The placement and size of birds’ nests may have direct consequences for their breeding success. Here, we examined if the location and design of Rufous Bush Chat ( Cercotrichas galactotes) nests influenced their breeding success in the Al Amri Oasis, at the base of Saharan Atlas, north Algeria, in 2008–2009 and 2011–2013. The mean height of nests above ground level was 2.26 ± 0.09 (SE) m, ranging from 0.5 to 4.9 m and the mean nest-cup volume was 246.60 ± 11.82 (SE) cm ³ , ranging from 102.95 to 471.24 cm ³ . Nest-cup volumes were positively associated with the height of nests and breeding success was strongly positively associated with the height of nests above ground level. We conclude that pairs of Rufous Bush Chats that bred in higher nests had higher levels of breeding success because they suffered lower predation rates from ground-based predators than lower nests. Lower nests, which are more vulnerable to ground-based predators are likely to be smaller in order to make them less visible to visually searching predators and may also fit more snugly into the smaller leaf stems of smaller palms. These findings agree with the hypothetical predictions based on the properties of palm physical structure as a support for nests, the tree size structure of plantations and the risk of predation.

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...

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.

This study aimed to characterise mosquito species distribution based on the nature and type of breeding habitats and the influence of the vegetation that occupies these sites. Knowledge of variation in breeding site types can help in the design of optimal vector control strategies. In different areas of Biskra (southeast Algeria), mosquito immature stages were collected using standard dippers. Twenty-four breeding sites were found in four areas of Biskra (Chetma, Bbordj Ben Azouz, Sidi Okba and Biskra). With a total of 44 677 individuals, the inventory of Culicidae revealed 22 species distributed through six genera from 2009 to 2013. Three species — Aedes caspius, Culex pipiens and Culiseta longiareolata — were the most predominant, occupying several different types of permanent and temporary breeding sites. In addition, analysis of the distribution of species based on the flora occupying these sites revealed that Culex laticinctus, Aedes annulipes, Anopheles sergentii, Culiseta longiareolata, Culex pipie...

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.