The ECORAT project - Natural Resources Institute

The ECORAT project: developing ecologically-basedrodent management for the southern African regionDr Steven Belmain and co-authors*Since the seminal book by Singleton etal. on ecologically-based rodent management(EBRM) published in 1999,the field of rodent management researchhas been re-invigorated to look beyondthe use of rodenticides. Despite thispost-rodenticide renaissance, rodentscontinue to be a growing pest problem.Research on the ecology of rodents,their impact on people’s livelihoodsand effective control is still very muchrequired. Considering their importanceas measured by their multiple impactsacross health and agriculture, rodentscontinue to be a relatively neglectedfield of research, and research capacityon rodent biology and control remainswoefully deficient in developed anddeveloping countries alike. In thisregard, transforming and applying scientificknowledge of EBRM into sustainableand cost-beneficial managementstrategies remains a high priority.The Ecorat project is contributing to thefield of EBRM research by generatingbasic ecological knowledge and buildingresearch capacity, and then usingthese resources to implement EBRMin collaboration with African farmingcommunities to provide practical pestmanagement solutions.Since January 2007, Ecorat has beencarrying out many different researchactivities, some related to rodent ecology(e.g. population dynamics, habitatutilization), rodent biology (taxonomy,breeding), rodent–human interactions(disease risks, spatial proximity) and thesocial sciences (knowledge, attitudes andpractices of agricultural communitieswith respect to rodents and their control,the pre-existing costs of rodent damageand the costs and benefits of rodentcontrol). This multidisciplinary teamof researchers works together within aconsortium drawn from institutions inNamibia, South Africa, Swaziland andTanzania, with central coordination providedby the Natural Resources Institutein the UK and an international panel ofexpert evaluators*.Understanding the rodentsThe Ecorat project is relatively uniquein basing its research within rural agriculturalcommunities, looking at allthe problems pest rodents may causeto people’s livelihoods. To do this, thescientific team works closely with farmersand households to understand rodentecology within and around their householdsand cropping fields. Researchmethods such as habitat surveys usingremoval trapping, capture–mark–recapturegrids using Sherman traps, and radiotracking individually tagged animals arebeing used to collect baseline ecologicalknowledge on the temporal and spatialdynamics of rodent populations withinrural African farming communities incertain regions of Tanzania, Swazilandand Namibia. This work has shown usthat rodent population dynamics can beextremely complex. Rural agriculturalcommunities are fundamentally comprisedof a mosaic of different habitats.For example, trapping rodents acrossdifferent habitats (e.g. houses, peridomesticareas, public areas, crop fields,fallow areas) results in very differentproportions of different rodent speciesin different localities. So although ina general sense, Rattus rattus tends todominate inside people’s homes andMastomys natalensis dominates peridomestically,there is much potential forinter-species interactions and high spe-*Natural Resources Institute, Universityof Greenwich; Tel: +44 1634 883761;Email: s.r.belmain@gre.ac.uk. Co-authorsand team members of the Ecorat project:Nomfundo Dlamini a , Seth Eiseb b , FrikkieKirsten c , Thembálilahlwa Mahlaba a , RhodesMakundi d , Phane Malebane c , Emil vonMaltitz c , Apia Massawe d , Ara Monadjem a ,Loth Mulungu d , Edward Siwiya b , PeterTaylor e , Vasana Tutjavi b and StevenBelmain f .Habitat surveys are carried out in several different habitats found in rural African villages (e.g.farmer’s fields, fallow land, houses, market areas). The animals captured are removed andprocessed to collect taxonomic, breeding and disease information which informs decisionmaking when designing ecologically-based rodent management strategies (Steven Belmain/University of Greenwich)aUniversity of Swaziland; b National Museumof Namibia; c Plant Protection ResearchInstitute, South Africa; d Sokoine Universityof Agriculture, Tanzania; e Durban NaturalScience Museum, South Africa; f NaturalResources Institute, University of Greenwich,UK.Ecorat advisory panel: Peter Brown g ,Herwig Leirs h and Grant Singleton i . g CSIRO,Australia; h University of Antwerp, Belgium;iInternational Rice Research Institute,Philippines.136International Pest Control

