Crop Damage by Wild Animals

section i general discussions

G.M. Wani

Ph.D ; D.V.M (Germany)

FN ISSGAPU, FN DAAD

Director Extension Education / SAMETI

Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir

Shalimar, Srinagar, 191121

 

 

 

A brief global review to ***** the damage caused to cultivated crops by wild animals around the world. The review was attempted in response to a recommendation of ICAR Regional Committee No.1 held in Oct, 2007 at Solan, H.p. presided over by Hon’ble Director General, ICAR Dr. Mangala Rai inauguration was chaired by Hon’ble Agriculture Minister J&K, Jenab Ab. Aziz Zargar.

                                                                Author

 

                                   

 

 

 

Published by:  Director State Agricultural Management and Extension Training Institute of Kashmir (SAMETI-K) , SKUAST-K , Shalimar , Post Box: 461, G.P.O, Srinagar.

 

 

                     Publication No: SAMETI/Pub/3/1000/January, 2008

 

 

 

P.O.Box: 461, GPO, Srinagar, E.Mail: Wanimohyuddin@yahoo.com

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Introduction:

 

       Wild animal-human conflicts have started since beginning of human era from Adam and Eve. This conflict of wilderness made man to hide in caves and he was called as “Cave man”. Slowly, with his advancement it is he who invented Axe and other weapon in stone and iron ages to frighten the wild animals, initially. Later on he hunted them to save himself. This feeling of uncertainty and fear of wild animals and wilderness reduced with the invention of fire. He made sharp weapons of bones and iron. These initial weapons were the beginning of this conflict, Animal human conflict.

Thirty thousand years ago, the human population rose to 6 million. They were still hunters. With the invention of fire, he set fire a vast majority of sanctuaries, which scared wild life and they migrated from his neighborhood. Many forests, hills and difficult terrains were still beyond the reach of man three thousand years before, although human population has increased to 60 million. Man has already started primitive agriculture. He had made his terrains and wild life scared by him left his close habitats and searched for fresh abodes. Man by now had lust for fur, horns, ornaments and other forest resources. He invented many means to frighten whole wild life. He became a “Danger “not only for wild animals but for his own species, environment and eco-biodiversity.

Three hundred years ago he industrialized crop production and produced enough food, for nearly 600 million people. This continued and from 30 year now he is feeding 6000 million people. Today we have a global food security for 7.5 billion. Human food security gains resulted in reduction of all other wild species, thus, the origin of wild- life- human conflict is the lust of man for more food, more luxury or sometimes fun for hunting or fur. This reduced wild life reserves and now a open conflict came into existence.

Many man-wild life conflicts have been reported from Gir forests of Gujarat, Rajaji National Park in UP and many other states where forest lands became cultivable lands. Elephants, wild boars, monkeys, squirrels, deer , birds like crows, parakeets, wild dogs, jackals, gaur, sambur, langure, fowls, pea cocks, neilgai, Hippos, biats, blackbirds, rodents, wild pigs, feral species, primates, beetles, foxes, pigeons, feral hogs and a variety of other species damage crops. The carnivores even attack human too. These attacks are for search of food or their loss of habitat. Many such accidents came to be known in Jammu and Kashmir. The bear leopod and other wild animals are reducing in number. Their habitats used by human.

The human causalities are due to carnivorous species, but herbivores inflict economic and human losses too. The crop damages by wild life has been the new threat to agricultural productivity throughout the world. This also concerns us in Asia and India. This review is aimed to find out:

1.       Extent of damage to crops.

2.       Nature of crop damage

3.       Ways and means to prevent these losses.

4.       A strategic planning to drive a line between wildlife conservation and farm economics especially in India.

 

Executive Abstracts and Strategic elementaries: [EASE]

1.     Importance

                   Species causing crop damages ranges from elephant’s wild birds, monkeys, squirrels, deer, parakeet, wild dogs, foxes, deer and many others like Neilgai. On an average this damage to crops by wild animals amounts to U$ 961 per hectare. It is much more than an Indian Farmer earns from a hacter annually. Therefore, by these estimates, the damages are spectacular and economically important.

2.       Human Elephant conflicts (HEC):

          i) Economic Losses:

                   Among elephants crop raiding is common. The crops near their home ranges are damaged more. Elephants damaging crops had twice big ranges than those who did not damage the crops. Thus, more proximity of the crops near their ranges are prone to crops damages. Train accidents instigate elephants more to crop or human damages. Indonesia saw more frequent raids of elephants on crops. Human elephant conflict (HEC) is frequent and poses serious challenges in Africa. Both male groups and family group attacks have been observed. HEC losses in West Bengal were worth 3.2 croses of Rupees. This damage occurred in 3368sq kms.radius. The numerical number of elephants was 62 only. Assam observes damages to the woodcutters by elephants Asian wild Elephants raid and damage crops in herds of 10-13 individuals or big herds comprising 50-74 elephants. In Darjeeling district alone over an area of 200 kms. East to west, in last two decades 277 houses were demolished by elephants, killing 66 people in 5 districts. As a result of this conflict 23 elephants lost their lives. In 2001, economic loss of the order of US fifty thousand dollars was estimated to be inflicted by elephants. This scenario necessitates comprehensive measures to be taken to lessen these damage. The review of the measures, around the world suggest following few studies to be undertaken and resultant measures to be applied to lessen these damages.

ii)     Mitigation of losses:

          Methods developed and used to mitigate crop damages by elephants consisted of frightening of animals by drum beating, firegracks or even air gun fires. Guarding the crops by fences or even using electric fencing or raising poles and wiring may be effective. Chemical based deterrents, and electric fencing have been found to reduce crop damages. High voltage electric fencing using energizers in west have prevented wild animals damaging crop but this preposition may not be applicable in areas where even habitations do not have access to electricity. However, this method may act as a temporary boundary separating wild and domestic habitats. This could prevent intrusions from sly vatic to domestic foci. Guarding fields, digging trenches, modifying cropping patterns have a possibility of reducing man elephant conflicts or Human elephant conflicts. A 30% open space between two habitats may help to avoid HEC. This means a distance to be maintained between cropping fields and elephant habitates. A proper investigation on these lines is needed. A grid based geographical information system (GIS) with a 25Km2 resolution may help to have cost effective data source to analyze these situations. There is urgent need of identifying spatial predictors of HEC. On the basis of this study one can suggest or plan mitigation strategies, early warnings of attacks, use of barriers and deterrents. The utility of the methods could be assessed for land use and livelihood strategies to limit HEC.

