Importance relative de la disponibilité en îlots et du risque de prédation terrestre pour la sélection de l’habitat de nidification des Charadriiformes coloniaux dans le salin de Sfax (Tunisie)

Salinas are highly valued habitats for the conservation of ground-nesting colonial waterbirds in the Mediterranean, yet they often lack islets, preferred breeding habitats for these species. In this paper, we evaluated the relative importance of island availability and terrestrial predation risk for nesting habitat selection of five species of colonial Charadriiformes (Avocet, Little Tern, Common Tern, Gull-billed Tern and Slender-billed Gull) in the Sfax Salina (Tunisia), one of the most important breeding areas of these species along the southern Mediterranean coast. We monitored colony settlement pattern, colony size and colony site features used by the birds in 2004 and 2005. In total, 101 sites were occupied during the two years of study. These occupied sites included 19 isolated islets, which represent the total number of available inaccessible islets in the studied salina. 92.6% of the 8277 breeding pairs counted in 2004 and 86.3% of the 7844 breeding pairs counted in 2005 settled on accessible sites. Our results also show that the occupation of accessible sites began before the occupation of isolated ones. We propose that these accessible sites should be considered as ecological traps resulting from the overall lack of isolated sites. Finally, because dikes are an unlimited habitat for nesting, we identify the environmental cues selected by colonial Charadriiformes within this habitat to develop guidelines for the construction of attractive isletsEn zone Méditerranéenne, les salins sont de plus en plus considérés comme un habitat particulièrement important pour la nidification des oiseaux d'eau coloniaux. Toutefois, ces salins manquent le plus souvent d'îlots isolés et inaccessibles aux prédateurs terrestres, ce qui est de nature à exposer les colonies d'oiseaux à une importante pression de prédation, diminuant ainsi leur succès reproducteur. L'importance relative de la disponibilité en îlots inaccessibles et de la pression de prédation terrestre comme clefs possibles dans le processus de sélection des sites de nidification par ces oiseaux a été rarement élucidée. Ainsi, l'objectif de ce travail est d'examiner cette question en utilisant des données sur la nidification de cinq espèces de Laro-limicoles (Avocette élégante, Sterne naine, Sterne pierregarin, Sterne hansel et Goéland railleur) dans le salin de Sfax, l'un des plus importants sites de nidification de ces oiseaux sur la rive sud de la Méditerranée. Ces données ont été recueillies grâce à un suivi des colonies de nidification installées sur un total de 101 sites au cours de deux saisons de reproduction successives (2004 et 2005). Parmi ces sites, 19 correspondent à des îlots complètement isolés, soit le nombre total de sites inaccessibles aux prédateurs terrestres du salin. La très grande majorité des effectifs reproducteurs se sont installés sur des sites accessibles (92,6% et 86,3% des 8277 et des 7844 couples recensés en 2004 et 2005 respectivement). Nos résultats montrent aussi que l'occupation des sites accessibles précède généralement celle des sites inaccessibles et que les caractéristiques physiques sélectionnées par les oiseaux pour le choix de ces sites accessibles varient selon les espèces. Globalement, l'ensemble de nos résultats suggère qu'en absence d'un nombre suffisant d'îlots isolés, les digues, parcourues par les prédateurs terrestres, représentent des pièges écologiques pour les oiseaux d'eau coloniaux nichant dans ce salin. Ces résultats sont enfin utilisés pour proposer un mode de création de sites de nidification attractifs pour les oiseaux

Resistance status to deltamethrin pyrethroid of Culex pipiens pipiens (Diptera: Culicidae) collected from three districts of Tunisia

Objectives: The aim of the present study was to determine the susceptibility status of Culex pipiens pipiens populations against deltamehtrin insecticide. Methods: Larvae of Culex pipiens pipiens were collected from three breeding places in Northern and Southern Tunisia between 2003 and 2005. Early third and late fourth instars were tested against deltamethrin pyrethroid insecticide. Cross-resistance with DDT resistance was evaluated in studied samples to estimate the role of target site insensitivity and two synergists including piperonyl butoxide (Pb) and S,S,S-tributyl phosphorotrithioate (DEF) were used to estimate the role of detoxification enzymes. Results: Our results revealed that the level of deltamehtrin resistance ranged from 0.67 to 31.4. We also showed the non-involvement of kdr resistance in pyrethroid resistance and no cross-resistance with DDT resistance was detected in all studied populations including the most resistant one. Synergists study on the resistant population (sample # 1) showed the involvement of CYP450 in the recorded resistance to the deltamethrin insecticide. Conclusion: The results obtained from this study should be considered in the current control programs to combat mosquitoes in Tunisia