cies diversity within any given habitat.This is not only important in the contextof designing spatially and temporallytargeted rodent management, butalso with regards to potential zoonoticdisease transmission. Understandingthis complexity of rodent populationswithin rural communities takes time,and Ecorat research on rodent ecologywill continue for many months yet inorder to capture the seasonal changeswe expect in rodent breeding rates andabundance and the critical times whenpre- and post-harvest agricultural damageis experienced.Understanding the rodent managersOne of the big problems in developingbetter rodent management strategiesis to understand their true impact onpeople’s livelihoods. Although manyfarmers will understand that rodentsare a problem and damage their fieldcrops, stored food and personal possessions,awareness among farmers aboutthe level and scope of damage is oftenunderestimated. For example, rodentscan transmit more than 60 different diseases,although the symptoms of manymay be confused with other diseasesabout which awareness is higher (e.g.malaria). It is, therefore, important toraise awareness and generate accurateinformation about the multiple damagescaused by rodents, producing informationthat correctly shows levels of lossand contamination, and disease risks.Providing people with the true cost ofrodents on their livelihoods allows themto consider how much they can investCommunity meetings, such as this one at avillage in northern Namibia, are frequentlyheld to bring Ecorat scientists and communitiestogether. The community provides informationon their problems experienced withrodent pests and the scientific staff explainsomething about current Ecorat researchactivities taking place in their community(Steven Belmain/University of Greenwich)Rodents eat nearly all crops that people try to grow. This maize from a farmer’s store inTanzania has had the highly nutritious germ selectively removed by rats, making the grainuseless as seed material for next year’s cropping as well as reducing its nutritive quality if theremainder is consumed by people or livestock (Steven Belmain/University of Greenwich)(traps, poisons, labour) in controllingrodents.Understanding people’s attitudestowards rats, the perceived problemsand how they manage them is essentialwhen considering how to use newecological knowledge about rodents formore effective pest management. TheEcorat project team has collected informationfrom farming households usingquestionnaires and group meetings tounderstand more about people’s beliefs.For example, few small-scale farmersunderstand the different modes of actionof acute and chronic rodent poisons, andwill often choose cheap acute poisonsas they find carcasses near the poisonin the morning, which they rarely seewhen using chronic poisons because therodents die much later, often back intheir burrows. Small-scale farmers inAfrica largely monitor efficacy of anyrodent management activity through a‘body count’ which can, unfortunately,be highly misleading, particularly ifhouseholds engage in rodent controlwhen rodent populations are alreadyvery high. Such misconstrued beliefscan lead to wrong pest managementchoices and wasted time and money.Understanding these human perceptionsis very important for the design ofEBRM as well as developing the trainingand knowledge transfer requiredwithin a community to more effectivelymanage its rodent pest problems.EBRM interventionsAlthough effective rodent control methodsexist, their poor application andadaptation to local situations often resultin treatment failures, leading to apathyand widespread acceptance of rodentpests in the environment. Current rodentcontrol practices are almost exclusivelybased on the use of rodenticides. Misuseof these poisons is unfortunately commonin many African countries where highlydangerous and illegal poisons are used,which poses a threat to human healthand environmental contamination. Moreimportantly, misused rodenticides maynot significantly reduce the rodent population,therefore having little impact onreducing the damage caused by rodents.Because rodenticides can be expensiveand difficult to use safely, other rodentmanagement methods involving trappingand environmental management can bemore appropriate for the rural agriculturalsituations found in Africa.Based on the information collectedabout rodents and rodent managers, theEcorat project has recently begun anintervention programme in cooperationwith communities that involves inten-May/June 2008 137

