DOI: 10.5061/dryad.qjq2bvqnh
title: Itinerant lifestyle and congregation of lesser kestrels in West Africa

description: Trans-Saharan migrants often spend a large proportion of their annual
 cycle wintering in the Sahel. Advances in fieldwork and tracking
 technology have greatly enhanced our ability to study their ecology in
 these areas. Using GPS-tracking we aimed to investigate the little-known
 non-breeding movements of the lesser kestrel Falco naumanni in sub-Saharan
 Africa. We segment non-breeding tracks (n = 79 tracks by 54 individuals)
 into staging events (131± 25 days per non-breeding cycle), itinerant
 movements between staging sites (11 ± 10 days), and non-directed
 exploratory movements (6 ± 5 days). We then describe timing and
 directionality of itinerant movements by male and female kestrels
 throughout the non-breeding season. Regardless of sex, lesser kestrels
 spent on average 89% of the non-breeding season staging at 2 (range = 1–4)
 sites in West Africa. At the end of September, kestrels arrived along a
 broad front throughout the northern Sahel. By December, however, they
 congregated into two distinct clusters in Senegal and along the
 Malian-Mauritanian border. The birds stayed for longer periods and showed
 greater daily activity in the latter areas, compared to their first and
 intermediate ones. Among 24 individuals tracked along multiple annual
 cycles, 20 individuals consistently used the Senegalese or
 Malian-Mauritanian cluster. The remaining four birds used these clusters
 only after 2-3 years of tracking or switched between clusters across
 years. The eastward and westward itinerant movements of lesser kestrels
 during the non-breeding season, coupled with their tendency to cluster
 geographically towards the end, differ from the southward movements of
 other insectivorous raptors in West Africa. While 31% of Spanish lesser
 kestrels converged in Senegal, where roosts of &gt; 20,000 birds are
 known, 68% moved into the Malian-Mauritanian border region where more
 groundwork is needed.
description: Fieldwork was conducted in Spain during the
 breeding seasons of 2016–2020. A total of 216 adults were captured
 near the colony using balchatri or mist nets. They were also captured
 within the nest (such as nestboxes or other cavities) before egg laying,
 at the end of the incubation period or during the chick-rearing
 phase. We used two models of solar
 GPS-UHF biologgers from
 different manufacturers (GPSminiDatalogger, Microsensory LS, Córdoba,
 Spain; and NanoFix GEO+RF, Pathtrack Ltd., Leeds, UK.). The
 GPS-UHF loggers weighing 5.5 g (including harness, ~3.8 % of the mean
 weight at capture, males = 146.0 g ± 35 SD; females = 148.0 g ±
 29) were attached as
 backpacks with a Teflon harness. Locations were stored on-board and
 downloaded via a UHF base station placed in the vicinity of the colony.
 Overall, we analysed 79 non-breeding
 tracks from the 54 adult birds (25 males and 29 females) from 20 breeding
 sites All data analyses were conducted in R (V 4.2.3), and all figures were
 produced with <em>ggplot2</em>. The full data was
 resampled to a 1-h interval, allowing
 deviations of up to 20 min.  We calculated movement metrics
 using the R package ‘fossil’. All the mixed linear models were implemented
 using the ‘lme4’ package. We determined daily sunrise/sunset times using
 the "StreamMetabolism" package.
