Research Projects and Activities
Current research in Asia
- Laos: Rodent management in the uplands of Laos
- Myanmar: Ecolocically-based management of rodents in rainfed cropping systems
- Indonesia & Vietnam: Implementation of rodent management in lowland rice production systems
Australian Youth Ambassadors for Development
Links with IRRI
- Bangladesh: International research project on rodent biology and management
Education, communication and extension
Current research in Australia
Biological control of mice by viral-vectored immunocontraception
This research formed part of the former Pest Animal Control Cooperative Research Centre, and is now being undertaken through CSIRO Entomology. It aims to reduce the population numbers of foxes, rabbits and mice by targeting fertility rather than mortality.
Immunocontraception is the process of inducing the body's immune system to attack the reproductive cells of its own species, thus preventing the animal from breeding. The proposed vector for the distribution of the contraceptive agent (currently the egg protein ZP3) in mice is a mouse virus (currently mouse cytomegalovirus or MCMV). This process is known as virally-vectored immunocontraception.
This multi-disciplinary mouse project involves collaboration between population ecologists, virologists, immunologists, molecular biologists and reproductive physiologists from CSIRO, the PAC CRC and the University of Western Australia. The work is supported by the Grains Research and Development Corporation (GRDC), the PAC CRC and in-kind contributions from the participating institutions.
For further information contact Dr Lyn Hinds, CSIRO Entomology.
Ecology of mouse populations and predictions of mouse plagues
Capture-mark-release studies have been conducted on mouse populations in agricultural lands in northwest Victoria since November 1982. This region has a Mediterranean type climate with an average annual rainfall of 330 mm. The main crops are winter cereals (wheat and barley).
Apart from a 2.5 year break in 1990-1992, data have been collected every 3-6 weeks on mouse population size, structure, breeding, body condition and habitat use. These data indicate that above average autumn rainfalls followed by a series of key rainfall events are required to generate a plague two years later. Drought conditions can intervene to prevent a mouse plague developing.
Key biological information required for plague prediction are:
- mouse population density at the start of the breeding season, and
- average litter size during the first 3 months of the breeding season.
Once a prediction has been made, regular monitoring of fluctuations in population size, proportion of female mice breeding and the length of the breeding season enable predictions to be updated.
The probability of high mouse numbers in the Victorian mallee wheatlands can be assigned 18 months prior (up to 50% probability), but is more accurate within 6 months of the event (up to 85% probability). High mouse numbers in this area have been successfully predicted 18 and 20 months prior to their occurrence in 1994 and 1997 respectively. Recent updates on Australian mouse numbers are shown on the resources page.
A word of caution : the mechanism of mouse plague formation can be markedly different for different agricultural regions in Australia.
For further information contact Peter Brown.
Modelling of mouse plagues in Australia
A review of mouse plague models in Australia in 1991 identified the need for the development of robust models which better explain the mechanisms of mouse plague formation.
Using the substantial ecological dataset from the Victorian mallee wheatlands, this type of model will be developed to predict the processes influencing wild mouse populations. This will not only improve our understanding of how plagues form, but will also allow refinement of plague prediction. In addition, these models will be a powerful tool for predicting the effects of different control techniques, such as immunocontraception. This work is supported in part by the PAC CRC, ACIAR and GRDC.
For further information contact Peter Brown or Tony Arthur.
Best farm management practices to control mouse plagues in Southern NSW
This research and extension project, involving CSIRO, the New South Wales Department of Agriculture and the Irrigation Research and Extension Committee, was based in the Murrumbidgee Irrigation Area near Coleambally. This project built on a previous project run in collaboration with the Victorian Department of Natural Resources and Environment.
The collaborating groups critically assessed farming practices currently used for rodent control, and formulated sustainable, cost-effective management options that can be applied on and around farms to keep mouse numbers below plague proportions. The project also examined the relationship between live-capture traps and census cards (amount eaten of 10 x 10 cm paper soaked in canola oil) and the relationship between the density of mice and damage to crops.
A panel of farmers and state government officials from New South Wales, Victoria, Queensland and South Australia advised the research team. The project was supported by the Bureau of Rural Sciences.
