Eric W. M. Stienen

Research Institute for Nature and Forest | INBO · Diversity of species

Seabirds exhibit considerable behavioural flexibility in foraging investment in order to meet the nutritional needs of their chicks during variable environmental conditions. Although regulation of offspring provisioning is generally thought to be related to species-specific constraints imposed by central place foraging, some studies suggest differe...

Through before–after control-impact designed ship-based seabird surveys, seabird displacement occurring after the installation of an offshore wind farm at the Belgian Bligh Bank in 2010 was studied. Results demonstrate that northern gannet (Morus bassanus), common guillemot (Uria aalge) and razorbill (Alca torda) avoided the wind farm area, and dec...

Individual variation in timing of breeding is a key factor affecting adaptation to environmental change, yet our basic understanding of the causes of such individual variation is incomplete. This study tests several hypotheses for age-related variation in the breeding timing of Lesser Black-backed Gulls, based on a 13 year longitudinal data set tha...

We studied sex differences in collision mortality in adult Common Terns (Sterna hirundo) at a wind farm in the direct vicinity of a breeding site in Zeebrugge, Belgium in 2005– 2007. In total, 64 fatalities were collected and sexed, of which 64% were males. Uneven sex ratio among these birds was most pronounced during the period of incubation and e...

Fitness consequences of variation in body mass growth and body condition were studied in a Sandwich Tern Sterna sandvicensis colony on Griend, Dutch Wadden Sea, during 1990–2000. Body mass increment during the linear growth phase predicted nestling survival probabilities accurately. Chicks growing less than 8 g per day had low survival probabilitie...

In colonial breeding species, the number of adverse social interactions during early life typically varies with breeding density. Phenotypic plasticity can help deal with this social context, by allowing offspring to adjust their behaviour. Furthermore, offspring may not be unprepared since mothers can allocate resources to their embryos that may p...

Colonial breeding provides benefits such as reduced predation risk, but also entails costs due to the enhanced levels of competition. In particular, it may require a significant amount of time and energy to establish a territory at the onset of reproduction, which in turn can impose carry-over effects on subsequent reproductive investments. Here we...

Human activities benefit a range of animal species, the resulting presence of which in cities can have negative societal consequences. One example are food subsidies, which buffer natural variation in food availability and allow these species to maintain larger populations. These buffers will likely gain importance under future environmental change...

There is a growing awareness that experience may play a major role in migratory decisions, especially in long-lived species. However, empirical support remains to date scarce. Here, we use multiyear GPS-tracking data on 28 adult Lesser Black-backed Gulls (Larus fuscus), a long-lived species for which migratory strategies typically consist of a seri...

Background Parental care benefits the offspring, but comes at a cost for each parent, which in biparental species gives rise to a conflict between partners regarding the within-pair distribution of care. Pair members could avoid exploitation by efficiently keeping track of each other’s efforts and coordinating their efforts. Parents may, therefore,...

Individual niche variation is common within animal populations, and has significant implications for a wide range of ecological and evolutionary processes. However, individual niche differences may also temporally vary as a result of behavioural plasticity. While it is well understood how niche variation is affected by changes in resource availabil...

Research on the space use and behaviour of waterbirds yields important insights on human‐wildlife interactions of ecological and societal importance under global change. The extent to which dynamic (within‐season) changes in anthropogenic landscapes affect these interactions is poorly understood. Lesser Black‐backed Gulls (Larus fuscus) are promine...

Mens & Vogel, 59 (1): 22-33.

Monitoring plastic in stomachs of beached northern fulmars for OSPAR’s Ecological Quality Objectives (EcoQOs) has been incorporated into the European Marine Strategy Framework Directive (MSFD). This paper aims to provide the appropriate tools to interpret the monitoring results. MSFD requires a data-derived threshold value (Fulmar-TV) representing...

The diet of seabirds can yield important insights into the status of economically and ecologically important fish. By analyzing the otoliths found in the birds’ droppings, researchers can observe which fish the birds eat in which abundances. However, identifying the species based on an otolith image is quite labor-intensive and requires particular...

Background Habitat loss can force animals to relocate to new areas, where they would need to adjust to an unfamiliar resource landscape and find new breeding sites. Relocation may be costly and could compromise reproduction. Methods Here, we explored how the Lesser black-backed gull (Larus fuscus), a colonial breeding seabird species with a wide e...

