cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5441/001/1.g2n3ps20
title: Data from: Migration strategy as an indicator of resilience to change in two shorebird species with contrasting population trajectories [curlew sandpipers]

description: (1) Many migratory birds are declining worldwide. In line with the general causes for the global biodiversity crisis, habitat loss, pollution, hunting, over-exploitation and climate change are thought to be at the basis of these population declines. Long-distant migrants seem especially vulnerable to rapid anthropogenic change, yet, the rate of decline across populations and species varies greatly within flyways. We hypothesize that differences in migration strategy and notably stopover-site use, may be at the basis of these variations in resilience to global change. (2) By identifying and comparing migration strategies of two very closely related shorebird species, the Curlew sandpiper (Calidris ferruginea) and the Red-necked stint (Calidris ruficollis), migrating from the same non-breeding site in Australia to similar breeding sites in the high Russian Arctic, we aimed to explain why these two species express differential resilience to rapid changes within their flyway resulting in different population trajectories in recent times. (3) Based on 13 Curlew sandpiper and 16 Red-necked stint tracks from light-level geolocator tags, we found that individual Curlew sandpipers make use of fewer stopover areas along the flyway compared to Red-necked stints. Furthermore, and notably during northward migration, Curlew sandpipers have a higher dependency on fewer sites, both in terms of the percentage of individuals visiting key stopover sites and the relative time spent at those sites. While Curlew sandpipers rely mainly on the Yellow Sea region, that has recently experienced a sharp decline in suitable habitat, Red-necked stints make us of additional sites and spread their relative time en-route across sites more evenly. (4) Our results indicate that differential migration strategies may explain why Curlew sandpipers within the East Asian-Australasian Flyway are declining rapidly (9.5-5.5 % per year) while Red-necked stints remain relatively stable (-3.1 to 0 %). We consider that more generally, the number of sites per individual and among a population, the spatial distribution across the flyway, as well as the relationship between the time spent over sites may prove to be key variables explaining populations and species’ differential resilience to environmental change.
DOI: 10.5441/001/1.4f03k6s5
title: Data from: Vultures respond to challenges of near-ground thermal soaring by varying bank angle

description: Many large birds rely on thermal soaring flight to travel cross-country. As such, they are under selective pressure to minimise the time spent gaining altitude in thermal updrafts. Birds should be able to maximise their climb rates by maintaining a position close to the thermal core through careful selection of bank angle and airspeed, however, there have been few direct measurements of either parameter. Here we apply a novel methodology to quantify the bank angles selected by soaring birds using on-board magnetometers. We couple these data with airspeed measurements to parameterise the soaring envelope of two species of Gyps vulture, from which it is possible to predict “optimal” bank angles. Our results show that these large birds respond to the challenges of gaining altitude in the initial phase of the climb, where thermal updrafts are weak and narrow, by adopting relatively high, and conserved, bank angles (25-35°). The angle of bank decreased with increasing altitude, in a manner that was broadly consistent with a strategy of maximising the rate of climb. However, the lift coefficients estimated in our study were lower than those predicted by theoretical models and wind-tunnel studies. Overall, our results highlight how the relevant currency for soaring performance changes within individual climbs; when thermal radius is limiting, birds vary bank angle and maintain a constant airspeed, but speed increases later in the climb in order to respond to decreasing air density.
DOI: 10.5441/001/1.f4r24r5r
title: Data from: Individual tracking reveals long-distance flightpath control in a nocturnally-migrating moth

description: Each year, trillions of insects make long-range seasonal migrations. These movements are relatively well understood at a population level, but how individual insects achieve them remains elusive. Behavioral responses to conditions en route are little studied, primarily owing to the challenges of tracking individual insects. Using a light aircraft and individual radio tracking, we show that nocturnally migrating death’s-head hawkmoths maintain control of their flight trajectories over long distances. The moths did not just fly with favorable tailwinds; during a given night, they also adjusted for head and crosswinds to precisely hold course. This behavior indicates that the moths use a sophisticated internal compass to maintain seasonally beneficial migratory trajectories independent of wind conditions, illuminating how insects traverse long distances to take advantage of seasonal resources.
DOI: 10.5441/001/1.c741t5b6
title: Data from: Anosmia impairs homing orientation but not foraging behaviour in free-ranging shearwaters

