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doi:10.1016/j.cr

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Instituto de Eco

Crop Protection 25 (2006) 933–939

www.elsevier.com/locate/cropro

Damage by large mammals to subsistence crops within a protected areain a montane forest of Bolivia

Eddy Pereza,1, Luis F. Pachecoa,�,2

aEstacion Biologica Tunquini, Instituto de Ecologıa, Casilla 10077, Correo Central, La Paz, Bolivia

Received 29 June 2005; received in revised form 30 November 2005; accepted 2 December 2005

Abstract

Damage caused by wildlife to human economic activities represents a serious problem to conservation efforts. Conflict resolution

efforts are particularly complex in Bolivian protected areas, which generally harbour human populations that settled there before the

establishment of the protected area. We carried out a study that estimated wildlife damage to crops using paired exclosures and open

(control) fields, in a protected area in Bolivia, that was primarily montane forest. We compared the performance (proportion of attacked

plants and total crop yield) of three crop species within and outside of the exclosures. Simultaneously we recorded the wildlife species that

visited crop fields by means of track plots, and identified their share in the damage events. Damage was significantly higher in control

fields for two out of three crop species. Total yield was higher, though not significantly, in exclosures for all three crop species. Brown

agouties (Dasyprocta variegata) was the most frequent wildlife species in crop fields and was responsible for some crop damage; however,

collared peccaries (Tayassu tajacu) caused complete crop loss in two cases. We discuss our results from a broad management perspective

and propose that conservation efforts, especially in Bolivia and other third world countries, should consider both applying methods to

reduce wildlife damage and direct or indirect economic compensation. The latter could be achieved through the commercial use of non-

threatened local wildlife species.

r 2006 Elsevier Ltd. All rights reserved.

Keywords: Wildlife damage; Yungas; Tayassu; Dasyprocta; Nasua

1. Introduction

Conflicts between wildlife and people have an importantimpact in the relationship between human communitiesand the administration of protected areas (Nyhus andWilson, 2000; Archabald and Naughton-Treves, 2001). Themain conflicts result from wildlife damaging crops, preyingon domestic animals, or transmitting wildlife diseases todomestic animals or humans (Elıas and Valencia, 1984;Sukumar, 1991; Ojasti, 2000; Treves and Karanth, 2003).

In Latin America, wildlife damage to crops deservesspecial attention because the majority of people residingnear or within protected areas depend upon agriculture,

e front matter r 2006 Elsevier Ltd. All rights reserved.

opro.2005.12.005

ing author. Tel./fax: +591 2 2771442.

ess: luispacheco11@yahoo.com (L.F. Pacheco).

ess: Universidad de Los Lagos, Fuchslocher 1305, Casilla

hile.

ress: Centro de Postgrado en Ecologıa y Conservacion,

logıa, Casilla 10077, Correo Central, La Paz, Bolivia.

and any losses would negatively affect their already meagereconomy (Elıas and Valencia, 1984). The few studies thatquantify crop losses in the region indicate that rodents andbirds damage between 4% and 77% of the potential crop(Elıas and Valencia, 1984; Bilenca and Kravetz, 1995;Chediack, 1995; Ojasti, 2000). In a more recent study in thePeruvian Amazon, Naughton-Treves et al. (2003) reporthigh damage rates by large mammals, such as brownagouties (Dasyprocta variegata), pacas (Agouti paca),tayras (Eira barbara), capybaras (Hydrochaeris hydro-

chaeris), tapirs (Tapirus terrestris) and peccaries (Tayassu

pecari and T. tajacu).In Bolivia, people live within the boundaries of most

protected areas. Conflicts caused by wildlife damage tocrops have begun to threaten the long-term management ofprotected areas and wildlife conservation. Morales (2003)estimates that wildlife, mainly Andean bears (Tremarctos

ornatus) and skunks (Conepatus chinga), were responsiblefor the loss of 18% (min ¼ 0.8%; max ¼ 85.0%) of the

ARTICLE IN PRESSE. Perez, L.F. Pacheco / Crop Protection 25 (2006) 933–939934

total corn crop in the Apolobamba Natural Area ofIntegrated Management.