 

3.       Dear-Nilgai Damages.

          A survey of 2500 farms in UK revealed that 69% (n=192) cereal crops were damaged by deer. This damage costed £500 per annum per farm. Damages varied with deer density. In USA too deer damages comprised of crop loss, landscape damages, car accidents and property damages. Nilgai damages alongwith deer damages are common in India too. Tree cover of Acacia in the area is generally used as shelter by Nilgai. We have encountered huge crop damage in Mathura (CIRG) and nearby area by Nilgai visits. Grazing and browsing of Nilgai inflict losses on farms. This is regarded as a mammalian crop threat by the farmers. This behaviour of their inflict ozone injury to the young sapling, so precious for the growth of trees in Indian semi-arid farms.

 

          Corn damages by deer in USA amounts to 6.6.% per hectare. In an area where a farmer owned 125 hectare on an average 55 hectares were used to sow corn. There is a 6.6% loss of the product which is a huge economic loss. Similar damages by deer in Ontario, Canada, Portugal, Japan, South America and other parts of the world have been reviewed. In Virginia too a study involving 1506 agricultural producer farmers revealed 58% of them experiencing deer damages. Ways and means to prevent such attacks on crops have been reviewed. Most of the possible measures to be adopted are similar to these described for elephants (HEC).

 

4.    Other Mammal and bird damages

 

          Monkey damages maize, sweet potato and other crops. It is suggested to reduce or change cropping pattern or alternating with non-agricultural activities near location of monkey habitats. Various methods are reviewed. Bat damage, Hygo crop damages in Japan, Grape wine damages by bats in Andra Pradesh, India have been studied. Crop economic loss assessment has been reviewed in these pages. Clover rather than grass can reduce wild mammal damages. Alley cropping of black walnuts helped to save soyabean and maize crop damages. Pesticide damages wildlife and minimize their attacks, enclosures and other electric fencing help to avoid such damage. Can one use harmful means to save crops, need a suitable strategy to preserve ecology and biodiversity. Both crops and wild animals need security and conservation. A management strategy is needed to safeguard human and wildlife equally.  A policy framework is envisaged.

 

          Blackbird crop damage in USA amounts to 5-8 million dollars. A considerable sum of crores of rupees have been estimated to be damages in the form of crop, human and property losses by wild animals, birds and other rodents in India. Many measures to reduce these losses are needed and have been reviewed.

 

 

 

 

 

Review

1. Wild animals damaging crops

To elephants wild boar, porcupine, rheus macaque (Macaca mulatta), hoary-bellied squirrel, barking deer (Muntiacus muntjak), red-breasted parakeet (Psittacula alexandri), and wild dog are wild animals damaging crops.

Methods developed and being used to mitigate man-wildlife conflict include, frightening the animals; guarding the crops; and using some sort of scarecrow and traps (Miah et al 2001).

Accurate estimation of crop damage by wildlife (raccoons, white-tailed deer, and coyotes) often requires labour-intensive sampling procedure. Variable area transect (VAT) sampling has been identified as a potential labour-saving alternative to quadrat sampling ( Engerman et al 2002).

 

2. Wild life Human conflicts

Agricultural landowners suffer in the form of damage to crops, livestock, and other property. Some wildlife agencies maintained abatement and compensation programmes. A model of deer-inflicted crop damage used to facilitate agency decisions regarding deer densities and distribution, abatement use, and to forecast compensation. The model is applied to field-level compensation claims in Wisconsin, USA. The results are consistent with theory, ( Yoder J, 2002).

 

3.  Crop Economic loss due to wild life

          People’s perceptions were discerned through participatory discussions covering 419 households distributed in 10 villages in the buffer zone. Traditional uncodified rights of local people were substantially reduced through policy interventions set in since 1860s. Local people as well as tourists have been excluded from the core zone covering an area of 625 km2 since 1982. Deterioration of rural economy due to damage to crop and livestock by wildlife and, termination of opportunities of income from wild medicinal plant resources and tourism in the core zone were the key negative impacts of conservation policy felt by more than 90% of respondents. Mean annual economic loss per household was estimated as Rs.1285, Rs. 1195 and Rs.156 due to damage caused by wildlife to food crops, fruit trees and beehives, respectively, Rs. 1587  due to ban on collection of wild medicinal plants for marketing and Rs.7904 due to ban on tourism in the core zone. The Reserve authority granted compensation for livestock killed by wildlife but it was hardly 5% of the market value of killed livestock as assessed by the people. People did not appreciate much the present benefits from the reserve management in the form of wages for carrying out afforestation work, partial compensation for livestock depredation and availability of solar power devices, wool, and spinning devices. Approximately 95% respondents identified empowerment of local people in respect of realizing income from timber from dead/diseased trees in community forests, income from medicinal plants in buffer zone and opening of the core zone for tourism as potential development options. Improvement in rural economy, the prime concern of local people, has not received as much attention as legal enforcement of protection by the reserve management. There is a need for developing policies and management actions that serve the economic interests of local people together with enhancement of environment conservation goal (Maikhuri et al 2001).

 

4.  Crop selection:

Damage was less (34%) in experimental carrot as multiple crop than  carrots as only crop planted (62% damage). Staggered plantings of canola, which continuously produced flowers, was the most effective lure crop of the green manure crops we tested. Carrot producers should use electric fences or 2.4-m woven wire fences, perhaps combined with staggered canola plantings, to reduce carrot depredations ( Schwab et al 2001).

          The colver, rather than fertilized grass, is more effective cover crop on AFAs, against damage by migratory geese. The sward should be managed to encourage clover growth, which would probably involve frequent cutting but no fertilizer. Further research is needed on clover replenishment rate over the winter season and possible benefits of clover leys to other wild life (McKay et al 2001). Alley cropping of black walnuts and percent with maize and soyabean rotations may avoid will animal damages. Tree –crop ratio of 1:10 may help( Godsey, 2000).