description: Shearwaters deprived of their olfactory sense before being displaced to distant sites have impaired homing ability but it is unknown what the role of olfaction is when birds navigate freely without their sense of smell. Furthermore, treatments used to induce anosmia and to disrupt magneto-reception in displacement experiments might influence non-specific factors not directly related to navigation and, as a consequence, the results of displacement experiments can have multiple interpretations. To address this, we GPS-tracked the free-ranging foraging trips of incubating Scopoli’s shearwaters within the Mediterranean Sea. As in previous experiments, shearwaters were either made anosmic with 4% zinc sulphate solution, magnetically impaired by attachment of a strong neodymium magnet or were controls. We found that birds from all three treatments embarked on foraging trips, had indistinguishable at-sea schedules of behaviour and returned to the colony having gained mass. However, we found that in the pelagic return stage of their foraging trips, anosmic birds were not oriented towards the colony but that coastal navigation was unaffected. These results support the case for zinc sulphate having a specific effect on the navigational ability of shearwaters and thus the view that seabirds consult an olfactory map to guide them across seascapes.
DOI: 10.5441/001/1.276
title: Data from: The price of being late: short- and long-term consequences of a delayed migration timing [delayed birds]

description: Choosing the right migration timing is critical for migrants because conditions encountered en route influence movement costs, survival, and, in social migrants, the availability of social information. Depending on lifetime stages, individuals may migrate at different times due to diverging constraints, affecting the composition of migration groups. To examine the consequences of a delayed migration timing, we artificially delayed the migration of juvenile white storks (Ciconia ciconia) and thereby altered their physical and social environment. Using nearly continuous 1 Hz GPS trajectories, we examined their migration behaviour, ranging from sub-second level performance to global long-distance movement, in relation to two control groups. We found that delayed storks experienced suboptimal soaring conditions, but better wind support and thereby achieved higher flight speeds than control storks. Delayed storks had a lower mortality rate than the control storks and wintered closer to the breeding area. In fact, none of the delayed storks reached the traditional African wintering areas. Thus, our results show that juvenile storks can survive migrating at the ‘wrong’ time. However, this had long-term consequences on migration decisions. We suggest that, when timing their migration, storks balance not just energy and time, but also the availability of social information.
DOI: 10.5441/001/1.b800b7c3
title: Data from: Intra-African movements of the African Cuckoo Cuculus gularis as revealed by satellite telemetry

description: Despite many bird species migrating regularly within the African continent, in response to rainfall and breeding opportunities, documented evidence of the spatiotemporal patterns of such movements is scarce. We use satellite telemetry to document the year round movement of an intra-African migrant breeding in the savannah zone of sub-Saharan Africa, the African Cuckoo. After breeding in central Nigeria, the birds migrated to more forested sites in the Adamawa region of Cameroon (n=2) and western Central African Republic (n=1). Departure from the breeding ground coincided with deteriorating environmental conditions whereas arrival at the non-breeding sites matched period of increasing vegetation greenness. Migratory movements generally occurred during dark hours. In total, an average distance of 748 km in 66 days was covered during the post-breeding migration and 744 km in 27 days during return journey with considerable individual variation and with more stopover sites used during post-breeding migration. The diversity of migration routes followed suggests a relatively variable or flexible initial migration strategy, high individual route consistency as well as high fidelity for non-breeding grounds.
DOI: 10.5441/001/1.sj8t3r11
title: Data from: Why do kestrels soar?

description: Individuals allocate considerable amounts of energy to movement, which ultimately affects their ability to survive and reproduce. Birds fly by flapping their wings, which is dependent on the chemical energy produced by muscle work, or use soaring-gliding flight, in which chemical energy is replaced with energy harvested from moving air masses, such as thermals. Flapping flight requires more energy than soaring-gliding flight, and this difference in the use of energy increases with body mass. However, soaring-gliding results in lower speeds than flapping, especially for small species. Birds therefore face a trade-off between energy and time costs when deciding which flight strategy to use. Raptors are a group of large birds that typically soar. As relatively light weight raptors, falcons can either soar on weak thermals or fly by flapping with low energy costs. In this paper, we study the flight behavior of the insectivorous lesser kestrel (Falco naumanni) during foraging trips and the influence of solar radiation, which we have adopted as a proxy for thermal formation, on kestrel flight variables. We tracked 35 individuals from two colonies using high frequency GPS-dataloggers over four consecutive breeding seasons. Contrary to expectations, kestrels relied heavily on thermal soaring when foraging, especially during periods of high solar radiation. This produced a circadian pattern in the kestrel flight strategy that led to a spatial segregation of foraging areas. Kestrels flapped towards foraging areas close to the colony when thermals were not available. However, as soon as thermals were formed, they soared on them towards foraging areas far from the colony, especially when they were surrounded by poor foraging habitats. This reduced the chick provisioning rate at the colony. Given that lesser kestrels have a preference for feeding on large insects, and considering the average distance they cover to capture them during foraging trips, to commute using flapping flight would result in a negative energy balance for the family group. Our results show that lesser kestrels prioritize saving energy when foraging, suggesting that kestrels are more energy than time-constrained during the breeding season.
DOI: 10.5441/001/1.292
title: Data from: Study "American Herring Gulls - GPS - Lobster Bay, Southwest Nova Scotia, Canada"

