“Closer‐to‐home” strategy benefits juvenile survival in a long‐distance migratory bird

Abstract

Human‐induced changes in the climate and environment that occur at an unprecedented speed are challenging the existence of migratory species. Faced with these new challenges, species with diverse and flexible migratory behaviors may suffer less from population decline, as they may be better at responding to these changes by altering their migratory behavior. At the individual level, variations in migratory behavior may lead to differences in fitness and subsequently influence the population's demographic dynamics. Using lifetime GPS bio‐logging data from 169 white storks (Ciconia ciconia), we explore whether the recently shortened migration distance of storks affects their survival during different stages of their juvenile life. We also explore how other variations in migratory decisions (i.e., time, destination), movement activity (measured using overall body dynamic acceleration), and early life conditions influence juvenile survival. We observed that their first autumn migration was the riskiest period for juvenile white storks. Individuals that migrated shorter distances and fledged earlier experienced lower mortality risks. In addition, higher movement activity and overwintering “closer‐to‐home” (with 84.21% of the tracked individuals stayed Europe or North Africa) were associated with higher survival. Our study shows how avian migrants can change life history decisions over only a few decades, and thus it helps us to understand and predict how migrants respond to the rapidly changing world.

moveVis: Animating movement trajectories in synchronicity with static or temporally dynamic environmental data in r

“…To represent movement trajectories and environmental data, moveVis uses the move and raster classes implemented in the move and raster packages (Hijmans, ; Kranstauber, Smolla, & Scharf, ). We illustrate the use of the package with a temporal subset of GPS data covering migratory movements of white storks Ciconia ciconia collected by Cheng, Fiedler, Wikelski, and Flack () and Fiedler et al (). The temporal subset is included in moveVis as an example dataset.…”

“…As an example, Figure shows the single spatial frame created from the migration movements of white storks C. ciconia on a terrain base map (Cheng et al, ; Fiedler et al, ). For retrieving and composing base maps, moveVis utilizes slippymath , an r package for dealing with Slippy Map tile servers (McBain & Sumner, ).…”

Daily energy expenditure in white storks is lower after fledging than in the nest

“…We discarded the first 72 h after device implantation because of potential interference from the surgical procedure. We also discarded the day of death (determined using criteria from Cheng et al, 2019). We examined the pre-and postfledging phases separately with fledging being defined as the first of three consecutive days during which the maximum distance to the nest was larger than 500 m. Because some individuals took longer to fledge (they might have been younger during tagging), we cut the pre-fledging phase to the last 12 days prior to fledging to examine the same number of days for all individuals.…”

Determination of nest occupation and breeding effect of the white stork by human-mediated landscape in Western Poland

“…Currently, a significant fraction of the breeding population has become sedentary (Sanz-Aguilar et al 2015), and other groups stop the migration in Europe or North Africa. For example, in the German population of white storks, over 80% out of 169 juveniles equipped with transmitters stayed in Europe or North Africa, which increased their survival probability (Cheng et al 2019). Many of them use landfills as stopovers sites and foraging grounds (Arizaga et al 2018).…”