Genetic tools in the management of invasive mammals: recent trends and future perspectives

Abstract

Invasive non‐native species are now considered to be one of the greatest threats to biodiversity worldwide. Therefore, efficient and cost‐effective management of species invasions requires robust knowledge of their demography, ecology and impacts, and genetic‐based techniques are becoming more widely adopted in acquiring such knowledge. We focus on the use of genetic tools in the applied management of mammalian invasions globally, as well as on their inherent advantages and disadvantages. We cover tools that are used in: 1) detecting and monitoring mammalian invaders; 2) identifying origins and invasive pathways; 3) assessing and quantifying the negative impacts of invaders; and 4) population management and potential eradication of invasive mammals. We highlight changes in sequencing technologies, including how the use of techniques such as Sanger sequencing and microsatellite genotyping, for monitoring and tracing invasive pathways respectively, are now giving way to the use of high‐throughput sequencing methods. These include the emergence of environmental DNA (eDNA) metabarcoding for the early detection of invasive mammals, and single nucleotide polymorphisms or whole genomes to trace the sources of invasive populations. We are now moving towards trials of genome‐editing techniques and gene drives to control or eradicate invasive rodents. Genetic tools can provide vital information that may not be accessible with non‐genetic methods, for the implementation of conservation policies (e.g. early detection using systematic eDNA surveillance, the identification of novel pathogens). However, the lack of clear communication of novel genetic methods and results (including transparency and reproducibility) to relevant stakeholders can be prohibitive in translating these findings to appropriate management actions. Geneticists should engage early with stakeholders to co‐design experiments in relation to management goals for invasive mammals.

A review of mammal eradications on Mediterranean islands

“…Molecular techniques should be adopted to establish whether the eradication failed, or the island was reinvaded, as, in the absence of these analyses, it is difficult to support one of the two hypotheses (Abdelkrim et al ). Advances in genetics make it possible to improve the management of alien species by evidencing colonisation pathways, the presence of individuals resistant to anticoagulants, and the origins of reinvasions (Ragionieri et al , Browett et al ). Significant improvements are expected in the field of biosecurity, at least for rodents, mainly via standardisation of techniques in order to strengthen biosecurity programmes following eradication, which would bring lasting benefits to ecosystems freed from rats.…”

Current status of American mink Neovison vison in Great Britain: a review of the evidence for a population decline

“…Alternative monitoring methods should be explored, such as eDNA, which could provide low‐cost data on several aquatic and semi‐aquatic species simultaneously (e.g. Rees et al , Browett et al ). For all methods, the key will be standard recording protocols, accessibility and data sharing.…”

Where’s wallaby? Using public records and media reports to describe the status of red‐necked wallabies in Britain

“…Scat analysis could be used to assess likelihood of competition with native species and disease transmission potential. Genetic tools such as environmental DNA metabarcoding could also be used to detect wallaby presence in a given location (Browett et al., 2020).…”