Assessing animal welfare impact of fourteen control and dispatch methods for house mouse (Mus musculus), Norway rat (Rattus norvegicus) and black rat (Rattus rattus)

Population control of the house mouse (Mus musculus), Norway rat (Rattus norvegicus) and black rat (Rattus rattus) is common practice worldwide. Our objective was to assess the impact on animal welfare of lethal and non-lethal control methods, including three dispatch methods. We used the Sharp and Saunders welfare assessment model with eight experts scoring eleven control methods and three dispatch methods used on the three species. We presumed the methods were performed as prescribed, only taking into account the effect on the target animal (and not, for example, on non-target catches). We did not assess population control efficacy of the methods. Methods considered to induce the least suffering to the target animal were captive-bolt traps, electrocution traps and cervical dislocation, while those with the greatest impact were anticoagulants, cholecalciferol and deprivation. Experts indicated considerable uncertainty regarding their evaluation of certain methods, which emphasises the need for further scientific research. In particular, the impact of hydrogen cyanide, chloralose and aluminium phosphide on animal welfare ought to be investigated. The experts also stressed the need to improve Standard Operating Procedures and to incorporate animal welfare assessments in Integrated Pest Management (IPM). The results of our study can help laypeople, professionals, regulatory agencies and legislators making well-informed decisions as to which methods to use when controlling commensal rodents.

Rodent management and cereal production in Asia: Balancing food security and conservation

Rodents present a major problem for food security in Asia where smallholder farming families are particularly vulnerable. We review here recent developments in the biology and management of rodent pests in cereal cropping systems in Asia. The past decade has seen a strong focus on ecologically-based rodent management (EBRM), its adoption in field studies significantly increased rice yields (6-15%) and income (>15%) in seven Asian countries. EBRM principles have also been successfully applied to maize in China. We provide case studies on EBRM in Cambodia, on interactions between rodent pests and weeds, and on the importance of modified wetlands for biodiversity and rodent pest management. Knowledge on post-harvest impacts of rodents is increasing. One research gap is the assessment of human health impacts from a reduction of rodent densities in and around houses. We identify 10 challenges for the next decade. For example, the need for population modelling, a valuable tool missing from our toolbox to manage rodent pests in cereal systems. We also need to understand better the interactive effects of cropping intensification, conservation agriculture and climate change. Finally, new management approaches such as fertility control are on the horizon and need to be considered in the context of smallholder cereal farming systems and mitigating health risks from zoonotic diseases associated with rodents. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Can humans outsmart rodents? Learning to work collectively and strategically

Context Rodents are one of the major constraints in Asian rice production, both in pre- and post-harvest. Rodents are often perceived by farmers in developing countries to be consistently outsmarting humans – a belief that needs to be overcome. Ecologically based rodent management (EBRM) is a possible solution to manage rodent populations effectively, which in turn can help sustain food security in Asia. Well coordinated community action is necessary to effectively carry out EBRM. This paper considers the socio-cultural challenges of EBRM. Aims To determine whether a multi-stakeholder partnership, facilitated through experiential learning and the use of existing social capital, can generate collective actions for strategic rodent management. Methods Participatory action research was employed in the implementation of EBRM in irrigated rice systems in the Red River Delta in Vietnam. Both quantitative and qualitative methods were used including household surveys, focus group discussions and key informant interviews. Key results The multi-stakeholder partnership and participatory approach effectively generated adoption of EBRM. The strong linkages between extension and political organisations generated diffusion of EBRM into neighbouring provinces. The adoption of EBRM reduced rodenticide use (50%), decreased rice areas with rodent damage (93%), increased rice yields (10–14%), increased economic returns for farmers (20%), strengthened farmers’ collective actions, and changed farmers’ perspectives on rodent management towards a biologically sustainable approach. Conclusions Humans can indeed outsmart rodents through the use of EBRM principles that rely on community actions. Sustainable community actions can be achieved through participatory approaches and a multi-stakeholder partnership built on existing social capital of the society and local communities. Overall, the adoption of EBRM meant better rice yields, higher economic returns for farmers, and reduced human health and environmental risks. Implications To address the problem of sustainable adoption by farmers of an agricultural technology for natural resource management, active participation of various stakeholders through a multi-stakeholder partnership is essential. This partnership should emanate from the social capital of the society, such as the networks of organisations across different scales, from the national to the village level, and the cultural norms and values adhered to by the members of the society and local communities.