 

5.  Elephan- human conflicts:

Conflicts between elephants (Elephas maximus) and human occur in Rajaji National Park (RNP), Uttar Pradesh, one of eleven reserves designated in India, to conserve Asian elephants. Elephant-human. The conflicts in RNP from 1996 to 1999 were studied, and all human and elephant deaths or injuries caused by conflict were recorded. The impact of human colonies on elephant movement was studied in 18 villages along 17 km of the sourthern boundary of the study site and 4 village in the Chilla-Motichur corridor. Three male and four female elephants were radio tracked for 1-2 years. Primary conflicts included crop raiding, competition between humans and elephants for vegetation, and elephant mortality due to train accidents. Adult males that raided crops had home ranges twice as large as adult males that did not raid crops. Elephants only damaged crop of fields that occurred within their home ranges. Field trails of chemical based deterrents and electric fencing should be tried to reduce crop damage. Train speeds need to be reduced to prevent accidental elephant mortality (Williams et al 2001).

 

Wild Elephant damages:

          A rapid village and field assessments, data survey showed. Elephants raided crops at a rate of 0.53 elephants per day in Indonesia. The frequency of crop raiding was related to vegetation type along the park border, the size and presence of rivers, and the distance to the park’s Elephant Training Centre (ETC), which houses about 150 captive elephants. Wild elephants damaged at least 450000  m2 of maize, rice, cassava, beans and other annual crops, and close to 900 coconut, banana and other perennial trees in the area surveyed. Elephants killed or injured 24 .Villagers try to reduce elephant damage by guarding fields, digging trenches between the park and their fields, and modifying their cropping patterns. Elephants-human conflict decreases the probability of support from local people for conservation efforts. The approaches are suggested consist of elephant trenches, electric fences, external support to affected villages, and compensation to villagers for any damage caused (Nyhus et al 2000).

          This study explores land use conflict in south east Kajiado District, Kenya. The results of household surveys conducted with farmers and herders in 1977 and 1996 to examine changes in land management strategies are compared. The conflict reflects ongoing competition over access to scarce land and water resources between herding, farming and wildlife are the reason of damage of crops. This man-animal conflict needs understanding the conditions that have created the present conflicts (Compbell et al 2000).

It is, therefore, suggested that 30% open space be used as a basic division for stratifying thickets into low –use and high-use categories for deer density estimation. The proportions of each type could be derived from grid-square measurements of aerial photographs (Latham J 2000).

 

 

Human elephant conflict

          Human-elephant conflict (HEC) in Africa occurs wherever these two species coincide, and poses serious challenges to wild life managers, local communities and elephants alike. Mitigation requires a details understanding of underlying patterns and processes. Although temporal patterns of HEC are relatively predictable, spatial variation has shown few universal trends, making it difficult to predict where conflict will take place. Crop raiding was further subdivided into incidents involving only male elephants or family groups. A relatively fine-resolution, systematic, grid –based method was used to assign the locations of conflict incidents, and spatial relations with underlying variables were explored using correlation analysis and logistic regression. Crop raiding was clustered into distinct conflict zones. Both occurrence and intensity could be predicted on the basis of the area under cultivation and, for male elephant groups, proximity to major settlement. Conversely, incidents human injury and death were less predictable but were correlated with proximity to roads. A grid-based geographical information system (GIS) with a 25km2 resolution utilizing cost-effective data source, combined with simple statistical  tools, was capable of identifying spatial predictors of HEC, At finer resolutions spatial autocorrelation compromised the analyses. Synthesis and application. These results suggest that spatial correlates of HEC can be identified, regardless of the *** of the elephants involved. Moreover, the method described here is fully transferable to other sites for comparative analysis of HEC. Using these results to map vulnerability will enable the development and deployment of appropriate conflict mitigation strategies, such as guarding, early warning systems, barriers and deterrents. The utility of such methods and their strategic deployment should be assessed alongside alternative land-use and livelihood strategies that limit cultivation within the elephant range (Sitati et al 2003).

          Human elephant conflicts (HEC) in west Bengal was an economic loss worth 3.2 crores. This much damage occurred in 3368 sq km radius inhibiting 62 elephants (Singh et al 2002)

 

6.   Kerala Survey

Crop damage by wild animals in Kerala, India, was studied from 1993 to 1996. Data were collected from the offices of the Kerala Forest Department, field survey and from the intensive study area at Marayur, Idukki District. Forty-five species of crops were destroyed by wild animals in Kerala, the species commonly destroyed by wild animals were paddy, coconut plam , plantains , cassava , arecanut, coffee, oil plam , pepper , jack tree, mulberry and manago. The main animals involved in crop damage were elephant (Elephas maximus), gaur (Bos gaurus),sambar (Cervus unicolor), wild boar (Sus scrofa), bonnet macaque (Macaca radiate), common langur (Presbytis entellus), blacknaped hare (Lepus nigricollis) and pea fowl (Pavo cristatus). Among these, elephants and  wild board gave maximum damage . Of the total compensation claimed by the farmers, only 8.2% was sanctioned by the Kerala Forest Department. The highest crop damage (30%) was recorded from the forest ranges coming under the Northern Circle: pinapple (47%) , sweet potato (47%), tapioca (42%), alocasia (39%) , beans (25%) and plantains (23%) recorded highest percentage of damage. In the intensive study area at Marayur, 28 species of crops were damaged and highest damage was during the summer months. At maximum damage was due to elephant (72%) followed by gaur (62%) , sambar (17%) and wild boar (16%) . Tiger (Panthera tigris), panther (leopard) (Panthera pardus) and wild dog (Conine alpinus) were the main cattle lifters in the state. A total of 31 deaths and 64 injuries caused by wild animals were recorded from the state during the period 1983 to 1993. Thirteen indigenous methods used for controlling the crop damage had been identified. High voltage electric fencing using energizer was effective for stopping elephants and other herbivores from entering the agriculture fields. Crop damage is found to be linked to the cropping pattern and location of the agriculture fields. Short term and long-term measures needed to prevent the crop damage are discussed (Jayson  EA,1999).