For further information contact Peter Brown.
Walpeup Watering Experiment
Feral house mice do quite well for themselves in the semi-arid cropping environments of Australia. In some years they increase to very high numbers and cause damage to crops, while in other years their density remains low. To get a better understanding about what conditions lead to high mouse numbers, we set about manipulating some of the key factors that regulate mice (eg availability of food, water, and shelter). Our experiment is set up as a factorial design with combinations of each treatment and replication. The experiment is being conducted on wheat farms around Walpeup in the central mallee wheatlands of northwestern Victoria.
On each treatment site we are monitoring the mouse population abundance, rate of breeding and survival of mice over time. We are supplying food in small plastic containers so that only mice can access the food, and water is provided in 20 litre drums with small nozzles that only mice can use. We are also putting out chicken wire that is held off the ground to offer mice some protection form predators.
It is too early to make any firm conclusions about our results, but we are starting to see that each treatment is giving some benefit to mice, but it depends on the time of year, growth stage of the crop and general conditions that prevail (eg good rainfall). The information we gain from this experiment will be useful in refining our models for predicting mouse plagues (see Modelling of mouse plagues in Australia and Mouse Plagues Fact sheet (pdf file 393 Kb)) and also for developing methods for managing mice (see fact sheets).
Rats in Urban Areas
Rats have co-existed with humans, especially in urban areas, for thousands of years. Australian urban areas, especially port cities, are host to two species of introduced rat pests, the Black Rat (Rattus rattus) and the Norway Rat (Rattus norvegicus). These species have been identified as potential carriers of diseases that can affect humans, such as Hantaan virus (Haemorrhagic fever), Murine typhus (Rickettsia typhus), Leptospirosis, Rat bite fever (Spirillium minor) and the Plague (Yersinia pestis).
Research is currently being carried out to determine the extent of this potential threat to human health. Of interest also is their impact to industry, households and recreational areas.
Tammar wallaby work
Current marsupial research activities include reproductive physiology,
biology and the management of problem species, with this work now being undertaken at CSIRO Entomology. We also
study the mechanisms that regulate reproduction in marsupials
and use the Tammar wallaby, Macropus eugenii, as
our model experimental species.
research falls under the following topics:
Regulation of embryonic diapause in tammar wallabies
Implantation in marsupials – a molecular and immunohistological approach
Development of oral delivery mechanisms for marsupials which have
ruminant-like digestive system
Lactation - analysing milk compnents for bioactives and probiotics
Disease models - pathology of infection with hydatids
For more information contact Lyn Hinds, CSIRO Entomology.
Current research in Asia
Laos: Rodent management in the uplands of Laos
In the uplands of SE Asia, shifting cultivation is one of the dominant production systems. The rural communities that live in these environments are amongst the poorest in Asia. Rodents are a major constraint to production of rice, maize, sorghum, etc., and farmers identify rodents as the problem they have the least control over.
This project (to be completed December 2006) in the uplands of Laos is a follow-up to a recently completed ACIAR funded project in Indonesia, Vietnam and Laos. The main objective of the previous project was to develop sustainable and ecologically sensitive methods for rodent management. In Indonesia and Vietnam the emphasis was on assessing the effectiveness of village level management using a community approach and the incorporation of the trap-barrier system (TBS). In Laos, variants of the TBS were assessed in shifting cultivation farming systems in rainfed upland environments, but the primary objective for Laos was to understand the species that were likely to cause damage to crops and stored food, and to understand some of the basic movements, habitat use and breeding dynamics of the key pest species on which to base control options.
The main objectives of this project are:
- To test integrated rodent management control strategies in upland shifting cultivation systems based on our understanding of population dynamics of the key rodent pests.
- To determine the sociological and cultural factors that influence farmers’ decisions on the adoption of rodent management by conducting pre- and post-survey of knowledge, attitudes and practices (KAP).
- To compete the taxonomic rodent key for Laos and translate the key into Lao.
- To develop the capacity and involvement of government and NGO extension for establishing adoption pathways of ecologically-based rodent management.
We will have two study sites:
- Luang Namtha where there have been chronic high levels of rat problems in the past three years (we will work together with the National Rice Research Program, NRRP).
