﻿Blacklists do not necessarily make people curious about invasive alien species. A case study with Bayesian structural time series and Wikipedia searches about invasive mammals in Italy

Jacopo Cerri,Sandro Bertolino,Lucilla Carnevali,Andrea Monaco,Piero Genovesi

doi:10.3897/neobiota.71.69422

Abstract

Blacklists of invasive alien species (IAS) are a popular tool for managing and preventing biological invasions. Moreover, blacklists also have the potential to make the general public more curious about biological invasions, usually by benefiting from media coverage and providing accessible examples of IAS. We have tested if the implementation of the first List of IAS of Union concern by the European Union increased visits to Wikipedia pages on invasive alien mammals in Italy. We adopted causal impact analysis to quantify changes in the overall volume of visits to pages about invasive alien mammals that appeared on the list, by using pages about native mammals as a control. Following the publication of the first Union list, there was no increase in the amount of visits to Wikipedia pages on invasive mammals, regardless of their inclusion in the Union list. Rather, visits to Wikipedia were irregular in time, coinciding with media coverage of single, charismatic species. Our results indicate that important policymaking initiatives do not necessarily increase curiosity about biological invasions, even when they are covered by generalist media and are relatively easy to understand. We would therefore emphasise that policymaking initiatives should be coupled with adequate communication campaigns and should adopt communication guidelines for generalist media.

Highlights

In recent years, blacklists and accept-lists have become standard policy tools for tackling biological invasions (Genovesi and Shine 2004)
The second one included invasive alien species (IAS) that did not appear on the Union list and that were present in Italy in August 2016: the Eastern cottontail (Sylvilagus floridanus), the American mink (Neovison vison), the Barbary sheep (Ammotragus lervia) and Finlayson’s squirrel (Callosciurus finlaysonii) (Loy et al 2019)
Our findings do not highlight any effect of the implementation of the first Union list over the volume of visits to Wikipedia pages on invasive alien mammals that were included in the list (Fig. 2)

Summary

Introduction

Blacklists and accept-lists have become standard policy tools for tackling biological invasions (Genovesi and Shine 2004). Accept-lists (or “white” or “positive” lists) identify those alien species which carry a low risk of becoming invasive, or impacting, and which are able to be traded, maintained in captivity or present in nature (Kaiser 1999; Perrings 2005). Both blacklists and accept-lists are based on risk assessments: in the former case, the aim is to ban a species from a country or a geographic area; in the latter case, the purpose is to demonstrate its “safety” for the environment and/or human well-being. 5 Member States and another European country (Norway) developed accept-lists, mostly for specific taxa (Eurogroup for Animals 2020; Toland et al 2020)

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Conclusion