Our study site, Cotapata National Park and NaturalArea of Integrated Management (CNP), has an estimatedpopulation of 1500 people (Patzi, 1999), and the conflict ofwildlife attacking crops existed before the establishment ofthe protected area in 1993. Prior to 1993, local peoplemanaged the conflict by shooting animals within theirfields. This helped reduce damage by wildlife and alsoprovided a cheap source of protein for peasant families.This approach appears reasonably sustainable as nowildlife species has been reported locally extinct in thearea as a result of hunting (Roldan, 2001).

Hunting was banned at CNP in 1996 as part of theactions taken to protect wildlife and was implemented forone year. However, people’s complaints about wildlifedamaging crops increased. To control damage, mostfarmers used poison while others continued hunting.Hunters felt that wildlife abundance declined to the pointit was unproductive to continue hunting in crop fields andblamed the use of poison for the decrease. These eventsnegatively affected relationships between local people andthe park’s administration and conservation institutions inthe area. Given the complexity of this situation, wequantified crop damage by wildlife as a first step todeveloping an effective strategy to manage the conflict. Wepresent our results and discuss possible solutions in thecontext of global biodiversity conservation.

2. Material and methods

2.1. Study site

The study was carried out in Chairo, a small (20 families)peasant community inside CPN, Bolivia (681180–161200

SW, 681030–161050 NW, 671430–161100 NE y161180 SE;

Fig. 1. Tunquini Biological Station (EBT) and study area within the

Cotapata Nacional Park, Bolivia.

Fig. 1). The �58,000 ha reserve is characterized by steeptopography, with altitudes between 5500 and 1200m.Agriculture is the main economic activity of the loweraltitude portion of the park and it is mainly restricted(for climatic conditions) to the Yungas Montane Forestvegetation type, between 1200 and 1600m (Ribera-Arismendi, 1995; Paniagua-Zambrana et al., 2003). Com-mercial crops at CNP are mainly coffee and fruits (orangeand tangerine). Subsistence crops include yucca (Manihot

esculenta), walusa (Colocasia esculenta, Xanthosoma sp.),racacha (Arracacia xanthorriza), corn (Zea mays) andpeanut (Arachis hypogea). Livestock production andbeekeeping are almost absent, while another increasinglyimportant source of revenues is tourism.Mammals considered harmful to crops include: collared

peccary, brown agouti, paca, pacarana (Dinomys branickii),coatimundi (Nasua nasua), brown capuchin monkey (Cebus

apella) and several small rodents among the mammals. Thefollowing species of birds also cause crop damage: Dusky-green Oropendola (Psarocolius atrovirens), CrestedOropendola (P. decumanus), Purplish Jay (Cyanocorax

cyanomelas), Speckle-faced Parrot (Pionus tumultuosus),and Black-winged Parrot (Apalopsittaca melanotis).

2.2. Experimental design

We designed this study to estimate damage to annualcrops by terrestrial vertebrates 41 kg. Some observationson damage caused by birds, small rodents, and arborealmammals are also presented. People perceived that wildlifedamaged up to 100% of production, especially whenpeccaries were involved. Most studies evaluating wildlifedamage to crops are based on surveys that gatherinformation from the affected people, and/or pointestimates of damage in crop fields. Although these researchdesigns allow for large sample sizes and may cover hugestudy areas, results may be obscured by other factors, suchas the time of planting, soil type, plot size, quality of seeds,and the impact of invertebrate pests. Furthermore, localpeople may provide imprecise and/or biased informationbecause of a lack of direct experience measuring damage ortheir personal feelings towards wildlife. Therefore, weopted for a small study (n ¼ 11 fields) that controlled forthese variables.All field data (except for yield) were collected directly by

the researchers and individual farmers. Planting time wasabout the same (+/� one month) for all fields and yielddata was gathered until the end of the cropping period foreach field.Fieldwork was carried out between July 2001 and

December 2002, with the direct participation of 11 farmersof Chairo. Each farmer worked in his own field usingcustomary practices. Crop choice was the farmers’ deci-sion. Most planted a combination of yucca, walusa,and corn. After planting, each of the 11 fields was dividedin two plots of similar size and disposition. A 1-m high,10-cm wire mesh exclosure was constructed around one

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Table 1

Planting density (plants/m2) of three crops in exclosures and control plots

in Parque Nacional Cotapata, Bolivia

E. Perez, L.F. Pacheco / Crop Protection 25 (2006) 933–939 935

randomly selected plot from each pair to exclude cursorialanimals 41 kg. The remaining open plots served ascontrols.