Evaluation of resistance to temephos insecticide in Culex pipiens pipiens larvae collected from three districts of Tunisia

Background: Mosquitoes are considered as the main groups of arthropods that cause nuisance and public health problems. Objectives: Evaluation of resistance to temephos insecticide in Culex pipiens pipiens larvae collected from three districts of Tunisia. Methods: Late third and early fourth instars larvae of Culex pipiens pipiens were collected in three localities of Northern and Southern Tunisia. Field collected populations were tested against temephos insecticide and compared to bioassays of a susceptible reference strain. The cross-resistance between temephos and propoxur, and the polymorphism of over-produced esterases and AChE 1 were investigated. Results: Studied populations exhibited tolerance to temephos with low and high levels of resistance. The resistance ratio (RR50) values of temephos ranged from 1.34 to 114. Synergists and starch electrophoresis showed that the metabolic resistances were involved in the recorded resistance. Likewise, the resistant target site (acetyl cholinesterase: AChE 1) was responsible for the recorded resistance to temephos compound in Culex pipiens pipiens. Conclusion: The low and high resistance recorded to temephos insecticides is particularly interesting, because it leaves a range of tools useable by vector control services. However, further studies are needed to determine its spread and anticipate vector control failure where these insecticides are used. DOI: https://dx.doi.org/10.4314/ahs.v19i1.8 Cite as: Tabbabi A, Daaboub J, Laamari A, Cheikh RB, Feriani M, Boubaker C, Jha IB, Cheikh HB. Evaluation of resistance to temephos insecticide in Culex pipiens pipiens (Diptera: Culicidae) larvae collected from three districts of Tunisia. Afri Health Sci. 2019;19(1): 1361-1367. https://dx.doi.org/10.4314/ahs.v19i1.

Maternal Antibody Transmission in Relation to Mother Fluctuating Asymmetry in a Long-Lived Colonial Seabird: The Yellow-Legged Gull Larus michahellis

Female birds transfer antibodies to their offspring via the egg yolk, thus possibly providing passive immunity against infectious diseases to which hatchlings may be exposed, thereby affecting their fitness. It is nonetheless unclear whether the amount of maternal antibodies transmitted into egg yolks varies with female quality and egg laying order. In this paper, we investigated the transfer of maternal antibodies against type A influenza viruses (anti-AIV antibodies) by a long-lived colonial seabird, the yellow-legged gull (Larus michahellis), in relation to fluctuating asymmetry in females, i.e. the random deviation from perfect symmetry in bilaterally symmetric morphological and anatomical traits. In particular, we tested whether females with greater asymmetry transmitted fewer antibodies to their eggs, and whether within-clutch variation in yolk antibodies varied according to the maternal level of fluctuating asymmetry. We found that asymmetric females were in worse physical condition, produced fewer antibodies, and transmitted lower amounts of antibodies to their eggs. We also found that, within a given clutch, yolk antibody level decreased with egg laying order, but this laying order effect was more pronounced in clutches laid by the more asymmetric females. Overall, our results support the hypothesis that maternal quality interacts with egg laying order in determining the amount of maternal antibodies transmitted to the yolks. They also highlight the usefulness of fluctuating asymmetry as a sensitive indicator of female quality and immunocompetence in birds

Pacifica: Poetry International: Revolutions in Tunisian Poetry

A collection of contemporary poetry from Tunisia, including poems in translation with their French and Arabic original texts

Nesting phenology and breeding performance of the Slender-billed Gull Chroicocephalus genei in Sfax salina, Tunisia

In 2010, nine colonies of Slender-billed Gull Chroicocephalus genei bred at Sfax salina in south-eastern Tunisia totalling 7 912 breeding pairs. This amounted to >50% of the breeding population for the entire Mediterranean region. Colony initiation and egg laying occurred between late April and late May, with two distinct nesting peaks. Colony size ranged from 21 to 5 850 breeding pairs and was not correlated with the area of the breeding site or with laying date. The modal clutch size was three eggs for early colonies and two eggs for later ones. Egg volume was 37.5 cm3 on average, with first-laid eggs generally larger than those that followed in the same clutches. Hatching success, estimated by the Mayfield method, was lower in early colonies (37%) than later ones (59%), but birds nesting early fledged 0.85 chicks pair−1 compared to 0.45 chicks pair−1 by late breeders. Breeding performance was negatively affected by nest and chick predation, mainly by stray dogs Canis familiaris and Yellow-legged Gulls Larus michahellis.OSTRICH 2012, 83(1): 13–1