Background: Research on the space use and behavior of waterbirds—as highly mobile of wetland habitats—yields important insights on human-wildlife interactions of ecological and societal importance under global change. The extent to which dynamic (within-season) changes in anthropogenic landscapes affects these interactions is poorly understood. Les...

Current emission and mobilization rates of mercury (Hg) in the environment pose extensive threats to both wildlife and human health. Assessing the exposure risk and effects of Hg contamination in model species such as seabirds is essential to understand Hg risks at the population and ecosystem levels. The Lesser Black‐backed Gull (Larus fuscus), a...

Species breeding in urban environments are highly prone to a wide variety of non-natural, human activities, which range from short-term disturbances to the degradation or loss of suitable habitat. The latter in turn may force individuals to relocate to new sites for foraging or breeding, both of which presumably entails fitness costs due the trade-...

Background: Animals can obtain a higher foraging yield by optimizing energy expenditure or minimizing time costs. In this study, we assessed how individual variation in the relative use of marine and terrestrial foraging habitats relates to differences in the energy and time investments of an avian generalistic feeder (the Lesser Black- backed Gull...

Since 2005, the Research Institute for Nature and Forest (INBO) has been engaged in a monitoring program aiming to study seabird displacement effects caused by offshore wind farms in the Belgian part of the North Sea. Here we report our findings for the C-Power wind farm at the Thornton Bank after six years of post-construction monitoring. Results...

Among seabirds, lesser black-backed gulls (Larus fuscus) are considered to be at high risk of colliding with offshore wind turbines. In this respect, we used GPS tracking data of lesser black-backed gulls caught and tagged in two colonies along the Belgian North Sea coast (Ostend and Zeebrugge) to study spatial patterns in the species’ presence and...

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...

By realising the conservation objectives for European habitats it is assumed that a large number of species will benefit from these measures as well. In this analysis, we test this hypothesis for 142 species of conservation priority in Flanders. To do so, we use the potential habitat approach, i.e. mechanistic models that translate the ecological p...

Eutrophication of aquatic ecosystems is a global problem with major ecological and economic impacts. In many lakes and reservoirs, guanotrophication occurs when roosting waterbirds import nutrients (nitrogen and phosphorus) from surrounding terrestrial habitats. To date, nutrient loading by waterbirds has been estimated based on censuses in the abs...

Human-mediated food sources offer possibilities for novel foraging strategies by op-portunistic species. Yet, relative costs and benefits of alternative foraging strategies vary with the abundance, accessibility, predictability and nutritional value of anthropogenic food sources. The extent to which such strategies may ultimately alter fitness, can...

The huge surface area assigned to current and future offshore wind farm (OWF) developments has raised concern over the impact of displacement and resultant habitat loss on seabird populations. The North and Baltic Seas host most of the world’s OWFs, and numerous local studies have aimed to assess displacement effects on a range of seabirds. Extensi...

While competition is generally presumed to promote intraspecific niche diversification, populations of many apparent generalist species still exhibit considerable individual variation in foraging specialization. This suggests that different cost-benefit trade-offs may underlie individual variation in foraging specialization. Indeed, while specializ...

Free-ranging animals are often used as bioindicators of both short- and long-term changes in ecosystem health, mainly to detect the presence and effects of contaminants. Birds, and gulls in particular, have been used as bioindicators over a broad range of marine and terrestrial ecosystems. In this study, we standardise the conditions for the use of...

Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...

Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...

Tracking devices are increasingly used to monitor individual movement patterns continuously and in high resolution. However, carrying a device could potentially compromise an individual’s physiology or behaviour, thereby making tracking data unreliable for detailed behavioural measurements. To this end, we assessed the possible consequences of the...

Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...

Sex-, size- or age-dependent variation in migration strategies in birds is generally expected to reflect differences in competitive abilities. Theoretical and empirical studies thereby focus on differences in wintering areas, by which individuals may benefit from avoiding food competition during winter or ensuring an early return and access to prim...

Generalist species can potentially exploit a wide variety of resources, but at the individual level they often show a certain degree of foraging specialization. Specific foraging strategies, however, may increase exposure to environmental contaminants that can alter the cost-benefit balance of consuming particular food items. The Lesser Black-backe...

