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- Data packageData from: Study "GPS tracking of bobcats and coyotes in northern Washington"(2023-05-19) Prugh, Laura R.The challenge that large carnivores face in coexisting with humans calls into question their ability to carry out critical ecosystem functions such as mesopredator suppression outside protected areas. In this study, we examined the movements and fates of mesopredators and large carnivores across rural landscapes characterized by substantial human influences. Mesopredators shifted their movements toward areas with twofold-greater human influence in regions occupied by large carnivores, indicating that they perceived humans to be less of a threat. However, rather than shielding mesopredators, human-caused mortality was more than three times higher than large carnivore–caused mortality. Mesopredator suppression by apex predators may thus be amplified, rather than dampened, outside protected areas, because fear of large carnivores drives mesopredators into areas of even greater risk from human super predators.
- Data packageData from: Study "Satellite tracking of black-capped petrels, 2019"(2023-05-30) Satgé, Yvan G.; Keitt, Bradford S.; Gaskin, Chris P.; Patteson, J. Brian; Jodice, Patrick G.R.
- Data packageData from: Timing is critical: consequences of asynchronous migration for the performance and destination of a long-distance migrant(2023-07-25) Acácio, Marta; Catry, Inês; Soriano-Redondo, Andrea; Silva, João Paulo; Atkinson, Philip W.; Franco, Aldina M.A.Background: Migration phenology is shifting for many long-distance migrants due to global climate change, however the timing and duration of migration may influence the environmental conditions individuals encounter, with potential fitness consequences. Species with asynchronous migrations, i.e., with variability in migration timing, provide an excellent opportunity to investigate how of the conditions individuals experience during migration can vary and affect the migratory performance, route, and destination of migrants. Methods: Here, we use GPS tracking and accelerometer data to examine if timing of autumn migration influences the migratory performance (duration, distance, route straightness, energy expenditure) and migration destinations of a long-distance, asynchronous, migrant, the white stork (Ciconia ciconia). We also compare the weather conditions (wind speed, wind direction, and boundary layer height) encountered on migration and examine the influence of wind direction on storks’ flight directions. Results: From 2016 to 2020, we tracked 172 white storks and obtained 75 complete migrations from the breeding grounds in Europe to the sub-Saharan wintering areas. Autumn migration season spanned over a 3-month period (July–October) and arrival destinations covered a broad area of the Sahel, 2450 km apart, from Senegal to Niger. We found that timing of migration influenced both the performance and conditions individuals experienced: later storks spent fewer days on migration, adopted shorter and more direct routes in the Sahara Desert and consumed more energy when flying, as they were exposed to less supportive weather conditions. In the Desert, storks’ flight directions were significantly influenced by wind direction, with later individuals facing stronger easterly winds (i.e., winds blowing to the west), hence being more likely to end their migration in western areas of the Sahel region. Contrastingly, early storks encountered more supportive weather conditions, spent less energy on migration and were exposed to westerly winds, thus being more likely to end migration in eastern Sahel. Conclusions: Our results show that the timing of migration influences the environmental conditions individuals face, the energetic costs of migration, and the wintering destinations, where birds may be exposed to different environmental conditions and distinct threats. These findings highlight that on-going changes in migration phenology, due to environmental change, may have critical fitness consequences for long-distance soaring migrants.
- Data packageData from: Non-breeding ecology of a Neotropical-Nearctic migrant, the Common Nighthawk (Chordeiles minor): Habitat, activity patterns, molt, and migration(2023-07-27) Fariña, Nestor; Villalba, Olga; Pagano, Luis G.; Bodrati, Alejandro; Stein, Eliza; Norris, Andrea R.; Cockle, Kristina L.Long-distance migratory aerial insectivores are among the most threatened groups of birds breeding in North America, yet little is published about the two-thirds of their annual cycle that unfolds in South America. To study non-breeding ecology and migration of the Common Nighthawk (Chordeiles minor), we observed, captured, and GPS-tagged individuals at Reserva Natural Rincón de Santa María, an Important Bird Area on the Paraná River in Corrientes, Argentina, from 2017 to 2022 (237 captures, 95 individuals, 556 GPS fixes from 8 females). Common Nighthawks arrived at the reserve (late November to mid-January) partway through flight feather molt; primaries 8, 9, and 10 molted consecutively until early February, followed by body feathers. Three tagged females spent December/January to March at the reserve, May to August in Florida (USA), and October/November to December/January in the Cerrado (Brazil), and at least one traveled 1800 km while molting P8. Recapture rates across seasons were 44% for females and 25% for males. Small body size and breeding locations in Florida are consistent with the chapmani subspecies previously recorded from Argentina. Direct observations and GPS tracking (8 individuals) revealed that nighthawks roosted during the day in mature exotic pines; foraged over pines and native grasslands for 26–41 min within ~40 min after sunset, nearly always in silence; and rested for the remainder of the night in native grasslands, on roads, or on rocky platforms. Common Nighthawks should be included among the growing number of migratory species that exhibit long-distance movements between stationary sites during their long non-breeding period. Our results also suggest site fidelity to non-breeding areas, a continuous molt-migration strategy, and some nuanced migratory connectivity. Programs aiming to conserve long-distance migratory aerial insectivores should support long-term monitoring led from the Global South, especially in the Cerrado and southern South America. Please see Appendix 1 for a Spanish translation of this article.
- Data packageData from: The price of being late: short- and long-term consequences of a delayed migration timing [delayed birds](2023-07-28) Bontekoe, Iris D.; Hilgartner, Roland; Altheimer, Sylvia; Flack, AndreaChoosing 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.
- Data packageData from: The price of being late: short- and long-term consequences of a delayed migration timing [control birds](2023-07-28) Bontekoe, Iris D.; Flack, Andrea; Fiedler, WolfgangChoosing 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.
