Les outardes Houbara et Macqueen’s: Études génétique, morphométrique et phylogéographique

Korrida, A. 2012. Les outardes Houbara “Chlamydotis undulata” et Macqueen’s “Chlamydotis macqueenii“: Études génétique, morphométrique et phylogéographique. Thèse de Doctorat National, Université Ibnou Zohr, Agadir.

PDF (5.73 Mb) in Toubkal : Le Catalogue National des Thèses et Mémoires

Résumé :

Chez les outardes Houbara et Macqueen’s de l’écozone du Paléarctique, nous avons testé et quantifié la diversité biologique sur plusieurs niveaux hiérarchiques (espèces, sous-espèces, gènes et métapopulations) en vue de leur conservation ex-situ.

Les études génétiques sur les populations sauvages utilisant des loci nucléaires (microsatellites) et un marqueur mitochondrial (un fragment de 1042 pb du gène cytochrome b) ont permis d’évaluer et de tester la diversité génétique, le flux migratoire, les scénarios de colonisation, les relations phylogénétiques, les unités biologiques de conservation et les patrons historiques et démographiques élucidant les distributions biogéographiques contemporaines des trois constituants du genre Chlamydotis. Contrairement aux espèces des zones tempérées et boréales, les périodes glaciaires de l’époque du Pléistocène semblent être à l’origine des expansions démographiques chez les espèces désertiques d’outardes Houbara et Macqueen’s. Les tests globaux de différenciation génétique des deux marqueurs moléculaires se sont montrés contradictoires pourtant complémentaires. La discussion des différents facteurs génétiques responsables a pu confirmer ou infirmer le contraste moléculaire observé.

Nous avons mené trois autres études sur des cheptels d’outardes marocaines élevés en captivité. La modélisation mathématique des caractéristiques de croissance chez l’outarde marocaine a facilité la détermination, sous certaines conditions de captivité, du taux de croissance en plus de quatre types de croissances asymptotiques et allométriques. Les résultats ont révélé que le bec et la tarso-métatarse atteignent rapidement l’asymptote, ce qui explique leur utilisation précoce dans le déplacement et le forage, alors que la plus grande croissance allométrique des ailes permettra aux oiseaux de fuir les prédations éventuelles.

L’étude du registre d’élevage d’un troupeau multi-générationnel a montré une généalogie récente et peu profonde, mais a rendu possible la caractérisation de plusieurs paramètres généalogiques. L’intervalle de génération chez l’outarde marocaine a été estimé à 4.6 ans, le coefficient de consanguinité moyen à 1.6% et l’accroissement en paire du coefficient de parenté à 1.3%. L’absence de goulots d’étranglement a été justifiée par des valeurs égales de fondateurs efficaces (fe) et d’ancêtres efficaces (fa). Cette étude à montré d’un côté, la bonne stratégie d’élevage suivie de 1993 à 2002 visant à augmenter le flux migratoire au sein du troupeau et à freiner l’apparition de la dépression de consanguinité et de l’autre côté, une absence de planification des accouplements à partir de 2004 qui a été mise en évidence par des taux élevés de consanguinité et de parenté.

Finalement, le contrôle de la diversité génétique via des approches métapopulationnelles, nous a permis de comparer et de discuter les différentes stratégies et politiques d’élevage conservatoire ex-situ de l’espèce marocaine (Chlamydotis undulata undulata).

Les résultats et les informations génétiques inférés de ces différents projets d’études populationnelles devraient permettre une meilleure valorisation et un maintien raisonnable et durable de la diversité génétique et biologique de ces ressources naturelles menacées d’extinction.

Chlamydotis macqueenii

MacQueen’s Bustard (Chlamydotis macqueenii), UAE (photo: Shankar S., licence: CC-by)

Abstract:

For ex-situ conservation ends, biological diversity of the Houbara and Macqueen’s Bustards occurring at the Palearctic ecozone, was assessed at several hierarchical levels including species, subspecies, genes, and metapopulations.

Genetic studies on wild populations have implemented both nuclear loci (microsatellites) and a 10423bp fragment of the mitochondrial cytochrome b gene, and enabled the assessment of genetic diversity, gene flow, colonization scenarios, phylogenetic relationships, biological units, as well as demographic and historical factors that might explain the current biogeographic distribution of the species that constitute the Chlamydotis genus. In contrast to temperate species, glacial periods of the Pleistocene epoch might be responsible for the demographic expansions of the desert-adapted Houbara and Macqueen’s bustards. Global tests of genetic structuring using the two molecular markers were found to be contradictory, however complementary. Discussion of the different responsible factors had confirmed or invalidated the observed molecular contrast.