- Luang Prabang (Hadsua) where NAFRI and IRRI have a long term FPR study (we will link with the Integrated Uplands Agricultural Research Program, IUARP).
This is an ACIAR funded project in collaboration with the National Rice Research Program and the Integrated Uplands Agricultural Research Program in Laos.
For further information contact Peter Brown.
Myanmar: Ecologically-based management of rodents in rainfed cropping systems
Following an in-country consultation between ACIAR and the Myanmar Ministry of Agriculture in mid 2002, reducing rodent impacts in agriculture was identified as an important priority for Myanmar. Consultation with two groups of village farmers (80 km apart) and with the Chairman of Okshitpin township (a region that suffered high pre-harvest damage to their main monsoon crop in 2001) identified rodent pests as in the top three constraints of crop production. The farmers in the two villages estimated mean losses in production due to rats at 11.5% and 30%, respectively, in the 2000/01 monsoon rice crop; their main crop of the year.
Agriculture is a major component of the Myanmar economy, contributing 53% to its GDP with 71% of the labour force involved in agriculture (see IRRI fact sheet (pdf file)). The main crops are paddy rice, corn, oilseed, sugarcane and pulses. Rodents cause significant damage to each of these commodities, particularly to rice. There has been a national initiative since 1992 to increase the area double-cropped with rice. Chronic rat problems have accompanied double-cropping elsewhere in SE Asia, whereas acute, sporadic, rodent problems are generally associated with rainfed single rice crops.
Little is known in Myanmar about the identity and geographic distribution of the major rodent pest species, let alone the biology of the main pest species. We started an ACIAR funded research project in Myanmar in January 2003 (to be completed in Dec. 2005) to attain such knowledge.
The main objectives of this project are:
- To identify the key pest species and their pre- and post-harvest impact in the dominant rainfed lowland farming system.
- To determine environmental factors that might influence the timing and severity of rodent damage.
- To understand the knowledge, attitudes and practices (KAP) of farmers towards rats and the current individual and community approaches to controlling them.
- Develop and trial options for community based, ecologically sensitive, rodent management in the rainfed lowland cropping environment. This is being achieved through field trails of various existing and novel methods of community ecologically-based rodent management and through consultation with farmer groups.
- To train in-country extension staff in principles and practices of rodent biology, ecology and management, and integrate them into Asian rodent network through IRRI Rodent Ecology Work Group.
This is an ACIAR funded project in collaboration with the Myanmar Agriculture Service in Myanmar.
For further information contact Peter Brown.
Indonesia & Vietnam: Implementation of rodent management in lowland rice production systems
Rodents are substantial pests in lowland irrigated rice. They cause significant losses pre and post-harvest and are carriers of disease of humans and livestock. In Asia, pre-harvest rice losses from rats are estimated to be between 5 and 10%. A loss of 6% of SE Asia rice production amounts to approximately 36 million tonnes; enough rice to feed the population of Indonesia (215 million people) for 12 months. Farmers often use inappropriate methods to reduce the impacts of rodents, and rely heavily on chemicals, causing risks to non-target species and to the environment, and generally providing poor return on investment. In irrigated rice crops, rodent pests are the number one pre-harvest pest in Indonesia and amongst the top three pests in Vietnam.
A previous ACIAR-funded project in these cropping systems identified and successfully tested, at a village level, integrated ecologically-based rodent management (IEBRM) of rodent pests in lowland irrigated rice. Projects took place in West Java, Indonesia, and the Red River delta, Vietnam. In Indonesia, the benefit-to-cost ratio for all seasons and years averaged 25-to-1 but varied considerably from year to year between a low of no benefit to a high of 63-to-1. In Vietnam, rodent densities were consistently low, however, there was marginally less rodent damage in the treated villages compared to the control villages. In addition, rodenticide use in the treatment villages fell by 49% in Indonesia and 66% in Vietnam. The economic benefits alone of integrated IEBRM were equal to or better than that achieved by conventional management actions based on rodenticides.
We are currently developing a new project that will focus on pathways of adoption to promote these as community management methods at a district level (study sites of approximately 1,000 ha). We will examine pathways to extend the technologies to the provincial and regional level in lowland irrigated rice systems. We will work closely with farming comunities in both countries to develop methods to promote rodent control activities.