 

7.  Bird crop damages

 

Use of non-lethal method to avoid crop damages by bird have been reported. Blueberry damages by cedar waxwings (Bombycilla cedrotun were minimized. (Avery et al 2002).

 

8. Wild Bird damage

 

          In the northern Great Plains of USA,  conflicts between red-winged black birds (Agelaius phoeniceus) and sunflower (Helianthus annus)  growers have intensified since the late 1960s due  to the expanded  commercial production of sunflowers. We studied the potential population effects of the removal of up to 2 million red-winged blackbirds annually under a 5 year programme of baiting during spring with DRC-1339 (3-choloro-4 methalalanine) treated rice. They also examined whether lethal control, in combination with current levels of breeding habitat management, would be cost effective in decreasing depredation of sunflower crops during  late summer. They evaluated the cost benefit ration for 4 culling scenarios involving (1) variable annual cullus, not exceeding 2 million birds, with and without density compensation (i.e. ,a positive density-dependent response) on adult survival and (2) culls of 2 million birds annually with and without density compensation .We constructed a red –winged blackbird population model  represented as an age-based matrix and calibrated to stable growth. We assumed a total population of 27 million birds on 1 April (week 1), representing the red-winged blackbird breeding population staging in eastern Southern Dakota and migrating into North Dakota.Under each culling scenario, we reduced the stable red-winged blackbird population (Equally for females and males) and project the population through week 23 of the annual cycle (2 Sep). We then evaluated the associated costs of the management relative to potential sunflower crop losses, assuming $0.07 in damage per bird and  4% loss to other factors. Variable annual culls, likely the more biologically realistic model scenarios, yielded mean annual removals of 1 240 560 (SE=12 328) birds with density compensation and 1 231 620 (SE=28 811) birds without density compensation,, with cost benefit ratios of 1:2.3 and 1:3.6, respectively. Annual intrinsic rates for the model population over  the 5 year period ranged from 1-4 to 4.8%. Considering potential variability in the effectiveness of the cull and  the combination of direct and indirect costs,we contend  that the realized benefits to sunflower growers by lethal control of red-winged blackbiards via spring baiting , in combination with current nonlethal management efforts, would likely be negligible (Blackwell et al 2003).

          The efficacy of hydrolyzed casein (HC) and retail products that contain HC in reducing deer damage to trees and shrubs was determined in a field experiments conducted in USA during 2004-05. The results of the experiments indicate the suitability of HC as a deer repellent. Technical grade HC completely eliminated browsing damage to evergreen shrubs (Gaultheria shallon) and conifers (Thuja plicata). Retail sources of HC were not as effective as the pure hydrolyzed protein (Kimball et al 2005).

 

 

9. Blackbird damages

          The economic impact of blackbirds can be severe to rice producers in the United States. One approach to managing this damage is the application of bird-deterrent chemical to the crop. Previous pilot trials suggested that caffeine offered potential as a safe, economical bird repellent. In this study, cage feeding trials  with female red –winged blackbirds and male brown headed cowbirds confirmed that a treatment rate of 25000 ppm caffeine on rice seed reduced consumption as much as 76% . Trials with mixed species blackbirds flocks in  a 0.2-ha flight pen resulted in just 4% loss of caffine-treated rice compared to 43% loss of untreated rice. . Field trials of a 10 000 ppm caffeine treatment in Louisiana revealed > 90% of caffeine-treated rice seed remained unconsumed on days 2 and 3 of the study whereas blackbirds consumed > 80% of the untreated seed. As a rice seed treatment to deter blackbirds, caffeine appears to be effective, economical and environmentally safe, although additional aquatic toxicity testing is desirable. Improvements in formulation will be needed to make the compound practical for general agricultural spray applications and to extend the adherence of caffeine to rice seeds in field conditions ((Avery et al 2005).

 

10. Deer damage

A questionnaire was distributed to over 2500 farms to know damage  caused by lowland deer to crops, trees and vegetation. Results from the questionnaire showed that 69% (n=1192) of responding farmers had deer on their holdings and that Roe and Fallow were the most frequently seen species. On those farms with deer present, cereals were the most commonly damaged crop (44%), but only 15% of these farmers claimed that the annual cost of damage to cereals exceeded £500 each year for the whole farm. Validation assessments were based on two visits to assess deer damage to the crop, with a deer species/density assessment during the March assessment and an assessment of grain yield and quality during the August assessment. Respondents were generally accurate in the density and species of deer reported. The percentage of the farm suffering damage attributable to deer was very variable, generally being higher at the first assessment than the second. The figures calculated for yield loss were generally low, Farmers were poor at estimating the economic impact of deer damage when compared to validation data, but a number of parameters may have changed in the two years between the questionnaire distribution and validation, including changes in deer density, crop rotations, and the marked drop in grain prices, which may account for some of the inaccuracies. There were no statistically significant relationships between deer damage assessments and yield loss, either for individual species or both species combined. The relationship between Roe deer damage at the harvest assessment and Roe deer density was significant (Post et al, 2001).

Wildlife managers must consider the public’s preferences for wildlife population levels when determining management policies. 849 farmers, hunters and the general public of Maryland. USA, were surveyed in 1996 to determine their preferences for increasing, maintaining, or decreasing deer population numbers. Using a random utility theoretic framework, the factors that explain preferences such as residential location, socioeconomic characteristics, landscape damage, agricultural yield loss and vehicle accidents were analyzed. Results suggested that the majority of people benefit from deer and want to keep deer population at current levels. Other characteristics such as age, income, education, and residential location have minor or no impact on preferences. Property damage, crop loss, landscape damage, and car accidents appear to be the biggest concerns ( Curtis et al 2001).