description: Anthropogenic food subsidies attract opportunistic generalists like gulls in high densities, which may lead to negative impacts on human communities and local ecosystems. Managing impacts requires understanding why gulls use particular natural or industrial sites at different times of day or phases of the breeding cycle. Use of natural and human-influenced habitats likely varies temporally as gulls alter schedules and site selection to match the predictability of different resources as they vary through space and time relative to patterns in human activities and natural rhythms, whilst gull resource requirements and restrictions to movement also shift with changing reproductive demands. We quantified seasonal and circadian patterns in American herring gull interactions with anthropogenic and natural sites throughout breeding using GPS data from 15 gulls tracked over three years. We examined the weekly probability of gull occurrence at distinct destinations (e.g., islands, offshore, fish processing plants), and how occurrence varied with time of day, weekday/weekend, and tide phase, using GLMMs with a binomial response for destination-specific occurrence. Probability at the colony varied predictably through the breeding season (highest attendance from dusk to dawn, during incubation and early chick rearing), providing confidence in the modelling approach for detecting temporal patterns in behaviour. Gulls visited other islands mostly outside incubation and chick rearing, from dusk through night, likely roosting. Occurrence offshore where interaction with fishing vessels is possible was highest from dusk to dawn, but was the most likely destination during incubation and early chick rearing. Occurrence at fish plants gradually increased until after fledging when attendance was highest from Aug-Oct coincident with the peak of Atlantic herring processing, and was more likely during the weekdays, during working hours, and during low and flood tide. Gulls in southwest Nova Scotia, Canada, have the behavioural flexibility to adapt to natural rhythms and human schedules when beneficial, enabling them to thrive in a region where industry and natural resources are abundant. These findings can provide information to guide when and where to test different subsidy management strategies locally, while also considering potential increased pressures on island ecosystems.
DOI: 10.5441/001/1.35fs26kq
title: Data from: The secret life of oilbirds: new insights into the movement ecology of a unique avian frugivore

description: Background: Steatornis caripensis (the oilbird) is a very unusual bird. It supposedly never sees daylight, roosting in huge aggregations in caves during the day and bringing back fruit to the cave at night. As a consequence a large number of the seeds from the fruit they feed upon germinate in the cave and spoil. Methodology/Principal Findings: Here we use newly developed GPS/acceleration loggers with remote UHF readout to show that several assumptions about the behaviour of Steatornis caripensis need to be revised. On average, they spend only every 3rd day in a cave, individuals spent most days sitting quietly in trees in the rainforest where they regurgitate seeds. Conclusions/Significance: This provides new data on the extent of seed dispersal and the movement ecology of Steatornis caripensis. It suggests that Steatornis caripensis is perhaps the most important long-distance seed disperser in Neotropical forests. We also show that colony-living comes with high activity costs to individuals.
DOI: 10.5441/001/1.5jp8mq2v
title: Data from: Autumn migration and wintering site of a wood warbler Phylloscopus sibilatrix breeding in Denmark identified using geolocation

description: Background: Basic knowledge of detailed spatiotemporal migration patterns is lacking for most migratory bird species. Using the smallest available geolocator, we aim to map autumn migration and wintering areas of north European wood warblers Phylloscopus sibilatrix and compare the spatiotemporal pattern with recoveries of individuals ringed across Europe. Results: A tracked wood warbler migrated south-south-east to sub-Saharan Africa in Sudan and then west-south-west to winter in Côte d’Ivoire. The timing and route fits well within the distribution of ring recoveries although the westward movement after the Sahara crossing is not revealed by the ring recoveries, but only few recoveries south of Sahara exist. Conclusions: The surprising westward movement south of the Sahara supplements the overall pattern revealed by ring recoveries and aids our understanding of the connectivity and site dependence in this generally declining species.
DOI: 10.5441/001/1.3v106n1n
title: Data from: Spatial ecology of copperhead snakes (Agkistrodon contortrix) in response to urban park trails

