Report prepared in support of implementing the IAS regulation in Belgium Authors: Adriaens, T., Branquart, E., Gosse, D., Reniers, J., Vanderhoeven, S. FEASIBILITY OF ERADICATION AND SPREAD LIMITATION FOR SPECIES OF UNION CONCERN SENSU THE EU IAS REGULATION (EU 1143/2014) IN BELGIUM Acknowledgements We are grateful to Olaf Booy (UK Non-Native Species Secretariat), Peter Robertson and Aileen Mill (Newcastle University) for in- depth discussions on the manageability protocol, the sharing of information and their openness for collaboration. We thank Sander Devisscher for data handling and the production of the distribution maps and summary tables. We thank Hugo Verreycken, Luc Denys, Jo Packet and Pieter Boets for comments on some of the scenarios and strategies. Maxime Coupremanne assisted in gathering literature. We are grateful to the Belgian Committee on Invasive Alien Species for discussions and support. We thank INBO for financially supporting the workshop organization. We thank Sander Devisscher and Maxime Coupremanne for their practical help during the workshop, as well as Vincent Fiévet and Jim Casaer for the help they provided with the live translation during the workshop discussions. We thank all of the assessors who willingly provided their assessments on the feasibility of management for the Union List species in Belgium (Annex 3): Adrien Latli, Alain De Vocht, Anne-Laure Jacquemart, Arnaud Monty, Bart Vandevoorde, Bram D’hondt, Denis Parkinson, Dido Gosse, Diederik Strubbe, Elena Tricarico, Etienne Branquart, Filip Verloove, Frank Huysentruyt, Gerald Louette, Hugo Verreycken, Iris Stiers, Jane Reniers, Jim Casaer, Jo Packet, Johan van Valkenburg, Koen van Roeyen, Luc Baufay, Luc Denys, Marijke Thoonen, Paul Stebbins, Pieter Boets, Quentin Groom, Quentin Rome, Sam Provoost, Sarah Descamps, Sonia Vanderhoeven, Tim Adriaens, Vinciane Schockert, Wouter Van Landuyt. Lastly, we are grateful to all the invasion managers and experts who participated to the workshop for their feedback and active participation in the discussions: Adrien Latli, Alain De Vocht, Anja Goossens, Arnaud Monty, Benoit Garin, Bram D'hondt, Carole Van Roy, Céline Noulard, David Claeys, Dido Gosse, Diederik Strubbe, Elodie Nise, Emma Cartuyvels, Emmanuelle Sarat, Esmeralda Uskokovic, Etienne Branquart, Franck Minette, Frank Huysentruyt, Frédéric Mouchet, Henk de Jong, Hugo Verreycken, Iris Stiers, jean-philippe bizoux, Jelle Van den Berghe, Jim Casaer, Jo Packet, Johan De Beule, Johan Van Valkenburg, Johan Vander Heyden, Josse Gielen, Juan-Pablo Pertierra, Karel Van Moer, Katrien Hendrickx, Kenny Meganck, Koen Van Roeyen, Kris Schurmans, Luc Denys , Luc Baufay, Maarten Vangansbeke, Maarten Vanwesemael, Manou Pfeiffenschneider, Marielle Brasseur, Marijke Thoonen, Maxime Coupremanne, Myriam Dumortier, Nathalie Fonder, Olivier Beck, Paul Van Loon, Pauline Ducarme, Peter Staljanssens, Pierre Joye, Pieter Boets, Pieter Huybrechts, Pieter Van Dyck, Quentin Groom, Renaud Bocquet, Rik Puls, Ronny De Keer, Samuel Vander Linden, Sander Devisscher, Sarah Descamps, Sofie Standaert, Sonia Vanderhoeven, Spyridon Flevaris, Stéphan Adant, Thierry Sluyters, Tijl Schelfhout, Tim Adriaens, Ugolin Martin, Vincent Fiévet, Wim Dirckx, Wouter Van Landuyt, Xavier Rollin and Yasmine Verzelen. How to cite this report: Adriaens, T., Branquart, E., Gosse, D., Reniers, J., Vanderhoeven, S. 2019. Feasibility of eradication and spread limitation for species of Union concern sensu the EU IAS Regulation (EU 1143/2014) in Belgium. Report prepared in support of implementing the IAS Regulation in Belgium. Institute for Nature and Forest Research, Service Public de Wallonie, National Scientific Secretariat on Invasive Alien Species, Belgian Biodiversity Platform. DOI: https://doi.org/10.21436/17033333. Depot number D/2019/3241/285 2 Summary Robust evidence is needed to ensure management of invasive alien species (IAS) is feasible and resources are used effectively. Risk assessments are of limited use to decide on species management because the feasibility of different options is not considered. Risk management provides a structured evaluation of management options including an assessment of practical, resource, societal, ethical and legal constraints. We used this approach in Belgium to assess the feasibility of management for 43 species of Union Concern sensu the EU IAS Regulation (1143/2014) that came into force on January 2015 and urges member states to make decisions on species management. We organized an online participatory process involving more than 40 experts with experience in species management using an adaptation of the UK Non-Native Risk Management scheme (NNRM) (Booy et al. 2017). NNRM uses semi-quantitative response and confidence scores to assess key criteria