Mohamed Kouidri

Despite its hyperarid climate, the Sahara Desert encompasses some large oases with extensive but rather fragile wetlands that are inhabited by Charadriforms. In this study we analyse the reproductive ecology of two species of Recurvirostridae, Black-winged Stilts Himantopus himantopus (more numerous) and Pied Avocets Recurvirostra avosetta (less numerous), nesting in an unstable habitat of the Saharan wetland of Chott Ain El Beida, Algeria, North Africa. The onset of egg laying was more stable and similar between years in Black-winged Stilts (15–19 April, on average, N = 315) than in Pied Avocets (13–21 April, on average, N = 73). Black-winged Stilts and Pied Avocets showed opposite yearly trends in egg laying dates. Clutches composed of 4 eggs dominated in both these species. They did not differ in hatching success of complete clutches (on average 73% and 77%, respectively). Average weights of eggs decreased from year to year during 2005–2007, suggesting that the individual quality of breeding birds decreased over the study years, probably corresponding with the progressive deterioration of the habitat. In the Black-winged Stilt, but not in the Pied Avocet, egg sizes decreased with the progress of the laying period. Another difference between egg-related aspects of the breeding ecology of these species was that only in Black-winged Stilts egg shape tended to affect hatching success of clutches, so that clutches of more elongated eggs had higher hatchability. To conclude, some aspects of breeding performance of waders may have a different form even in closely related species, depending on changing ecological conditions.

This work focused on monitoring the reproductive phenology of the chaffinch Fringilla coelebs africana for two successive seasons (2016 and 2017) in the mountains of the El Kala National Park (North East Algeria). We searched for nests in the tree stratum or by direct observation of breeding pairs carrying building materials from mid-March to the end of June and found a total of 34 nests that were measured without affecting the breeding process. The results show that nests were built at an average height of 6.3m from the ground. The laying period was 46 days (Early April to mid-May) and the average laying date was May 2. The mean of clutch size is 3.2 eggs per brood. All the previous traits are similar to those recorded in Europe. The mean hatching success rate was 43.1% and the average breeding success rate was 36.3%. These two values are relatively low compared to those found in European populations.

Les forêts de l’Atlas saharien représentent la bordure sud des aires de distribution naturelle du pin d’Alep ( Pinus halepensis Mill.). Elles sont exposées à un stress climatique lié à la sécheresse et aux attaques de la chenille processionnaire (CP, Thaumetopoea pityocampa Schiff.). L’objet de notre travail consiste à étudier la variation du taux d’infestation par la CP et la densité de celle-ci en utilisant des facteurs climatiques et les paramètres dendrométriques. Le taux d’infestation par la CP (7,82 %) et la densité de celle-ci (2,74 ± 2,61 nids/arbre) ont été moins importants dans nos pinèdes que dans celles du nord. Il est apparu que les attaques de CP augmentent principalement avec la baisse du nombre de jours de gelée et de canicule. Les paramètres dendrométriques ont été négativement corrélés avec la densité de CP par arbre. En revanche, cette dernière a été positivement corrélée avec le taux de défoliation. Les résultats ont été discutés dans un cadre biogéographique à la lumière des connaissances sur la répartition de la CP du pin d’Alep et en relation avec les conditions climatiques.

In oviparous taxa such as birds, clutch characteristics (e.g. egg size, egg mass and the number of eggs) can be considered as energetic investment in reproduction. In this paper, we study variation in the principal component indices of egg size and shape in Rufous Bush Chats (Cercotrichas galactotes) breeding in date palm plantations in the Al Amri Oasis, north Algeria, in 2008–2009 and 2011–2013. For descriptive and comparative purposes, we also present characteristics of egg length, breadth, volume, shape and mass. The size and shape indices as well as dimensions and masses of the eggs laid by particular females tended to be similar to one another, with most variation occurring between clutches (significant repeatabilities for all egg traits). Variation in the size of eggs was influenced by the year-laying date interaction, while variation in the shape (elongation) of eggs was marginally significantly affected by the year-laying date interaction. Year had a significant factor effect on the size of eggs. We also found that hatching success was affected by interactions between year and egg size and shape principal components, thus confirming the existence of fitness-related consequences of variation in the traits of Rufous Bush Chat eggs. Notably, we found that in some years hatching success increased with the elongation of eggs.

We examined the variation in the date of the onset of egg laying and clutch size in three peripheral populations of the Afrocanarian Blue Tits Cyanistes teneriffae ultramarinus at the edge of the species and subspecies geographic range. This study was carried out in three study sites, 130–290 km apart, in similar geographic conditions of the South Border Range of the Saharan Atlas in Algeria. Mean altitudes of nesting territories were between 1327 and 1437 m a.s.l. Habitats of the study sites were covered by the secondary, human-modified vegetation, ranging from a maquis shrubland, with the Holm oak Quercus ilex shrubs to woodlands dominated by the Atlas cedar Cedrus atlantica or by the Aleppo pine Pinus halepensis. 169 wooden nest-boxes were monitored for breeding parameters (laying dates and clutch sizes) during the breeding seasons 2007–2009 and 2011–2013. The timing of egg laying was relatively late for the latitude of the study sites, with overall mean laying dates varying between the study ...

Amount and quality of resources may be variable and generally poor in habitats of marginal avian populations living at the edge of species breeding range. We studied variation in egg traits (length, breadth, volume and shape) in three populations of the African Blue Tit Cyanistes caeruleus ultramarinus inhabiting degraded habitats in highlands of Algerian Saharan Atlas at mean altitudes 1328–1437 m a.s.l. We found high within-clutch repeatability of all the egg traits studied. As theoretically expected in peripheral parts of the species geographic range, there was considerable variation in egg-size traits among the study populations, with eggs being distinctly smaller and more elongated at a site characterised by most human-modified habitat composed of maquis scrubland with rare Pistacia trees. Egg length and shape tended to be affected by the altitude of nest site and by clutch size, but not laying date. We found some effects of egg traits on hatching and fledging success, suggesting that fitne...