description: NOTE: An updated and larger version of this dataset is available. See https://doi.org/10.5441/001/1.1rs3j824. ABSTRACT: Urban forests and parks are important for recreation and may serve as a natural corridor for commuters. The consequences of human-mediated disturbance in natural areas are documented for avian and mammalian species. Less is known about the consequences of human disturbance on reptile species, specifically snakes, residing in natural refuges within the urban matrix. Thus, we examined the spatial activity of copperheads (Agkistrodon contortrix) in regard to pedestrian trails within an urban forest. We used radio telemetry to track snakes during the active season and estimated distances moved in between relocations, distances to the nearest trail and home range size for individuals. We found sex and season, but not distance to the nearest trail, affected the distance snakes moved. In addition, we observed a weak, positive relationship between home range size and average distance to the trail. Sex, season and body condition did not explain snake distance to the trail, but individual patterns were variable for snakes compared to random locations generated from snake relocations. Our study indicates copperheads may be tolerant of low-level human disturbances found in an urban forest. Further work should be done to quantify levels of disturbance, such as trail use, and compare the behavior of reptiles across urban park types and locations.
DOI: 10.5441/001/1.ht5jf68h
title: Data from: High foraging site fidelity and spatial segregation among individual great black-backed gulls

description: Individual foraging site fidelity, whereby individuals repeatedly visit the same foraging areas, is widespread in nature, and likely benefits individuals through higher foraging efficiency and potentially, higher breeding success. It may arise as a consequence of habitat or resource specialisation, or alternatively, where resources are abundant or predictable, the partitioning of space might guarantee individuals exclusive foraging opportunities. We tracked seven adult great black‐backed gulls Larus marinus at a North Sea colony from early incubation to the end of the breeding season in 2016, providing a total of 1,170 foraging trips over a mean ± SD tracking period of 67 ± 16 days. There was clear spatial segregation between individuals, with almost no overlap of their core areas (50% utilisation distribution) during incubation and chick‐rearing. Core areas were relatively small and there was high repeatability (R ± SE) in foraging parameters, including initial departure direction (0.73 ± 0.11), foraging range (0.41 ± 0.14) and cumulative distance travelled (0.19 ± 0.1) throughout the breeding season. Despite the low spatial overlap, there was little evidence of differential habitat use by individuals. The near‐exclusive individual foraging areas of this species, usually considered to be a generalist, indicate that where there is high resource availability throughout the breeding season and a small local population, individuals appear to adopt a territorial strategy which likely reduces intraspecific competition.
DOI: 10.5441/001/1.5k6b1364
title: Data from: Forecasting spring from afar? Timing of migration and predictability of phenology along different migration routes of an avian herbivore [Svalbard data]

description: 1. Herbivorous birds are hypothesized to migrate in spring along a seasonal gradient of plant profitability towards their breeding grounds (green wave hypothesis). For Arctic-breeding species in particular, following highly profitable food is important, so that they can replenish resources along the way and arrive in optimal body condition to start breeding early. 2. We compared the timing of migratory movements of Arctic-breeding geese on different flyways to examine whether flyways differed in the predictability of spring conditions at stopovers, and whether this was reflected in the degree to which birds were following the green wave. 3. Barnacle geese (Branta leucopsis) were tracked with solar Argos/GPS PTTs from their wintering grounds to breeding sites in Greenland (N = 7), Svalbard (N = 21) and the Barents Sea (N = 12). The numerous stopover sites of all birds were combined into a set of 16 general stopover regions. 4. The predictability of climatic conditions along the flyways was calculated as the correlation and slope between onsets of spring at consecutive stopovers. These values differed between sites, mainly because of the presence or absence of ecological barriers. Goose arrival at stopovers was more closely tied to the local onset of spring when predictability was higher and when geese attempted breeding that year. 5. All birds arrived at early stopovers after the onset of spring and arrived at the breeding grounds before the onset of spring, thus overtaking the green wave. This is in accordance with patterns expected for capital breeders: first they must come into condition; at intermediate stopovers arrival with the food quality peak is important to stay in condition and at the breeding grounds early arrival is favoured so that hatching of young can coincide with the peak of food quality. 6. Our results suggest that a chain of correlations between climatic conditions at subsequent stopovers enables geese to closely track the green wave. However, the birds’ precision of migratory timing seems uninfluenced by ecological barriers, indicating partly fixed migration schedules. These might become non-optimal due to climate warming and preclude accurate timing of long-distance migrants in the future.
DOI: 10.15468/dl.q379w7
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
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}

 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0075533-240626123714530/datasets/export for details.