Ruben Fijn

Bureau Waardenburg bv · Division of Bird Ecology

Arctic Terns Sterna paradisaea have an exceptionally long-distance migration, annually travelling back and forth between the Arctic and the Antarctic. Birds from Greenland, Iceland and the USA were recently found to spend most of the non-breeding period in the Weddell Sea, a small part of the large Antarctic range of Arctic Terns. Based on ring rec...

Assessing the impacts of avian collisions with wind turbines requires reliable estimates of avian flight intensities and altitudes, to enable accurate estimation of collision rates, avoidance rates and related effects on populations. At sea, obtaining such estimates visually is limited not only by weather conditions but more importantly because a h...

Breeding success of seabirds critically depends on their foraging success offshore. However, studies combining at-sea tracking and visual provisioning observations are scarce, especially for smaller species of seabirds. This study is the first in which breeding Sandwich Terns were tracked with GPS-loggers to collect detailed data on foraging habita...

Summary Study aim In this report the results are presented of a study of the effects of the Offshore Wind farm Egmond aan Zee (OWEZ) on flight patterns of birds in the area. Targeted species of interest were local seabirds (such as gulls, divers, gannets, scoters, guillemots and auks), migrating seabirds (such as divers and scoters) and migrating n...

Developing efficient foraging strategies is critical for survival, especially during the high-mortality post-fledging period in birds. This period is particularly challenging for migratory species, where juveniles must navigate unfamiliar environments with limited experience and knowledge. Our study focused on the foraging strategies of 20 juvenile...

In 2023 zijn de grote sterns in de Noord-Hollandse kolonies geteld met drones. Hieronder wordt beschreven hoe die tellingen zich verhouden tot de ontwikkeling van de Noordzeepopulatie in de afgelopen twintig jaar. Journal: Tussen Duin en Dijk.

A wide variety of attachment techniques have been used to track birds with electronic tags, with glue, tape, leg rings, neck collars and harnesses being the most common methods. In general, the choice of attachment method should strive to minimize tagging effects, but ensure that sufficient data are collected to address the research question at han...

In 2022, highly pathogenic avian influenza (HPAI) A(H5N1) virus clade 2.3.4.4b became enzootic and caused mass mortality in Sandwich Tern Thalasseus sandvicensis and other seabird species across northwestern Europe. We present data on the characteristics of the spread of the virus between and within breeding colonies and the number of dead adult Sa...

Offshore wind farms (OWFs) are a key part of efforts to mitigate the impacts of climate change. However, they have the potential to negatively impact seabird species through collisions with turbine blades, displacement from preferred foraging habitat and the perception of wind farms as a barrier to migrating or foraging birds. Whilst the data avail...

The expanding use of wind farms as a source of renewable energy can impact bird populations due to collisions and other factors. Globally, seabirds are one of the avian taxonomic groups most threatened by anthropogenic disturbance; adequately assessing the potential impact of offshore wind farms (OWFs) is important for developing strategies to avoi...

Seabirds have long lives, reproduce slowly and usually do not attempt to relay within the same breeding season after nest failure. In Sandwich Terns Thalasseus sandvicensis, renesting has never been documented despite the large number of studies on their breeding ecology and recorded prospecting behaviour after nest failure. In 2020, we observed ho...

In June 2023 a research project was initiated in one of the least known seabird colonies in the Netherlands; the Black-legged Kittiwake colony on former gas-production platform L7-B (53.60°N 4.20°E). Small numbers of breeding Black-legged Kittiwakes were first recorded at L7-B in June 2006. Over time the colony grew to approximately 200 breeding pa...

The duration of parental care varies widely among bird species. The crested terns Thalasseus spp. continue to feed their chicks at least sporadically for several months after fledgling. We recorded provisioning of a juvenile Sandwich Tern T. sandvicensis by its suspected parent at the wintering grounds in southern Namibia, more than 10,000 km away...

Movements of birds foraging in intertidal areas are often strongly linked to the tidal cycle, as water levels determine where and when birds can forage. The strength of this link likely depends on the ability to forage in habitats other than intertidal areas and on constraints imposed by breeding duties. Few studies have focused on the use of inter...

A bstract In 2022, highly pathogenic avian influenza (HPAI) A(H5N1) virus clade 2.3.4.4b became enzootic and caused mass mortality in Sandwich terns and other seabird species across northwestern Europe. We present data on characteristics of the spread of the virus between breeding colonies and the number of dead adult Sandwich terns recorded at bre...

Little Gull, the smallest gull species on Earth, is a rare breeding bird in the Netherlands, but the numbers of wintering and in particular migrating birds are much higher. In this paper we give an overview of the importance of Dutch waters for Little Gulls and present some of the knowledge gaps that exist for this elegant species. Over the past ye...

