Monitoring Mediterranean Lesser Crested Terns (Thalasseus bengalensis emigratus) in Libya

RAC/SPA-UNEP/MAP, 2014. Monitoring Mediterranean Lesser Crested Terns Thalasseus bengalensis emigratus. By Baccetti N. and Zenatello M. (Ed.), RAC.SPA, Tunis. 26p + Appendices. PDF

Summary:

The Mediterranean Lesser Crested Terns, Thalasseus bengalensis emigratus, is a Mediterranean endemic seabird, potentially vulnerable to many sources of threat. In 2012, within the framework of the MedMPAnet Project, a study was conducted on this species in Libya, especially in Garah, a potential future MPA where the largest fraction of the seabird global population is concentrated.

Actions and methods are described to monitor the breeding population of the Mediterranean Lesser Crested Tern, which is currently confined to Libya. The aim is providing a tool which will allow a coherent and safe approach to a population of extremely high conservation value, which is potentially vulnerable to many sources of threat, not least monitoring itself.

Assessing changes in population size, distribution and breeding success is crucial for conservation. We attempted to gather recent experiences carried out under the RAC-SPA umbrella to produce a document available for further sharing, that may ensure a correct continuation of activities in the next future. The monitoring guide of the Mediterranean Lesser Crested Tern population is now available on-line at the RAC-SPA website.

 Adult Mediterranean Lesser Crested Tern (Thalasseus bengalensis emigrates) and ringed juvenile at Garah, Libya

Adult Mediterranean Lesser Crested Terns (Thalasseus bengalensis emigrates) and ringed juvenile (c. 10 days old) at Garah, Libya. (photo: J. Sultana).

Breeding colony of the Mediterranean Lesser Crested Terns (Thalasseus bengalensis emigrates) at Garah, Libya

Breeding colony of the Mediterranean Lesser Crested Terns (Thalasseus bengalensis emigrates) at Garah, Libya. (photo: J. Sultana).

Irreplaceable area extends marine conservation hotspot off Tunisia: insights from GPS-tracking Scopoli’s shearwaters from the largest seabird colony in the Mediterranean

aGrémillet, D., Péron, C., Pons, J.-B., Ouni, R., Authier, M., Thévenet, M. & Fort, J. 2014. Irreplaceable area extends marine conservation hotspot off Tunisia: insights from GPS-tracking Scopoli’s shearwaters from the largest seabird colony in the Mediterranean. Marine Biology 161: 2669-2680.  doi:10.1007/s00227-014-2538-z

Abstract:

Recent meta-analyses identified conservation hotpots at the scale of the Mediterranean, yet those may be crude by lack of detailed information about the spatial ecology of the species involved. Here, we identify an irreplaceable marine area for >95 % of the world population of the Scopoli’s shearwater (Calonectris diomedea), which is endemic to the Mediterranean and breeds on the island of Zembra off Tunis. To this end, we studied the three-dimensional at-sea movements of 50 breeding adults (over a total of 94 foraging trips) in 2012 and 2013, using GPS and temperature–depth recorders. Feathers were also collected on all birds to investigate their trophic status. Despite Zembra being the largest seabird colony in the Mediterranean (141,000 pairs), the per capita home-range of Scopoli’s shearwaters foraging from this colony was not larger than that of birds from much smaller colonies, indicating highly beneficial feeding grounds in the Gulf of Tunis and off Cap Bon. Considering depleted Mediterranean small pelagic fish stocks, supposed to be Scopoli’s shearwater prey base, we therefore speculate that birds may now also largely feed on zooplankton, something which is supported by our stable isotopic analyses. Crucially, shearwater at-sea feeding and resting areas showed very little overlap with a conservation hotspot recently defined on the western side of the Gulf of Tunis using meta-analyses of species distributions relative to anthropogenic threats. We therefore propose a major extension to this conservation hotspot. Our study stresses the importance of detailed biotelemetry studies of marine megafauna movement ecology for refining large-scale conservation schemes such as marine protected area networks.

Ringing and tagging with a GPS mounted on TDR of Scopoli’s Shearwater (Calonectris diomedea), Zembra Archipelago, Tunisia

Ringing and tagging with a GPS mounted on TDR (temperature–depth recorders) of Scopoli’s Shearwater (Calonectris diomedea), Zembra Archipelago, Tunisia (photo: Initiative PIM).

2nd symposium on the conservation of coastal and marine bird species: 1st announcement

The main objective of the second Symposium is to review the current knowledge of the 25 bird taxa included in the SPA/BD Protocol and to discuss the most recent results of research and conservation work regarding these species. This symposium is also intended to provide an opportunity for Mediterranean ornithologists to exchange information and experience. Specialists from all over the Mediterranean region are invited to take part in this symposium.

