Wintering waterbird assemblages in the central part of the Gulf of Gabès in southern Tunisia

Hamza, F., Hammouda, A. & Selmi, S. (2016). Wintering waterbird assemblages in the central part of the Gulf of Gabès in southern Tunisia. Ostrich 87:  217–223. doi: 10.2989/00306525.2016.1207721
PDF

Abstract

Although the Gulf of Gabès is recognised as an Important Bird Area, several aspects of the ecology of waterbirds inhabiting this area still need to be investigated. We observed how waterbird foraging guilds varied among habitats. In total, 49 species belonging to 16 families were recorded. Winter visitors accounted for 73% of counts. The avifauna was dominated by shorebirds (52% of records), followed by large wading birds (25%), open-water birds (18%) and waterfowl (5%). However, the structure of local waterbird communities and their composition in terms of foraging guilds varied according to habitat type. The bird communities of sandy beaches were dominated by open-water birds, whereas large mudflats were dominated by shorebirds, and wadi estuaries showed a more even representation of foraging guilds. Locally rare species had narrow distributions, whereas locally abundant species were found widely within the gulf. For four species the 1% population level criterion of the Ramsar Convention was exceeded. Overall, our results show that the Gulf of Gabès hosts important numbers of waterbirds with different ecological requirements, which confirms the importance of this gulf as a wintering area for Palearctic waterbirds.

Rassemblements hivernaux chez les oiseaux aquatiques de la zone centrale du Golfe de Gabes en Tunisie méridionale

Bien que le Golfe de Gabes soit reconnu comme une zone importante pour la conservation des oiseaux, de nombreux aspects de l’écologie des oiseaux d’eau qui y vivent restent peu connus. Ainsi, l’objectif de ce travail était de décrire la diversité de l’avifaune hivernante dans ce golfe et d’étudier la variation de sa composition, en termes de guildes alimentaires, entre les différents types d’habitat qu’abrite cette région. Au total, 49 espèces appartenant à 16 familles ont été recensées. Les hivernants représentent 73% des effectifs enregistrés. Cette avifaune est dominée par les limicoles (52% des effectifs enregistrés) suivis par les grands échassiers (25%), les laridés (18%) et les canards (5%). Cependant, la structure des communautés locales et leurs compositions en termes de guildes varient en fonction de d’habitat. C’est ainsi que les avifaunes des plages sableuses sont dominées par les laridés, celles des vasières par les limicoles, alors que les estuaires des oueds abritent une avifaune plus équilibrée. Les espèces localement rares ont une répartition restreinte, tandis que les espèces localement abondantes ont une large distribution dans le golfe. D’autre part, pour quatre des espèces recensées, le critère de 1% de la Convention de Ramsar est atteint. Globalement, nos résultats montrent que le Golfe de Gabes abrite un effectif important d’oiseaux d’eau ayant des affinités écologiques variées, ce qui confirme l’importance de ce golfe pour l’avifaune Paléarctique.

Eurasian Spoonbill, Spatule blanche (Platalea leucorodia) ringed in The Netherlands and observed here in gulf of Gabès, Tunisia.

Eurasian Spoonbill, Spatule blanche (Platalea leucorodia). This bird was ringed in summer 2015 in The Netherlands. During the autumn migration, this spoonbill was observed in the gulf of Gabès, Tunisia. Usually, spoonbills from the Netherlands use the East Atlantic flyway and it is uncommon to observe them in Tunisia. This recovery of Dutch spoonbill is the 4th in Tunisia and the first for the gulf of Gabès (Foued HAMZA)

 

The migration of the Great Snipe (Gallinago media): intriguing variations on a grand theme

Lindström, Å., Alerstam, T., Bahlenberg, P., Ekblom, R., Fox, J. W., Råghall, J., & Klaassen, R. H. G. (2016). The migration of the great snipe Gallinago media: intriguing variations on a grand theme. Journal of Avian Biology 47: 321–334.
Free access (now)

Abstract:

The migration of the great snipe Gallinago media was previously poorly known. Three tracks in 2010 suggested a remarkable migratory behaviour including long and fast overland non-stop flights. Here we present the migration pattern of Swedish male great snipes, based on 19 individuals tracked by light-level geolocators in four different years. About half of the birds made stopover(s) in northern Europe in early autumn. They left the breeding area 15 d earlier than those which flew directly to sub-Sahara, suggesting two distinct autumn migration strategies. The autumn trans-Sahara flights were on average 5500 km long, lasted 64 h, and were flown at ground speeds of 25 m s−1 (90 km h−1). The arrival in the Sahel zone of west Africa coincided with the wet season there, and the birds stayed for on average three weeks. The birds arrived at their wintering grounds around the lower stretches of the Congo River in late September and stayed for seven months. In spring the great snipes made trans-Sahara flights of similar length and speed as in autumn, but the remaining migration through eastern Europe was notably slow. All birds returned to the breeding grounds within one week around mid-May. The annual cycle was characterized by relaxed temporal synchronization between individuals during the autumn–winter period, with maximum variation at the arrival in the wintering area. Synchronization increased in spring, with minimum time variation at arrival in the breeding area. This suggests that arrival date in the breeding area is under strong stabilizing selection, while there is room for more flexibility in autumn and arrival to the wintering area. The details of the fast non-stop flights remain to be elucidated, but the identification of the main stopover and wintering areas is important for future conservation work on this red-listed bird species.

The autumn (a) and spring (b) migration of great snipes travelling between the breeding site in Sweden and their winter quarters in central Africa

The autumn (a) and spring (b) migration of great snipes travelling between the breeding site in Sweden and their winter quarters in central Africa. Green dots show the breeding site according to the light geolocators, orange and yellow dots show stopover sites in Europe/northern Africa and sub-Saharan Africa, respectively, and blue dots the final wintering sites. Red solid lines mark the nonstop flights, and grey thin lines show shorter flights.

Predictors of the abundance of shorebirds and wading birds wintering in the Gulf of Gabès, Tunisia

Hamza, F. & Selmi, S. (2015). Habitat features and human presence as predictors of the abundance of shorebirds and wading birds wintering in the Gulf of Gabès, Tunisia. Marine Ecology Progress Series 540: 251–258.  doi: 10.3354/meps11500

Abstract:

Understanding ecological factors and processes affecting waterbird abundance is a major question in ecology and important for conservation purposes. In the Mediterranean, studies dealing with the determinants of waterbird abundance and distribution have mainly been concerned with European coastal habitats, whereas less attention has been paid to coastal areas in North Africa. In this work, we used count data to investigate the relevance of habitat features and human presence as predictors of the abundance of shorebirds and wading birds wintering in the Gulf of Gabès, a particularly important wintering quarter for many Palearctic waterbirds in Tunisia. We found that the strength and direction of the relationships between bird abundance and both habitat and human parameters varied among species, depending on their ecological requirements. Most species occurred more abundantly in large mudflats compared to narrow sandy beaches, while one species showed an opposite trend. We also found that the studied sites were frequently visited by local people, mainly for clam harvesting, thus sharing the intertidal habitats with birds. However, the abundance of most species did not decrease with increasing human presence, suggesting that traditional clam-harvesting activity did not seem to disturb birds. Nonetheless, we believe that further investigations of the interactions between birds and clam-harvesters are needed to better understand the role of traditional clam-harvesting activity in shaping the abundance and diversity of waterbirds wintering in the Gulf of Gabès.

Related papers (PDFs):

  • Sanderling (Calidris alba) colour-ringed in Iceland, and observed wintering in the Gulf of Gabès, Tunisia (Foued Hamza / Birding in Tunisia).
    Sanderling (Calidris alba) colour-ringed in Iceland, and observed wintering in the Gulf of Gabès, Tunisia (Foued Hamza / Birding in Tunisia).

L’avifaune aquatique de la zone littorale atlantique de Rabat-Bouznika (Maroc) : Composition, phénologie et reproduction

Hanane, S. 2014. L’avifaune aquatique de la zone littorale atlantique de Rabat-Bouznika (Maroc) : Composition, phénologie et reproduction. Thèse de Doctorat, Université Mohammed V–Agdal, Rabat.

PDF (6.75 Mb) in Toubkal : Le Catalogue National des Thèses et Mémoires.

