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Changes in the frequency of extreme climatic events (ECEs) can have profound impacts on individual fitness by degrading habitat quality. Organisms may respond to such changes through habitat selection, favouring those areas less affected by ECEs; however, documenting habitat selection in response to ECEs is difficult in the wild due to the rarity of such events and the long‐term biological data required. Sea level rise and changing weather patterns over the past decades have led to an increase in the frequency of coastal flooding events, with serious consequences for ground nesting shorebirds. Shorebirds therefore present a useful natural study system to understand habitat selection as a response to ECEs. We used a 32‐year study of the Eurasian oystercatcher (Haematopus ostralegus) to investigate whether habitat selection can lead to an increase in nest elevation and minimize the impacts of coastal flooding. The mean nest elevation of H. ostralegus has increased during the last three decades. We hypothesized that this change has been driven by changes in H. ostralegus territory settlement patterns over time. We compared various possible habitat selection cues to understand what information H. ostralegus might use to inform territory settlement. There was a clear relationship between elevation and territory settlement in H. ostralegus. In early years, settlements were more likely at low elevations but in more recent years the likelihood of settlement was similar between high and low elevation areas. Territory settlement was associated with conspecific fledgling output and conspecific density. Settlement was more likely in areas of high density and areas with high fledgling output. This study shows that habitat selection can minimize the effects of increasingly frequent ECEs. However, it seems unlikely that the changes we observe will fully alleviate the consequences of anthropogenic climate change. Rates of nest elevation increase were insufficient to

Phenotypic plasticity is a crucial mechanism for responding to changes in climatic means, yet we know little about its role in responding to extreme climatic events (ECEs). ECEs may lack the reliable cues necessary for phenotypic plasticity to evolve; however, this has not been empirically tested. We investigated whether behavioural plasticity in nest-site selection allows a long-lived shorebird (Haematopus ostralegus) to respond to flooding. We collected longitudinal nest elevation data on individuals over two decades, during which time flooding events have become increasingly frequent. We found no evidence that individuals learn from flooding experiences, showing nest elevation change consistent with random nest-site selection. There was also no evidence of phenotypic plasticity in response to potential environmental cues (lunar nodal cycle and water height). A small number of individuals, those nesting near an artificial sea wall, did show an increase in nest elevation over time; however, there is no conclusive evidence this occurred in response to ECEs. Our study population showed no behavioural plasticity in response to changing ECE patterns. More research is needed to determine whether this pattern is consistent across species and types of ECEs. If so, ECEs may pose a major challenge to the resilience of wild populations

Data have been collected on the breeding success of several characteristic coastal breeding birds in the Wadden Sea each year since 2005. Ten birds species considered representative of specific habitats and food groups are being monitored. The monitoring scheme on breeding success in coastal breeding birds is run as an ‘early warning system’ to follow the reproductive capacity of the bird populations in the Wadden Sea and understand the processes underlying fluctuations in populations. It is a valuable addition to the monitoring of population numbers and is carried out under a trilateral agreement with Germany and Denmark (TMAP). The results from 2015–2016 and an analysis of data series from the period 2005–2016 (sometimes longer) show that several species on average reared too few young to sustain stable population size in many of these years, especially the Eurasian Oystercatcher, Pied Avocet, Common Tern and Arctic Tern, and in recent years also the Black-headed Gull, whose breeding success has significantly declined since 1995. Other species showing a significant decline in breeding success are the Spoonbill and Common Tern. The only species to show any significant improvement in breeding success since 2005 is the Lesser Black-backed Gull, Sinds 2005 worden in de Waddenzee jaarlijks gegevens verzameld over het broedsucces van een aantal karakteristieke kustbroedvogels. Hiervoor worden tien vogelsoorten gevolgd die representatief worden geacht voor specifieke habitats en voedselgroepen. Het reproductiemeetnet kustbroedvogels wordt uitgevoerd als een ‘early warning systeem’ om het reproducerend vermogen van de vogelpopulaties in de Waddenzee te volgen en de achterliggende processen van populatieveranderingen te doorgronden. Het fungeert als een belangrijke aanvulling op de monitoring van aantallen en aantalsveranderingen en wordt uitgevoerd in het kader van trilaterale afspraken met Duitsland en Denemarken (TMAP). Uit de resultaten van 2015-2016 en analyse van gegevensreeksen uit de periode 2005-2016 (soms langer) blijkt dat een aantal soorten in veel jaren en gemiddeld genomen weinig jongen grootbrengen. Dit geldt vooral voor Scholekster, Kluut, Visdief en Noordse Stern, en in de afgelopen jaren ook voor Kokmeeuw, waarvan het broedsucces sinds 1995 significant is afgenomen. Andere soorten met een significant afnemend broedsucces zijn Lepelaar en Visdief. Alleen bij Kleine Mantelmeeuw was sinds 2005 sprake van een significante verbetering van het broedsucces.

