Chick growth and mortality characteristics (including predation risk) have been considered key selective factors to account for the evolution of the intermediate fledging strategy in Common Guillemots Uria aalge. The semi-precocial young... more
Chick growth and mortality characteristics (including predation risk) have been considered key selective factors to account for the evolution of the intermediate fledging strategy in Common Guillemots Uria aalge. The semi-precocial young leave the colony as small, partly feathered, flightless chicks at an age of c. 20 days at about one quarter of adult body mass and are accompanied by one of the adults (usually the male) when they swim out to sea. It is generally assumed that mortality rates in the colony are relatively low, while growth rates have been measured to be lower at the colony than at sea. Information on post-fledging dispersal of young and adults at sea in late summer (late June-September) is evaluated in this paper. Adult guillemots from North Sea colonies guide their offspring away from the colony. While doing so, they move rapidly through a coastal area with rich prey resources but with relatively high predation risk, and travel several hundreds of kilometres into the open sea where there are very few avian predators but where prey is low and patchy. Some were shown to end in distant areas with fewer predators and predictable prey resources. Meanwhile, the adults undergo a complete post-nuptial moult and become flightless for about 40-45 days. Laying, hatching and fledging in Common Guillemots are highly synchronised and with little variation in timing between years and very high success rates. In contrast, post-fledging chick survival is highly variable, which is understandable given the risky journey undertaken in often adverse environmental conditions. It is suggested that the selection pressure to defend or conquer breeding sites on proven successful ledges in autumn (starting only three months after 'normal' fledging) may strongly select for a timely departure from the colony. Chick care at sea allows the parents to become flightless while they undergo post-nuptial moult in time so that they can keep up with non-breeding adults and return to visit the breeding ledge in time.
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Migrating animals show remarkable diversity in migration strategies, even between individuals from the same population. Migrating longer distances is usually expected to be costlier in terms of time, energy expenditure and risks with... more
Migrating animals show remarkable diversity in migration strategies, even between individuals from the same population. Migrating longer distances is usually expected to be costlier in terms of time, energy expenditure and risks with potential repercussions for subsequent stages within the annual cycle. Such costs are expected to be balanced by increased survival, for example due to higher quality wintering areas or lower energy expenditure at lower latitudes. We compared reproductive parameters and apparent survival of lesser black-backed gulls ( Larus fuscus ) breeding in The Netherlands, whose winter range extends from the UK to West Africa, resulting in one-way migration distances that differ by more than 4500 km. Individuals migrating furthest arrived later in the colony than shorter distance migrants, but still laid in synchrony with the colony and consequently had a shorter pre-laying period. This shorter pre-laying period affected neither egg volumes nor hatching success. We found no relationship between migration distance and apparent survival probability, corresponding with previous research showing that annual energy expenditure and distance travelled throughout the year is similar across migration strategies. Combined, our results indicate an equal fitness payoff across migration strategies, suggesting there is no strong selective pressure acting on migration strategy within this population.
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Seabirds are particularly sensitive to marine oil pollution. Systematic surveys of beach-cast corpses of birds (‘beached bird surveys’) not only document the adverse effects of oil pollution on wild birds but are particularly useful for... more
Seabirds are particularly sensitive to marine oil pollution. Systematic surveys of beach-cast corpses of birds (‘beached bird surveys’) not only document the adverse effects of oil pollution on wild birds but are particularly useful for monitoring spatial and temporal patterns and trends in chronic oil pollution. In this chapter, we briefly review the history and current schemes of beached bird surveys around the North Sea and the development and sensitivity of the monitoring instrument, followed by an overview of the most recent developments and trends. Oil pollution at sea has been known since the late nineteenth century, and the first beached bird surveys were conducted in the 1920s. Oil rates (the proportion of seabirds found on the tideline that were oiled) remained very high until the late 1980s, but have since declined markedly. Protocols were modified in the late 1990s in order to obtain an internationally accepted monitoring instrument. The subsequent continuation of the declining trends in oil rates around the North Sea is discussed. The species composition of the seabirds most commonly found oiled suggests that coastal areas are currently more or less free from chronic oil pollution, while higher pollution levels occur around shipping lanes in areas with the highest shipping densities.
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Page 1. OLIESLACHTOFFERS OP DE NEDERLANDSE KUST, 2009/2010 ... Dit rapport kan als volgt geciteerd worden this report can be cited as follows: Camphuysen CJ 2010. Olieslachtoffers op de Nederlandse kust, 2009/2010. ...
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Research Interests: Engineering and HArbour
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Research Interests: Information Systems, Zoology, Biology, Ecology, Ibis, and 7 moreForaging, Fishery, Herring, Seabird, Fidelity, Time Budget, and Herring Gull
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Oil pollution is a serious issue in the Netherlands ever since merchant and military vessels with diesel engines gradually replaced vessels operating sails and steam engines in the early twentieth century. Arguably, the southern North Sea... more
Oil pollution is a serious issue in the Netherlands ever since merchant and military vessels with diesel engines gradually replaced vessels operating sails and steam engines in the early twentieth century. Arguably, the southern North Sea became one of the most heavily oil-polluted sea areas in the world as a result of chronic oil pollution. Major shipping incidents resulting in massive oil spills have, however, been rather rare within the area. In the early twenty-first century, the number of detected oil spills has markedly declined and levels of chronic oil pollution are currently rather low. Most detections of oil slicks are still concentrated around the major shipping lanes and off major ports such as Rotterdam and IJmuiden (leading to Amsterdam).
