0000000000124183
AUTHOR
Ugo Mellone
Ecological specialization to fluctuating resources prevents long-distance migratory raptors from becoming sedentary on islands
[Background]: The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora's falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors.…
Spatial ecology and habitat use of adult Booted eagles (Aquila pennata) during the breeding season: implications for conservation.
Fast-moving technological advances, such as satellite tracking technologies, are providing in-depth information of aspects of avian ecology hitherto unknown. In fact, detailed information about movement ecology and ranging behaviour of birds is important not only from the perspective of the basic ecology, but also from the conservation point of view. This is particularly important in European countries where agricultural intensification, land abandonment and the withdrawal of traditional management agro-forestry practices pose a threat to biodiversity. The Booted Eagle, likewise other forest raptors, is an adequate bioindicator of human-dominated agro-forestry Mediterranean landscapes in wh…
Interspecific comparison of the performance of soaring migrants in relation to morphology, meteorological conditions and migration strategies.
This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.
Wind effects on the migration routes of trans-Saharan soaring raptors: geographical, seasonal, and interspecific variation
Wind is among the most important environmental factors shaping birds’ migration patterns. Birds must deal with the displacement caused by crosswinds and their behavior can vary according to different factors such as flight mode, migratory season, experience, and distance to goal areas. Here we analyze the relationship between wind and migratory movements of three raptor species which migrate by soaring–gliding flight: Egyptian vulture Neophron percnopterus, booted eagle Aquila pennata, and short-toed snake eagle Circaetus gallicus. We analyzed daily migratory segments (i.e., the path joining consecutive roosting locations) using data recorded by GPS satellite telemetry. Daily movements of E…
Large birds travel farther in homogeneous environments
Aim: Animal movement is an important determinant of individual survival, population dynamics and ecosystem structure and function. Nonetheless, it is still unclear how local movements are related to resource availability and the spatial arrangement of resources. Using resident bird species and migratory bird species outside the migratory period, we examined how the distribution of resources affects the movement patterns of both large terrestrial birds (e.g., raptors, bustards and hornbills) and waterbirds (e.g., cranes, storks, ducks, geese and flamingos). Location: Global. Time period: 2003–2015. Major taxa studied: Birds. Methods: We compiled GPS tracking data for 386 individuals across 3…
Wintering habitats of Eleonora's FalconsFalco eleonoraein Madagascar
[Capsule]: Eleonora's Falcons wintering in Madagascar selected degraded humid forests and cultivated areas close to pristine humid forest. [Aims]: To identify the habitat preferences of Eleonora's Falcon Falco eleonorae on their wintering grounds in Madagascar, and to use this information to gain insights into the conservation priorities of this species. [Methods]: A total of 11 Eleonora's Falcons were captured in Spain in 2007 and 2008 and equipped with solar-powered satellite transmitters. We obtained information on five complete wintering events for three birds, two of them tracked for two consecutive years. Data were analyzed using geographic information system-based cartography. [Resul…
Diurnal timing of nonmigratory movement by birds: the importance of foraging spatial scales
Timing of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activit…
Moving in the Anthropocene: Global reductions in terrestrial mammalian movements
Made available in DSpace on 2018-11-26T17:44:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-26 Robert Bosch Foundation Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-…
Regional and age-dependent differences in the effect of wind on the migratory routes of Eleonora's Falcon.
During migration, birds can show different responses to wind in relation to distance to the goal, experience, ecological barriers and visibility of landmarks. We analysed the effect of wind (tailwinds and crosswinds) on daily movement rates (forward and perpendicular) of Eleonora’s falcons using ARGOS satellite telemetry, during their trans-continental autumn migration to Madagascar, in relation to the different crossed regions and individuals’ age class. Our results showed that the effect of wind on daily movement rates was not uniform, being stronger in the farthest region from the migration goal, the Sahara desert, with adults being more affected than juveniles in this region. In the Sah…
Spatial segregation of home ranges between neighbouring colonies in a diurnal raptor
AbstractEnhancement of information transfer has been proposed as a key driver of the evolution of coloniality. Transfer of information on location of food resources implies that individuals from the same colony share foraging areas and that each colony can be associated to a specific foraging area. In colonial breeding vertebrates, colony-specific foraging areas are often spatially segregated, mitigating intercolony intraspecific competition. By means of simultaneous GPS tracking of lesser kestrels (Falco naumanni) from neighbouring colonies, we showed a clear segregation of space use between individuals from different colonies. Foraging birds from different neighbouring colonies had home r…
Broad-front migration leads to strong migratory connectivity in the lesser kestrel (Falco naumanni)
Aim: Migratory animals regularly move between often distant breeding and non‐breeding ranges. Knowledge about how these ranges are linked by movements of individuals from different populations is crucial for unravelling temporal variability in population spatial structuring and for identifying environmental drivers of population dynamics acting at different spatio‐temporal scales. We performed a large‐scale individual‐based migration tracking study of an Afro‐Palaearctic migratory raptor, to determine the patterns of migratory connectivity of European breeding populations. Location: Europe, Africa. Methods: Migration data were recorded using different devices (geolocators, satellite transmi…
Data from: Large birds travel farther in homogeneous environments
Aim: Animal movement is an important determinant of individual survival, population dynamics, and ecosystem structure and function. Yet it is still unclear how local movements are related to resource availability and the spatial arrangement of resources. Using resident bird species and migratory bird species outside of the migratory period, we examined how the distribution of resources affect the movement patterns of both large terrestrial birds (e.g., raptors, bustards, hornbills) and waterbirds (e.g., cranes, storks, ducks, geese, flamingos). Location: Global Time Period: 2003 - 2015 Major taxa studied: Birds Methods: We compiled GPS tracking data for 386 individuals across 36 bird specie…
Data from: Moving in the Anthropocene: global reductions in terrestrial mammalian movements
Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects no…