The extent to which animal migrations shape parasite transmission networks is critically dependent on a migrant's ability to tolerate infection and migrate successfully. Yet, sub-lethal effects of parasites can be intensified through periods of increased physiological stress. Long-distance migrants may, therefore, be especially susceptible to negative effects of parasitic infection. Although a handful of studies have investigated the short-term, transmission-relevant behaviors of wild birds infected with low-pathogenic avian influenza viruses (LPAIV), the ecological consequences of LPAIV for the hosts themselves remain largely unknown. Here, we assessed the potential effects of naturally-acquired LPAIV infections in Bewick's swans, a long-distance migratory species that experiences relatively low incidence of LPAIV infection during early winter. We monitored both foraging and movement behavior in the winter of infection, as well as subsequent breeding behavior and inter-annual resighting probability over 3 years. Incorporating data on infection history we hypothesized that any effects would be most apparent in naïve individuals experiencing their first LPAIV infection. Indeed, significant effects of infection were only seen in birds that were infected but lacked antibodies indicative of prior infection. Swans that were infected but had survived a previous infection were indistinguishable from uninfected birds in each of the ecological performance metrics. Despite showing reduced foraging rates, individuals in the naïve-infected category had similar accumulated body stores to re-infected and uninfected individuals prior to departure on spring migration, possibly as a result of having higher scaled mass at the time of infection. And yet individuals in the naïve-infected category were unlikely to be resighted 1 year after infection, with 6 out of 7 individuals that never resighted again compared to 20 out of 63 uninfected individuals and 5 out of 12 individuals in the

The extent to which animal migrations shape parasite transmission networks is critically dependent on a migrant’sability to tolerate infection and migrate successfully. Yet, sub-lethal effects of parasites can be intensified through periods ofincreased physiological stress. Long-distance migrants may, therefore, be especially susceptible to negative effects of parasiticinfection. Although a handful of studies have investigated the short-term, transmission-relevant behaviors of wild birdsinfected with low-pathogenic avian influenza viruses (LPAIV), the ecological consequences of LPAIV for the hosts themselvesremain largely unknown. Here, we assessed the potential effects of naturally-acquired LPAIV infections in Bewick’s swans, along-distance migratory species that experiences relatively low incidence of LPAIV infection during early winter. We monitoredboth foraging and movement behavior in the winter of infection, as well as subsequent breeding behavior and interannualresighting probability over 3 years. Incorporating data on infection history we hypothesized that any effects would bemost apparent in nai¨ve individuals experiencing their first LPAIV infection. Indeed, significant effects of infection were onlyseen in birds that were infected but lacked antibodies indicative of prior infection. Swans that were infected but had surviveda previous infection were indistinguishable from uninfected birds in each of the ecological performance metrics. Despiteshowing reduced foraging rates, individuals in the nai¨ve-infected category had similar accumulated body stores to re-infectedand uninfected individuals prior to departure on spring migration, possibly as a result of having higher scaled mass at thetime of infection. And yet individuals in the nai¨ve-infected category were unlikely to be resighted 1 year after infection, with6 out of 7 individuals that never resighted again compared to 20 out of 63 uninfected individuals and 5 out of 12 individualsin the re-infected ca

