A study on the Cory’s shearwater will help protecting new marine areas in international waters

This is the monograph Migración y ecología espacial de las poblaciones españolas de pardela cenicienta, which shows a million locations of these sea birds.

This new publication gathers research studies driven by experts on the study of marine birds, their spatial ecology and preservation, from the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio), IMEDEA and SEO/BirdLife. These scientific teams have conducted a series of researches over a decade, to know about the basic aspects of the ecology of the shearwater and improve its preservation. By collecting this work, this publication is now presenting, for the first time, many of these aspects, which were still unpublished.

More than a million locations with track and trace systems

Cory's shearwater (Calonectris diomedea) is one of the most representative birds in our seas. With populations that are suffering a severe decline, it was chosen as Bird of the Year in 2013 by the association SEO/BirdLife as an emblematic species that reflects the problem of preservation of marine birds in our seas.

Within the frame of the study, from 2007 to 2015, experts marked 460 shearwaters with GPS and other devices in 13 breeding colonies around different regions of Spain: the Balearic Islands, Castellón, Murcia, Almería, Galicia, Canary Islands and Chafarinas Islands. A total of more than a million locations, and the results all the movements of these birds throughout the year in details, as well as their open sea ecology (feeding areas, resting areas, and movements during their mating season, hibernating areas, characterization of their ecology, and migration corridors that connect breeding areas with hibernating areas). According to the authors, this is one of the most ambitious studies conducted so far to work on the ecology of bird movement in the country using new generation track and trace technologies.

The shearwater's long journey through the ocean

During their mating season, adults can easily leave the nest for days and travel hundreds of kilometres in search of food. Their migration journeys to hibernating areas are even more impressing, since they go around the South Atlantic and reach the Indian Ocean.

"In particular, the Mediterranean population uses four different hibernating areas, which are the Canary Current, Angola and Namibian waters, the central Atlantic waters and the Gulf of Guinea. In Atlantic colonies, the five hibernating areas are the Benguela Current, the Agulhas Current, the Brasil Current and the central South Atlantic. Most of these birds are loyal to the same hibernating area over the years," says Jacob González-Solís, lecturer from the Department of Evolutionary Biology, Ecology and Environmental Sciences and IRBio, head of the working group on marine birds that led this study.

Being up on the species in order to improve their preservation

There is a greater amount of data on Cory's shearwater birds to conduct their tracings, mostly due the information used in this monograph. However, "so far there are only a few areas that were specifically proposed for their preservation beyond the State scope, despite of the importance of the international range for these species, as stated in this study," says José Manuel Arcos, head of the SEO/BirdLife marine program. "Protecting places that are relevant for the species in international waters or in other countries will require multilateral international agreements, a process BirdLife International has already started working on, with the identification and proposals by marine IBA," adds Arcos.

Knowing about the distribution of Cory's shearwater allows researchers to identify the places where their activity is overlapped with threats coming from human activity (such as the accidental catch in longlines and other fishing gears, the main threat that causes hundreds of bird deaths in the Mediterranean Sea every year. Analysing the overlap of these fishing activities with longlines will ease the design of preventive measures for each area. One of the future challenges lies within the fact that involved social and political actors aim to set effective preservation measures ─such as measures to reduce shearwater accidental catches in fisheries─ such as new generation tools for tracking and preservation systems on these species and their ecosystems.

At a State level, the data provided in this report, supports the areas that were previously identified in the inventory of the Important Bird and Biodiversity Areas (IBA), currently added to the Natura 2000 network as a Special Protection Area for Birds (ZEPA).

The new monograph is the third one in Migra program, an initiative driven by SEO/BirdLife in collaboration with Iberdrola España Foundation. Launched in 2011, Migra brings the latest technology on geolocalisation and remote monitoring to know about the movements of birds within and outside the country in detail.