linked with management feasibility: effectiveness, practicality, cost, impact, acceptability, window of opportunity and likelihood of re-invasion. The outcome of the assessment supports the Regulation implementation in Belgium, notably for the identification of a cost-effective management goals and techniques as required by Article 17 and 19 on IAS eradication and management, respectively. It provides an evidence base for Belgian management decisions through a transparent, standardized and repeatable process. The structured decision making and the participatory approach involving the Belgian expert community has added value in terms of engagement and support for the implementation of management action plans deriving from the risk management evaluation. In this report, we present the invasion scenarios and management strategies for Belgium developed for this exercice, not only for assessing feasibility of species eradication but also their spread limitation. Scenario & strategy writing were performed by the Research Institute for Nature and Forest (INBO), National Scientific Secretariat on IAS (NSS), le Départment d’Etude du Milieu Naturel et Agricole - Service Public de Wallonie (DEMNA) and the Belgian Biodiversity Platform (BBPF). The species accounts present the current species distribution and summarize data on their invasion history and current management in Belgium (invasion scenario). For species that are not present in the territory, the scenario described is an imaginary but theoretically realistic invasion scenario taking into account pathways, entry points, habitat and detection threshold of the species. We then drafted realistic management strategies for eradication and spread limitation. Spread limitation strategies were categorized based on species distribution extent: limiting species presence to a single or a few patches, containment of populations in core area(s), elimination of the most dispersive populations or maintenance of pest free areas. We hope the invasion scenarios might provide topical information on the Union List species and their situation in Belgium. Beside reporting on the Belgian manageability exercice, we hope the management strategies developed for Belgium could provide inspiration to practitioners and to other member states tackling invasive species of Union Concern. 3 Table of contents Executive summary ............................................................................................................................................... 6 1. Introduction .................................................................................................................................. 9 1.1 Context of the manageability assessment ........................................................................................... 9 1.1.1 Determining management options for the EU Regulation 1143/2014 ................................................ 9 1.1.2 Providing an evidence base for decision on management options and derogations ......................... 10 1.2 Objective ............................................................................................................................................ 10 1.3 Species considered ............................................................................................................................. 11 1.4 From feasibility scores to actual management in the field ................................................................ 13 2. Scenarios and strategies .............................................................................................................. 15 2.1 Invasion scenarios .............................................................................................................................. 15 2.2 Management strategies ..................................................................................................................... 15 2.3 General provisions not part of the management strategies .............................................................. 16 2.4 Workshop on Management of IAS of Union Concern ........................................................................ 23 3. Results 24 3.1 Vertebrates ........................................................................................................................................ 24 3.1.1 Egyptian goose Alopochen aegyptiacus (nijlgans, ouette d’Egypte) .................................................. 24 3.1.2 House crow Corvus splendens (huiskraai, corbeau familier) .............................................................. 29 3.1.3 Ruddy duck Oxyura jamaicensis (rosse stekelstaart, érismature rousse) .......................................... 32 3.1.4 Sacred ibis Threskiornis aethiopicus (heilige ibis, ibis sacré)