Managing Rats

Ecologically Based Rodent Management (EBRM)

Ecologically based rodent management has now taken center stage in Asia, Australia, and eastern Africa for management of rats in agricultural systems. This has not always been the case. In the 1960s, a wide range of chemical rodenticides became available on the global market. Research then focused on the toxicity of the poisons, on making them more palatable to the pests and less attractive to non-target species. Ecological studies of rodent pest species were an exception. With the development of resistance and increased tolerance of rodents to the rodenticides, and an increased awareness of ecological and human health issues associated with their use, attention in the mid-1990s turned back to ecology. People realized that we knew so little about the behavior, breeding ecology and habitat use of rodents that together drove their population dynamics.

The ecology of rodent pests is strongly influenced by the agricultural practices of smallholder farmers. And rodents are highly mobile, so if only a few farmers implemented good management practices, their crops would soon be reinvaded by rats from neighboring fields. Effective and sustainable ecologically-based rodent management therefore requires communities to become involved. Moreover, our understanding of the ecology of major pest species indicates that community management must be conducted much earlier than whatever farmers had been doing. We provide one example of EBRM for the ricefield rat, Rattus argentiventer; a species for which we have a reasonable understanding of its ecology in lowland rice-based landscapes. EBRM practices will vary for different species because their biology and ecology in specific agricultural landscapes are different.

Click here to view rodent ecologist Grant Singleton as he talks about EBRM and its uptake in Asia and soon Europe, and more.

Integrated actions to manage the ricefield rat, Rattus argentiventer, in lowland irrigated rice

In Indonesia, ecological studies in lowland irrigated rice fields provide the following MUST DO activities at a community level for effective management of the ricefield rat in rice.

  • Synchronize planting of crops within 2 weeks of one another; otherwise the breeding season of the ricefield rat is extended, leading to exponential population growth; 
  • Conduct community campaigns before the ricefield rat breeding season using local methods, such as trapping and fumigation, to control rats within 3 weeks of planting the crop; these community actions usually focus on village gardens, main irrigation channels, and roadsides; 
  • Keep irrigation banks less than 30 cm wide to make it difficult for rats to build nests; 
  • Clean up any grain spills at harvest and practice good hygiene around houses and gardens. 

Additional technology if chronic losses are greater than 10%

One simple technology added to the armory of rice farmers is a trap-and-fence system known as the Community Trap Barrier System. It comprises a plastic fence surrounding a small rice crop (20 x 20 m) planted 2-3 weeks earlier than the surrounding crop, with traps set into the plastic. At night, rats follow the line of the plastic until they reach a hole, which they enter to reach the rice but instead are caught in a trap.

Developing pesticide-free rodent control for southern Africa

posted Sep 12, 2010, 6:45 PM by IRRC Coordination Unit   [ updated Sep 7, 2014, 7:37 PM by G.Lavina@irri.org ]

Rodent populations cause devastating damage within African communities devastating growing and stored crops, carrying disease and damaging personal possessions. Steven Belmain reports on the ECORAT project, in which a consortium of largely African researchers, worked with communities in Tanzania, Namibia and Swaziland to develop sustainable and ecological strategies to manage and reduce and rat populations.

For the full story, click here Developing pesticide-free rodent control for southern Africa or download the attached pdf below.

Key to small mammals commonly found in agricultural areas in eastern and southern Africa

posted Sep 12, 2010, 6:35 PM by IRRC Coordination Unit   [ updated Sep 7, 2014, 7:41 PM by G.Lavina@irri.org ]

This key has been written to identify small mammals, and especially problem rodents, found in agricultural areas in Eastern and Southern Africa. Because it uses only characteristics which can be measured in the field it does not follow standard mammal (phylogenetic) taxonomy.

Click here Taxonomic key to small mammals or download the attached pdf below.

Rodents—gnawing away at crops, stored grain, and our health

posted Aug 4, 2010, 12:14 AM by IRRC Coordination Unit   [ updated Aug 4, 2010, 1:53 AM ]

Rats and mice have adapted well to the diversity of agricultural habitats created by humans. Some 42% of all mammal species are classified as rodents (animals that have continually growing incisor teeth and no canine teeth). Although fewer than 10% are significant agricultural pests, this still leaves over 200 species to manage. Rodents are an enigma in that they are the ultimate mammalian weed, living in almost every habitat on earth, yet they also play a pivotal role in nutrient cycling and water flows in many ecosystems and therefore the non-pest species need to be protected. (Pdf of the full article is attached below)

Of rice and rats

posted Aug 4, 2010, 12:00 AM by IRRC Coordination Unit   [ updated Sep 7, 2014, 7:40 PM by G.Lavina@irri.org ]

"Nature has sent the rats to our homesteads by thousands, and farmers are being eaten off the face of the earth by them." (Pdf of full article is attached below)

Rodent control (non-chemical) in lowland irrigated rice

posted Aug 3, 2010, 10:44 PM by IRRC Coordination Unit   [ updated Sep 7, 2014, 7:41 PM by G.Lavina@irri.org ]

Many rodents cause problems in rice. The main pests are the "Rice field rat" (Rattus argentiventer), the Black rat (Rattus rattus) and the lesser bandicoot rat (Bandicota bengalensis). Various mice can also cause problems. The presence of rats is usuallt associated with tracks in mud and rat holes in bunds and levees. (Pdf of the full article is attached below).

Non-chemical control of rodents in lowland irrigated rice crops

posted Aug 3, 2010, 10:34 PM by IRRC Coordination Unit   [ updated Sep 7, 2014, 7:39 PM by G.Lavina@irri.org ]

Rodents are a major agricultural pest across much of Southeast Asia. Pre-harvest rodent damage is increasing in many lowland irrigated rice crops as farming systems change towards multiple cropping and shortened fallow periods. The Community Trap Barrier System described in this note provides a cost effective, environmentally friendly method for managing two of the major rodent pests in lowland irrigated rice crops. (Pdf of full article attached below)

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