Dispersie na het broedseizoen, trek en overwintering van Grote Sterns <i>Thalasseus sandvicensis</i> uit de Voordelta = Post-breeding dispersal, migration and wintering of Sandwich Terns <i>Thalasseus sandvicensis</i> from the southwestern part of the Netherlands

The Sandwich Tern Sterna sandvicensis is a Dutch Red List species with a population of 19,000 pairs in the Dutch coastal zone. It winters off the coasts of Africa and a small populations migrates into the Mediterranean or stays even more north.. In the Netherlands, breeding takes places in a small number of colonies in the Delta area and the Waddensea. In this study, Sandwich Terns from the Delta colony on the Scheelhoek (Natura 2000 SPA ‘Haringvliet’) were investigated which forage during the breeding season in Natura 2000 SPA ‘Voordelta’. In total 30 adult Sandwich Terns were equipped with radio transmitters, a colourring and a plumage colour (picrinic acid or silver nitrate solution). Thanks to these markings birds could be followed in the colonies, from airplanes and from the coast. Several birds used the sand banks off the coast of their breeding colonies to rest after the breeding season. After a short while they dispersed in western and northern direction with sightings in the northern part of the Netherlands (outside and within other colonies). These were always failed breeders, possibly scouting other colonies for future breeding places. Some of these birds even left the Dutch coasts and appeared in Scotland and Denmark. Adults with young probably dispersed into the North Sea after a short stay around the sand banks off the coast near the colonies. They probably head to more nutrient rich areas in the North Sea and adjacent areas where the young birds can practice their fishing techniques before they move south. The adults can build-up here good fat reserves before the start of migration. In September, most of the marked Sandwich Terns were south of their breeding places and during their southward migration birds were seen along the coast of France and on Lanzarote (Canary Islands). Our results showed that using markers on birds could yield good data with a resighting percentage of 20% within only one year. Furthermore, the use of plumage colouring proved to be a good method for obtaining information of individual birds as these colourings attract the attention of observers and are ‘readable’ over large distances

Tracking terns:Year-round movement ecology of sandwich terns in a changing marine environment

Seabirds are excellent indicators of the health of the marine ecosystem. Studying and monitoring their distribution, abundance, diet and productivity can signal changes in prey availability, pollution, and non-natural mortality. Studying their foraging strategies and particularly (mechanisms in) habitat choice forms an important part of such studies. An important driver of the foraging strategy of seabirds is the way they transport prey to the colonies. Bulk-prey loaders store food during trips and regurgitate that to chicks on return. Single-prey loaders deliver individual prey items to their offspring. This latter strategy constrains the size of their foraging range. The aim of this thesis was to study movement of a single-prey loading seabird in relation to its environment and potential consequences of the interaction with anthropogenic developments at sea.Using modern tracking technology, this thesis presents a total of eleven chapters in which various studies on the foraging ecology and habitat selection of Sandwich Terns Thalasseus sandvicensis are described. These iconic seabirds of the North Sea are single-prey loading seabirds for unpredictable prey items in a heterogeneous foraging habitat close to the coast. This subject received less attention in contrast to long-ranging seabirds further offshore, yet, with the increasing expansion of anthropogenic activities in the coastal zone, it is of particular interest.The work in the thesis therefore not only describes movement and foraging behaviour, but also the effects of interaction between seabirds and anthropogenic developments at sea. To do so several novel methods needed to be developed to track terns and study prey items concurrently (Part I). Using these methods, it was possible to determine and predict habitat use of Sandwich Terns during the breeding season (Part II) as well as movement outside the breeding season (Part III). Finally, several aspects of the effect of anthropogenic activities within their foraging range on their movement ecology were studied (Part IV). The synthesis of the thesis summarizes all findings and discussed what tracking terns can learn us about the foraging ecology of seabirds, how the results can be used and future directions of tracking work on terns and seabirds in general

Tracking terns:Year-round movement ecology of sandwich terns in a changing marine environment

Seabirds are excellent indicators of the health of the marine ecosystem. Studying and monitoring their distribution, abundance, diet and productivity can signal changes in prey availability, pollution, and non-natural mortality. Studying their foraging strategies and particularly (mechanisms in) habitat choice forms an important part of such studies. An important driver of the foraging strategy of seabirds is the way they transport prey to the colonies. Bulk-prey loaders store food during trips and regurgitate that to chicks on return. Single-prey loaders deliver individual prey items to their offspring. This latter strategy constrains the size of their foraging range. The aim of this thesis was to study movement of a single-prey loading seabird in relation to its environment and potential consequences of the interaction with anthropogenic developments at sea.Using modern tracking technology, this thesis presents a total of eleven chapters in which various studies on the foraging ecology and habitat selection of Sandwich Terns Thalasseus sandvicensis are described. These iconic seabirds of the North Sea are single-prey loading seabirds for unpredictable prey items in a heterogeneous foraging habitat close to the coast. This subject received less attention in contrast to long-ranging seabirds further offshore, yet, with the increasing expansion of anthropogenic activities in the coastal zone, it is of particular interest.The work in the thesis therefore not only describes movement and foraging behaviour, but also the effects of interaction between seabirds and anthropogenic developments at sea. To do so several novel methods needed to be developed to track terns and study prey items concurrently (Part I). Using these methods, it was possible to determine and predict habitat use of Sandwich Terns during the breeding season (Part II) as well as movement outside the breeding season (Part III). Finally, several aspects of the effect of anthropogenic activities within their foraging range on their movement ecology were studied (Part IV). The synthesis of the thesis summarizes all findings and discussed what tracking terns can learn us about the foraging ecology of seabirds, how the results can be used and future directions of tracking work on terns and seabirds in general

A Shadow Place: Plumwood Mountain

This photo essay features the journey from the main highway, up a long bush track, to Australian environmental philosopher Val Plumwood\u27s home in a clearing amongst dense, temperate rainforest, on the edge of a steep escarpment. The highway is the contact zone, where humans and other beings collide with one another. The intention of this photo essay is to draw attention to such contact zones, acting as conduits to our urban environments, and to ask us to acknowledge the shadow places along the way that make a different kind of contribution to our lives

The Multiple Faces of the Marmot: Associations with the Plague, Hunting, and Cosmology in Mongolia.

Mongolians have long known of the association between marmots and the plague. We examine their understanding of the marmot not only as a biological species that can harbour the plague, but also from a cosmological perspective as a chimerical being with potential punishment on hunters who have transgressed ancient taboos. To do so we deconstruct the multiple image of the chimerical marmot in legends, stories, and beliefs. Many Mongolians believe that if the marmot is over-exploited and the population decimated through excessive hunting, hunting households may be punished with infections of the plague