Disputation: Camilla Olsson

Se disputationen live: https://hkr-se.zoom.us/j/62971506964 

Titel: From flyway to field: Ecology and management of geese in agricultural landscapes  

Opponent: Toni Laaksonen, Professor, University of Turku

Betygsnämnd: Bodil Elmhagen, docent, Svenska Jägareförbundet
Anders Hedenström, Professor, Lunds universitet
Friederike Woog, Doktor, Natural History Museum Stuttgart

Huvudhandledare: Johan Månsson, docent, Sveriges lantbruksuniversitet och Johan Elmberg, professor i zooekologi, Högskolan Kristianstad

Biträdande handledare: Lovisa Nilsson, Sveriges lantbruksuniversitet och Ingunn Tombre, Norwegian Institute for Nature Research

Abstract

Climate change and new agricultural practices have driven a rapid increase in numbers of most European goose populations (Anser, Branta spp.) and a northward expansion of their wintering range, raising growing concerns related to grazing damage to agricultural crops. To mitigate such conservation conflicts, contemporary knowledge about movement patterns and foraging site selection is needed to inform management decisions. This thesis provides ecological insights to guide management and damage prevention, from flyway to field level. Specifically, it addresses migratory patterns, foraging site selection, and local movements by geese in agricultural landscapes. My studies are based on flock surveys of multiple goose species, data derived from Greylag geese fitted with GPS devices, and data on landscape features and field characteristics. My results show that two radically different types of migration strategies occur among Greylag geese breeding in Sweden. Geese in southernmost Sweden are largely resident and remain close to their breeding sites year-round, whereas geese breeding in central Sweden still migrates. My results further show that fields located within 4 km from a roost site and situated more than 150 m from nearest forest edge or human infrastructure have a high probability to attract Greylag geese. My studies also demonstrated that selection patterns tend to vary depending on goose species, season and availability, although stubble fields in general, and barley stubble in particular, were generally selected. The combined results from my studies highlight the complexity of goose behaviour, requiring coordinated strategies and joint efforts across multiple spatial scales, from international flyway-level cooperation to collaboration among neighbouring farms and authorities, to successfully integrate the knowledge derived from my study for more accurate risk assessment and effective damage prevention.