 

11. Sika deer population in Japan

          Sika deer Cervus nippon population in eastern Hokkaido, Japan, increased rapidly during 1990-1998 . This increase appeared to have halted in 1999-2000, probably due to increased hunting and nuisance control. The period of rapid increase was associated with a disproportionately rapid increase in compensation paid for deer damage to crops. We studied changes in diet during 1990-2000, as reflected by stable isotope ratios of C and N in tooth collagen. We hypothesized that isotope ratios would demonstrate dietary shifts related to population levels and/or time, and that shifts in isotope ratios would be consistent with increasing individual  consumption of pasture grasses at higher population levels, delta 13C isotope ratios of tooth collagen in 3 year-old sika indicated a diet dominated by C3 plants throughout the period, and that forage species other than pasture grasses and dwarf bamboo Sasa nipponica ( the main crop and woodland understory plants,  respectively) were important elements. There was a significant decline in the delta 13C isotope ratio during  1990-2000 in both males and females, delta 15N values showed no trend with time for males, but increased over time in females. Indices of population (Sightings per Unit Effort, SPUE) were negatively correlated with female delta 13C, and positively correlated with female delta 15N, values indicating a shift in diet over the period , especially among females. This shift may be related to population and/or offtake levels, in particular  the rapid increase in female offtake for nuisance control and hunting during the period. The data are consistent with a relative increase in pasture grass consumption per individual at higher population levels, however, other  explanations of the data are equally plausible. Possible dietary changes, and other factors, influencing the observed shift in isotope ratios are discussed. Although statistically significant, the magnitude of dietary shifts  nevertheless appeared small, and did not provide evidence which would justify modifying the current policy, of limiting crop damage through managed population reduction to about 25% of peak levels( Halley et al 2006).

 

12.  White-tailed deer damages

          White-tailed deer (Odocoileus virginianus) may cause more damage than any other species of wildlife. These damages include crop loss, automobile and aviation collisions, disease transmission, environmental degradation, and destruction of ornamental  plantings. One practical method of controlling deer damage is the use of exclusionary fences. The relatively high cost of labor and materials required to build effective fences has limited most applications to the protection of orchards, vegetable farms, other high –value resources, and mitigation of human health and safety risks. Improvements in fence technology resulting in less expensive, yet effective fence have expanded the use of fence to manage damage caused by deer. Fence typically installed to manage white-tailed deer damage include wire or plastic mesh, electrified high-tensile steel wire, and electrified polytape or polyrope fence. They reviewed the scientific literature on fencing to determine which fence designs would be the most effective for excluding deer in a variety of situations (VerCauteren et al 2006).

          The installation of fences to protect agricultural products, natural resources, or other areas from deer (Odocoileus spp.) can be expensive and potential benefits of fencing are difficult to quantify. A rational method is needed to help evaluate whether fencing can be cost effective and which fence designs will be optimal for particular applications. They describe an interactive, dynamic simulation model that conducts economic analyses and predicts economic benefit associated with fences for crops relative to area and perimeter of protected plot, value of crop, percentage of crop damaged by deer annually prior to fencing, efficacy of fence, and costs of fence materials and labor. Users of the model can easily adjust these variables to fit their individual situations and needs. By running a series of simulations, model users can answer questions related directly to fence efficacy and cost-effectiveness (VerCauteren K et al 2006).

 

13. Corn damage by wild life

          Corn damages in USA were estimated at 6.6 per hac due to wild life. The white tailed deer was the wild animal responsible for loss. The average hacters owned by farmers were 125 out of which 55 hectares were sown corn. (Tzilkowsi et al 2002).

 

14.  Deer Damage

          Deer (Odocoileus spp.) can cause substantial damage to agricultural crops, resulting in economic losses for producers. They developed a deer activated bio-acoustic frightening device to reduce white-tailed deer (O, virginianus) damage in agricultural fields. The device considered of an infrared detection system that activated an audio component which broadcast recorded distress and alarm calls of deer. They tested the device against unprotected controls in cornfields during the silking-tasseling stage of growth in July 2001. The device was not effective in reducing damage: track-count indices (F1,4=0.02), corn yield (F1,9=1.27,P=0.289), and estimated damage levels (F1,10=0.87, P=0.374) did not differ between experimental and control fields. The size (F2,26=1,00,P=0.380), location (F2,25=0.39,P=0.684), and percent overlap (F2,25=0.20,P=0.818) of use-areas of radiomarked female deer did not differ between during and after treatment periods. They concluded that the deer-activated bio-acoustic device was not effective in protecting cornfields in this study; however, the device may be more effective in small areas such as gardens or for high value crops that do not grow tall enough to offer protective cover (Gilsdorf et al 2004).

          White –tailed deer (Odocoileus virginianus) cause millions of dollars of damage to agricultural crops annually . They tested the effectiveness of propane exploders and Electronic Guards (Pocatello Supply Depot, Pocatello, Id). For reducing deer damage in corn fields during the silking-tasseling stage of growth. Track-count indices (F2,7=0.70,P=0.532), corn yield (F2,6=0.14, P=0.873), and estimated damage levels (F2, 12=1,45 P=0.272) did not differ between experimental and control fields. The size (F2,11=0.08,P =0.924), Location  (F2,9=0.30, P=0.750), and percent overlap (F2,9=0.46, P=0.644) of use –areas of radiomarked female deer in the vicinity of experimental fields did not differ  among before, during and after 18 day treatment periods. In a related study, we placed propane exploders in cornfields within use-areas of 12 radiomarked female deer. The deer did not react appreciably to the devices; the size (F2, 17=0.08, P=0.921), location (F2,22=1.37, P=0.275), and percent overlap (f2,10=0.47, P=0.636) of deer use areas did not differ among before, during, and after 14 day treatment periods. They conclude that propane exploders and Electronic Guards have limited potential for reducing deer damage to corn at the silking-tasseling stage (Glisdorf et al 2004l.

 

          A welfare measure for wildlife damage to Ontario (Canada) field crop producers during the 1998 was. The welfare measure presented in this study provides a more accurate picture of losses from wildlife damage to agricultural. Other damage estimates based on yield loss overstate the damage since benefits from wildlife are netted out. Results for the Ontario field crop producers indicate that the magnitude of the difference between the value of the yield loss and the welfare measure of damage is approximately 50%. This difference indicates that most farmers were willing to tolerate the wildlife damage they experienced (Heigh et al 2001).

 

15. Grapevine damages

          In field trials in 1999-2000 in Gundla Pochampally, Andhra Pradesh, India , the incidence of damage to green grapevines was studied. Visits to the vines by bats begain around 45 minutes after sunset and foraging continued until 1 hour  before sunrise. Damage occurred to ripe fruit only, and increased around harvesting time, percentage damage ranged from 0 to 100% (Bhargavi et al, 2001).