Three further studies were conducted on Moroccan captive-bred stocks. Modeling the growth characteristics of the birds under particular captivity conditions has made possible the determination of growth rates in addition to four types of asymptotic and allometric growths. The results showed that the early development of the beak and the shank are relatively important to locomotion and foraging, while the highest allometric growth of the wing span indicates its importance for quick flight from potential predators.

The study of a multigenerational studbook has revealed a recent and shallow genealogy although, several genealogical parameters were characterized. For the Moroccan Houbara breed, the average generation interval was computed to 4.64 years, the average inbreeding coefficient to 1.6%, and the paired increase in coancestry to 1.3%. The similar effective numbers of ancestors (fa) and founders (fe) indicated the absence of bottleneck events within the flock. On one hand, this study highlighted a good breeding strategy that was applied from 1993 to 2002 and aimed to increase migration and to avoid the inbreeding depression within the breed, on the other hand increased coancestry and inbreeding values were detected during the 2004 breeding season, which could reflect the low expertise in the breeding operation.

Finally, genetic diversity evaluation using metapopulational approaches has permitted the comparison and discussion of different strategies and policies with regard to ex-situ conservation of Moroccan Chlamydotis undulata undulata.

Genetic information and results inferred from the different population studies should contribute to the future control, valorization, and management of genetic and biological diversity of this natural resource.

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)

Status and breeding ecology of the Common Moorhen in Algeria

Samraoui, F., Alfarhan, A. H., & Samraoui, B. (2013). Status and breeding ecology of the Common Moorhen Gallinula chloropus in Algeria. Ostrich 84: 137-144.
doi:10.2989/00306525.2013.823130
PDF  in ResearchGate.net

Abstract:

The status of the Common Moorhen Gallinula chloropus in Algeria and its breeding ecology in North Africa are reported for the first time. Nest site selection and breeding parameters were studied at two contrasting sites in north-east Algeria: Boussedra, an unprotected freshwater marsh of 55 ha subject to anthropogenic influence, during 2005 and 2008, and Lake Tonga, a protected freshwater marsh of 2 400 ha in 2009. Most nests (92%) at Boussedra were located in dense stands of lesser bulrush Typha angustifolia, whereas a few were found on lower branches of tamarisk Tamarix gallica trees. In contrast, at Lake Tonga nests were predominantly found on Scirpus lacustris (41%) or associated with alder trees Alnus glutinosa (32%). Egg-laying at both sites occurred between early April and the end of June. There was a significant decrease in egg volume as the breeding season progressed. Mean clutch size at Lake Tonga (7.8 ± 2.9, N = 23 clutches) did not differ significantly from that at Boussedra (6.7 ± 2.1, N = 14 clutches). Similarly, hatching success (67 –72%) and predation rate of nests with eggs (16–28%) did not vary significantly between sites. The Common Moorhen may be more resilient than marsh specialists to anthropogenic changes.

Moorhen (Gallinula chloropus) in its nest

Common Moorhen (Gallinula chloropus) at its nest. (Peter aka anemoneprojectors on Flickr, license: CC-by-sa)

Status and diurnal behavior of the Greater Flamingo in Algerian eastern high plains

Bouaguel, L., Saheb, M., Bensaci, E., Bougoudjil, S., Bouslama, Z. & Houhamdi, M. (2013). Status and diurnal behavior of the Greater Flamingo Phoenicopterus roseus in Algerian eastern high plains. Annals of Biological Research 4 (8): 232-237.   PDF

Abstract:

The Grater Flamingo Phoenicopterus roseus has been well studied during the last decade in Algeria leading to highlight some aspects of its distribution, status, movements, and population dynamics. Knowing that an important part of the country has rarely or never been investigated, we studied the status and behaviour of the species in two newly discovered wintering populations (Sebkhat Ouled Amara and Sebkhat Ouled M’barek) in the Northern limit of Sahara, Khenchela, Algeria. The number of individuals was higher in Sebkhat Ouled Amara than Sebkhat Ouled M’barek showing peaks of 8 000 and 1 452 in the winter, respectively. Diurnal activity budget revealed that feeding was the most dominant activity representing 73.5% of all activities. Locomotion, flight, preening, courtship, and resting accounted for 12.3%, 6.2%, 4.0%, 2.8%, and 1.3%, respectively. There was no marked seasonal change in the behaviour of flamingo except for courtship which increased in the breeding season. Diurnal activity rhythms showed that locomotion, preening, and resting decreased in the afternoon while courtship and flight increased.

