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Herons and ibis are colonially nesting waders which, owing to their number, mobility and trophic role as top predators, play a key role in aquatic ecosystems. They are also good biological models to investigate interspecific competition between sympatric species and predation; two processes which structure ecological communities. Odonata are also numerous, diverse, mobile and can play an important role in aquatic ecosystems by serving as prey for herons and ibis. A relationship between prey size and bird predator has been observed in Numidia wetlands (NE Algeria) after analyzing food boluses regurgitated by six species of birds (Purple Heron, Black-crowned Night Heron, Glossy Ibis, Little Egret, Squacco Heron and Cattle Egret) during the breeding period, which also shows a temporal gradient for the six species. Both the Levins index and preliminary multivariate analysis of the Odonata as prey fed to nestling herons and ibis, indicated a high degree of resource overlap. However, a distinction of prey based on taxonomy (suborder and family) and developmental stage (larvae or adults) reveals a clear size dichotomy with large-sized predators (Purple Heron, Black-crowned Night Heron and Glossy Ibis) preying on large preys like Aeshnids and Libellulids and small-sized predators feeding mainly on small prey like Zygoptera. Overall, the resource utilization suggests a pattern of resource segregation by coexisting nesting herons and ibis based on the timing of reproduction, prey types, prey size and foraging microhabitats.

Summary. An appraisal of the status and distribution of waterbirds of Algeria: indicators of global changes? North Africa is generally thought to play a key role for wintering and staging migrant birds. This study presents a detailed assessment of the status of waterbirds of Algeria with an emphasis on changes in species composition and distribution of breeding wetland and marine birds. A total of 97 species of waterbirds were identified with 41 species breeding. Marked environmental changes in North Africa over the past two hundred years that are relevant to waterbirds have included wetland drainage, persecution, introduction of exotic fish, increases in open-air refuse dumps and climate change. These changes have affected waterbirds differentially with some species increasing in numbers and expanding their range and others teetering on the verge of local extinction. When examining changes in the present breeding avifauna since the nineteenth century or the mid-twentieth century, the guild renewal rates ...

The status and breeding success of Glossy Ibis (Plegadis falcinellus) in Numidia, Algeria and factors affecting its conservation in Algeria and North Africa were investigated during 2002–2007. After a century and a half of apparent interruption, reproduction was once again noted at Lake Fetzara and three new breeding sites: Dakhla, Chatt and Lake Tonga. At the latter site, colonies shifted location annually between 2002 and 2006 and were often split into subcolonies located on distinct islets. Egg-laying occurred between mid-April and the end of June, beginning over a month earlier in 2004 than in 2005. Mean clutch size for the combined three study years (2004, 2005 and 2007) was 3.7 ± 0.6 (N = 49 clutches). Hatching success amounted to 89% (29 clutches) and an average of 2.7 ± 0.9 chicks per nest survived to twelve days. Habitat loss and degradation as well as lack of management plans are identified as major threats to the future of the Glossy Ibis in Algeria.

The reproductive ecology of the Cattle Egret ( Bubulcus ibis ) in a monospecific colony was monitored in 2003 at Sidi Achour, north-eastern Algeria. A set of physical characteristics were quantified to investigate their influence on breeding success. Prior to hatching, roughly one-third of the nests were subjected to vandalism in one single incident, which highlighted the anthropogenic influence on the reproductive success of Cattle Egrets breeding close to urban areas. Mean clutch size was 3.10 ± 0.13 eggs per nest (n = 31 complete clutches). The mean clutch size did not vary significantly when lost clutches were taken into account: 2.99 ± 0.09 eggs per nest (n = 86 nests). Clutch size, which exhibited a marked seasonal decline, correlated marginally with nest diameter and height above water but not with the location of a nest within a colony (central or peripheral). Hatching success for complete clutches was high (83.0%) and an average of 2.29 ± 0.18 chicks per nest survived to 12–15d of age. Growth curves of developing nestlings were estimated from repeated measurements of mass, tarsus, head and beak length, and wingspan. The last chicks (C- and D-chicks) to hatch had lower growth rates and/or survivorship than the first (A-) or second (B-) hatched chicks. L'ecologie de la reproduction du Heron garde-boeufs ( Bubulcus ibis ) a ete etudiee en 2003 dans une colonie monospecifique a Sidi Achour, dans le nord-est algerien. Une serie de descripteurs a ete quantifie pour explorer son influence sur le succes de la reproduction. Avant l'eclosion, pres d'un tiers des nids a ete vandalise lors d'un incident unique qui souligne l'influence anthropique sur le succes de reproduction du Heron Garde-boeufs nichant a proximite des centres urbains. La grandeur de ponte moyenne est de 3.10 ± 0.13 oeufs par nid (n = 31 pontes completes). La grandeur de ponte moyenne ne change pas significativement si les nids vandalises sont pris en compte. La grandeur de ponte est correlee significativement avec le diametre du nid et la hauteur de celui-ci par rapport au niveau de l'eau mais pas avec la location du nid au sein de la colonie (centre vs peripherie). Le succes d'eclosion des pontes completes est elevee (83.0%) et une moyenne de 2.29 pulli par nid ont survecu a l'age de 12–15 jours. Des courbes de croissance des poussins ont ete elaborees a partir de mesures repetees du poids, tarse, bec et envergure. Les derniers poussins eclos (C- et D-) a des taux de croissance et/ou de survie moindres que les premiers (A- et B-) poussins eclos. Ostrich 2007, 78(2): 481–487

We conducted a survey of large branchiopods (Crustacea, Branchiopoda) of the major salt lakes of Algeria, particularly those of the eastern Hauts Plateaux. The aim of the survey was to complement a previous survey that focused on the freshwater habitats of Numidia, northeast Algeria. The study revealed 8 species, with one taxon new to Algeria and North Africa (Chirocephalus salinus). Data on the status, phenology and habitats of collected and previously known species are presented for 19 taxa. The distribution of many species has been greatly extended and the co-occurrence of Artemia tunisiana and Branchinella spinosa has been recorded. The studied salt lakes, owing to a large production of fairy shrimps, support a great number of wintering and breeding waterbirds, but are subject to increasing human pressure.

During 2002–2007, we assessed the status of the Purple Heron Ardea purpurea in Numidia, Algeria by surveying all the major wetlands in the region. We located six distinct breeding sites; four of these were not previously known. We also investigated nest site selection and determined the species’ reproductive success at Dakhla, a dunary pond during two successive years (2006 and 2007). The egg laying period was comparable to that reported for southern Europe (March–May) and a seasonal change of breeding success was recorded. A growth curve was derived for developing nestlings and the impact of an ectoparasite (mite) infestation upon nestling’s growth was considered. We also examined 73 food boluses regurgitated by nestlings and identified 329 prey items. Fish, mainly Gambusia holbrookii and Cyprinus carpio, dominated by mass, whereas insects, mainly aquatic Coleopteran larvae and aeshnids (Odonata), were the most frequent prey (67.1%). Loss of habitat is identified as a major threat to the future of colonial herons in Algeria. OSTRICH 2010, 81(3): 189–196