 

16.   Hippo damage

          The introduction to the paper described the various ecological effects known to result from grazing, movement along paths, and wallowing by the common hippo. Hippopotamus amphibious. The study reported was carried out at Kainji Lake National Park., Nigeria, during  the dry season periods {of 1991 and 1992} . The method adopted by Agnew, A.D.Q. (East African Wildlife Journal (1966) 4, 38-46) was used to assess hippo foraging footprints at three hippo pool sites. A total of 32 footpaths were enumerated out of which 18 were located at Kaii hippo pool site, while the frequency of utilization of paths was also higher for this site relative to those in other area. The upstream-downstream trend in hippo occupancy of dry  season water pools could expose the hippo to crop damage conflicts at the peripheral areas.

 

17.  Hygo-Japan-mammal crop damages

 

          Mammals inhabiting  Hyogo consist of seven orders, 17 families and about 40 species. Except for Lagomorpha and  Artiodactyla, the remaining five orders among them include species which need some protection and they total about 55% of all species excluding extinct, introduced and feral species. Ecological information in Hyogo prefecture has been accumulated in few protection-required species there is no recent information of spatial distribution on Oriental water-shrew, Japanese noctule-bat and Japanese dormouse; and little information on Japanese shrew, Japanese horse-shoe bat, Japanese large –footed bat. Schreiber’s bent-winged bat, Japanese tube-nosed bat, common parti-colored bat, Japanese squirrel, Japanese small flying-squirrel, Japanese giant flying-squirrel, smith’s vole harvest mouse and Japanese badger. Damage and population managements is also necessary in sika deer and Japanese wild boar, to reduce their crop–damaging, and comprehensive management in Japanese black bear, an endangered local population, to prevent human-bear fatal accident. Habitat alteration due to human activities, however, has affected the population sizes and spatial distribution of all these, mammals in Hyogo. Habitat management has priority over damage. Fundamental and applied scientific studies and understanding of ecology and wildlife management science needs promotion by citizens (Mitani M 2000).

 

18. Monkey damage

 

          Forty-seven property owners in Entebbe, Uganda were questioned about vervet monkey activities on their property. The objective was to investigate the interactions between humans and vervet monkeys in an agricultural area adjacent to a forest zone. Other studies have reported that farms located within 300 m of a forested boundary probably incur the greatest risk of crop-raiding. Two other factors that may influence susceptibility to vervet crop-raiding were also examined: the types of crops grown and the types of direct preventive measures used. The effect of these two factors on vervet crop-raiding is not straight forward. However, the distance a property is located from the forest edge is an important factor influencing vervet crop raiding. Surveyed  gardens 200 m from the  forest edge received significantly less crop –raiding than farms located  100 or 50m (P=0.040,< alpha=0.05). In this study, 8 out of 13 farmers (61.5%) said that maize, sweet potato, or both, were most likely to be damaged by the vervets. Other crops singled out by the farmers are receiving damage by the vervets were bananas, mangoes, groundnuts and yam. They suggest that the development of non-agricultural  activities on land directly adjacent to forested areas may reduce vervet crop –raiding by deterring vervets from traveling greater distances from the forest edge due to increased obstacles or risks  (Saj et al 2001).

 

19. Bait damage

          The longevity of zinc phosphide (ZP) on whole wheat bait  was determined at the end of the “dry” and “wet” seasons,  is Western Australia.. While the total rainfall during the two trials was 74 mm and 155mm, substantial loss of ZP was recorded only after significant rainfall events. Irrespective of season, the loss of ZP from bait applied in bait stations was minimal. The maximum recorded loss was 17% and this occurred after  21 days’ exposure during the wet season where the bait stations were placed in-crop. Nevertheless, regardless of the application method, sufficient ZP always remained on the wheat bait. Theoretically  it was lethal to rats for at least 8-14 days (Twigg et al.,  2001).

20.Venezuela experience:

          In Venezuela, lethal control of wintering Dickcissels (Spiza Americana) is considered a threat to the species survival. To help farmers protect their rice and sorghum crops from by Dickcissels and to minimize the killing of large numbers of these birds, alternative non-lethal crop protection measures are needed. To that end, the responses of captive Dickcissels to three bird-repellent chemicals (anthraquinone,methyl anthranilate and methiocarb) applied to rice seed were evaluated. In one-cup feeding trials, treatments of methiocarb (0.05% g/g, applied as Mesurol 75%  wettable powder) and anthraquinone (0.5%, applied as Flight Control) reduced consumption of rice by 70% relative to pretreatment consumption. Other anthraquinone treatments (0.05,0.1%) and methyl authranilate (0.05%) were inrffective. In two –cup trials, with untreated millet as the alternative food, consumption of rice treated with 0.05 and 0.1%  anthraquinone was reduced by 90% relative to pretreatment levels. Overall, Dickcissels responded to the repellents similarly to the red-winged blackbird (Agelaius phoeniceus). Because Flight Control has been used successfully to reduce blackbird use of rice fields in the USA, the prospect is good for successful reduction of damage to repening rice by Dickcissels in Venezuela, particularly if repellent use is coupled with the establishment of alternative feeding sites ( Avery et al 2001). Deer selected carrots over all green manure crops.

 

21. Nilgai damages in India

           Crop-damage by nilgai has been widely reported from India.  Are give Nilgai is for increasing in this region. Lack of natural predators, deforestation overgrazing and the protection of these animals from Hindu communities are reasons for their overpopulation. Tree cover of Acacia are generally used by nilgai as a day time shelter but not food,  therefore it goes for crop-raiding in the late evening and at night, jumping across 6-7 feet high stone wall, barbed fencing and fences of dead or live thorny plant material and any other fencing/barrier made to protect the crop-. Due to habit of both grazing as well as browsing they devore every kind of farm species (both rabi and kharif crops). It has been observed that eating less but destroying more by trampling and causing damage are therefore regarded as serious mammalian crop pest and farmers wants to get ride of this unconventional pest. The farmers chase them away by just following them by making loud sound by crackers or air gun fires, following through tractors, empty tin or dried pumpkin filled with small stones and connected with strings. Technically, carrots(enclosures), trenching or power fencing are suggested to mitigate the crop damage. Secondly, animals could be translocated to wildlife sanctuaries from the sites they seen overcrowded or severe crop raiding problems (Goyal et al 2000).