Résumé:

Sur la zone littorale de Rabat-Bouznika, des dénombrements réguliers, de janvier 1999 à décembre 2001, ont permis de définir le rythme de migration des espèces d’oiseaux d’eau les plus fréquentes ainsi que leurs statuts phénologiques. Quarante neuf espèces ont fréquenté le site, dont 24 régulières. Les Limicoles et les Laridés sont les groupes les plus dominants. Le suivi de la reproduction a concerné l’Oedicnème criard, la Glaréole à collier, le Gravelot à collier interrompu et la Sterne naine. Ces quatre espèces déposent leurs œufs à même le sol avec une production d’œufs/nid qui avoisine 2 : 1,88 pour l’Oedicnème criard, 2,20 pour la Glaréole à collier, 2,89 pour le Gravelot à collier interrompu et 2,51 pour la Sterne naine. La ponte débute à la dernière décade de mars pour l’Oedicnème criard et le Gravelot à collier interrompu suivi, à la première quinzaine d’avril, par la Glaréole à collier et au début mai par la Sterne naine. Le maximum de l’activité reproductive est enregistrée durant les mois de mai et juin. La durée de la saison de reproduction est plus étalée chez les nicheurs sédentaires (Oedicnème criard et Gravelot à collier interrompu) que chez les migrateurs nicheurs (Glaréole à collier et Sterne naine). Le succès à l’éclosion a été de 49% chez la Glaréole à collier, de 51.5% chez la Sterne naine, de 58.4% chez le Gravelot à collier interrompu et de 71% chez l’Oedicnème criad. Sur cette portion de côte, les plus importants facteurs d’échec ont été le piétinement, le ramassage et l’abandon des œufs. Malgré ces sources de dérangements, la zone littorale de Rabat-Bouznika continue à accueillir une centaine de couples d’oiseaux d’eau nicheurs.

Eclosion des poussins

Eclosion des poussins.

Autres thèses et mémoires de Magister.

Breeding ecology studies of Collared Pratincoles Glareola pratincola in the Central Hauts Plateaux of Algeria

Benasci, E., Boutera, N. Cherief, A., Saheb, M, Moali, A. & Houhamdi, M. 2014. Breeding ecology studies of Collared Pratincoles Glareola pratincola in the Central Hauts Plateaux of Algeria. Wader Study Group Bulletin 121 (1): 43–48.
PDF in ResearchGate.net

Abstract:

The breeding biology of Collared Pratincoles Glareola pratincola was studied for the first time in Algeria in 2010 at a natural salt lake at Dayet El Kerfa, in the semi-arid Hauts Plateaux. The breeding attempts of 35 pairs on three different islets were monitored. The mean laying date was 13 May (range: 28 April to 2 June). Mean clutch size was 2.0, but 47% of the nests had one or three eggs. Hatching success was 97%; only one nest failed. Clutch size, egg size, nest dimensions and hatching success did not vary between nests placed in the centre of an islet and nests closer to the shore. Our study contrasts with results reported for other Mediterranean breeding areas (in Morocco, France and Spain), showing differences in laying dates, clutch size and laying period. The beginning of egg laying at Dayet El Kerfa was three weeks later than on the N Atlantic coast of Morocco (28 April at Dayet El Kerfa and 7 April in Morocco), three weeks earlier than in Spain and two weeks earlier than in France. Clutch sizes were smaller than in other breeding areas in the Mediterranean basin. The range of hatching dates (25 days) was less than half that reported for a coastal area in Morocco; this is probably related to the almost complete absence of nest predators at Dayet El Kerfa, so no pairs renested. The hatching success of 97% was the highest of all breeding sites in the Mediterranean basin.

Collared Pratincole (Glareola pratincola)

Collared Pratincole (Glareola pratincola) (photo: Ferran Pestaña on flickr, license: CC-by-sa).

Etude de la phénologie migratoire des limicoles dans la lagune et les salines de Sidi Moussa, Maroc

Joulami, L., Rguibi Idrissi, H., Bazairi, H., Lopes, R.J. & El Hamoumi, R. 2013. Etude de la phénologie migratoire des limicoles dans la lagune et les salines de Sidi Moussa (Maroc). Bulletin de l’Institut Scientifique, Rabat, section Sciences de la Vie 35: 131-140. PDF

Résumé:

Des dénombrements mensuels des limicoles ont été réalisés de mars 2010 à février 2012 dans la lagune de Sidi Moussa et les salines adjacentes. Au total 24 espèces ont été recensées dont trois espèces nicheuses régulières (Glareola pratincola, Charadrius alexandrinus et Himantopus himantopus). Les espèces les plus abondantes sont Calidris alpina, Charadrius hiaticula, Charadrius alexandrinus, Pluvialis squatarola, Himantopus himantopus et Tringa totanus. L’analyse des patterns migratoires des espèces n’ont pas montré de variations significatives entre les années contrairement à l’évolution des effectifs totaux des limicoles qui enregistrent des variations marquant les différentes saisons du cycle phénologique des espèces. Les effectifs les plus élevés sont notés durant la migration postnuptiale (automne). Ils vont par la suite enregistrer une diminution pour se stabiliser durant la période d’hivernage. Les déplacements prénuptiaux ne sont pas bien décelés. Une légère augmentation des effectifs est notée en février marquant le début de passage de retour. Certaines espèces peuvent laisser sur place de faibles contingents d’estivants. C’est le cas du Bécasseau variable qui montre une forte corrélation avec l’effectif total et du Chevalier gambette avec un début d’estivage précoce (mai). Les deux espèces nicheuses, l’Echasse blanche et le Gravelot à collier interrompu évoluent différemment dans le site. Au moment où la première espèce ne marque aucune variation saisonnière, la deuxième enregistre des passages migratoires notoires pour se stabiliser lors de l’hivernage et de l’estivage. Les effectifs du Pluvier argenté notés en estivage montrent des différences significatives avec ceux notés durant les autres saisons du cycle phénologique, marquées par une certaine stabilité. Pour le Grand Gravelot, les effectifs enregistrés en estivage montrent des différences significatives uniquement avec ceux de la migration postnuptiale.

Study of the migratory waders phenology in the lagoon and salines of Sidi Moussa (Morocco).

Abstract:

Monthly counts of waders were conducted from March 2010 to February 2012 in Sidi Moussa lagoon and adjacent salines. In total 24 species were identified, including three regular breeding species in the site (Glareola pratincola, Charadrius alexandrinus and Himantopus himantopus). The most abundant species are Calidris alpina, Charadrius hiaticula, Charadrius alexandrinus, Pluvialis squatarola, Himantopus himantopus and Tringa totanus. The analysis of migration patterns of the species did not show significant variations between years in contrast to the trends in total numbers of waders that showed marked variations between the different seasons of the annual cycle of the species. The highest numbers are recorded during the autumn passage. Numbers will subsequently decrease and stabilize during the wintering season. Prenuptial movements are not well detected. A slight increase in numbers was noticed in February marking the beginning of the return passage. Some species can leave on the site small flocks of summering individuals. This is the case of Dunlin which shows a strong correlation with the total numbers and the Redshank with an early summering (May). Both breeding species, Black-winged Stilt and the Kentish Plover evolve differently in the site. When no seasonal variation was noted for the first species, migration passages are well marked for the second and numbers stabilize during the wintering and summering. The Grey Plover numbers noted during the summer show significant differences with those recorded during other seasons of the annual cycle, marked by certain stability. For Ringed Plover, numbers recorded in summer showed significant differences only with those of the autumn passage.

Related papers:

El Malki, S., Hanane, S. Joulami, L. & El Hamoumi, R. 2013. Nesting performance of the Black-winged Stilt and Collared Pratincole on a Moroccan coastal wetland: a comparison between natural and artificial habitats. Wader Study Group Bulletin 120 (1): 47–52.

Sidi Moussa lagoon and salines

Sidi Moussa lagoon and salines

Nesting of Black-winged Stilt and Collared Pratincole on a Moroccan coastal wetland

El Malki, S., Hanane, S. Joulami, L. & El Hamoumi, R. 2013. Nesting performance of the Black-winged Stilt and Collared Pratincole on a Moroccan coastal wetland: a comparison between natural and artificial habitats. Wader Study Group Bulletin 120 (1): 47–52.
PDF in ResearchGate.net

Abstract:

In 2011, we investigated the breeding performance of two wader species, Black-winged Stilt Himantopus himantopus and Collared Pratincole Glareola pratincola in a natural habitat, marshes, and in an artificial one, salinas (saltpans), in the Sidi Moussa-Walidia wetland complex on the Atlantic coast of Morocco. Data on nest-placement, clutch-size, egg-dimensions, nest-density, egg-laying chronology and hatching-success were collected from 117 nests: 31 of Black-winged Stilt (25 in marshes and 6 in salinas) and 86 of Collared Pratincole (36 in marshes and 50 in salinas). The results show no consistent differences in nest-density, clutch-size, egg-dimensions or nesting success between the two habitats. However, in both habitat types and species, variations were found in the distribution of nest initiation over the breeding season. Both habitats appeared to provide similar nesting conditions for Black-winged Stilts and Collared Pratincoles. Nonetheless, further research is needed to determine the combined effects of human disturbances and local predators on nest site selection and reproductive performance on these species in the two habitats. These studies will also facilitate management decisions aimed at maximising both gains to avian biodiversity and enhancing the welfare of people.