 In addition, we used
 third-party public data from: 
 Country borders via: https://www.naturalearthdata.com/downloads/50m-cultural-vectors/  Topography: alt_30s_bil via https://geodata.ucdavis.edu/climate/worldclim/1_4/grid/cur/ The main inland water (e.g. rivers and deltas) present in Senegal, Gambia, Mauritania and Mali via: https://www.diva-gis.org/ 
description: # Data for: Itinerant lifestyle and congregation of lesser kestrels in
 West Africa * File name: README.md * Authors: Lina Lopez-Ricaurte * Other
 contributors: Wouter M.G. Vansteelant, Jesús Hernández-Pliego, Daniel
 García-Silveira, Susana Casado, Fernando Garcés-Toledano, Juan
 Martínez-Dalmau, Alfredo Ortega, Beatriz Rodríguez-Moreno, Javier
 Bustamante * Date created: 2023-09-06 Accompanying Paper and Data --- *
 Paper Title: "Itinerant lifestyle and congregation of lesser kestrels
 in West Africa" * Paper identifier: 10.1111/jav.03063 * Dataset
 Title: Data for: Itinerant lifestyle and congregation of lesser kestrels
 in West Africa * Persistent Identifier:
 https://doi.org/10.5061/dryad.qjq2bvqnh * Creators: Lina Lopez-Ricaurte *
 Dataset Contributors: Wouter M.G. Vansteelant, Jesús Hernández-Pliego,
 Daniel García-Silveira, Susana Casado, Fernando Garcés-Toledano, Juan
 Martínez-Dalmau, Alfredo Ortega, Beatriz Rodríguez-Moreno, Javier
 Bustamante * Date of Issue: 2023-09-05 *** Methodological Information ===
 * Methods of data collection/generation: see manuscript for details- -
 -Description of the data and file structure Pre-processed tracking data
 and metadata on Dryad === Details for: LK\_fulldata\_resampled.txt ---
 Description: a text file containing the tracking data (complete annual
 cycle) of 54 lesser kestrels tagged at 28 breeding sites across Spain.
 Format(s): .txt Size(s): 39.269 KB * ID: identifier device * date: date *
 indday: identifiers for unique bird days, composed of columns ID and a day
 number with 0000 = 1 Sept * trip: identifier of unique trips, composed
 from columns ID, year and months. s1 (Jan, Feb, Mar, Apr, May) and s2
 (Jun, Jul, Aug, Sept, Oct, Nov,Dic) * date\_time: timestamp in UTC * LON:
 longitude in decimal degrees, WGS84 * LAT: latitude in decimal degrees,
 WGS84 * month: month * year: year * yday: day of year (0-365) * sex:sex
 (f=female, m= male) * POP: name of the country in which the bird was
 tagged (in our case -Spain) * daynight: day and night locations * cycle: a
 factor indicating the season to which the data belongs, such as summer,
 autumn migration, winter, or spring migration, for a specific year. *
 type2: a factor showing the segmentation of the track in different stages:
 breeding, migration, winter, winter.exploratory * type: a factor
 indicating the segmentation of the track into various stages: breeding,
 migration, winter.first, winter.transit, winter.inter.first,
 winter.exploratory, winter.inter.second, winter.last, winter.inter.third,
 winter.inter.fourth, winter.inter.fifth, winter.exploratory.outlier (i.e.
 long trip of up to 100 km north to West Sahara, followed by a return to
 Kaolack) * colony: represents 20 distinct colonies located within Spain.
 See Supporting information S1 for details. Details for:
 Metadata\_segmentation.csv *** * Description: a comma-delimited file
 containing the full individual metadata of lesser kestrels to segment
 tracks into different stages. * Format(s): .csv * Size(s): 67 KB *
 Variables: * ID: identifier of the device * cycle: a factor indicating the
 season to which the data belongs, such as summer, autumn migration,
 winter, or spring migration, for a specific year. * date: date format
 dd/mm/yyyy * type: a factor indicating the segmentation of the track into
 various stages: breeding, migration, winter.first, winter.transit,
 winter.inter.first, winter.exploratory, winter.inter.second, winter.last,
 winter.inter.third, winter.inter.fourth, winter.inter.fifth,
 winter.exploratory.outlier (i.e. long trip of up to 100 km north to West
 Sahara, followed by a return to Kaolack) * colony: represents 20 distinct
 colonies located within Spain. See Supporting information S1 for details.
 * logger\_type: the type of biologger: GPSminidatalogger, PathTrack
 Third-party data *** Links to other publicly accessible third-party data *
 country borders via:
 https://www.naturalearthdata.com/downloads/50m-cultural-vectors/ * the
 main inland water (e.g. rivers and deltas) present in Senegal, Gambia,
 Mauritania and Mali via: (Source: Digital Chart of the World, Danko 1992)
 via https://www.diva-gis.org/ * topography: alt\_30s\_bil via
 https://geodata.ucdavis.edu/climate/worldclim/1\_4/grid/cur/