Greater Flamingo (Phoenicopterus roseus), Oum el-Bouaghi

Greater Flamingo (Phoenicopterus roseus), Oum el-Bouaghi, eastern Algeria. (Bilel Golf in Zones Humides Algériennes)

Distribution, breeding and time budget of Ruddy Shelduck in the Hauts Plateaux, Algeria

Boulkhssaïm, M., Ouldjaoui, A., Alfarhan, A. H. & Samraoui, B. (2013). Distribution, breeding phenology and time budget of Ruddy Shelduck Tadorna ferruginea during the annual cycle in the Hauts Plateaux, north-east Algeria. Ostrich 84 (2): 129-136.   DOI:10.2989/00306525.2013.821680
PDF in ResearchGate.net

Abstract:

Between September 2003 and July 2006, the reproductive biology and time budget of the Ruddy Shelduck Tadorna ferruginea was studied in the wetland complex of Oum el Bouaghi, north-east Algeria. Our results indicate a marked post-breeding dispersal of the Ruddy Shelduck to the eastern Hauts Plateaux where more than 1 000 birds (one-third of the estimated north-west African population) may gather in autumn. Dispersal is again conspicuous at the end of the wintering period when most birds leave the area to return to their breeding grounds. In 2004 and 2005, successful nesting was recorded at five sites. In both years, territoriality was exhibited from March to June and broods, ranging from nine to 14 chicks (mean = 11.1 ± 1.8, N = 16), were recorded between 21 May and 7 July. We also monitored the diurnal time budget of the Ruddy Shelduck over a two-year period. Feeding, most intense in late autumn and winter, occupied 50.6% of the daily activities with a distinct gradual seasonal decrease coinciding with the start of the breeding period. Ruddy Shelduck relied more upon surface feeding in shallow waters but displayed flexibility of feeding behaviour when water level fluctuated.

Ruddy Shelduck Tadorna ferruginea (Sergey Yeliseev, license CC-by-nc-nd)

Ruddy Shelduck Tadorna ferruginea (Sergey Yeliseev, license CC-by-nc-nd)

First breeding record of Grey Wagtail (Motacilla cinerea) for Tunisia

Olioso G., Pons, J.-M. & Touihri, M. 2013. First breeding record of Grey Wagtail Motacilla cinerea for Tunisia. Bulletin of the African Bird Club 20 (1): 76-77.
PDF in ResearchGate.net

Résumé:

Première donnée de nidification de la Bergeronnette des ruisseaux Motacilla cinerea en Tunisie. Un nid de la Bergeronnette des ruisseaux a été trouvé le 18 mai 2012 au centre de vacances d’Aïn Soltane, Jendouba, Tunisie. Il s’agit de la première preuve de reproduction de l’espèce dans le pays.

Text:

In the Maghreb, Grey Wagtail Motacilla cinerea is known to breed in Morocco and Algeria (Isenmann & Moali 2000, Thévenot et al. 2003). In Tunisia, proof of breeding was lacking, although the observation of a pair uttering alarm-calls near a stream in the Kroumirie Mountains, in the north-west, in April 2000, suggested the species had a nest there (Isenmann et al. 2005).

During 8–21 May 2012, while staying at the holiday centre of Aïn Soltane, Governorat of Jendouba, north-western Tunisia, we regularly observed a pair of Grey Wagtails uttering alarm-calls and carrying food. We eventually mist-netted the male (see attached photo). On 18 May, we found the pair’s rather voluminous nest under the beams supporting the roof of a house; it contained at least three downy chicks. The staff of the holiday centre subsequently indicated a second nest, placed in the same situation, but in another building, that had held a first clutch earlier in the season.

References:

Isenmann, P., Gaultier, T., El Hili, A. Azafzaf, H., Dlensi, H. & Smart, M. 2005. Oiseaux de Tunisie / Birds of Tunisia. Paris: Société d’Études Ornithologiques de France.

Isenmann, P. & Moali, A. 2000. Oiseaux d’Algérie / Birds of Algeria. Paris: Société d’Études Ornithologiques de France.

Thévenot, M., Vernon, R. & Bergier, P. 2003. The Birds of Morocco: An Annotated Checklist. BOU Checklist No. 20. Tring: British Ornithologists’ Union & British Ornithologists’ Club.

 Grey Wagtail (Motacilla cinerea), Tunisia

Adult male Grey Wagtail (Motacilla cinerea), Aïn Soltane, Tunisia, 16 May 2012 (Georges Olioso / Internet Bird Collection)