See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/282742117 Rodents in agriculture and forestry Article · January 2015 CITATIONS READS 17 3,559 2 authors, including: Grant R Singleton International Rice Research Institute 261 PUBLICATIONS 5,779 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Closing Rice Yield Gap Project (CORIGAP) View project Closing Rice Yield Gaps in Asia with reduced environmental footprint (CORIGAP) View project All content following this page was uploaded by Grant R Singleton on 09 January 2016. The user has requested enhancement of the downloaded file. 3 Rodents in Agriculture and Forestry B.J. Wood1 and G.R. Singleton2 1Merrivale Research, Exton Lane, Exeter, UK; 2International Rice Research Institute (IRRI), Metro Manila, Philippines Introduction agriculture (broad sense), an overview of which is the theme of this chapter. Rodents occur in virtually every terrestrial Since the previous edition of the book, environment that supports life, be it wild, work in other regions, in particular China and agricultural or urban. Many species com- Africa, has intensified and become access- prise relatively small individuals with the ible to an international audience. There has capacity to multiply rapidly. Generally, ro- been wider awareness of the environmental dents are omnivorous, feeding mainly on factors that regulate population sizes, and plant materials, which may include seeds, how to amend the situation to minimize the leaves, roots, whole young plants, fruit, grain threat, an approach that has crystallized as ‘eco- and tree bark; and animal tissue, for ex- logically based rodent management’ (EBRM). ample, insects, snails, other invertebrates Much of this is covered in three multiple- and the bodies of vertebrates. They may also authored works, all edited by Singleton et al. feed on living plants and animals, and by (Singleton et al., 1999a, 2003a, 2010a). This scavenging. Some species are fairly restricted chapter aims to be a guide to the recent litera- in diet, but most are quite versatile, and ture. Inevitably, it is selective, with a high pro- some can adapt readily to manufactured portion of the citations from reviews. food products and wastes. Many species are The accounts given are divided by geo- fossorial, nesting and living much of the time graphic region and then further subdivided, in burrows; others live at ground level, pro- in some cases, by specific crop. Ricereceives gressing through tree climbing to completely wide coverage, as justified by its importance arboreal species. Rodents are represented in as a world food source, and because it is un- all climatic zones from arctic tundra to the doubtedly subject to very heavy and not al- equatorial tropics, and they include species ways fully recognized losses to rats. that are well adapted to arid conditions. In common with most taxonomic groups, ro- dents show a tendency to having a greater Species Involved number of species in warmer, wetter envir- onments. All of these characteristics pre- Pest species are to be found among the three dispose rodents to live freely in competition major suborders of rodents, the Myomorpha with humans (i.e. to be pests), including (rats, mice, voles, hamsters, gerbils, jirds, mole their role in important depredations in rats), the Sciuromorpha (the squirrel-like © CAB International 2014. Rodent Pests and their Control, 2nd Ed (A.P. Buckle and R.H. Smith) 33 34 B.J. Wood and G.R. Singleton rodents), and the Hystricomorpha (porcu- by far the predominant pests (namely, Arvi- pines, cane rats and other, usually larger, canthis niloticus in the north and Mas- rodents). The species complex infesting a tomys (Praomys) natalensis in the south), particular agroecosystem varies according with just a few others in specific circum- to geographical location and type of habitat. stances. In Malaysia, Medway (1978) listed Broadly, these are temperate, subtropical or 19 species of Rattus, but only four or five tropical, and whether they are wet or arid. have become significant pests of agricul- Whereas there are variations in species be- ture. Some of the non-pest species are now tween the large land masses, there is a ten- assigned to other genera (Payne et al., dency towards analogous types, more or 1985; Francis, 2008). Records from China less closely related biologically, in corres- give 168 species of rodents in 14 families ponding environments. (Wang and Deng, 1984) but only a few have Altogether, relatively few of the large become pests. number of known rodent species have be- In this account, biological names (Eller- come pests. Southern (1979) (citing Morris, man, 1941, 1949) are given, favouring the 1965), mentions 1729 rodent