For further information contact Peter Roebeling.
Australian youth ambassadors for development
Over the past year a research team from the Philippines Rice Research Institute (PhilRice) led by Ravi Joshi and Evelyn Gergon, has been studying the impacts of rodents on rice crops in the rice terraces of Banaue, in northern Luzon . These spectacular terraces are thought to be over 2,000 years old and are often referred to as the eighth wonder of the world. A member of the Rattus rattus complex is the major rodent pest and farmers rank rats amongst their top two pests. Preliminary findings also indicate that some of the native rodent species may be playing an important ecological service through eating the golden apple snail, an important pest of rice, and giant earthworms that are eroding some of the terraces.
There have been two recent international additions to the PhilRice rodent research team. Rachel Miller is an Australian Youth Ambassador for Development (AYAD) funded by the Australian Agency for International Development. Rachel arrived in the Philippines in late March 2004 to undertake a 10-month assignment. Alex Stuart is a MSc student from Reading University, UK. He arrived in the Philippines in April and will spend three months there. Rachel will examine the breeding ecology and habitat use of the main rodent pest species. Ravi Joshi and Grant Singleton (CSIRO) will supervise Rachel. Alex will examine the habitat use and diet of some of the native rodent species living in and around the rice terraces. Grant Singleton and Colin Prescott (Reading University) will supervise Alex.
Alex Stuart Rachel Miller
Links with IRRI
Grant Singleton has acted as a consultant on rodent issues at IRRI since 2001. See the IRRI knowledge bank for lectures presented at IRRI for a training course on rodent research and management.
The rodent management team also maintains the International Rodent Pest Network bulletin board email list in support of the IRRI Rodent Ecology Working Group.
Bangladesh: International research project on rodent biology and management
Rodents are one of the major pest constraints to increased agricultural production in Bangladesh. Rice continues to be the most important crop in Bangladesh. Although effective rodent management tools and techniques exist, their poor application and adaptation to particular agro-ecological situations often result in treatment failures, leading to apathy and widespread acceptance of rodent pests in the environment. Using rodent management tools and techniques require a good understanding of rodent biology and their localised impacts upon people’s livelihoods. Rodent pests disproportionately affect the poorest people who are less likely to possess appropriate knowledge and access to proven technology.
An international research project on rodent biology and management near Comilla, east of Dhaka and near the border of India, started in April 2002. There are four main objectives of this project:
- Understand the impact of rodents upon diversified rice-based systems of rural communities.
- Understand the impact of existing control strategies used by small-scale farmers upon rodent population dynamics, the environment and socio-economic capital.
- Develop new rodent control strategies through farmer participatory research.
- Develop and disseminate policy recommendations to stakeholders involved in rodent pest control.
This research is led by Dr Steve Belmain at the Natural Resources Institute, University of Greenwich, UK, in collaboration with the Bangladesh Rice Research Institute; the Community Ecology Group, CSIRO Sustainable Ecosystems; the Association for Integrated Development, Comilla, Bangladesh; and the Vertebrate Pest Division, Bangladesh Agricultural Research Institute. The project is funded by the Crop Protection Programme (CPP) managed by NR International in the UK and the Poverty Elimination through Rice Research Assistance (PETRRA) programme managed by the IRRI Bangladesh office.
Education, communication and extension
Master Class on Rodent Ecology and Management (IRRI, May/June 2003)
A 3-week Master Class on Rodent Ecology and Management took place in May/June (2003) at the International Rice Research Institute (IRRI) Training Centre, Philippines. Participants from 13 different countries were sponsored by the ATSE Crawford Fund, IRRI and the Australian Centre for International Agricultural Research (ACIAR). In the first week, participants were exposed to the theoretical aspects of rodent ecology, population dynamics and modeling, and ecological management of rodents. In the second week, they focused on taxonomy, breeding biology of rodents, how to construct a trap-barrier system, and damage assessment. Through hands-on use of freshly caught rats and mice, and preserved specimens from other Asian countries, participants learned how to identify rodents using dichotomous keys and a computer-based “Lucid Key.” The course focused strongly on field ecology. Seventeen participants, not deterred by a typhoon, undertook four different field-based projects, which often involved long hours of work, from 6:00 a.m. to 10:00 p.m. The field-based projects were farmers’ surveys, radio tracking, habitat distribution of rodents, and commensal rodents.