Nesting ecology of Pied Avocet Recurvirostra avosetta in Sfax salina, Tunisia

Even though Sfax salina in Tunisia hosts a significant part of the Mediterranean population of Pied Avocet Recurvirostra avosetta, data on the breeding ecology of this species in this area are lacking. Such data are nonetheless necessary, not only for the understanding of the ecology and dynamics of this species in general, but also for conservation purposes. In this paper we use the results of a one-year monitoring of nests in Sfax salina to provide information on its nesting parameters, in particular nesting phenology, colony size and hatching success. Our results show that Pied Avocets formed dense colonies at the beginning of the nesting season, but colony size decreased  as the nesting season advanced. Clutch size varied between 1 and 7 eggs, similar to other Mediterranean and European populations. Hatching success, estimated by the Mayfield method, was relatively low, mainly due to predation by stray dogs. Overall, our work shows that relatively high nest losses occur here. It also highlights the need for management efforts aiming to enhance the reproductive success in this artificial habitat. Creation of suitable and safe nesting sites is proposed.OSTRICH 2011, 82(1): 11–1

Relative importance of island availability and terrestrial predation risk for nesting habitat selection of colonial Charadriiformes in Sfax salina (Tunisia)

Salinas are highly valued habitats for the conservation of ground-nesting colonial waterbirds in the Mediterranean, yet they often lack islets, preferred breeding habitats for these species. In this paper, we evaluated the relative importance of island availability and terrestrial predation risk for nesting habitat selection of five species of colonial Charadriiformes (Avocet, Little Tern, Common Tern, Gull-billed Tern and Slender-billed Gull) in the Sfax Salina (Tunisia), one of the most important breeding areas of these species along the southern Mediterranean coast. We monitored colony settlement pattern, colony size and colony site features used by the birds in 2004 and 2005. In total, 101 sites were occupied during the two years of study. These occupied sites included 19 isolated islets, which represent the total number of available inaccessible islets in the studied salina. 92.6% of the 8277 breeding pairs counted in 2004 and 86.3% of the 7844 breeding pairs counted in 2005 settled on accessible sites. Our results also show that the occupation of accessible sites began before the occupation of isolated ones. We propose that these accessible sites should be considered as ecological traps resulting from the overall lack of isolated sites. Finally, because dikes are an unlimited habitat for nesting, we identify the environmental cues selected by colonial Charadriiformes within this habitat to develop guidelines for the construction of attractive islets.Importance relative de la disponibilité en îlots et du risque de prédation terrestre pour la sélection de l’habitat de nidification des Charadriiformes coloniaux dans le salin de Sfax (Tunisie). En zone Méditerranéenne, les salins sont de plus en plus considérés comme un habitat particulièrement important pour la nidification des oiseaux d’eau coloniaux. Toutefois, ces salins manquent le plus souvent d’îlots isolés et inaccessibles aux prédateurs terrestres, ce qui est de nature à exposer les colonies d’oiseaux à une importante pression de prédation, diminuant ainsi leur succès reproducteur. L’importance relative de la disponibilité en îlots inaccessibles et de la pression de prédation terrestre comme clefs possibles dans le processus de sélection des sites de nidification par ces oiseaux a été rarement élucidée. Ainsi, l’objectif de ce travail est d’examiner cette question en utilisant des données sur la nidification de cinq espèces de Laro-limicoles (Avocette élégante, Sterne naine, Sterne pierregarin, Sterne hansel et Goéland railleur) dans le salin de Sfax, l’un des plus importants sites de nidification de ces oiseaux sur la rive sud de la Méditerranée. Ces données ont été recueillies grâce à un suivi des colonies de nidification installées sur un total de 101 sites au cours de deux saisons de reproduction successives (2004 et 2005). Parmi ces sites, 19 correspondent à des îlots complètement isolés, soit le nombre total de sites inaccessibles aux prédateurs terrestres du salin. La très grande majorité des effectifs reproducteurs se sont installés sur des sites accessibles (92,6% et 86,3% des 8277 et des 7844 couples recensés en 2004 et 2005 respectivement). Nos résultats montrent aussi que l’occupation des sites accessibles précède généralement celle des sites inaccessibles et que les caractéristiques physiques sélectionnées par les oiseaux pour le choix de ces sites accessibles varient selon les espèces. Globalement, l’ensemble de nos résultats suggère qu’en absence d’un nombre suffisant d’îlots isolés, les digues, parcourues par les prédateurs terrestres, représentent des pièges écologiques pour les oiseaux d’eau coloniaux nichant dans ce salin. Ces résultats sont enfin utilisés pour proposer un mode de création de sites de nidification attractifs pour les oiseaux.Ali Chokri Mohamed, Sadoul Nicolas, Selmi Slaheddine, Bechet Arnaud. Relative importance of island availability and terrestrial predation risk for nesting habitat selection of colonial Charadriiformes in Sfax salina (Tunisia). In: Revue d'Écologie (La Terre et La Vie), tome 66, n°4, 2011. pp. 367-382

