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
Use of Confined Dogs for Reducing Deer Damage to Apple Orchards
We assessed the efficacy of free-ranging dogs, confined by buried fences and electronic collars, for reducing deer damage to apple trees in three commercial apple orchards in Oswego County, New York State. During 1995 and 1996, we monitored paired dog-protected and control plots in each orchard. Within dog-protected areas, the percentage of damaged buds was lower, and fruit yield was higher in both 1995 and 1996 than for control plots. Gross economic returns were higher from dog-protected than control plots in both 1995 (by 51%) and 1996 (by 184%). After two seasons of growth, trees planted in May 1995 had nearly three times the cross-sectional area, and were 60% taller if they were in dog-protected rather than control plots. Dogs provided increased economic returns for growers at much lower cost than conventional barrier fencing.
A CURRENT ASSESSMENT OF VOLE DAMAGE AND NUMBERS AND OF METHODS USED TO CONTROL VOLES IN ONTARIO APPLE ORCHARDS
A province-wide eva lua t ion o f the amount, d i s t r i b u t i o n , source and c o n t r o l o f damage t o Ontar io apple t rees was i n i t i a t e d . Data wereobtained from 280 responses t o a quest ionnai re d i s t r i b u t e d t o growers across Ontario, and from t r a p censuses i n three widely separa ted areas. Meadow voles (Microtus pennsyl vani cus) damaged o r dest royed 8,423 t rees i n o u r quest ionnai re sample and o ther mamnals damaged another 10,307 t rees . No re1 a t ionsh ip was found between a p p l i c a t i o n o f roden t i c ide and l e v e l s o f damage, b u t roden t i c ide t rea ted b a i t s sharp ly reduced numbers o f voles on our t r a p p l o t s . Orchards wi t h h igh l e v e l s o f damage were on average only oneth i rd as l a r g e as the average orchard i n our t o t a l sample. A l l damage by voles appeared t o be caused by meadow voles and no p ine voles (M. pinetorum) were found. Numbers o f voles va r ied g r e a t l y among our three study areas. Future work w i l l concentrate on fac to rs causing h igh l e v e l s o f damage and on the r e l a t i o n s h i p between d ispersa l o f voles and the e f fec ts o f r o d e n t i c i d e treatment. I n t r o d u c t i o n I n Ontario, the re has been very l i t t l e systematic research i n t o the amount and c o n t r o l o f damage caused by herbivorous mammals i n apple orchards, desp i te abundant evidence from growers t h a t t h i s damage i s extens ive and c o s t l y (Brooks and Schwarzkopf 1981). I n 1981, Ontar io growers sought t o suppor t a research program t h a t would determine the amount o f damage caused by voles and t h a t would develop more economical and e f f e c t i v e c o n t r o l measures than those t h a t e x i s t now. I n September 1981, we i n i t i a t e d a four-year research program. The ob jec t i ves o f the f i r s t phase o f t h i s research were: 1. To i d e n t i f y the mammalian species causing damage t o Ontar io f r u i t t rees. 2. To q u a n t i f y the e x t e n t o f mammalian pest damage i n Ontario. 3. To assess the nature and e f fec t i veness o f cu r ren t management and con t ro l pract ices. 4. Using t rapp ing techniques, t o est imate dens i t i es o f voles i n orchards i n three areas o f the province. From in fo rmat ion obtained dur ing t h i s i n i t i a l phase, we have formulated research plans d i r e c t e d toward the long-term goals of the p r o j e c t . S p e c i f i c a l l y , these goals a re t o develop recommendations t o advise growers on cos t and l a b o r e f f i c i e n t methods t o reduce t r e e damage by rodents and, w i t h i n these constra in ts , t o recommend methods t h a t minimize the use o f tox icants i n c o n t r o l . Methods and M a t e r i a l s 1. Ques t ionna i re I n Se~tember 1981. auest ionnaires were d i s t r i b u t e d bv mai l t o 1100 apple' growers i n 0 n i a r i o . These quest ionnaires provided informa t i o n on: (a) t r e e composit ion ( i .e., number, age, va r ie ty , e tc . ) and s i z e o f the orchard; (b) methods (i.e., t iming, and frequency o f use o f herb ic ides, rodent ic ides, mowing, c u l t i v a t i o n , e tc . ) of h a b i t a t management and rodent pest con t ro l used by growers; ( c ) amount o f damage i n f l i c t e d on t rees by mammalian pests; and (d) general l o c a t i o n o f the orchard, depth o f w i n t e r snow cover and o ther f a c t o r s . Returned quest ionnai res (280) were a1 located t o f o u r regions (F ig . 1 ) . A. Lake E r i e = a l l counties border ing on Lake E r i e B. Centra l Ontar io = a l l counties from Lambton t o York C . Georgian Bay = count ies o f Grey, Simcoe and Wel l ington D. Eastern Ontar io = a l l counties eas t of York. 2. Tra i n Pro rams St:da:d I i ?e-t rappi nq and snap-trappinq techniques ( ~ a v i s 1956, Krebs e t a1. 1969, ~ e n z u l l i e t a1. 1980, '~ tockrahm e t a1. 1981, Webster and Brooks 1981) were used t o i d e n t i f y rodent species res iden t i n apple orchards and t o est imate populat ion l e v e l s o f these species. Trap g r i d s were es tab l i shed i n orchards i n Haldimand-Norfol k muni c i p a l i t y , Grey County, and Pr ince Edward County (F ig . 1 ) . The study orchards were se lec ted because they had experienced damage by voles i n prev ious years. Sampling was conducted i n such widely dispersed t r a p g r ids , because the Ontar io Pest ic ides Advisory Committee (OPAC) expressed i n t e r e s t i n determining whether i t would be f e a s i b l e t o est imate vo le l e v e l s across apple growing areas o f Ontar io on the bas is of samples f rom a s i n g l e g r id . Four 0.21-ha l i v e t r a p g r ids were establ ished i n each o f the th ree sample areas. Trapping comenced i n e a r l y September and ended i n mid-December. Each area was trapped throughout f o u r consecutive 24-h per iods on th ree occasions (Cycles 1, 2, and 3), g i v i n g a t o t a l o f 12 days and 12 n igh ts t rapping on each study g r i d . Ba i ted Sherman l i v e t raps were s e t a t each g r i d marker w i t h 5 m between markers. Traps were locked open f o r 24 h before each four-day Cycle began. Captured animals were marked w i t h numbered ear tags, weighed, sexed and released. Reproductive a c t i v i t y was a lso noted. F ive 0.21-ha g r i d s were establ ished on the three areas f o r snap-