- Data packageData from: Multi-scale movement syndromes for comparative analyses of animal movement patterns(2023-10-18) Kays, Roland; Hirsch, Ben T.; Caillaud, Damien; Mares, Rafael; Alavi, Shauhin; Havmøller, Rasmus Worsøe; Crofoot, Margaret C.Background: Animal movement is a behavioral trait shaped by the need to find food and suitable habitat, avoid predators, and reproduce. Using high-resolution tracking data, it is possible to describe movement in greater detail than ever before, which has led to many discoveries about the behavioral strategies of particular species. Recently, enough data been become available to enable a comparative approach, which has the potential to uncover general causes and consequences of variation in movement patterns, but which must be scale specific. Methods: Here we introduce a new multi-scale movement syndrome (MSMS) framework for describing and comparing animal movements and use it to explore the behavior of four sympatric mammals. MSMS incorporates four hierarchical scales of animal movement: (1) fine-scale movement steps which accumulate into (2) daily paths which then, over weeks or months, form a (3) life-history phase. Finally, (4) the lifetime track of an individual consists of multiple life-history phases connected by dispersal or migration events. We suggest a series of metrics to describe patterns of movement at each of these scales and use the first three scales of this framework to compare the movement of 46 animals from four frugivorous mammal species. Results: While subtle differences exist between the four species in their step-level movements, they cluster into three distinct movement syndromes in both path- and life-history phase level analyses. Differences in feeding ecology were a better predictor of movement patterns than a species’ locomotory or sensory adaptations. Conclusions: Given the role these species play as seed dispersers, these movement syndromes could have important ecosystem implications by affecting the pattern of seed deposition. This multiscale approach provides a hierarchical framework for comparing animal movement for addressing ecological and evolutionary questions. It parallels scales of analyses for resource selection functions, offering the potential to connect movement process with emergent patterns of space use.
- Data packageData from: Thermal soaring in tropicbirds suggests that diverse seabirds may use this strategy to reduce flight costs(2023-09-03) Garde, Baptiste; Fell, Adam; Krishnan, Krishnamoorthy; Jones, Carl G.; Gunner, Richard; Tatayah, Vikash; Cole, Nik C.; Lempidakis, Emmanouil; Shepard, Emily L.C.Thermal soaring can offer substantial reductions in flight cost but it is often assumed to be confined to a relatively narrow group of fliers (those with low wing loading relative to their body mass). Using high-frequency movement data, including magnetometry and GPS, we identified thermal soaring in a seabird previously thought to use only flapping flight; red-tailed tropicbirds (Phaethon rubricauda). We tracked 55 individuals breeding on Round Island, Mauritius, and examined the environmental conditions that predicted thermal soaring in 76 trips (ranging from 0.8 to 43 h, mean= 5.9 h). Tropicbirds used thermal soaring and gliding flight for 13% of their flight time on average (range 0 - 34%), in association with both commuting and prey-searching/ pursuits. The use of thermal soaring showed strong variation between trips, but birds were more likely to soar when flying with tailwinds. This enables them to reduce their flight costs without a substantial increase in trip duration, which is pertinent in the breeding season when they are constrained by time and the need to return to a central place. Birds may therefore be able to increase the amount of thermal soaring outside the breeding season. Overall, we suggest that thermal soaring may be more widespread than previously thought, given that birds without specific morphological adaptations for this behaviour can soar for extended periods, and the bio-logging approaches best-placed to detect thermal soaring (high-frequency GPS/ magnetometry) tend to be used in the breeding season, when thermal soaring may be less likely.
- Data packageData from: Fitness, behavioral, and energetic trade-offs of different migratory strategies in a partially migratory species(2023-08-03) Soriano-Redondo, Andrea; Franco, Aldina M.A.; Acácio, Marta; Payo-Payo, Ana; Martins, Bruno Herlander; Moreira, Francisco; Catry, InêsAlternative migratory strategies can coexist within animal populations and species. Anthropogenic impacts can shift the fitness balance between these strategies leading to changes in migratory behaviors. Yet some of the mechanisms that drive such changes remain poorly understood. Here we investigate the phenotypic differences, and the energetic, behavioral, and fitness trade-offs associated with four different movement strategies (long- and short-distance migration, and regional and local residency) in a population of white storks (Ciconia ciconia) that has shifted its migratory behavior over the last decades, from fully long-distance migration towards year-round residency. To do this, we tracked 75 adult storks fitted with GPS/GSM loggers with triaxial acceleration sensors over 5 years, and estimated individual displacement, behavior, and overall dynamic body acceleration, a proxy for activity-related energy expenditure. Additionally, we monitored nesting colonies to assess individual survival and breeding success. We found that long-distance migrants travelled thousands of kilometers more throughout the year, spent more energy, and >10% less time resting compared to short-distance migrants and residents. Long-distance migrants also spent on average more energy per unit of time while foraging, and less energy per unit of time while soaring. Migratory individuals also occupied their nests later than resident ones, later occupation led to later laying date and reduced number of fledglings. However, we did not find significant differences in survival probability. Finally, we found phenotypic differences in the migratory probability, as smaller-sized individuals were more likely to migrate, and they might be incurring in higher energetic and fitness costs than larger ones. Our results shed light into the shifting migratory strategies in a partially migratory population and highlight the nuances of anthropogenic impacts on species behavior, fitness, and evolutionary dynamics.
- Data packageData from: Study "American Herring Gulls - GPS - Lobster Bay, Southwest Nova Scotia, Canada"(2023-08-29) Mallory, Mark L.; Craik, Shawn; Allard, Karel A.; Gutowsky, SarahAnthropogenic 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.