The diet of terns is often considered indicative for the availability of prey or shifts in prey communities. So far, most studies focused on the chick diet. Here we study the diet of breeding adult Sandwich terns based on faecal samples collected in five different colonies in Belgium and the Netherlands in 2007-2015. Breeding adult Sandwich terns i...

Environmental stressors have the potential to induce perturbations in the development of young individuals, leading to aberrant and unstable development. This may manifest as fluctuating asymmetry (FA; small, non-directional changes in the bilateral symmetry of morphological traits). Although widely regarded as a proxy for stress effects, the use o...

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...

Among most species of birds, survival from hatching throughout the first year of life is generally lower than subsequent survival rates. Survival of young birds during their first year may depend on a combination of selection, learning, unpredictable resources, and environmental events (i.e., post-fledging factors). However, knowledge about post-fl...

Since 2005, the Research Institute for Nature and Forest (INBO) performs monthly BACI‐designed surveys to study seabird displacement following the construction of offshore wind farms in the Belgian part of the North Sea. For the first time since its completion in 2013 we report our findings for the C‐Power wind farm at the Thorntonbank, and we also...

Fishery discards subsidise the food supply of a large community of scavenging seabirds, thus substantially influencing seabird ecology. Seabird preference for certain types of discards determines the number and composition of discards available for non-avian marine scavengers. To quantify both portions of discards temporally as well as spatially, w...

In this data paper, Bird tracking - GPS tracking of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast is described, a species occurrence dataset published by the Research Institute for Nature and Forest (INBO). The dataset (version 5.5) contains close to 2.5 million occurrences, recorded by 101 GPS trackers mounte...

Bird collision assessments are generally made at the scale of a single wind farm. While especially in offshore situations such assessments already hold several assumptions, even bigger challenges exist on estimating the cumulative impact of multiple wind farms and the impacts at population level. In this paper, the number of collision victims at Be...

Prior to the construction of an offshore wind farm at the Belgian Thorntonbank, local seabird abundance was studied by means of ship-based surveys. ‘Seabirds at sea’ count data, however, exhibit extreme spatial and temporal variation, impeding the detection of human impacts on seabird abundance and distribution. This paper proposes a transparent im...

Fishery discards in the Belgian part of the North Sea are a source of food for Herring Gulls Larus argentatus and Lesser Black-backed Gulls L. fuscus. To understand the importance of discards for local L. argentatus and L. fuscus populations, single-item discard experiments were performed at four offshore distances from the gullery of the Port of Z...

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...

1. Beach nourishment, the placement of sand onto a sediment-starved stretch of coast, is widely applied as a soft coastal protection measure because of its reduced ecological impact relative to hard coastal protection. In order to predict effects on the intertidal sandy beach ecosystem, we developed a simulation model that integrates species envelo...

Fisheries discards generate a major food source for scavenging seabirds and have been shown to significantly affect seabird ecology. Seabirds scavenge mainly on specific types of discards. Roundfish for instance are more easily swallowed than benthic invertebrates with protrusions. This implies that the amount of discards that becomes available to...

LifeWatch INBO: building a terrestrial and freshwater observatory in Flanders, Belgium

Discards generated from marine fisheries have significantly affected species populations and community composition of seabirds through mechanisms such as competition, predator–prey interactions and nutrient transfer. Our understanding of the fate of discards beyond seabird scavenging is fragmented, but it is likely that similar mechanisms come into...

The Research Institute for Nature and Forest (INBO) is in charge of investigating changes in seabird distribution following the offshore wind farm development at the Belgian part of the North Sea. Since 2005, three years before the construction of the very first offshore wind turbine, INBO therefore performs monthly seabird surveys through the impa...

To monitor the impact on birds following the construction of two offshore wind farms in the Belgian part of the North Sea, a twofold strategy was followed. Monthly ship-based seabird surveys allowed for a detailed displacement effect assessment, while radar research aimed at studying avoidance behaviour and barrier effects. Both methods provided in...

Several gull species were shown to be attracted to the offshore wind farms at the Belgian part of the North Sea, which is hypothesised to result from increased roosting possibilities or enhanced feeding conditions. Birds inside the wind farms were mainly observed resting on the water or the turbine foundations, but there is also few but increasing...