More information at the Regional Activity Centre for Specially Protected Areas (RAC/SPA) website: http://rac-spa.org/birds_symposium

1ère annonce au deuxième symposium sur la conservation des oiseaux côtiers et marins en Méditerranée

 L’objectif principal de ce deuxième Symposium est la revue des connaissances actuelles de 25 taxons d’oiseaux inclus dans le Protocole ASP/DB et la discussion des récents résultats de recherche et de travaux de conservation concernant ces espèces. Le symposium fournit aussi une opportunité pour les ornithologues Méditerranéens pour l’échange d’informations et d’expériences. Les spécialistes de toute la région Méditerranéenne sont invités à prendre part à ce symposium.

Plus d’information dans le site-web du RAC/SPA:
http://rac-spa.org/fr/symposium_oiseaux

 2nd symposium on the conservation of coastal and marine bird species

2nd symposium on the conservation of coastal and marine bird species in the Mediterranean

The vulnerable Osprey population of the Al Hoceima National Park, Morocco: present status and threats

Monti, F., Nibani, H., Dominici, J.M., Idrissi, H.R., Thévenet, M., Beaubrun, P.C. & Duriez, O. (2013). The vulnerable Osprey breeding population of the Al Hoceima National Park, Morocco: present status and threats. Ostrich 84(3): 199–204.
doi: 10.2989/00306525.2013.865280

Abstract:

In the Mediterranean, most areas belonging to the initial distribution range of the Osprey Pandion haliaetus have been lost and local populations have disappeared in recent decades because of persecution. Even though direct management actions have allowed local partial recovery, the Mediterranean population currently only holds a few tens of breeding pairs and is still exposed to local extinction risks. One of the last Mediterranean Osprey breeding areas lies along the North African coast between Morocco and Algeria. In this paper, we report new information on the Osprey population within the Al Hoceima National Park, Morocco. The status of the population for 2012 and 2013 is reported and compared with data collected during the period 1983–1990. A reduction in number of nests and breeding pairs was observed and a 35.7% decrease in the population size recorded. In addition, we discuss the main identified threats to Osprey habitats (e.g. dynamite and poison fishing) that affect the Osprey breeding population in this area. In this context, we stress the necessity for urgent measures to be adopted at the local scale for the protection of this vulnerable population in the light of a sound conservation strategy also at the scale of the Mediterranean.

Osprey (Pandion haliaetus) at Al Hoceima National Park, Morocco

Osprey (Pandion haliaetus) at Al Hoceima National Park, Morocco (photo: A. El Idrissi Essougrati).

Articles about Mediterranean raptors:

Découverte de la plus importante colonie algérienne du Faucon d’Éléonore Falco eleonorae.

Breeding biology of Eleonora’s Falcon, Falco eleonorae Gené, 1839 (Accipitriformes Falconidae), in Northeast Algeria at Sérigina Island.

Circannual variation in movement patterns of the Black Kite (Milvus migrans migrans): a review

Panuccio, M., Agostini, N., Mellone, U., & Bogliani, G. (2014). Circannual variation in movement patterns of the Black Kite (Milvus migrans migrans): a review. Ethology Ecology & Evolution 26: 1-18.    DOI:10.1080/03949370.2013.812147
PDF in ResearchGate.net

Abstract:

The nominal subspecies of the Black Kite is a summer resident in Europe and Asia that winters mostly in western Africa, although numbers of birds wintering in the Mediterranean area are increasing. During migrations, tens of thousands are observed migrating through the Strait of Gibraltar between Spain and Morocco, along the eastern side of the Black Sea, and in the Middle East, while substantial numbers cross the central Mediterranean and the Bosphorus. This paper provides a review of research concerning migration and its relationship with foraging behaviour in a circannual perspective. In particular, research made both by satellite tracking and by visual observations suggests a more evident time-selected migration during autumn rather than spring. Moreover, differences in timing occurring among different flyways could be explained either by different rates of intra-specific competition in areas with different breeding density and/or by different distances between wintering and breeding grounds.

