Homepage RIVM Homepage CBS Homepage WUR
Ecosystems > Dunes Print version
Search Compendium. Type in one or more keywords.
Scroll through the Environmental Data Compendium below via the menus.
The sitemap of the Environmental Data Compendium
List of updates to the Environmental Data Compendium

Fox and seagulls in the dunes

The fox returned to the dunes some thirty years ago, with the result that the number of breeding seagulls has decreased. In recent years, the number of foxes in the dunes has remained more or less stable.

Trends in the fox


Foxes were first sighted in the dunes in 1968, but did not establish in many dune areas until after 1975. Now, only the dunes on the Wadden islands are without foxes. In spite of the decline in rabbits (an important source of food for foxes), the numbers of foxes are not declining significantly.

Trends in seagulls


Seagull populations can survive better in fox-free areas (the Wadden area) than in areas with foxes (the mainland dunes). Part of the seagull population has moved to towns and cities and to the farmland behind the mainland dunes.

There used to be large colonies of seagulls in the mainland dunes until the mid 1980s, but after the rapid increase in numbers of foxes in the early 1980s, these colonies disappeared because of predation of the eggs, fledglings and adults. Nowadays seagulls breed exclusively in places that foxes cannot reach, such as the islets in the infiltration ponds, and hawthorn bushes.

Technical note


The data on the fox and seagulls are from two of the Ecological Monitoring Network's national monitoring networks: for mammals active by day, and for breeding birds. The index figures for common gull and herring gull refer to the number of breeding pairs.

References


  • Dijk, A.J. van, M.J.T. van der Weide, R. Kleefstra, D. Zoetebier en C. Plate (2001). Kolonievogels en zeldzame broedvogels in Nederland in 1999. SOVON-monitoringrapport 2001/08. SOVON Vogelonderzoek Nederland. Beek-Ubbergen.
  • PWN Waterleidingbedrijf Noord-Holland (2000). Vossen in het Noord-Hollands Duinreservaat in de periode 1995-1998. Alterra rapport 197. Alterra. Wageningen.
  • Til, M. van, P. Ketner en S. Provoost (2002). Duinstruwelen in opmars. De Levende Natuur, 103 (3):74-77.
  • Verstrael, T. en A.J. van Dijk (1997). Vos of grassen? Broedvogels in de Nederlandse duinen sinds 1984. Limosa, 70 (4):163-178.

Relevant sections and indicators in the Environmental Data Compendium
This page was last changed on 21 April 2004  (version 01).