Compared to other animal movements, prospecting by adult individuals for a future breeding site is commonly overlooked. Prospecting influences the decision of where to breed and has consequences on fitness and lifetime reproductive success. By analysing movements of 31 satellite-and GPS-tracked gull and tern populations belonging to 14 species in E...

Aerial surveys of seabirds and marine mammals in 2021-2022.

Flight heights and behaviour of 1460 Sandwich Terns Thalasseus sandvicensis in the Dutch North Sea were recorded with a laser range finder during ship-based surveys in 2020 and 2021. Over 87% of all Sandwich Terns were flying below 20 m, and fewer than 1.5% were recorded above 40 m, leading to a two-fold increase in the collision risk model estimat...

Where and when animals forage depends on the spatio-temporal distribution and catchability of their prey. In dynamic environments, animals can repeatedly target areas that provide predictable availability of prey or may search for ephemeral conditions of high prey availability. However, how foraging behaviour is initiated in response to static vers...

Distribution and abundance of seabirds and marine mammals in the Dutch North Sea

Avian migration is recorded over long distances, but some species winter much closer to their breeding sites or do not migrate at all. Specifically, the family of gulls Laridae shows great within and among species variation in migration. However, the migration ecology of many gull species is still unknown, even for abundant and widespread species s...

Great Cormorants Phalacrocorax carbo sinensis are considered generalist predators feeding in a variety of marine and freshwater habitats on many different prey species. Recently however, there is increasing evidence that even seemingly generalist species can often be regarded as a diverse group of individual specialists sometimes induced by sex-spe...

Atlantic puffins are scarce winter visitors in the Dutch sector of the North Sea (Dutch Continental Shelf, DCS). In February 2020, high numbers were noted during the seabird and marine mammal aerial surveys from the MWTL monitoring scheme. A distance sampling analysis suggests that nearly 10,000 Atlantic puffins must have been present in the DCS, w...

In deze rubriek worden resultaten van lopende projecten gepresenteerd. Omdat het om bevindingen uit lopend onderzoek gaat, kunnen de uitkomsten nog voorlopig van aard zijn.

The southern North Sea is part of an important flyway for nocturnal bird migration, but is also risky as it stretches over a large surface of water. Selecting nights with suitable weather conditions for migration can be critical for a bird’s survival. The aim of this study is to unravel the weather-related bird migration decisions, by providing a d...

Mini-special over natuureiland Griend In het septembernummer van De Levende Natuur staat Griend in de schijnwerpers. De ongestoorde, centrale ligging in de Waddenzee, met hoogwatervluchtplaatsen en rondom foerageergronden, maakt van dit natuureiland een ideale stop-over voor trekvogels. In het broedseizoen broeden er bovendien 20 duizend paar kokme...

The southern North Sea is part of an important flyway for nocturnal bird migration, but is also risky as it stretches over a large surface of water. Selecting nights with suitable weather conditions for migration can be critical for a bird's survival. The aim of this study is to unravel the weather-related bird migration decisions, by providing a d...

On their migratory journeys, terrestrial birds can come across large inhospitable areas with limited opportunities to rest and refuel. Flight over these areas poses a risk especially when wind conditions en route are adverse, in which case inhospitable areas can act as an ecological barrier for terrestrial migrants. Thus, within the East‐Atlantic f...

Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardized and systematic aerial and vessel surveys, with recorded animal densities interpolated across study areas. However, distribution maps at basin and monthly scales have previously not be...

Seabird and Marine Mammal monitoring in the Dutch North Sea

Accurate quantification of flight speeds is a prerequisite to accurately predict the numbers of collision victims of proposed wind farms using collision rate models that are a vital part of Environmental Impact Assessments. We used GPS-loggers on Sandwich Terns to collect novel data on instantaneous flight speeds during foraging trips, separated fo...

In the Netherlands, wintering Common Scoters usually concentrate north of the eastern Wadden Islands, and to a lesser extent in the southwestern Voordelta. In some years however, concentrations are found at other sites. In 2015/16 large numbers of scoters were recorded off the Dutch coast near Bergen/Camperduin. Numbers were estimated from counts o...

Bird and marine mammal monitoring in the Dutch North Sea

Aim To gain insight in the flight speeds, flight heights, diurnal and nocturnal activity of Herring Gull Larus argentatus and Lesser Black-backed Gull Larus fuscus at sea through the use of modern tracking techniques. Methods We used long-term GPS data collected year-round from birds in the UK, the Netherlands and Belgium. Data were filtered to inc...

On 21 February 2011 an aerial survey of Great Crested Grebes was carried out along the coast of Holland to assess how well the thousands of Great Crested Grebes can be counted from the air. The maximum number of grebes known to winter in this area is over 30 000 birds (about 10% of the total Northwest-European population), but variation between yea...