Tracking tiles are made using ordinary ceramicbathroom tiles which are blackened withsoot using an oil lamp. The tracking tiles arethen placed in people’s homes and checkedfor signs of rodent activity as a way to monitorthe impact of rodent management activitieson the rodent population over time (StevenBelmain/University of Greenwich)sively trapping rodents. Trapping isorganized at the community level, withtraps rotating around the community inorder to share the costs. This ensuresthat the rodent population is reducedat a sufficiently large enough scale toreduce the effects of immigration backinto the intervention zone. In additionto the trapping programme, environmentalmanagement activities to reducerodent access to stored food, water andharbourage within communities are demonstrated.Monitoring the impact of theEBRM intervention takes place by firstlymonitoring changes to the rodent population.This is done by measuring the relativeabundance of rodents in the EBRMintervention villages in comparison withnon-intervention villages nearby that aresimply carrying on with their indigenousrodent management activities. This comparisonis done with limited removaltrapping surveys and non-invasive indicatorssuch as the placement of trackingtiles to measure overall rodent activitylevels within the communities.Secondly, the Ecorat project is workingwith the communities to measurethe impact of the EBRM interventionon levels of field crop and stored fooddamage and other observed effects (e.g.rat bites, damage to blankets). We hopethat these activities carried out in partnershipwith the communities will convincethem on the costs and benefits ofEBRM and lead to sustainable changesin pest management practice.Further information about the projectcan be found through the website: www.nri.org/ecoratAcknowledgementsThe Ecorat project is fundedthrough EuropeAid of the EuropeanCommission via the ICART Programme(Implementation and Coordination ofAgricultural Research and Training)for the Southern African DevelopmentCommunity.Further readingTaylor, P.J., Arntzen, L., Hayter, M., Iles,M., Frean, J. and Belmain, S.R. (2008)Understanding and managing sanitaryrisks due to rodent zoonoses in an Africancity: beyond the Boston Model. IntegrativeZoology 3, 38–50.Belmain, S.R. (2007) Rats, an ecologicallybased approach for managing a global problem.Low External Input and SustainableAgriculture 23(4), 18–20.Mulungu, L.S., Makundi, R.H. , Massawe,A.W. and Leirs, H. (2007) Relationshipbetween sampling intensity and precisionfor estimating damage to maize caused byrodents. Integrative Zoology, 2, 131–135.Makundi, R.H., Massawe, A.W. andMulungu, L.S. (2006) Breeding seasonalityand population dynamics of three rodentspecies in the Magamba Forest Reserve,Western Usambara Mountains, north-eastTanzania. African Journal of Ecology, 45,17–21.Skonhoft, A., Leirs, H., Andreassen, H.P.,Mulungu, L.S. and Stenseth, N.C. (2006)The bioeconomics of controlling an Africanrodent pest species. Environment andDevelopment Economics, 11, 453–475.Singleton, G.R., Sudarmaji, Jacob, J. andKrebs, C.J (2005) Integrated management toreduce rodent damage to lowland rice cropsin Indonesia. Agriculture, Ecosystems andEnvironment. 107, 75–82.Singleton, G.R., Brown, P.R. and Jacob, J.(2004) Ecologically-based rodent management:its effectiveness in cropping systemsin South-East Asia. NJAS WageningenJournal of Life Sciences. 52(2), 163–171.Aplin, K.A., Brown, P.R., Jacob, J., Krebs,C.J. and Singleton, G.R. (2003). Fieldmethods for rodent studies in Asia and theIndo-Pacific. ACIAR Monograph 100. ACIAR,Canberra, Australia. 223 pp.Singleton, G.R., Hinds, L.A., Krebs, C.J. andSpratt, D.M. (eds.) (2003) Rats, mice andpeople: rodent biology and management.Australian Centre for International AgriculturalResearch, Canberra, Australia. 564 pp.Singleton, G.R., Hinds, L.A., Leirs, H. andZhang, Z. (eds.) (1999) Ecologically-basedrodent management. Australian Centrefor International Agricultural Research,Canberra, Australia. 494 pp.138International Pest Control