Crop (n) Exclosures Controls Pa

Median Range Median Range

Walusa (9) 2.6 1.1–7.3 1.7 0.8–7.5 0.44

Yucca (8) 2.1 0.4–4.8 1.9 0.5–3.7 0.78

Corn (9) 3.1 1.0–8.4 3.2 1.0–9.7 0.31

aPaired sample Wilcoxon test, a ¼ 0:05.

2.3. Damage assessment and yield

We calculated the cultivated area for each field andestimated baseline seedling density for each crop (beforeany damage occurred) based on counts in six 1-m2 quadratsrandomly distributed within each part of the field. Seedlingdensity was used to estimate the starting total number ofplants for each cultivated species for both exclosuresand controls. Once a month, between December 2001and May 2002, we counted the number of damaged plants(whose production would be null) at each field and withthe aid of farmers tried to identify the species responsiblefor the depredation based on tracks and distinctivetooth marks. Losses are presented as the percentage ofdamaged plants out of the total planted, for each crop field,and plot type. Harvest extended over several weeks andtotal biomass harvested was recorded by farmers, differ-entiating yields from exclosures and controls. For corn,crop data in number of ears were transformed to dry grainweight, using the conversion of 0.130 kg/ear (mean of30 ears) to allow for a direct comparison with the othercrop species.

Animal visitations were recorded on 1-m2 track plots(Simonetti and Huareco, 1999) distributed along theborder of each field, and separated by 5–8m, resulting in20–46 track plots per field. Additionally, a line of 9–10track plots (about 30m apart) was placed along a pathfrom each field into the surrounding forest. Track plotswere activated (litter removed and covered with a thin layerof sieved soil) once a month, from October 2001 throughDecember 2002 and checked 24 h later. Percent visitationrates were calculated as the number of visits divided by thetotal number of track plots available for all samplingperiods combined. To evaluate possible changes in visita-tion associated with crop maturity, percent visitation wasalso determined by sample period (February to June). Dueto the steep topography of the study area (average 70%),most track plots were slightly inclined. Because of slippagea large proportion (29.9%) of tracks were unidentifiableand, therefore, were excluded from analysis.

2.4. Statistical analysis

Differences between exclosures and controls in theproportion of damage caused by each animal species, andtotal yield for each crop were assessed with a paired dataWilcoxon test with a ¼ 0:05 (Zar, 1999). To evaluatepossible impacts of damage on yield, we divided cropweight by the estimated number of plants remainingfollowing the final damage assessment (estimated numberof plants in the field minus number of damaged plants),and repeated the analyses for each crop.

3. Results and discussion

Statistical analyses are restricted to those crop speciesthat were represented in more than seven fields. Actualsample size differed among these crops (walusa n ¼ 9,yucca n ¼ 8, corn n ¼ 9) because of differences in cropcomposition among fields. In addition, one field was lost toabandonment and two farmers did not provide reliableinformation on yucca yield. The cultivated area averaged897.8m2 (sd ¼ 336.25) within exclosures and 834.7m2

(sd ¼ 243.67) in control plots. Plant density did not differbetween exclosures and controls for any of the crops(Table 1).

3.1. Wildlife visitations

From a total of 4349 track plots activated during the 14months of the study (3207 around fields and 1042 in theforest paths), an average of 16.1% (sd ¼ 9.3) were visitedby some animal each month. Species considered harmfulrepresented 64.1% of the visits, and 6.0% belonged tospecies considered unharmful, like nine banded armadillos(Dasypus novemcinctus), opossums (Didelphis albiventris,D. marsupialis), brocket deer (Mazama sp.) and smallfelids. Agoutis were the most frequent visitors (30%) andattacked more fields than other taxa. Collared peccariesvisited fields less frequently (�10%) and had only oneincursion in the exclosures (Fig. 2). Incursions of cursorialanimals 41 kg into the exclosures occurred where fencingwas difficult because of terrain. Although wildlife crossingfences are commonly reported (Thompson, 1978; Thoulessand Sakwa, 1995; Huygens and Hayashi, 1999) most of thedamage caused by animals entering exclosures in our studywas positively identified. However, these intrusions prob-ably precluded the detection of statistical differences in thecomparison of yields. We suggest that fencing in futurestudies should be checked every day to avoid animalsenlarging small holes. This was not done during this studybecause farmers were responsible for each one’s fence.Track information suggests that the activity of agoutis,

and especially coatis concentrated around fields during theharvesting months for corn (January–February), while thatof agouties, and pacas seemed to be higher around fields

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Fig. 3. Temporal variation in the proportion of tracks in fields and surrounding forests for (a) collared peccaries (Tayassu tajacu), (b) brown agouties

(Dasyprocta variegata), (c) pacas (Agouti paca), and (d) Coatimundis (Nasua nasua).