Data have been collected on the breeding success of several characteristic coastal breeding birds in theWadden Sea each year since 2005. Ten birds species considered representative of specific habitats and foodgroups are being monitored. The coastal breeding birds reproduction monitoring network is run as an ‘earlywarning system’ to follow the reproductive capacity of the bird populations in the Wadden Sea andunderstand the processes underlying fluctuations in populations. It is a valuable addition to the monitoring ofpopulation numbers and is carried out under a trilateral agreement with Germany and Denmark (TMAP). Theresults from 2014 show that many species of coastal breeding birds are still facing difficulties. The breedingsuccess of Eurasian Oystercatcher, Pied Avocet, Black-headed Gull, Common Tern and Arctic Tern inparticular is too low or much too low to maintain a stable population. In contrast, the breeding success ofHerring Gull is better than a few seasons ago. Erection of electric fencing around breeding sites of PiedAvocet and Black-headed Gull to protect them from predation has led to higher nest success. The maincauses of poor breeding performance appear to be predation by foxes and brown rats and insufficient foodavailability for the young, Sinds 2005 worden in de Waddenzee jaarlijks gegevens verzameld over het broedsucces van een aantalkarakteristieke kustbroedvogels. Hiervoor worden tieSn vogelsoorten gevolgd die representatief wordengeacht voor specifieke leefgebieden en voedselgroepen. Het reproductiemeetnet kustbroedvogels wordtuitgevoerd als een ‘early warning systeem’ om het reproducerend vermogen van de vogelpopulaties in deWaddenzee te volgen en de achterliggende processen van populatieveranderingen te doorgronden. Hetfungeert als een wezenlijke aanvulling op de monitoring van status en trends in populatiegrootte en wordtuitgevoerd in het kader van trilaterale afspraken met Duitsland en Denemarken (TMAP). Uit de resultaten uit2014 blijkt dat nog steeds veel soorten kustbroedvogels het moeilijk hebben. Het broedsucces van vooralScholekster, Kluut, Kokmeeuw Visdief en Noordse Stern is (ruim) onvoldoende om de populatie op peil tehouden. Zilvermeeuw lijkt daarentegen beter te presteren dan een aantal seizoenen terug. Het uitrasterenvan de broedende Kluten bij de Klutenplas en Kokmeeuwen in Oterdum (met elektrisch raster tegenpredatie) heeft een hoger nestsucces tot gevolg gehad. Oorzaken van slechte broedresultaten lijken vooralpredatie door Vossen en Bruine ratten en een te geringe voedselbeschikbaarheid voor de jongen

Animal-borne accelerometers measure body orientation and movement and can thus be used to classify animal behaviour. To univocally and automatically analyse the large volume of data generated, we need classification models. An important step in the process of classification is the segmentation of acceleration data, i.e. the assignment of the boundaries between different behavioural classes in a time series. So far, analysts have worked with fixed-time segments, but this may weaken the strength of the derived classification models because transitions of behaviour do not necessarily coincide with boundaries of the segments. Here we develop random forest automated supervised classification models either built on variable-time segments generated with a so-called ‘change-point model’, or on fixed-time segments, and compare for eight behavioural classes the classification performance. The approach makes use of acceleration data measured in eight free-ranging crab plovers Dromas ardeola.

This paper reports on new discoveries and new possibilities due to the deployment of the UvA Bird Tracking System (UvA-BiTS; Bouten et al. 2013) in our investigations of the behavioural ecology of Oystercatchers. This GPS tracker is powered by solar cells and not only stores GPS locations, but also measurements with a tri-axial accelerometer, which can be used to infer behaviour (Shamoun-Baranes et al. 2012; fig. 4). Since 2008, 72 Oystercatchers were fitted with such GPS trackers. Contrary to our expectations, Oystercatchers breeding in the polder of Ameland, where they can feed on earthworms and tipulid larvae, continued to visit the Wadden Sea mudflats throughout the breeding season, just like birds breeding on the saltmarsh of Schiermonnikoog (Fig. 1). We were equally surprised to learn that the breeding populations on both islands included migrants. Whereas many breeding birds remained within 10 km of the breeding territory throughout the winter (Fig. 2), a minority moved much greater distances to a clearly distinct wintering area (Fig. 4). Fidelity to a particular wintering area was high, irrespective of distance moved. We also show examples of the potential of UvA-BiTS to address important scientific questions. Young birds must find a good place to learn how to survive and Fig. 5 shows the behaviour of such a bird: it stays for several months in a particular location and then moves to a new location. Once an individual is sufficiently proficient at surviving, it can enter the competition for breeding territories as a club-bird, usually at the age of three years. Figure 6 compares the ranging behaviour of a non-breeder to that of a breeder at the height of the breeding season