Analyse comparative de la richesse avifaunistique du salin de Sfax dans le contexte tunisien et méditerranéen

Summary. — Comparative analysis of the avifaunistic richness of the Sfax salina in the and Mediterranean context. — The present comparative analysis of the waterbirds community of the salina aimed at examining if local and regional factors may explain the numbers, the specific and diversity of wintering waterbirds in this salina by comparison (i) with other Tunisian wetlands, the wintering season ; (ii) with six highly protected western Mediterranean salinas during the wintering the breeding season. This is a first evaluation of the importance of the Sfax salina for waterbirds in to advocate for a better designation of protection in relation to its high richness. Our results show that salina is nationally and internationally important for both wintering and breeding waterbirds. It is that this high value is essentially explained by (i) the permanent salt-making activity all over the year water and food resources abundant and predictable from January to December, (ii) the proximity to the of Gabes, a large tidal area which is a major wintering site for waterbirds and (iii) a significant part of contingency. If a high proportion of the waterbirds of Tunisia is present in the Sfax salina, RAMS criterion is moreover attained for at least five wintering and breeding waterbirds. However, only the ZICOICOICO label, which has no regulatory value, is attributed to this site. Hence, the designation of the Sfax Salina as RAMS AR site is strongly recommended for a better protection.Résumé. — Nous présentons ici une analyse comparative de l’avifaune du salin de Sfax dans le but d’examiner si des facteurs intrinsèques et environnants expliquent les effectifs, la composition spécifique et la diversité des oiseaux d’eau de ce salin (i) durant l’hivernage comparativement aux zones humides tunisiennes, (ii) durant l’hivernage et la reproduction comparativement à un échantillon de six salins de l’ouest de la Méditerranée faisant l’objet de fortes mesures de protection. Ce travail constitue une première évaluation de l’importance du salin de Sfax pour les oiseaux d’eau afin qu’il bénéficie d’une désignation à la hauteur de sa richesse. Nos résultats montrent que le salin de Sfax revêt une importance nationale et internationale pour ses effectifs hivernants et nicheurs d’oiseaux d’eau. Nous proposons que cette richesse exceptionnelle s’explique par (i) la permanence de l’activité salinière tout au long de l’année, procurant ainsi une ressource en eau et en nourriture abondante et prévisible durant tous les mois de l’année, (ii) la proximité du golfe de Gabès dont l’estran constitue un site d’hivernage de toute première importance pour les oiseaux d’eau et (iii) une part de contingence historique non négligeable. En plus d’accueillir une proportion significative des oiseaux hivernants et nicheurs de Tunisie pour un grand nombre d’espèces, les effectifs du salin de Sfax répondent aux critères requis pour la désignation RAMS AR pour cinq espèces d’oiseaux d’eau hivernants et nicheurs. Pourtant ce site ne bénéficie que du label ZICOICOICO qui n’a aucune valeur réglementaire. Nous recommandons donc la désignation du salin de Sfax comme zone humide RAMSMSAR afin de favoriser sa protection.Ali Chokri Mohamed, Sadoul Nicolas, Medhioub Khaled, Bechet Arnaud. Analyse comparative de la richesse avifaunistique du salin de Sfax dans le contexte tunisien et méditerranéen. In: Revue d'Écologie (La Terre et La Vie), tome 63, n°4, 2008. pp. 351-369

Physiological impacts of pollution exposure in seabird's progeny nesting in a Mediterranean contaminated area

Aquatic wildlife is exposed through trophic transfer of hazardous substances to several threats inducing physiological impairments. We aimed at assessing the impact of contamination in one of the hot spots of pollution along Mediterranean coasts, the gulf of Gabes in Tunisia, on Common tern Sterna hirundo, a piscivorous top predator bird. Firstly, we compared the reproductive effort of breeding adults through clutch size distribution in three sites with different levels of pollution. Then, a battery of genotoxicity and oxidative stress biomarkers was carried out to assess physiological impairments in chicks. While defense mechanisms showed a depletion, lipid peroxidation and genotoxicity increased significantly according to pollution level. The multi-biomarker approach used here, discriminated chicks according to contamination degree of their nesting sites. Increases in genotoxicity and oxidative stress were correlated to a decrease in chick body mass known to lead to long-term impacts on juvenile survival and recruitment in birds