Seabird and marine mammal monitoring in the Dutch North Sea

Capsule: Lesser Black-backed Gulls Larus fuscus breeding 30 km from the coast in the Netherlands focussed entirely on terrestrial food sources and reached relatively high breeding success.Aim: To gain insight in the foraging ecology, habitat use and breeding performance of inland-breeding Lesser Black-backed Gulls.Methods: We received data from sev...

Renewable energy is an increasing demand, and governments of North Sea countries are looking at developing offshore wind farms to help meet sustainability demands. The first at-sea wind farms have become operational in several countries, or are under construction, but many more are on the drawing board. Altogether, around 100 offshore wind farms ar...

Download via Deltares: http://kennisonline.deltares.nl/product/30737 Het kabinet heeft in 2006 in een planologische kernbeslissing een besluit genomen over het Project Mainportontwikkeling Rotterdam (PMR). Onderdeel hiervan is de aanleg van de Tweede Maasvlakte, een nieuw haven- en industriegebied. De aanleg en aanwezigheid hiervan hebben mogelijk...

Multiple tracking methods (colour-rings, plumage-markings and GPS-loggers) revealed that adult Sandwich Terns Thalasseus sandvicensis from the Netherlands showed prospecting behaviour in other colonies within Northwest Europe. Birds were recorded from a few kilometres to over 850 km away and in different countries around the Southern North Sea. Our...

By 2013, six of 27 Black Terns (Chlidonias niger) from four Dutch colonies that had received light level geolocators in 2010-2011 had been recaptured. All six recovered individuals migrated to West Africa, but whereas one individual flew there nonstop, the others made stops of varying length en route. These included flights of 2,000-6,000 km betwee...

Cormorants are regarded as generalists that opportunistically feed on a variety offish species with different hunting techniques in diverse habitats. To study habitat use, time budgets and foraging behaviour, in 2012 we deployed GPS loggers on 11 Great Cormorants breeding at a near-coastal colony at Voorne in the northern Delta region, Zuid-Holland...

Abstract: In the period 2003-2011 offshore platforms in the North Sea have been successfully used for ornithologi- cal monitoring programs following standardised observation protocols. As most seabird observers have a strong interest in other large marine animals, marine mammal observations were included in these systematic observa- tion protocols...

Each winter ∼ 30% of the Northwest European Bewick's Swan Cygnus columbianus bewickii population feeds in Polder Wieringermeer, the Netherlands, on waste crops left after the harvest. The area has also become important for generating energy as a result of wind farm development. This study analyses pre-and post-construction data on Bewick's Swan dis...

In preparation for a field study on wild birds, we conducted an experiment on captive Great Cormorants Phalacrocorax carbo sinensis to evaluate methods of attaching GPS loggers. Loggers (65 g) were attached to two injured cormorants in a bird rehabilitation centre. One logger was attached to the first bird with TESA tape and another logger to the s...

Several methods, each with specific advantages and disadvantages, are frequently used to obtain diet samples from seabirds. The collection of regurgitates (REG) as well as samples from the stomach water-off-load (WOL) or flushing technique are some of the most commonly used approaches. During the Austral breeding season of 2005/06 diet samples from...

Food web knowledge is a prerequisite for adequate resource management in the Antarctic ecosystem. Accurate dietary specifications for the major consumers within the Antarctic ecosystem are needed. Procellariid species are the most numerous avian species in Antarctica and account for 20% to 40% of the overall consumption by seabirds in the area. Die...

The number of offshore wind farms is increasing rapidly, leading to questions about the environmental impact of such farms. In the Netherlands, an extensive monitoring programme is being executed at the first offshore wind farm (Offshore Windfarm Egmond aan Zee, OWEZ). This letter compiles the short-term (two years) results on a large number of fau...

The Important Bird Area (IBA) programme is a worldwide initiative of BirdLife International aimed at identifying and protecting a network of critical sites for the conservation of the world's birds. The criteria used by BirdLife to identify IBAs are clear, standardised and have been the framework for protecting and improving bird conservation aroun...

The Dutch consortium "NoordzeeWind" operates the first offshore wind farm in Dutch North Sea waters. The park, consisting of 36 turbines on monopiles, is located NW of IJmuiden harbour, some 8 NM off the Dutch mainland coast. Named after the nearest town ashore, the park will be known as "Offshore Wind farm Egmond aan Zee" (OWEZ). A second offshore...

Plaatsing van windturbines is op land al enkele tientallen jaren gemeengoed. De bouw van offshore windparken is pas in de laatste tien jaar volop begonnen. Het onderzoek aan effecten op vogels is in volle gang. Drie typen effecten van windturbines op vogels zijn vastgesteld: aanvaring (vogelsterfte door botsing met rotor of mast), verstoring (habit...