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Geese begin to threaten nature, agriculture and air traffic

European goose populations have grown so much in the last 40 years that they have gone from being relatively threatened to numbers that themselves present a threat to agriculture, biodiversity and air safety.

Many parts of Europe are beginning to experience an annual biological 'invasion' from the air in recent years. This ‘invasion’ is beginning to pose new challenges to air traffic, nature conservation and agriculture as the numbers of some northern-breeding wild goose populations have exploded. With similar complaints from so many parts of western Europe along their flyways relating to the same populations of geese, the responsible statutory authorities have joined together to begin to compile international management plans to effectively deal with the problem.

Following restrictions on hunting and provision of protected areas, the number of some goose populations has grown exponentially in the last 40 years. For example, numbers of Barnacle Geese that formerly bred only in the Russian Arctic and wintered in Western Europe have grown from a modest 20,000 in the 1970s, to number as many as 1.5 million now, during which time the population also has started to breed across Western Europe in increasing numbers.

Similar growth spurts have been witnessed amongst White-fronted and Greylag Geese, which have also topped one million individuals wintering in Europe. Other goose species are showing similar trends, with some increasing at up to 10 percent per annum.

Finding solutions to conflicts

A series of new articles has just been published in a special issue of the Swedish scientific journal Ambio detailing how the increases in numbers of species such as the Barnacle, White-fronted, Barnacle and Pink-footed Geese have taken these populations from being relatively threatened to numbers that themselves present a threat to agriculture, biodiversity and air safety. The articles also provide guidance on how to deal with such problems now and how to avoid and resolve further conflicts in the future.  Edited and coordinated from the Danish Centre for Environment and Energy at the Department of Bioscience, Aarhus University, experts from around the Northern Hemisphere have contributed the benefit of their combined specialist expertise and experiences.

"We can now see how dramatically changes in goose abundance can affect both nature conservation and agriculture. Geese now flock to food in such increasing densities that biodiversity and farming interests can be seriously affected" says Professor Jesper Madsen from the Department of Bioscience, Aarhus University.

Threats to air safety

However, geese also pose an increasing threat to flight safety, with authorities at several European airports struggling to alleviate their local problems with geese. Their large body size and social tendency to occur in groups means that geese pose a particular threat to flight safety, with increasing numbers of geese colliding with aircraft (so-called bird strikes). Airport collisions between aircraft and geese can be eliminated between and around the runways on site by scaring, but can also occur on flight approach with geese flying to and from roosts or on migration. As well as spring and autumn migration of large numbers of Barnacle Geese passing through Copenhagen Airport’s airspace, the species is now increasingly breeding in urban areas of Europe, constituting a year-round problem.

Jesper Madsen believes that there are several reasons why the geese are currently doing incredibly well.  "Geese have far less disturbed nesting sites, because humans have increasingly withdrawn from their Arctic breeding grounds. At the same time, many countries have protected wild geese or restricted their hunting, at a time when modern agriculture offers a limitless larder for geese - and of course, the geese have learned to use it" says Jesper Madsen.

New European platform to support goose management

These growing conflicts, inadequate local solutions and lack of adequate large scale conflict resolution have conspired to precipitate the urgent need to coordinate management of goose populations throughout Europe at the flyway scale. Based on recommendations from the gathered Danish and European researchers and managers, it has been decided that a new umbrella organization for the management of geese in Europe should be set up.  This has now been established under the auspices of the African-Eurasian Waterbird Agreement (AEWA) under the United Nations. This body supports representatives from the nature conservation and environmental agencies from 20 European countries, while Aarhus University will play a central role in coordinating the data centre for this construction.

"We need to deliver data and assessments to decision makers, who will all meet annually to coordinate the management of problem goose populations across national borders based on common objectives. Against this background, the authorities must manipulate hunting quotas, changes of hunting season and implement other measures to address the problems associated with geese, so that they can thrive in places where they neither threaten sensitive natural areas, agricultural land nor air safety” says Jesper Madsen.

Read more about the geese in the special issue of Ambio here link.springer.com/journal/13280/46/2/suppl/page/1 in English)

For further information, please contact Professor Jesper Madsen jm@bios.au.dk or tel: +45 87158692