DOI: 10.5061/dryad.g79cnp5z7
title: Cory’s, Scopoli’s, and Cabo Verde shearwaters non-breeding locations

description: Aim: in highly mobile species, Migratory Connectivity (MC) has relevant
 consequences in population dynamics, genetic mixing, conservation, and
 management. Additionally, in colonially breeding species, the maintenance
 of the breeding geographical structure during the non-breeding period,
 i.e., a strong MC, can promote isolation and population divergence, which
 ultimately can affect the process of lineage sorting. In geographically
 structured populations, studying the MC and differences in environmental
 preferences among colonies, populations, or taxa can improve our
 understanding of the ecological divergence among them. Location: Atlantic
 Ocean and Mediterranean Sea. Methods: we investigated the MC and
 non-breeding ecological niche of three seabird taxa from the genus
 Calonectris (n = 805 individuals). Using 1,346 year-round trips from 34
 different breeding colonies we assess the level (from taxa to colony) at
 which MC,  and non-breeding spatial and environmental
 segregation, emerge. Results: at a taxon level, we found a clear
 difference in the non-breeding distributions between Cory’s (C. borealis)
 and Scopoli’s (C. diomedea) shearwaters, and a clear ecological divergence
 between Cory’s and Cape Verde (C. edwardsii) shearwaters. At an
 intermediate aggregation level we found that birds breeding in proximity
 had similar non-breeding habitat preferences, while birds breeding in very
 distant colonies (and therefore classified in different populations) had
 different non-breeding habitat preferences. Furthermore, within each
 taxon, we found more structure (i.e., stronger MC) and non-breeding
 divergence at an intermediate aggregation level than at the colony scale,
 where MC was weak. Main conclusions: These results suggests that
 conspecifics from nearby colonies mix in common non-breeding areas, but
 not with birds from more distant colonies or different taxa. These results
 support the need for management and conservation strategies that take in
 account this structure when dealing with migratory species with high
 connectivity.
description: Positions were obtained with Global Location Sensors (GLS; Wilson
 et al. 1992), which provide one or two positions per day, using daylight
 to calculate longitude from the time of twilight and latitude from the
 length of the day (light period). Detailed deployment information for each
 colony can be found in Morera‐Pujol et al. (2023). Twilight events
 calculated from the light measurements were visually inspected and
 corrected when interferences near the twilights were detected. Locations
 were obtained from the light data using either Intiproc® (Migrate
 Technology Ltd.) or Biotrack® (Biotrack Ltd.) software, or the
 <em>GeoLight</em> package in R (Lisovski and Hahn 2012). To
 eliminate biases due to incorrect latitude estimations during or near
 equinoxes (Ekstrom 2004) we removed position data from 20 days before and
 after the equinoxes. In addition, we removed unrealistic positions by
 applying a quadratic speed filter following McConnell et al.
 (1992). We visually inspected tracks to assign a
 phenological state to each position. Based on the distance between
 consecutive positions and directionality of movement, we classified
 periods as “residency” when for at least four days the distance between
 consecutive positions was short and the movement non-directional
 (following Dias et al. 2011). The residency periods during the breeding
 season and around the breeding colonies were classified as “breeding”. The
 residency periods outside the breeding season were classified as “main
 non-breeding” (the longest) and “staging” (the rest of them). Movement
 periods (long distances between consecutive locations and directionality)
 were classified as “migration”. For our analysis we used only the
 residency periods during non-breeding.
description: # Cory’s, Scopoli’s, and Cabo Verde shearwaters non-breeding locations
 Access this dataset on Dryad
 [https://doi.org/10.5061/dryad.g79cnp5z7](https://doi.org/10.5061/dryad.g79cnp5z7) ## Description of the data and file structure Non-breeding locations of Cory’s shearwaters (Calonectris borealis), Scopoli’s shearwaters (C. diomedea), and Cabo Verde shearwaters (C. edwardsii) tracked from the colonies of Berlenga, Chafarinas, Corvo, Faial, Graciosa, Montaña Clara, Pico, Selvagem, Sisargas, Terreros, Timanfaya, Veneguera, and Vila for Cory’s shearwaters; Cala Morell, Chafarinas, Filfla, Frioul, Giraglia, Gozo, Lavezzi, Linosa, Malta, Na Foradada, Na Pobra, Palomas, Pantaleu, Paximada, Porquerolles, Riou, Strofades, Tremiti, and Zembra for Scopoli’s shearwaters; and Curral Velho and Raso for Cabo Verde’s shearwaters. Animals were tracked between the years of 2006 and 2016. These data were used for [https://doi.org/10.1111/ddi.70013](https://doi.org/10.1111/ddi.70013) The data is in a tabular spreadsheet with columns containing species, colony, unique identifiers for each bird and trip, latitude, longitude, year of tracking (1st year, 2nd year, etc.), and an ordering column that allows the positions (each row is a position) to be ordered to form a track. ## Sharing/Access information A more complete version of this dataset (including breeding and migratory period locations), and additional data of following years can be found in the seabird tracking database (https://www.seabirdtracking.org/). This dataset was also used in the publication [https://doi.org/10.1111/ddi.13642 ](https://doi.org/10.1111/ddi.13642)and are also accessible at [https://doi.org/10.34810/data232. ](https://doi.org/10.34810/data232) ## Code/Software Analysis of this data was performed in R, and the code is available at [https://github.com/VirginiaMorera/Migratory-connectivity]()