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Marine oil pollution has been an issue of concern for at least a century. The earliest reports contained outrage over oil-contaminated dead seabirds found ashore. This paper reports on observed trends in strandings and oil rates of Common... more
Marine oil pollution has been an issue of concern for at least a century. The earliest reports contained outrage over oil-contaminated dead seabirds found ashore. This paper reports on observed trends in strandings and oil rates of Common Guillemots Uria aalge to illustrate the history of oil pollution and its effects in the North Sea. This paper is also a tribute to Peter Hope Jones, who brought systematic beached bird surveys and oil-spill impact assessments to a higher level, by implementing detailed research on affected wildlife. In recent decades, unexpectedly, the oil problem has disappeared almost completely from the North Sea. Given the global nature of current environmental issues, including the climate and biodiversity crises, it may be instructive to examine the background to this stunning success. A short history of major oil events is presented, including the measures taken to reduce the oil problem. It required a succession of major oil incidents to push the community ...
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High pathogenicity avian influenza (HPAI) profoundly impacted several seabird populations during the summers of 2021 and 2022. Infection spread rapidly across colonies, causing unprecedented mortality. At Foula, Shetland, 1500 breeding... more
High pathogenicity avian influenza (HPAI) profoundly impacted several seabird populations during the summers of 2021 and 2022. Infection spread rapidly across colonies, causing unprecedented mortality. At Foula, Shetland, 1500 breeding adult great skuas Stercorarius skua, totalling about two tonnes of decomposing virus-laden material, died at the colony in May−July 2022. Carcasses were left where they died as Government policy was not to remove dead birds. The factors influencing risk of further spread of infection are uncertain, but evidence suggests that HPAI can persist in water for many months in cool conditions and may be a major transmission factor for birds living in wetlands. We investigated risk of further spread of infection from water samples collected from under 45 decomposing carcasses and in three freshwater lochs/streams by sampling water in October 2022, by which time the great skua carcasses had rotted to bones, skin, and feathers. No viral genetic material was dete...
Research Interests: Biology, Waterfowl, Seabird, Shetland, Charadriiformes, and 4 morePathogens, Feather, Outbreak, and Oncorhynchus
Seasonal migrations are used by diverse animal taxa, yet the costs and benefits of migrating have rarely been empirically examined. The aim of this study was to determine how migration influences two ecological currencies, energy... more
Seasonal migrations are used by diverse animal taxa, yet the costs and benefits of migrating have rarely been empirically examined. The aim of this study was to determine how migration influences two ecological currencies, energy expenditure and time allocated towards different behaviors, in a full annual cycle context. We compare these currencies among lesser black-backed gulls that range from short- (< 250 km) to long-distance (> 4500 km) migrants. Daily time-activity budgets were reconstructed from tri-axial acceleration and GPS, which, in conjunction with a bioenergetics model to estimate thermoregulatory costs, enabled us to estimate daily energy expenditure throughout the year. We found that migration strategy had no effect on annual energy expenditure, however, energy expenditure through time deviated more from the annual average as migration distance increased. Patterns in time-activity budgets were similar across strategies, suggesting migration strategy does not limi...
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In animal ecology, energy expenditure is used for assessing the consequences of different behavioural strategies, life‐history events or environments. Animals can also influence energy expenditure through instantaneous behavioural... more
In animal ecology, energy expenditure is used for assessing the consequences of different behavioural strategies, life‐history events or environments. Animals can also influence energy expenditure through instantaneous behavioural responses to their external environment. It is therefore of interest to measure energy expenditure of free‐ranging animals across seasons and at high temporal resolutions. Heart rate has historically been used for this, but requires invasive surgery for long‐term use. Dynamic body acceleration (DBA) is an alternative proxy for energy expenditure that is simpler to deploy, yet few studies have examined how it performs over extended time periods, or for species using different locomotory modes, especially passive modes like soaring flight. We measured DBA alongside heart rate in free‐ranging lesser black‐backed gulls, a seabird that moves using flapping flight, soaring and walking, and rests on both land and water. Our objectives were to compare the relative...
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Data of seasonal orographic lift per cell (corresponding to Figure 4a
1. Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardised and systematic aerial and vessel surveys, with recorded animal... more
1. Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardised and systematic aerial and vessel surveys, with recorded animal densities interpolated across study areas. However, as individual surveys have restricted spatial and temporal coverage, distribution maps at basin and monthly scales have previously not been possible. 2. This study develops an alternative approach consisting of: (1) collating diverse survey data to maximise spatial and temporal coverage, (2) using detection functions to estimate variation in the surface area covered (km2) among these surveys, standardising measurements of effort and animal densities, (3) developing species distribution models (SDM) that overcome issues with heterogeneous and uneven coverage. 3. 2.68 million km of survey data in the North-East Atlantic between 1980 and 2018 were collated and standardised. SDM using Generalized Linear Mod...