In the vast majority of migratory bird species studied so far, spring migration has been found to proceed faster than autumn migration. In spring, selection pressures for rapid migration are purportedly higher, and migratory conditions such as food supply, daylength, and/or wind support may be better than in autumn. In swans, however, spring migration appears to be slower than autumn migration. Based on a comparison of tundra swan Cygnus columbianus tracking data with long-term temperature data from wheather stations, it has previously been suggested that this was due to a capital breeding strategy (gathering resources for breeding during spring migration) and/or to ice cover constraining spring but not autumn migration. Here we directly test the hypothesis that Bewick's swans Cygnus columbianus bewickii follow the ice front in spring, but not in autumn, by comparing three years of GPS tracking data from individual swans with concurrent ice cover data at five important migratory stop-over sites. In general, ice constrained the swans in the middle part of spring migration, but not in the first (no ice cover was present in the first part) nor in the last part. In autumn, the swans migrated far ahead of ice formation, possibly in order to prevent being trapped by an early onset of winter. We conclude that spring migration in swans is slower than autumn migration because spring migration speed is constrained by ice cover. This restriction to spring migration speed may be more common in northerly migrating birds that rely on freshwater resources., In the vast majority of migratory bird species studied so far, spring migration has been found to proceed faster than autumn migration. In spring, selection pressures for rapid migration are purportedly higher, and migratory conditions such as food supply, daylength, and/or wind support may be better than in autumn. In swans, however, spring migration appears to be slower than autumn migration. Based on a comparison of tundra swan Cygnus columbianus tracking data with long-term temperature data from wheather stations, it has previously been suggested that this was due to a capital breeding strategy (gathering resources for breeding during spring migration) and/or to ice cover constraining spring but not autumn migration. Here we directly test the hypothesis that Bewick's swans Cygnus columbianus bewickii follow the ice front in spring, but not in autumn, by comparing three years of GPS tracking data from individual swans with concurrent ice cover data at five important migratory stop-over sites. In general, ice constrained the swans in the middle part of spring migration, but not in the first (no ice cover was present in the first part) nor in the last part. In autumn, the swans migrated far ahead of ice formation, possibly in order to prevent being trapped by an early onset of winter. We conclude that spring migration in swans is slower than autumn migration because spring migration speed is constrained by ice cover. This restriction to spring migration speed may be more common in northerly migrating birds that rely on freshwater resources.

Animal-borne sensors enable researchers to remotely track animals, their physiological state and body movements. Accelerometers, for example, have been used in several studies to measure body movement, posture, and energy expenditure, although predominantly in marine animals. In many studies, behaviour is often inferred from expert interpretation of sensor data and not validated with direct observations of the animal. The aim of this study was to derive models that could be used to classify oystercatcher (Haematopus ostralegus) behaviour based on sensor data. We measured the location, speed, and tri-axial acceleration of three oystercatchers using a flexible GPS tracking system and conducted simultaneous visual observations of the behaviour of these birds in their natural environment. We then used these data to develop three supervised classification trees of behaviour and finally applied one of the models to calculate time-activity budgets. The model based on accelerometer data developed to classify three behaviours (fly, terrestrial locomotion, and no movement) was much more accurate (cross-validation error = 0.14) than the model based on GPS-speed alone (cross-validation error = 0.35). The most parsimonious acceleration model designed to classify eight behaviours could distinguish five: fly, forage, body care, stand, and sit (cross-validation error = 0.28); other behaviours that were observed, such as aggression or handling of prey, could not be distinguished. Model limitations and potential improvements are discussed. The workflow design presented in this study can facilitate model development, be adapted to a wide range of species, and together with the appropriate measurements, can foster the study of behaviour and habitat use of free living animals throughout their annual routine.