species, but names used in the articles cited. Internet only 125 are reported as pests in this chap- sources, including Wikipedia, have also ter. This rather small proportion applies sometimes been used. Common names are just as much to the tropics as elsewhere. mentioned where they are widely used. The Thus, Delany and Happold (1979) list 240 taxonomic affinities of the rodent genera species in 12 families in Africa, but two mentioned in the chapter are summarized myomorph species (or species groups) are in Table 3.1. Table 3.1. A listing by suborder and family of the rodent genera mentioned in this chapter. Suborder Family Subfamily (where relevant): Genus Hystricomorpha Abrocomidae Abrocoma Hystricidae Hystrix Myocastridae Myocastor Octodontidae Octodon, Spalacopus Thryonomidae Thryonomys Myomorpha Cricetidae Arvicolinae: Arvicola, Myodes (= Clethrionomys), Lagurus, Lemmus, Microtus, Neofibre, Ondatra, Pitymys (subgenus of Microtus) Cricitinae: Cricetulus, Cricetus Neotominae: Peromyscus Sigmodontinae: Eligmodontia, Holochilus, Oryzomys, Sigmodon Gliridae Glis, Graphiurus Muridae Deomyinae: Acomys, Uranomys Gerbillinae: Meriones, Tatera Murinae: Apodemus, Arvicanthis, Bandicota, Berylmys, Chiropodomys, Dasymys, Hylomyscus, Lemniscomys, Lophuromys, Mastomys, Melomys, Millardia, Mus, Nesokia, Niviventer, Oenomys, Praomys, Rattus, Rhabdomys, Stochomys Nesomyidae Cricteomyinae: Cricetomys Spalacidae Cannomys, Myospalax, Rhizomys, Spalax Sciuridae Callosciurus, Citellus, Cynomys, Eutamias, Funisciurus, Funambulus, Marmota, Paraxerus, Sciurotamias, Sciurus, Spermophilus, Tamias, Xerus Sciuromorpha Geomyidae Thomomys Heteromyidae Perognathus Sciuridae Callosciurus, Citellus, Cynomys, Eutamias, Funisciurus, Funambulus, Marmota, Paraxerus, Sciurotamias, Sciurus, Spermophilus, Tamias, Xerus Rodents in Agriculture and Forestry 35 Incidence of Rodent Problems reserves, limiting growth and, at crucial times, reducing winter survival and nutrient value, In temperate zones, rodent pests of pasture and posing competition with livestock. Field and field crops originate mainly from grass- crops may suffer direct loss of the utilized land species, and those of forestry and or- part (fruit, leaf, corm, etc.), but often the effect chards mainly from woodland species. is indirect (e.g. reduced stature, quality or Numbers tend to be cyclic, increasing in the competitive ability against weeds). growing season and declining in winter. There can be big variations between years. Northern Europe Much the same broad ecotype subdivi- sions occur in warm temperate and subtrop- ical climates, but population fluctuations Rodent outbreaks have been known in Euro- are generally less. Arid conditions may in- pean agriculture from prehistory, and severe volve regular but short and sparse rainy crop damage is still common (see Pelz, 2003 periods. Rodents adapted to arid environ- for reviews; and Jacob and Tkadlec, 2010). ments can be damaging to any crops grown Incidence is strongly cyclic, depending on in them. In the equatorial tropics, the stead- fluctuating environmental factors, with a ier climates tend to be continuously condu- gradation away from locations with more cive to rodent increase. Population numbers marked winters. Rodents sometimes reach may fluctuate in response to rain and crop plague proportions, for example, in Hungary seasons, but in perennial crops tend to- in 1964–1965, the common vole, Microtus wards relative stability. Highland tropics arvalis, caused extensive damage in most share some of the features and species of cultivated fields despite control efforts both subtropical and tropical environments. covering 3.6 million ha, which proved to be Often, certain species become closely too late (Myllymaki, 1979). The most serious associated with particular crops, especially depredators in grassland include M. arvalis those that provide all the requirements for a in east and interior Europe, and the field species to complete its life cycle when the vole, M. agrestis, in north-west Europe (Jacob crop is grown on a large scale. This leads to and Tkadlec, 2010). The former can reach another broad distinction, that between resi- very high populations, recording over −1 dent rodent pests, those of regular seasonal 2000 ha or much more on occasion. M. incidence and those of periodic invasions. agrestis generally occurs at a density of 100– −1 This ecological perspective is evaluated 400 ha . Where their ranges overlap, M. further in the Synthesis section towards the agrestis is mainly a woodland species. The end of the chapter (see also Chapter 1). It is bank vole, Myodes glareolus, across the re- −1 key to evaluating loss potential from a rodent gion, generally peaks at about 100 ha