A review of mammal eradications on Mediterranean islands

Abstract

Impacts of alien invasive species on island communities and ecosystems may be even more detrimental than on the mainland. Therefore, since the 1950s, hundreds of restoration projects have been implemented worldwide, with the aim of controlling or eradicating alien species from islands. To date, no review has been focused on eradication on Mediterranean islands. To fill the gap, I reviewed the available information concerning mammal eradications so far carried out on Mediterranean islands, examining the details of several aspects of project implementation and monitoring. I obtained data for 139 attempted eradications on 107 Mediterranean islands in eight countries, with Greece, Italy, and Spain accounting for the highest number. Eradication projects targeted 13 mammal species. The black rat Rattus rattus was the target of over 75% of the known attempted eradications in the Mediterranean Basin; other species targeted were feral goat Capra hircus, house mouse Mus musculus, European rabbit Oryctolagus cuniculus, and domestic cat Felis catus. The most widely adopted technique was poisoning (77% of all eradications), followed by trapping (15%) and hunting (4%). However, techniques were largely target‐specific. The average failure rate was about 11%. However, this percentage varied according to the specific mammalian order, and eradications of Carnivora failed more often than those of other mammals. Among rodents, house mouse eradication attained a very high failure rate (75%). Reinvasion occurred after 15% of successful eradications. A better understanding of the motivations of animal rights activists may improve the chance of success when eradicating charismatic or domesticated species. Furthermore, it is crucial to collect data and case studies about reinvasions, in order to strengthen biosecurity programmes following eradication. As in other parts of the world, the next frontier in alien mammal management on Mediterranean islands concerns the eradication of invasive species from inhabited islands.

Spatially explicit models as tools for implementing effective management strategies for invasive alien mammals

“…Eradication is a fundamental tool for protecting biodiversity from the negative effects of IAS (Howald et al , Robertson et al , Capizzi ). If removal actions do not obtain the expected result, the only option may be to move on to continuous control (Mill et al ).…”

Assessing the potential impacts of non-native small mammals in the South African pet trade

“…The species responsible for the maximum potential impact under this mechanism were the house mouse and the European rabbit. These species scored high because their impacts were mostly associated with major economic losses on agriculture, and also their eradication plans required the application of pesticides which are expensive and have negative impacts (Twigg et al 2002;Williams et al 2010;Haniza et al 2015;Capizzi 2020;Mill et al 2020). In developing countries, invasive rats and mice compete with humans for food (Stenseth et al 2003), targeting various crops such as cereals, rice, palm oil, fruits, cocoa, and sugarcane, which results in a significant economic loss and affects food security (Tobin and Fall 2004;Varnham 2006).…”

Predicting targets and costs for feral-cat reduction on large islands using stochastic population models

“…Following eradications to completion are essential to achieve density-reduction or eradication goals, but due to funding limitations or unforeseen circumstances, such programs are sometimes cancelled or stopped prematurely (Keitt et al 2011, Capizzi 2020). Depending on at what stage of eradication a program is stopped, the remaining population can rebuild to its pre-management densities or beyond (Armstrong et al 2001, Bradshaw et al 2007).…”