seabirds. Of historical note, the graellsii subspecies of the polytypic lesser blackbacked gull was described in 1857 by A. E. Brehm based on some specimens
captured in the harbour of Malaga (Spain) (Brehm 1857).
Despite the relevance of the region for seabirds, breeding populations are quite
small and restricted to a few suitable nesting sites (UNEP-MAP-RAC/SPA 2015).
The main breeding sites include wetlands, cliffs, and small islands/archipelagos that
offer some degree of protection. For example, the most important breeding sites for
Scopoli’s shearwater (Calonectris diomedea) are the Chafarinas Islands in Spain and
the Habibas and Rachgoun Islands in Algeria (Reyes-González and González-Solís
2016), whereas there are only a few breeding pairs of Cory’s shearwater (Calonectris
borealis) in the Chafarinas Islands. It has been suggested that the Almeria-Oran
oceanographic front is the actual divide between C. borealis and C. diomedea
(Gómez-Díaz et al. 2006). The Alboran Sea, Chafarinas Islands, and Alhucemas
Islands host large colonies of Audouin’s gull (Oro et al. 2006; Afán et al. 2010). This
species also breeds in other dispersal points on the north African coast and has been
observed recently in Ceuta (Guirado and Guirado 2015).
Different wetlands on both sides of the Alboran Sea that have been included in the
RAMSAR Convention host large colonies of breeding larids and waterbirds. On the
northern shore, these wetlands include the Punta Entinas-Sabinar National Park and
the Cabo de Gata salt marshes (Almeria, Spain) (Paracuellos and Nevado 2003;
Paracuellos 2006). On the southern shore (Morocco), they include the Sebkha Bou
Areg lagoon and the river Moulouya estuary, which is the most significant estuary
and floodplain complex of the largest river in the Maghreb. In these sites, emblematic breeding species are the little tern, Auoduin’s gull, and the slender-billed gull
(Ramsar Convention 2005).
Anthropized environments, such as large cities, are also used as nesting sites by
less demanding species such as the yellow-legged gull, which is well adapted to feed
on human refuse, discards, and so on (e.g. Sol et al. 1995; García-Barcelona et al.
2018). In fact, the yellow-legged gull is the most abundant breeding seabird species
in the Alboran basin with around 15,000 nesting pairs (Molina and Bermejo 2009;
Radi et al. 2018). Among wintering species, the Mediterranean gull, the lesser blackbacked gull, the northern gannet, and the Balearic shearwater should be mentioned
due to their abundance and ecological importance.
Due to high levels of primary productivity in the Alboran Sea, some species, such
as the Balearic shearwater, northern gannet, and Mediterranean gull, use this area for
feeding and foraging. Although the Balearic shearwater typically inhabits coastal
waters on the continental shelf (i.e. mainly the Levantine region of Spain and
Balearic Islands) (Louzao et al. 2006), it is also a frequent visitor to the Alboran
Sea, where it feeds and forages even during breeding period (Ruiz and Martí 2004;
Louzao et al. 2012). Given this behaviour, it has been recommended that countries
adjacent to the Alboran Sea should enact transboundary protection measures for this
critically endangered species (Louzao et al. 2012).
Three important bird areas have been designated in the Alboran Sea due to its
importance for the Balearic shearwater among others species (Arcos et al. 2009).
These three areas are Malaga bay, the Maro-Cerro Gordo cliffs, and Almeria bay,
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captured in the harbour of Malaga (Spain) (Brehm 1857).
Despite the relevance of the region for seabirds, breeding populations are quite
small and restricted to a few suitable nesting sites (UNEP-MAP-RAC/SPA 2015).
The main breeding sites include wetlands, cliffs, and small islands/archipelagos that
offer some degree of protection. For example, the most important breeding sites for
Scopoli’s shearwater (Calonectris diomedea) are the Chafarinas Islands in Spain and
the Habibas and Rachgoun Islands in Algeria (Reyes-González and González-Solís
2016), whereas there are only a few breeding pairs of Cory’s shearwater (Calonectris
borealis) in the Chafarinas Islands. It has been suggested that the Almeria-Oran
oceanographic front is the actual divide between C. borealis and C. diomedea
(Gómez-Díaz et al. 2006). The Alboran Sea, Chafarinas Islands, and Alhucemas
Islands host large colonies of Audouin’s gull (Oro et al. 2006; Afán et al. 2010). This
species also breeds in other dispersal points on the north African coast and has been
observed recently in Ceuta (Guirado and Guirado 2015).
Different wetlands on both sides of the Alboran Sea that have been included in the
RAMSAR Convention host large colonies of breeding larids and waterbirds. On the
northern shore, these wetlands include the Punta Entinas-Sabinar National Park and
the Cabo de Gata salt marshes (Almeria, Spain) (Paracuellos and Nevado 2003;
Paracuellos 2006). On the southern shore (Morocco), they include the Sebkha Bou
Areg lagoon and the river Moulouya estuary, which is the most significant estuary
and floodplain complex of the largest river in the Maghreb. In these sites, emblematic breeding species are the little tern, Auoduin’s gull, and the slender-billed gull
(Ramsar Convention 2005).
Anthropized environments, such as large cities, are also used as nesting sites by
less demanding species such as the yellow-legged gull, which is well adapted to feed
on human refuse, discards, and so on (e.g. Sol et al. 1995; García-Barcelona et al.
2018). In fact, the yellow-legged gull is the most abundant breeding seabird species
in the Alboran basin with around 15,000 nesting pairs (Molina and Bermejo 2009;
Radi et al. 2018). Among wintering species, the Mediterranean gull, the lesser blackbacked gull, the northern gannet, and the Balearic shearwater should be mentioned
due to their abundance and ecological importance.
Due to high levels of primary productivity in the Alboran Sea, some species, such
as the Balearic shearwater, northern gannet, and Mediterranean gull, use this area for
feeding and foraging. Although the Balearic shearwater typically inhabits coastal
waters on the continental shelf (i.e. mainly the Levantine region of Spain and
Balearic Islands) (Louzao et al. 2006), it is also a frequent visitor to the Alboran
Sea, where it feeds and forages even during breeding period (Ruiz and Martí 2004;
Louzao et al. 2012). Given this behaviour, it has been recommended that countries
adjacent to the Alboran Sea should enact transboundary protection measures for this
critically endangered species (Louzao et al. 2012).
Three important bird areas have been designated in the Alboran Sea due to its
importance for the Balearic shearwater among others species (Arcos et al. 2009).
These three areas are Malaga bay, the Maro-Cerro Gordo cliffs, and Almeria bay,
718
J. C. Báez et al.