 

22.  Pesticides and wildlife

A range of monitoring activities has shown impacts of anticholinesterase pesticides on UK wildlife, and continued risks are evident from laboratory and field experiments, together with the scale of use in the field. Along with other broad spectrum insecticides, many organophosphates have adverse direct effects on non-target arthropods in farmland, and so are likely to contribute towards indirect effects of pesticides on farmland biodiversity. The anticholinesterase insecticides have both lethal and sublethal effects on aquatic wildlife, however the history of recent incidents of damage to river ecology following the wider use of synthetic pyrethroid sheep dips, illustrates the need to consider the implications of changes in the use of alternative products when reviewing these insecticides ( Burn 2000).

 

          The use of anthraguinone-based flight control and methyl anthranilate-based non toxic avian foraging repellent we used to avoid crop damage by sandhill cranes. Thought both repellents were effective at deterring cranes from treated corn, neither has been tested on corn under field conditions. (Blackwell et al 2001).

          Oak seedlings were scientifically raised. Seedling mortality and wild life browse damages were minimal when certain herbicide mixture was used. Biologically and aesthetically, the procedure was extremely successful (Ezell et al 1999).

          Pre-commercially thinned (forests are less prone to moose damage (McLaren et al, 2000).

 

23.  Pesticide use in conflicts

          Pesticides can cause damage to man and beneficial organism. Some sub-lethal effects of pesticides were studied in birds with a view to identifying  characteristic biochemical responses that may be useful for the monitoring of exposure to sub-lethal levels in the field. Pesticides were used; demeton-S-methyl, (DSM),chlorpyriphos, chlorfenviphos, triazophos, pirimicarb, methiocarb and permethrin. Blood was collected before dosing, and 2,6,24,48 and 72 hours after the treatment from the brachial vein of birds. Enzyme, activities were assayed in the plasma or serum samples obtained. The assays used were GOT,MHD, GDH, SDH,GAMMA GT and ChE. The results showed an increase in plasma and serum GOT and gamma-GT levels were found in all animals treated with the previous pesticides. The level of ChE increased in birds after treatment with permethrin. It was concluded that the pesticides cause structural and functional changes in the liver and also, the measurement of the previous parameter activities may be useful for assessing exposure and sub-lethal effects of pesticides on the wildlife (Dahamna et al 2004).

 

 

24. IPM and crop losses

          The queensland sugar, industry has recently implemented a comprehensive integrated pest management (IPM) system to minimize crop losses from two antive rodent species, Rattus sordidus (canefield rat) and Melomy burtoni (climbing rat). These species inflicted approximately $25M of damage in a major outbreak in the  1999-2000 seasons. Both of these rodents are listed as common wildlife under the schedules of the queensland nature Conservation (Wildlife) Regulation 1994. The IPM programme is based on understanding the ecology and biology of each species. It incorporates a large-scale monitoring programme aimed at providing early warning of imminent rodent build up to avert major outbreaks. The industry has also  developed a memorandum of understanding with Queensland State Government, which delivers on the industry’s pest management needs, while providing an improved system of accountability for the taking of two of Queenslands native wildlife species. The consensus reached between the cooperating parties (The Bureau of sugar Experiment Stations, CANEGROWERS, regionally-based Cane Productivity Services, and the outcomes can be negotiated between rural industry and environmental interests (Hunt et al 2004)  .

          In Areas around Lake Mburo National Park ,large wild animals wander in close proximity to human settlement . This poses serious conflict in terms of crop damage. The integration of conservation with other land uses is difficult where densely settled agricultural land surrounds a protected area potentially containing problem animals, as is the case for several parks in Africa and Asia. The intensity of crop raiding was quantified through the use of random crop quadrants/plots and area estimation techniques in a portion of raided fields. The animal species concerned were documented from observations, footprints and any other marks left behind. Three variables were tested as predictors of damage; human population density, distance from the park boundary and season. In this study data is presented regarding crop loss in the different seasons of the year, analysis of crop damage variation and animal species involved in crop loss. A diverse assemblage of animals foraged on subsistence crops and analysis of crop damage revealed significant crop depreciation by wildlife( Kagoro et al 2004).

 

 

 

25.  Hawai Pest

          The apple snail, P.canaliculata, is an aquatic freshwater snail native to South America, Originally imported to Hawai’i as pets for the aquarium trade, they were soon introduced into wetland plots known as “lo’s” where taro (Colocasia esculenta), an economically and culturally significant crop, is grown. Some individuals reasoned that the snails, being edible, could be harvested as food, and that raising the snails along with the taro in the “Io’s” would provide income supplemental to the taro harvest with minimum additional input. This introduction of snails into the taro “lo’i” however, proved to be a disaster. Farmers failed to take into account the voracity , reproductive potential, and rapid growth of the snails. Because of the ideal conditions in the taro “lo’i”, the snails  multiplied rapidly and fed heavily on the taro shoots and corns in many cases, destroying a complete crop before harvest time. Hindisight has shown that the snails are dissipated via the irrigation system throughout the “lo’i” and then spread to the surrounding wetland areas. Large breeding populations are now established in wetland areas on the islands of Hawai’e, O’ahu, Kaua’I, and Maui. Some of  these wetlands are wildlife preserves with state and federal mandates that restrict the potential methods of eradication. Background information is provided on both P.canaliculata and taro to fully explain the challenges and opportunities that this situation presents (Tamaru et al 2006).