Over the past decades most goose populations have become increasingly dependent on agricultural crops during wintering and migration periods. The suitability of agricultural crops to support all nutritional requirements of migratory geese for the deposition of body stores has been questioned; feeding on agricultural crops may yield higher rates of fat deposition at the cost of reduced protein accretion due to an unbalanced diet. We compared amino-acid composition of forage, and investigated food-habitat use and dynamics and composition of body stores deposited by barnacle geese feeding on agricultural pasture and in natural salt marsh during spring migratory preparation. Overall content and composition of amino acids was similar among forage from both habitats and appeared equally suitable for protein accretion. There was no relationship between body composition of geese and their preferred food habitat. Fat and wet protein contributed with 67% and 33%, respectively, to body stores gained at a rate of 11 g/d throughout the one-month study period. We found no evidence of impaired protein accretion in geese using agricultural grassland compared to natural salt marsh. Our study supports the hypothesis that the expansion of feeding habitat by including agricultural grassland has played an important role in the recent growth of the East Atlantic flyway population of barnacle geese and other herbivorous waterbirds. Feeding refuges of improved grassland provide geese with an adequate diet for the deposition of body stores crucial for spring migration and subsequent reproduction, thereby alleviating the conflict with agriculture.

Over the past decades most goose populations have become increasingly dependent on agricultural crops during wintering and migration periods. The suitability of agricultural crops to support all nutritional requirements of migratory geese for the deposition of body stores has been questioned; feeding on agricultural crops may yield higher rates of fat deposition at the cost of reduced protein accretion due to an unbalanced diet. We compared amino-acid composition of forage, and investigated food-habitat use and dynamics and composition of body stores deposited by barnacle geese feeding on agricultural pasture and in natural salt marsh during spring migratory preparation. Overall content and composition of amino acids was similar among forage from both habitats and appeared equally suitable for protein accretion. There was no relationship between body composition of geese and their preferred food habitat. Fat and wet protein contributed with 67% and 33%, respectively, to body stores gained at a rate of 11 g/d throughout the one-month study period. We found no evidence of impaired protein accretion in geese using agricultural grassland compared to natural salt marsh. Our study supports the hypothesis that the expansion of feeding habitat by including agricultural grassland has played an important role in the recent growth of the East Atlantic flyway population of barnacle geese and other herbivorous waterbirds. Feeding refuges of improved grassland provide geese with an adequate diet for the deposition of body stores crucial for spring migration and subsequent reproduction, thereby alleviating the conflict with agriculture. Read More: http://www.esajournals.org/doi/abs/10.1890/ES11-00316.1, Over the past decades most goose populations have become increasingly dependent on agricultural crops during wintering and migration periods. The suitability of agricultural crops to support all nutritional requirements of migratory geese for the deposition of body stores has been questioned; feeding on agricultural crops may yield higher rates of fat deposition at the cost of reduced protein accretion due to an unbalanced diet. We compared amino-acid composition of forage, and investigated food-habitat use and dynamics and composition of body stores deposited by barnacle geese feeding on agricultural pasture and in natural salt marsh during spring migratory preparation. Overall content and composition of amino acids was similar among forage from both habitats and appeared equally suitable for protein accretion. There was no relationship between body composition of geese and their preferred food habitat. Fat and wet protein contributed with 67% and 33%, respectively, to body stores gained at a rate of 11 g/d throughout the one-month study period. We found no evidence of impaired protein accretion in geese using agricultural grassland compared to natural salt marsh. Our study supports the hypothesis that the expansion of feeding habitat by including agricultural grassland has played an important role in the recent growth of the East Atlantic flyway population of barnacle geese and other herbivorous waterbirds. Feeding refuges of improved grassland provide geese with an adequate diet for the deposition of body stores crucial for spring migration and subsequent reproduction, thereby alleviating the conflict with agriculture. Read More: http://www.esajournals.org/doi/abs/10.1890/ES11-00316.1