature Apple Orchards
The impact of winter deer (Odocoileus virginianus) browsing on apple production was studied in three commercial orchards in southwestern Wisconsin. Estimates of the proportion of apple buds available to deer, the percentage of available buds browsed, and the apple production were obtained for about 500 sample trees in 1975 and 1976. The accuracy and precision of estimation procedures were evaluated, and the relationship between browsing and production was analyzed. The availability of apple buds to browsing deer was primarily a function of the size and shape of the apple trees. Visual and photographic appraisal indicated that ellipsoids best described the shapes of apple tree crowns, so the proportion of buds available was calculated from equations for ellipsoid volumes for each tree. Good estimates of proportions of available buds browsed were obtained from bud and nip counts on a 2.5 percent sample of the trees, and subjective estimates of the proportion of available buds browsed were correlated with proportions calculated from the actual counts. Multiple regression analyses suggested that the degree of browsing was related to the cultivar, size, and location of the apple trees. In the orchards studied, 34 and 10 percent of the growing points were removed by deer in 1975 and 1976, respectively. Analyses indicated that deer browsing decreased apple production on size-controlled (dwarf and semidwarf) trees, but not on standard sized trees. Two methods of evaluating deer damage are proposed. The first method uses realized production figures and estimates of the percentage of the orchard browsed, whereas the second method requires only an estimate of buds browsed in the damaged areas to predict production loss.
The Tsetse Problem on the Eastern Cattle Route in the Gold Coast
1. Primary fly-belts round Makongo consisted of three different vegetational communities: a Cynometra-Vitex association along the main length of the Makongo river, on a clay soil; a Ficus congensis association along the river close to the town, on a sandy soil; and Isoberlinia doka woodland on moist sandy soil north-west and south of Makongo. 2. Secondary fly-belts of less dense vegetation occur in the orchard bush savannah round Makongo, and these are not colonised until the commencement of the rainy season. 3. Glossina tachinoides and G. palpalis both occurred in the riverside communities, and G. palpalis alone in the Isoberlinia woodland. 4. Along the river G. palpalis outnumbered G. tachinoides by 3:1 in the dry season. At the commencement of the rains G. tachinoides increased more quickly than G. palpalis , bringing their numbers very nearly equal, but at the end of the rains there was a decrease in G. tachinoides which restored the original proportion. 5. G. morsitans had been found at Makongo formerly but was not met with at the time of this investigation, its absence being due to the disappearance of the larger antelope from the neighbourhood. 6. Smaller game animals, small mammals and reptiles afforded an adequate food supply for tsetse in the fly-belts, and also passing herds of cattle, as well as natives from the village and travellers. 7. The distribution of G. palpalis within the fly-belts was markedly influenced by the proximity of a cattle road along which herds of cattle passed almost daily, and by village water-holes. 8. During the dry season the primary foci were always found to be the places of greatest relative humidity, and the fly does not tend to move out of these until the general atmospheric humidity has reached a certain fairly high degree. 9. In clearing the fly-belts the removal of all primary foci within a quarter of a mile of the town and of thick bush within 100 yards of water-holes was undertaken. The work lasted from the beginning of February to the end of March 1931. 10. The effect of clearing the Isoberlinia doka woodland was to banish G. palpalis completely, and it never returned to these clearings. 11. On clearing the riverside Ficus congensis fly-belt, G. tachinoides was practically eliminated for the first three months, but reappeared in the clearings in June when there was a general increase and up-stream migration of this fly. G. palpalis remained in this clearing in fluctuating numbers up to June, when observations were suspended. 12. 565 marked tsetse were liberated in the fly-belts immediately previous to clearing. Of G. palpalis 12·7% were recaptured in the clearings and 11% outside the clearings. Of G. tachinoides 5·5% were recaptured in the clearings and 6·8% outside.