E. Perez, L.F. Pacheco / Crop Protection 25 (2006) 933–939936

during the harvesting of walusa and yucca (March–July).Collared peccaries did not show a clear seasonal pattern ofvisitation, although a slightly higher proportion occurredduring May and July (Fig. 3). This may be due to therelatively large scale of their movements (Fragoso, 1999).Our field observations suggest that peccaries remain closeto one field for only 4–5 days at a time.

3.2. Crop damage and yield

The percentage of plants lost to wildlife was higher incontrols than in exclosures for walusa (66.6 times higher,

P ¼ 0:012) and yucca (10.1 times, P ¼ 0:025), but did notdiffer for corn (1.4 times, P ¼ 0:68; Table 2). In two controlplots walusa and yucca plantations were completely lost towildlife (particularly collared peccaries). These plots wereleft unattended for more than one week at a time. Similarresults are reported by Morales (2003) and Gillingham andLee (2003) who found that crop fields left unguarded forlonger times suffered higher and most severe damage fromwildlife than did guarded fields. Farmers in our study areatypically visited their fields once or twice a week. However,those who have jobs outside the community left their fieldsunguarded for longer than one week. Another factor

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Table 2

Comparison of damage in exclosure and control plots

Crop (n) Estimated mean number of planted individuals % plants lost/field mean (sd) % plants lost/field median (range) Pa

Excl. Contr. Excl. Contr. Excl. Contr.

Walusa (9) 2340 1807 0.35 23.32 0 0.53 0.012

(0.59) (43.52) (0–1.6) (0–100)

Yucca (8) 2072 1496 1.81 18.77 1.43 8.28 0.025

(1.98) (33.15) (0–4.8) (0.23–100)

Corn (9) 3516 3992 4.27 5.94 2.53 4.06 0.68

(3.06) (5.94) (1.14–9.58) (0.83–9.13)

Means and standard deviations are included to help illustrate differences.aPaired sample Wilcoxon test, a ¼ 0:05.

0%

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Walusa-E Walusa-C Yucca-E Corn-E Corn-C

% D

amag

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Unidentified Collared pecary CoatimundiBrown agouti Birds Capuchin monkeyMice Paca

Yucca-C

Fig. 4. Percentage of damaged plants by different animal species.

Exclosure and control plots are designated by E and C, respectively.

E. Perez, L.F. Pacheco / Crop Protection 25 (2006) 933–939 937

associated with wildlife damage to crops is the proximity offields to large blocks of forest (Nchanji, 2002; Naughton-Treves et al., 2003). However, all the fields in our studywere adjacent to either large blocks or continuous forest.

A total of 1793 corn plants were depredated withinexclosures, where coatis, and capuchin monkeys (whichclimbed over the fence), and birds were responsible for�35% of the plants lost. In controls, 2070 corn plants weredepredated, where agoutis caused �35% of the damage.Collared peccaries were responsible for 480% of the 664walusa plants depredated in control plots. Peccaries maycause great damage in a single visit; for example, theydepredated about 40 walusa plants in one single intrusionto an exclosure. Almost 50% of the 227 yucca plantsdepredated within exclosures were damaged by agoutis,while peccaries and agoutis were responsible for 460% ofthe 764 yucca plants depredated in control plots (Fig. 4).