 

26.  Chemical repellents

          Chemical feeding repellents applied to ripening sunflower might help reduce blackbird (lcteridae) damage, which is a chronic agricultural problems from seed information harvest. However, cost are high to develop and register new repellents for agricultural use. In 2003 and 2004, we evaluated feeding repellency of  8 pesticides registered by the Environmental Protection Agency for use in sunflower. Caged red-winged blackbirds (Agelaius phoeniceus) were fed unshelled sunflower seeds treated with the following pesticides: 5 pyrethroid insecticides, an organochlorine, an organophosphorus, and a gungicide. Compared to untreated refernce groups, feeding rates were reduced for 4 of the 5 pyrethroid insecticides. Only the organophosphorus (chlorpyrifos), however, significantly decreased feeding rates. More research on repellency effects of this product in field efficacy trials is probably warranted based on the results of our cage experiments. Depending on timing of application, registered insecticides with blackbird feeding repellency could provide supplemental economic benefits to sunflower producers through dual purpose use ((Linz et al 2006).

 

27. Persistent organic pollutants (POPS)

          Persistent organic pollutants (POPs) have spread throughout the global environment to threaten human health and damage ecosystems, with evidence of POPs contamination in wildlife, human blood, and ****** milk documented worldwide. Based on data from the US Food and Drug Administration, this article provides a brief overview of POPs residues in common foods in the USA food supply. The analysis focuses on 12 chemical compounds now targeted for an international phase out under the Stockholm convention on POPs. The available information indicates that POPs residues are present in virtually all categories of foods, including baked goods, fruit, vegetables, meat, poultry, and dairy products. Residues of five or more persistent toxic chemicals in a single food item are not unusual, with the most commonly found POPs being the pesticides DDT ( and its metabolites, such as DDE) and dieldrin. Estimated daily doses of dieldrin alone exceed the US Environmental Protection Agency and US Agency for Toxic Substances Disease Control reference dose for children. Given the widespread occurrence of POPs in the food supply and the serious health risks associated with even extremely small levels of exposure, prevention of further food contamination must be a national health policy priority in every country. Implementation of the Stockholm Convention will prevent further accumulation of persistent toxic chemicals in food. Early ratification and rapid implementation of this treaty should be an urgent priority for all governments (Schafer et al 2002).

 

28. Netherland experiences

          Traditionally, pink-footed geese Anser Brachyrhynchus wintering in Denmark, the Netherlands and Belgium have used the Danish sites only during mild winter, rapidly moving southwards in case of cold spells. Since the 1980s, an increasing number of geese have remained on the Danish wintering grounds despite cold spells, foraging on pastures Because winter wheat represented a reliable and profitable food source even in sever winter, the recent change in Agricultural practice has enhanced the development of a new wintering strategy of pink-footed geese, allowing a northward expansion of their winter range. Potentially, this will increase the crop damage conflict and may lead to further population growth ( Therkidsen et al 2000).

          Enclosure trials near Huron, CA in the San Joaquin Valley from 12 to 23 January 1999 , determine the efficacy of Flight Control TM (50% anthraquinone) and Mesurol R (75% methiocarb) in preventing horned lark damage to lettuce seedlings. Flight control TM (FC) and Mesurol R were evaluated as foliar sprays at application rates of 2.79 and 2.27 kg ha-1, respectively. Horned lark damage to lettuce seedlings treated with anthraquinone was greater (p=0.015) than for methiocarb R, 60 versus 20% , respectively, and seedlings in control plots were 100% destroyed. While this level of damage is probably unacceptable to lettuce growers, it should be remembered that the enclosure situation caused an artificially high bird pressure on the crop. Further studies in open fields under a more normal bird pressure are warranted ( York et al 2000).

 

29. Ozone injury

          Incidence and severity of visible foliar ozone injury on cutleaf coneflower (Rudbeckia laciniata L.) and crown-bread (Verbesina Occidentalis Walt). Were determined .It is thus a matter of consideration that zone injury may harm vegetation harmed by browsing or even cutting. Ozone injury was greatest on the lower leaves for both species sampled with over 95% of the injured leaves occurring on the lower 50% of the plant. This is the first report of foliar ozone injury on these plant species in situ, in the Park, illustrating the great variability in symptom expression with time, and within and between populations ( Chappelka et al 2003).

 

30. Protected arrears and humans

          Knowledge of conflicts between people and protected areas is required for the design of sustainable conservation strategies for the management of most protected areas. The study identifies the causes of conflicts between local people and the Benous Wildlife Conservation Area (BWCA), which includes the Benous National Park, In northern Cameroon. Informal interviews and questionnaires were administered to 114 households in three communities, and to 17 park staff and 7 professional hunting guides from July –October 1997. Crop damage affected 86% of the surveyed household, with 31% of crop income lost on average, and with the damage varying significantly between communities. Elephants, baboons, patas monkeys. Warthogs and green parrots accounted for 97% of crop damage, with the staple food maize and  millet being most affected. Of  the respondents 27% experienced livestock depredation, with 18% of livestock income lost  on average. The civet cat was the main predator. The involvement of local people in illegal activities, their  lack of access to natural resources, and damage by wildlife were identified as principal causes of conflicts. Local people, park staff and professional hunting guides had diverse and differing perceptions about the causes of the conflicts and made various suggestions for reduction of wildlife damage including animal scaring and controlled shooting. We conclude that, under current wildlife policy, conflict between people and BWCA  (Bonous Wildlife Conservation area) is difficult to resolve. To reduce conflicts and promote sustainable conservation, we suggest co-management of wildlife involving all stakeholders, establishment of crop damage control teams, and promotion of tangible benefits to  local people. There may be a requirement for site –specificity in management strategies (Weladji et al 2003).

 

31. Low technology use to avoid damages

           It is suggested that an integrated, community-based, low technological approach will be the most sustainable solution to this conflict ( Osborn et al 2003).

          Blackbirds (lcteridae) annually damage US$5-8 million of ripening sunflower in the northern Great Plains. Baiting blackbirds with avicide-treated rice during spring migration might reduce the regional breeding populations. birds can be successfully baited with avicide-treated rice placed in corn stubble (Linz et al 2003).

            Plant debris accumulation is viewed as a key factor determining small mammal abundance and potential damage in low-till agricultural ((Stermer et al 2003) areas.

          The projected total value of crop yield losses due to wildlife damage for buffer zone villages located in Garhwal Himalaya in about Rs.5 38 620 (US$15 389). Besides food grain, horticultural crops i.e apple, also suffered. Major wildlife

By: G M Wani

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