Distribution and breeding ecology of the Ferruginous Duck (Aythya nyroca) in Algeria

Djelailia, A., Baaziz, N., Samraoui, F., Alfarhan, A. H. & Samraoui, B. (2017). Distribution and breeding ecology of the Ferruginous Duck Aythya nyroca in Algeria. Ostrich 0(0) DOI: 10.2989/00306525.2017.1313331
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Abstract:

We conducted a survey of the distribution of Ferruginous Duck Aythya nyroca across Algeria and analysed the influence of nest-site characteristics on nesting success at a Ramsar site, Lake Tonga. The species was found to occupy different wetlands (freshwater lakes, brackish marshes and salt lakes) across three major climatic belts (subhumid coastal strip, semi-arid Hauts Plateaux and arid Sahara). Mean clutch size of successful nests was 13.3 ± 6.0 eggs (N = 26) with a hatching rate of 74% for successful clutches. Nesting success was recorded for 44% of nests with clutch desertion (72.7%) accounting for the majority of failed clutches. Egg size of the study population, which breeds at the southern limit of the species’ range, was significantly smaller than that of its northerly counterparts. Clutch size was negatively related to egg size and positively associated with depth of water below the nest, suggesting that older, more experienced or high-quality birds monopolised the safest sites. Successful clutches were significantly associated with tall vegetation, suggesting that when nesting is carried out mainly on offshore floating islets, protection against aerial predators and heat stress determine nesting outcome. Conspecific brood parasitism was significantly and positively associated with deferred egg-laying and smaller egg size, suggesting an age-dependent mechanism.

Distribution et reproduction du Fuligule nyroca Aythya nyroca en Algérie

Nous avons mené une enquête sur la distribution du Fuligule nyroca Aythya nyroca à travers l’Algérie en analysant l’influence des caractéristiques des sites de nidification sur le succès de la nidification au sein d’un site classé Ramsar: le Lac Tonga. L’espèce occupe différentes zones humides (lacs d’eau douce, marais d’eau saumâtre et lacs salés) à travers trois zones climatiques majeures (bande côtière subhumide, Hauts Plateaux semi-arides et Sahara). La grandeur de ponte moyenne est de 10,0 ± 2,96 œufs (N = 29 pontes) avec un taux d’éclosion de 74,7% pour les pontes réussies. Le taux de réussite a totalisé 44% des nids, avec une prédominance d’abandons des pontes causant l’échec de la reproduction (82%). La taille des œufs de la population étudiée est plus petite que celle des populations se reproduisant à des latitudes plus élevées. La grandeur de ponte est négativement associée à la taille des œufs et elle est positivement liée au niveau de l’eau: ceci suggère que les individus plus âgés, ayant plus d’expérience, ou ceux de meilleure qualité monopolisent les sites les plus sûrs. Les pontes réussies sont significativement associées à une végétation haute, suggérant que pour les nids construits sur des îlots flottants, une protection contre les prédateurs aériens et l’exposition au soleil, conditionne le succès de la nidification. Le parasitisme intra-spécifique a été positivement associé à une ponte tardive et à des dimensions réduites des œufs, suggérant un mécanisme dépendant de l’âge.

Ferruginous Duck (Aythya nyroca). Photo: Francis C. Franklin / CC-BY-SA, Wikipedia

Ferruginous Duck (Aythya nyroca). Photo: Francis C. Franklin / CC-BY-SA, Wikipedia

Mode de prédation très particulier du Faucon d’Éléonore (Falco eleonorae) sur l’Archipel d’Essaouira, Maroc Atlantique

Qninba, A., Benhoussa, A., Radi, M., El Idrissi, A., Bousadik, H., Badaoui, B. & El Agbani, M. A. (2015). Mode de prédation très particulier du Faucon d’Éléonore Falco eleonorae sur l’Archipel d’Essaouira (Maroc Atlantique). Alauda 83: 149–150.

Pas de résumé pour cet article, mais voir les détails de l’article en anglais ici : Eleonora’s Falcons keep or imprison their prey alive.

Voir aussi tous les articles sur le Faucon d’Éleonore (Falco eleonorae) dans ce blog.

 

Nest-site selection, breeding success and brood parasitism in the common moorhen (Gallinula chloropus) in Algeria

Meniaia, Z., Samraoui, F., Alfarhan, A. H., & Samraoui, B. (2014). Nest-site selection, breeding success and brood parasitism in the common moorhen Gallinula chloropus in Algeria. Zoology and Ecology 24: 305–313. doi:10.1080/21658005.2014.959281
PDF in ResearchGate.net

Abstract :

Between 2010 and 2012, we studied the breeding ecology of the common moorhen Gallinula chloropus at Lake Tonga, north-east Algeria. Nests were low lying (mean ± SD = 13.64 ± 5.07 cm) and located in tall, dense stands of Scirpus lacustris (72%). The egg-laying period was relatively short, between mid-April and the end of June, peaking in the first half of May. The mean overall clutch size ± SD was 7.03 ± 2.52 (N = 58 clutches) with a slight seasonal downward trend. Rates of successful clutches increased with egg-laying date and water depth mainly due to the seasonal decrease in nest predation and nest flooding. Nest predation, in contrast to nest flooding, was also negatively associated with water depth. The study documented relatively frequent cases of conspecific brood parasitism as well as rarely reported events of interspecific brood parasitism involving the common moorhen both as a host and as a parasite of other avian species.

Related:

Samraoui, F., Alfarhan, A. H., & Samraoui, B. (2013). Status and breeding ecology of the Common Moorhen Gallinula chloropus in Algeria. Ostrich 84 (2): 137-144.

Nest of Common Moorhen (Gallinula chloropus) with an egg and a chick

Nest of Common Moorhen (Gallinula chloropus) with an egg and a chick (Z. Meniaia et al. 2014).