Even though yield in control plots was only 37% and27% of that in exclosure plots for walusa and yucca,respectively, yield did not differ statistically between

exclosure and control plots for any of the three crops(Table 3). Adjusting yield for the number of plantsremaining did not alter these results. The relatively smallsample size and the high level of variation observed mayhave impaired our ability to detect statistical differences.The apparently contradictory results between the com-

parison of percentage of plants lost and total crop yield maybe explained by the fact that, regardless of the paireddesign, microsite differences and seed quality usually resultin a highly heterogeneous crop. Farmers begin harvestingthe best looking and most mature plants, whether in controlor exclosure plots, and may not finish harvesting during asingle period. Therefore, the best estimate of damage maybe the number of depredated plants. Although we did notfind statistically significant differences in the yields fromexclosures and controls, differences were large from thefarmer’s point of view. Averaging for the three cultivatedcrop types, the crop lost in control fields was �16%, whileonly �2% for the crops within exclosures. On the otherhand, the total yields for walusa and yucca in control fieldswere less than 40% and 30%, respectively, of that in theexclosures. Hence, the damage would be about 60–70% ofthe potential crop for these two crops.The damage to yucca cultivations in our study area was

larger than that reported by Naughton-Treves (1998) andHill (2000) in Uganda (mean ¼ 6.8% [sd ¼ 19.5%], and9%, [range 4.5–61%], respectively), and Nchanji (2002) inCameroon (15.1%). As reported in our study, the wildlifethat intruded most in the cultivations (primates in Ugandaand brown agouties in Peru) are not those that cause thelargest damage (Naughton-Treves, 1998; Hill, 2000, 2002;Naughton-Treves et al., 2003). Apparently, the greatestdamage is generally caused by the largest-bodied species:elephants in Uganda, tapirs in Peru (Naughton-Treves,1998, Naughton-Treves et al., 2003), and collared peccariesin our study site.

4. Management implications

Our analysis shows that wildlife cause considerable lossto local farmers. However, it would be naive to suggest to

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Table 3

Comparison of yield (kg) in exclosure and control plots for three crops

Crop (n) Exclosures Controls Pa

Total Median (range) Total Median (range)

Walusa (9) 3392.8 315.9 (24.3–1013.8) 1271.2 109.2 (0.0–400.6) 0.208

Yucca (6) 681.8 102.0 (0.0–223.8) 185.4 36.2 (0.0–57.4) 0.116

Corn (9) 327.1 28.5 (0.0–71.5) 414.7 19.0 (1.3–126.5) 0.789

aPaired sample Wilcoxon test, a ¼ 0:05.

E. Perez, L.F. Pacheco / Crop Protection 25 (2006) 933–939938

these people to simply leave their subsistence agriculturebecause wildlife probably makes it economically unprofi-table. Their response might be to eliminate wildlife locally.We believe that the conflict between wildlife and agricul-ture should be mitigated with two types of actions: (1)Creation of alternative sources of revenues for theinhabitants of CNP. For example, the administrators ofCNP and other institutions that work in the area aredeveloping ecotourism programs that could become alter-native sources of revenue for the farmers (e.g. Archabaldand Naughton-Treves, 2001). (2) Reduce the impact ofwildlife depredation by reducing loss and/or providingcompensation for damage caused by the wild fauna. Theseapproaches may enhance the peasant’s acceptance ofwildlife conservation.

The use of wire mesh for excluding animals from cropfields may not be a viable option. Installation cost (materialand manpower) is costly (� US$3.57/lineal meter), they arenot totally effective, require maintenance, and may reducethe value of the area for tourism. Another option is controlhunting, which was the traditional form of controllingwildlife before the park’s establishment. The efficiency ofcontrol hunting for reducing losses must consider farmer’stime, costs of ammunition and weapons and their main-tenance, and also, the benefit of bushmeat (Naughton-Treves et al., 2003). Because human presence influences thelevel of crop loss (Naughton-Treves, 1998; Hill, 2000;Morales, 2003; this study), increasing the time farmersdevote to vigilance (e.g. Hill et al., 2002; Gillingham andLee, 2003) may be another approach. We are conducting acomparison of the efficiency of control hunting vs. anincrease in human presence on fields and expect to reporton our results soon.

Reduction of losses may not be enough to eliminate theconflict because peasants will continue to perceive wildlifeas an agent of economic damage even if they get some formof non-cash benefit out of it. For example, only 3 of 24farmers in Tambopata-Candamo Reserve in Peru con-sumed meat for a value higher to the crop loss caused bywildlife (Naughton-Treves et al., 2003). Therefore, it isnecessary to compensate people for the conservation of thewild fauna that causes them an economic loss. In LatinAmerica, where 8% of the 790 million people suffer frommalnutrition (Pretty et al., 2003), this is exacerbated bywildlife crop damage. Given budgetary shortfalls and other