Flyways used by Black Kites (Milvus migrans migrans) during autumn migration

Flyways used by Black Kites (Milvus migrans migrans) during autumn migration (see the paper for details)

Annual cycle and migration strategies of Great Reed Warbler as revealed by a geolocator study

Lemke HW, Tarka M, Klaassen RHG, Åkesson M, Bensch S, Hasselquist D & Hansson.B. (2013) Annual Cycle and Migration Strategies of a Trans-Saharan Migratory Songbird: A Geolocator Study in the Great Reed Warbler. PLoS ONE 8(10): e79209. doi: 10.1371/journal.pone.0079209

Abstract:

Recent technological advancements now allow us to obtain geographical position data for a wide range of animal movements. Here we used light-level geolocators to study the annual migration cycle in great reed warblers (Acrocephalus arundinaceus), a passerine bird breeding in Eurasia and wintering in sub-Saharan Africa. We were specifically interested in seasonal strategies in routes and schedules of migration. We found that the great reed warblers (all males, no females were included) migrated from the Swedish breeding site in early August. After spending up to three weeks at scattered stopover sites in central to south-eastern Europe, they resumed migration and crossed the Mediterranean Sea and Sahara Desert without lengthy stopovers. They then spread out over a large overwintering area and each bird utilised two (or even three) main wintering sites that were spatially separated by a distinct mid-winter movement. Spring migration initiation date differed widely between individuals (1-27 April). Several males took a more westerly route over the Sahara in spring than in autumn, and in general there were fewer long-distance travels and more frequent shorter stopovers, including one in northern Africa, in spring. The shorter stopovers made spring migration on average faster than autumn migration. There was a strong correlation between the spring departure dates from wintering sites and the arrival dates at the breeding ground. All males had a high migration speed in spring despite large variation in departure dates, indicating a time-minimization strategy to achieve an early arrival at the breeding site; the latter being decisive for high reproductive success in great reed warblers. Our results have important implications for the understanding of long-distance migrants’ ability to predict conditions at distant breeding sites and adapt to rapid environmental change.

Great Reed Warbler Acrocephalus arundinaceus

Great Reed Warbler Acrocephalus arundinaceus (Vitaliy Khustochka on flickr, licence CC-by-nc)

Spatial patterns in North Africa:

The majority of males crossed the Mediterranean Sea and Sahara Desert without stopovers in a flight that exceeded 24 hours in duration, in a geographical window spanning from Tunisia/Algeria in the west to Libya in the east.

In spring, after crossing the Sahara desert, all great reed warbler males stopped just south of the Mediterranean Sea in northeast Algeria and western Tunisia. From the stopover in North Africa most males took off in a north-easterly direction towards Italy and Balkan, which allowed these birds to pass east of the Alps and to return more or less on the same track through Europe as taken in autumn.

A completely unexpected result was that all males spent 1-2 weeks at the end of April or beginning of May in a rather restricted area in north-eastern Algeria and western Tunisia, independent of where along the west–east axis of sub-Saharan Africa they had spent their second part of the winter.

Inferred migration routes, mid-winter movements and stopover sites from geolocator data of male great reed warblers

Inferred migration routes, mid-winter movements and stopover sites from geolocator data of male great reed warblers.
(A) Migration routes and mid-winter movements (blue: autumn; green: spring; yellow: mid-winter).
(B) Stopover sites (stays for more than 36-hours) in autumn (blue) and spring (green), and wintering sites (yellow). Breeding site is indicated (star). Data are for 8 males in autumn and winter, and 6 males in spring. doi:10.1371/journal.pone.0079209.g001

Morphometric sexing of Mediterranean Yellow-legged Gulls in Gabès, Tunisia

Hammouda, A. & Selmi, S. (2013). Morphometric sexing of Mediterranean Yellow-legged Gulls Larus michahellis michahellis breeding in the Gulf of Gabès, southern Tunisia. Ostrich 84 (2): 119-122.

Abstract:

Discriminant analysis functions have previously been determined for sexing Mediterranean Yellow-legged Gulls Larus michahellis michahellis from the western Mediterranean basin. However, data from eastern Mediterranean populations are lacking. In this work, we used morphometric data from a sample of 81 Mediterranean Yellow-legged Gulls (39 males and 42 females) breeding in the Gulf of Gabès in south-eastern Tunisia to (1) determine a dscriminant function useful for sex discrimination, and (2) assess the accuracy of previously published functions in sexing Mediterranean Yellow-legged Gulls from our study area. Our results showed marked sexual differences in all morphological measurements, with males being significantly larger than females. The best discriminant function included head length, bill depth and wing length, and accurately classified 93% of sampled birds. We also found that Mediterranean Yellow-legged Gulls from the Gulf of Gabès could accurately be sexed using discriminant functions determined for another North African population, but not with a function determined for a South European population, although distances between sites are almost the same.

Yellow-legged Gull (Larus michahellis)

Larus michahellis – Goéland leucophée – Yellow-legged Gull (Sébastien Bertru, license: CC-by-sa)