Although each group was responsible for one project, each participant worked one day on each of the other projects. Rodent specialists Dr. Grant Singleton, Mr. Peter Brown, and Dr. Ken Aplin supervised farmers’ surveys, radio trapping, and Mt. Makiling trapping projects, respectively, while the ecologist, Professor Emeritus Charles Krebs, supervised the commensal rodent project. The main objective of these projects was to expose the participants to different techniques essential for field research on rodents. Participants reported their project findings at the end of the course.
The course was a great success. We enjoyed excellent cooperation from the staff of the IRRI Training Center during a rather demanding course with field work involving early mornings and radio-tracking at night. They are to be commended on the work they did in ensuring everything ran smoothly. Special mention goes to the organisational efforts of Dr Zahirul Islam.
All the lectures presented during the course have been uploaded onto the IRRI Knowledge Bank in order of their presentation.
PhD student projects
Compensation by populations of rodent pests to perturbations (imposed control) in intensive cropping systems.
The focus of research for this thesis is directed at gaining a better understanding of:
- how rodent populations recover from control campaigns, and
- the interaction between rodents and crops.
This will lead to better management of rodents through appropriate timing of control and minimise damage to crops. The project will further develop the concept of Ecologically-Based Rodent Management (EBRM) that underlies the research conducted by the Rodent Research Group, CSIRO Sustainable Ecosystems.
All too often there is a focus on reducing rodent numbers without understanding what effect this has on the damage to the crop, or indeed how the crop might compensate for rodent damage. These interactions need to be studied in concert: there are few examples where this approach has been used. This thesis pieces together some important aspects of the understanding of the response of rodent species to control, the response of crops to damage attack by rodents and the relationship between the density of rodents and subsequent damage to crops.
Intrinsic regulation within feral populations of house mice
Free-living populations of wild house mice (Mus domesticus L.) cause significant agricultural and environmental impacts in southern and eastern Australia due to irregular outbreaks, commonly referred to as ‘mouse plagues’, which cause widespread financial, social and environmental damage. Understanding the key drivers for these fluctuations in mouse density is critical for the prediction and prevention of future outbreaks. To date, almost all models proposed to explain mouse plagues have focused on extrinsic divers such as rainfall and weather patterns. However, good rains are not always followed by a mouse plague, indicating that some other regulatory or feedback mechanism is also operating. The efficacy of other extrinsic processes that may regulate mouse populations, such as predation or disease, have also been questioned.
Intrinsic drivers in the form of spacing behaviours also have the potential to regulate mouse density by affecting dispersal, reproductive output and mortality. Moreover, intrinsic regulation is believed to be the key driver of density fluctuations in some rodent populations in the Northern Hemisphere. However, despite their potential importance, intrinsic drivers for population regulation have not previously been investigated for wild house mice.
In this thesis I have investigated a number of hypotheses for intrinsic regulation which were initially proposed for other vertebrate populations. A wide range of data were collected over the periods immediately before, during and after an outbreak using trapping, activity monitoring and genetic techniques. Predictions from each of the published hypotheses were then compared to the observed patterns in the field to distinguish between these conceptual models. An experimental manipulation was also undertaken to examine the influence of adult females on social spacing and population demography. Field observations and experimental results were consistent with models proposing a shift in spacing behaviour, especially among adult females, towards a closed territorial social system during the increase phase of a population outbreak. Social interactions appeared to be regulated at burrows by these females which limited the rate of immigration and prevented disruption of the local social structure. I propose that this shift is pivotal to plague formation because in the years that groups of related females can effectively defend their nests against infanticide, juvenile recruitment will be significantly improved. As a consequence, a large cohort of dispersers is produced and the population rapidly expands leading to an outbreak. This strategy may persist in the population between outbreaks because mice that form kin groups would contribute more to future generations, resulting in selection for this trait.
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