national priorities, it is unlikely that the Government ofBolivia could allocate part of its budget to compensate forlosses caused by wildlife. Money for compensation mustcome from an independent source and be sustainable overtime. We believe that local people must attach a positivevalue to wildlife to support its existence (Gillingham andLee, 2003), and commercial management of non-threa-tened animal and plant species can be used for this purpose(see Hutton and Leader-Williams, 2003). Funding couldalso come from ecotourism programs (Archabald andNaughton-Treves, 2001). Tourism is now the world’slargest industry and nature-based tourism is its fastestgrowing sector (Isaacs, 2000; Hutton and Leader-Williams,2003).Conservation of wildlife causes considerable economic

damage to farmers in the Yungas region of Bolivia. Thelong-term persistence of depredating species depends onlocal farmers’ tolerance of them. Farmers are unlikely tocare about the ecological–evolutionary arguments forwildlife conservation when their subsistence and well beingis threatened (see Balmford and Whitten, 2003). As Huttonand Leader-Williams (2003) point out, we must recognizethat most conservation will have to be achieved throughcooperation with rural people living in wilderness areas. Ifwe want farmers to act as allies in the conservation ofwildlife, we should carry out management programs thatreduce the economic damage caused by wildlife, as well asgenerate economic resources to be used for partialcompensation for the losses that occur despite ourinterventions.

Acknowledgements

This work was funded by the John D. and Catherine T.MacArthur Foundation (Project Conservation and Sus-tainable Development Planning at the Estacion BiologicaTunquini, Bolivia). We deeply appreciate the help offarmers at Chairo who collaborated with us: PedroCallisaya, Silverio Chuquimia, Daniel Coss, Lucio Cutili,Felipe Paredes, Dionisio Perez, Pedro Quispe, AlejandroRomero, Francisco Salas, and Juan Torres. Lisa Naugh-ton-Treves, Adrian Treves, Jeffrey Jorgenson, and twoanonymous reviewers made insightful comments thatimproved this manuscript.

ARTICLE IN PRESSE. Perez, L.F. Pacheco / Crop Protection 25 (2006) 933–939 939

References

Archabald, K., Naughton-Treves, L., 2001. Tourism revenue-sharing

around national parks in western Uganda: early efforts to identify and

reward local communities. Environ. Conserv. 28, 135–149.

Balmford, A., Whitten, T., 2003. Who should pay for tropical conserva-

tion and how could the costs be met? Oryx 37, 238–250.

Bilenca, D.N., Kravetz, F.O., 1995. Danos a maız por roedores en la

region pampeana (Argentina) y un plan para su control. Vida Silvestre

Neotropical 4, 51–57.

Chediack, A., 1995. Impacto de aves frugıvoras en mandarinas Murcott.

In: Brown, A.D., Grau, R. (Eds.), Investigacion, Conservacion y

Desarrollo en Selvas Sub tropicales de Montana. Proyecto de

Desarrollo Agroforestal/Laboratorio de Investigaciones de las Yun-

gas. Universidad Nacional de Tucuman, Argentina, pp. 141–148.

Elıas, D.J., Valencia, E., 1984. La agricultura latinoamericana y los

vertebrados plaga. Interciencia 9, 223–229.

Fragoso, J.M.V., 1999. Perception of scale and resource partitioning by

peccaries: behavioral causes and ecological implications. J. Mammal.

80, 993–1003.

Gillingham, S., Lee, P.C., 2003. People and protected areas: a study of

local perceptions of wildlife crop-damage conflict in an area bordering

the Selous Game Reserve, Tamzania. Oryx 37, 316–325.

Hill, C.M., 2000. Conflict of interest between people and baboons: crop

raiding in Uganda. Int. J. Primatol. 21, 299–315.

Hill, C.M., 2002. People, crops and wildlife: a conflict of interests. In: Hill,

C.M., Osborn, V., Plumptre, A.J. (Eds.), Human–wildlife conflict:

identifying the problem and possible solutions. Albertine Rift

Technical Report Series, vol. 1. Wildlife Conservation Society, Bronx,

NY, pp. 60–67.

Hill, C.M., Osborn, F.V., Plumptre, A.J., 2002. Human–wildlife conflict:

identifying the problem and possible solutions. Albertine Rift

Technical Report Series, vol. 1. Wildlife Conservation Society, Bronx,

NY.

Hutton, J.M., Leader-Williams, N., 2003. Sustainable use and incentive-

driven conservation: realigning human and conservation interests.