Urban rodent management in a third-world cityA key concern with rodent infestations indense urban settlements is the expected(but often unknown) human health risk.Informal settlements of the kind that havemushroomed in and around third-worldcities appear particularly at risk becauseof inadequate sewage, housing and infrastructure.A recent study in Durban, South Africa,was the first to investigate the risks fromrodent zoonoses (for plague, leptospirosisand toxoplasmosis) in both formal (commercial,industrial, harbour and formalresidential area) and informal (squattercamp) situations in a third-world city.Rodent control efforts in Durban, a cityof three million inhabitants, traditionallytarget the central harbour (the busiest inAfrica) and commercial districts of the city.However, rodent populations are knownto be increasing in informal markets andthe shack settlements that have sprung upthroughout the wider municipal area overrecent decades.The study (part of the ‘Ratzooman’– Rodent Zoonosis Management – Project:www.nri.org/ratzooman/) investigated (a)whether urban pest rodents pose real publichealth risks in both formal and informal sectors,(b) whether there are specific endemicdisease areas (‘hotspots’) for rodents andhumans and, if so, what the environmentaland socioeconomic correlates of these are;and (c) the relative merits of different managementinterventions (derived from the‘Boston Model’) to minimize the sanitaryrisk to humans.The success of the Boston Model, arodent management plan developed inand for a first-world city in the USAin the 1990s, is attributed to its centralizedapproach, well-defined responsibilitiesand firm accountability. Four componentsare key: (a) primary managementfunction: biologists trained in the fieldsof rodent control, geographic informationsystems (GIS) and contract management;(b) municipal functions: enforcement ofbylaws, refuse removal, environmentalsanitation; (c) pest control contractors: baiting,trapping, monitoring; and (d) publicparticipation championed by communityleaders and non-governmental organizations:public outreach and education, communitymeetings, door-to-door visits, literature,recognition of cultural differences.Clearly some of these will be absent insome third-world city settlements, but theDurban study investigated how the modelcould be adapted for these circumstances.Results of antibody/DNA testing of thesix rodent species caught in live trapsat 54 sites around Durban indicated norodents were seropositive for plague, butnine Norway rats (4% of total rodent catch)were seropositive for toxoplasmosis and 22(10%) for leptospirosis. Disease ‘hotspots’were concentrated in the shack settlementof Cato Crest and the commercial districtof Durban. Serology tests of humans livingin Cato Crest showed 0% exposure toplague, 23% to leptospirosis and 35% totoxoplasmosis.A socioeconomic survey of 90 householdshelped determine environmentaland socioeconomic disease risk factorsin Cato Crest. Based on the results, environmentalhygiene and rodent trappingcampaigns were launched in Cato Crest,with officials and the local communityextensively involved in both from theoutset. A committee was formed andfunds committed to a multi-prongedcommunity health awareness and actioncampaign. Educational brochures andquestionnaires (in the local isiZulu language)about personal hygiene, rodentbornediseases and other environmentalhealth issues were distributed to all5000 households in the settlement. Thiscampaign culminated in a clean-up dayin Cato Crest in June 2006 involvingall municipal service departments andthe local community. Following this,a year-long pilot study was initiated,employing local residents to distributebreak-back rodent traps to 100 CatoCrest households at a time (moving thetraps to new households on a monthlybasis), teaching them to undertakeintensive trapping and also to practisepersonal hygiene to minimize rodentcontact and help break disease transmissionroutes.The initiative owed much of its successto implementation of the principles inherentin the Boston Model, even though certainelements (e.g. sewer services, privatepest controllers, neighborhood services)were absent. Crucially, the same principlesthat contributed to success in Bostonwere found in Cato Crest: a scientificallydriven centralized approach, synergisticcooperation, and communication betweenscientists, city officials, vector-control specialistsand the community.Further information: Taylor, P.J.,Arntzen, L., Hayter, M., Iles, M., Frean, J.and Belmain, S. (2008) Understanding andmanaging sanitary risks due to rodent zoonosesin an African city: beyond the BostonModel. Integrative Zoology 3, 38–50.Peter J. Taylor, Durban Natural ScienceMuseum, eThekwini Libraries and HeritageDepartment, PO Box 4085, Durban, SouthAfrica; Email: taylorpeter@durban.gov.zaA clean-up campaign supported by all sectors was a key element to improving rodent managementin Cato Crest, Durban (Photo: Guy Redman/Durban Natural Science Museum)May/June 2008 151