Oryx 37, 215–226.

Huygens, O.C., Hayashi, H., 1999. Using electric fences to reduce Asiatic

black bear depredation in Nagano prefecture, central Japan. Wildlife

Soc. Bull. 27, 959–964.

Isaacs, J.C., 2000. The limited potential of ecotourism to contribute to

wildlife conservation. Wildlife Soc. Bull. 28, 61–69.

Morales, A., 2003. Danos causados por vertebrados silvestres en maizales

de Pajan, K’apna y Wayrapata ANMI Apolobamba La Paz Bolivia.

Tesis de Licenciatura, Universidad Mayor de San Andres, La Paz,

Bolivia.

Naughton-Treves, L., 1998. Predicting patterns of crop damage by wildlife

around Kibale National Park, Uganda. Conserv. Biol. 12, 156–167.

Naughton-Treves, L., Mena, J.L., Treves, A., Alvares, N., Radeloff, V.C.,

2003. Wildlife survival beyond park boundaries: the impact of slash-

and-burn agriculture and hunting on mammals in Tambopata, Peru.

Conserv. Biol. 17, 1106–1117.

Nchanji, A., 2002. Crop damage around northern Banyang-MBO wildlife

sanctuary. In: Hill, C.M., Osborn, V., Plumptre, A.J. (Eds.),

Human–Wildlife Conflict: Identifying the Problem and Possible

Solutions. Albertine Rift Technical Report Series, vol. 1. Wildlife

Conservation Society, Bronx, NY, pp. 68–78.

Nyhus, P., Wilson, R., 2000. Crop-raiding elephants and conservation

implications at Way Kambas National Park, Sumatra Indonesia. Oryx

34, 262–272.

Ojasti, J., 2000. Manejo de Fauna Silvestre Neotropical. In: Dallmeier, F.

(Ed.), SI/MAB Series # 5. Smithsonian Institution/MAB Biodiversity

Program, Washington DC, USA.

Paniagua-Zambrana, N., Maldonado-Goyzueta, C., Chumacero-Mosco-

so, C., 2003. Mapa de vegetacion de los alrededores de la Estacion

Biologica Tunquini, Bolivia. Ecologıa en Bolivia 38, 15–26.

Patzi, I., 1999. Poblacion y organizacion comunitaria. In: Ergueta, P.,

Garcıa, A.E. (Eds.), Diagnostico participativo: Recursos naturales y

patrimonio cultural del Parque Nacional y Area Natural de Manejo

Interado Cotapata TROPICO, La Paz, Bolivia, pp. 40–80.

Pretty, J.N., Morison, J.I.L., Hine, R.E., 2003. Reducing food poverty by

increasing agricultural sustainability in developing countries. Agric.

Ecosyst. Environ. 95, 217–234.

Ribera-Arismendi, M.O., 1995. Aspectos ecologicos, del uso de la tierra y

conservacion en el Parque Nacional y Area Natural de Manejo

Integrado Cotapata. In: de Morales, C.B. (Ed.), Caminos de Cotapata.

Instituto de Ecologıa, La Paz, Bolivia, pp. 1–84.

Roldan, A.I., 2001. Manual de los mamıferos silvestres del Parque

Nacional y Area Natural de Manejo Integrado Cotapata. BIOTA, La

Paz, Bolivia.

Simonetti, J.A., Huareco, I., 1999. Uso de huellas para estimar diversidad

y abundancia relativa de los mamıferos de la Reserva de la Biosfera—

Estacion Biologica del Beni, Bolivia. Mastozoologıa Neotropical 6,

139–144.

Sukumar, R., 1991. The management of large mammals in relation to

male strategies and conflict with people. Biol. Conserv. 55,

93–102.

Thompson, B.C., 1978. Fence-crossing behavior exhibited by coyotes.

Wildlife Soc. Bull. 6, 14–17.

Thouless, C.R., Sakwa, J., 1995. Shocking elephants: fences and crop

raiders in Laikipia District, Kenya. Biol. Conserv. 72, 99–107.

Treves, A., Karanth, K.U., 2003. Human-carnivore conflict and perspec-

tives on carnivore management worldwide. Conserv. Biol. 17,

1491–1499.

Zar, J.H., 1999. Biostatistical Analysis, fourth ed. Prentice-Hall Interna-

tional, Englewood Cliffs, NJ.