16 research outputs found

    Écologie trophique du Gobemouche gris Muscicapa striata en pĂ©riode de reproduction en AlgĂ©rie

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    The diet of the Spotted Flycatcher Muscicapa striata, a breeding migratory species in Algeria, was studied from May to October 1994 and from May to September 1995 at El Harrach, a locality south-east of Algiers. It was based mainly on insects, which represented 95.8% of the 1889 food items recovered from 356 faeces. 196 taxa were identified at different taxonomic levels, from order to species. Arachnida, Gastropoda, Crustacea and Myriapoda were only occasionally captured and hence slightly represented. Hymenoptera dominated (48.3% of individual insects, 25.6% being ants), followed by Coleoptera (17.5%), Diptera (12.5%) and Hemiptera (11.4%). Other orders were few in terms of preys. They seemed to be captured when the Spotted Flycatcher got an opportunity to do so. This study shows annual and monthly variations of the species consumed, indicating a high-level of plasticity in the diet. These variations correspond to the local availability and phenology of preys. In the suburban area of Algiers like elsewhere, the Spotted Flycatcher appears to be an opportunist feeder which, when preys are abundant, selects those that best fit its nutritional requirements, but which can use others and become more eclectic when food becomes scarceL'étude du régime alimentaire du Gobemouche gris Muscicapa striata, visiteur d'été nicheur en Algérie, a été conduite de mai à octobre 1994 et de mai à septembre 1995 à El Harrach, au sud-est d'Alger, à partir de l'analyse de 356 fientes. Au total, 1889 proies appartenant à 197 taxons ont été identifiées à divers niveaux taxinomiques, variant de l'ordre à l'espÚce. Le régime alimentaire est fondé sur les insectes, qui ont représenté en moyenne 95,8 % des proies ingérées par les oiseaux durant les deux saisons de reproduction 1994-1995. Les arachnides, gastropodes, crustacés et myriapodes n'ont été capturés qu'occasionnellement, et de ce fait représentés par des effectifs négligeables. Parmi les Insectes, les HyménoptÚres représentaient 48,3 % des proies, dont 25,6 % de fourmis. Avec respectivement 17,5, 12,5 et 11,4 % des proies, les ColéoptÚres, DiptÚres et HémiptÚres occupaient une place secondaire. Les autres groupes taxinomiques n'étaient que trÚs faiblement représentés et capturés occasionnellement. Les espÚces consommées différaient selon les saisons et les années, selon la disponibilité et la phénologie locales des proies. Dans la région d'Alger comme ailleurs, le Gobemouche gris apparaßt comme une espÚce assez opportuniste qui, lorsque les proies sont abondantes, sélectionne certaines, mais sait les remplacer par d'autres lorsqu'elles sont rares

    Comparative utilization pattern of trophic resources by White Storks Ciconia ciconia and Cattle Egrets Bubulcus ibis in Kabylia (Algeria)

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    The diets of White Storks and Cattle Egrets were studied by analysis of rejection pellets in the SĂ©baou valley, Kabylia, Algeria. 150 pellets from each species were collected, from April to August 1995 for the White Stork and from November 1994 to October 1995 for the Cattle Egret. Insects predominated in similar proportions in the diet of the two species, and represented respectively 97.1 and 92.7% in prey number as well as 57.2 and 67.4% in biomass. Coleopterans were the most numerous prey, but were only 7.1 and 8.2% in biomass. Orthopterans were 47.3% of the biomass ingested by the White Stork, and 58.8% of that ingested by the Cattle Egret, and seemed to be captured opportunistically, when human activities disturbed them. Variations in the diet of the two species, between colonies and during the course of the year, corresponded to the local availability and phenology of prey. The diets of the White Stork and Cattle Egret were very similar in terms of prey species, but differed sharply in prey size, which may be related to the birds’ different body size and bill morphology. As elsewhere, Cattle Egrets and White Storks in the SĂ©baou valley are opportunist predators which, when prey is abundant, select those items which suit them best, but can live on what they find when prey becomes scarce. This may largely explain the successful recent range expansion of the Cattle Egret in AlgeriaLes rĂ©gimes alimentaires ont Ă©tĂ© Ă©tudiĂ©s par l'analyse de 150 pelotes de rĂ©jection fraĂźchement rĂ©coltĂ©es d'avril Ă  aoĂ»t 1995 pour la Cigogne blanche et 150 autres de novembre 1994 Ă  octobre 1995 pour le HĂ©ron garde-boeufs. Dans la vallĂ©e du SĂ©baou, en Kabylie (AlgĂ©rie), les insectes dominaient tant dans le rĂ©gime alimentaire du HĂ©ron garde-boeufs que dans celui de la Cigogne blanche et reprĂ©sentaient respectivement 97,1 et 92,7 % du nombre de proies, ainsi que 57,2 et 67,4 % de la biomasse. Les colĂ©optĂšres furent les plus nombreux, mais ne reprĂ©sentaient que 7,1 et 8,2 % de la biomasse ingĂ©rĂ©e. Les orthoptĂšres reprĂ©sentaient respectivement 47,3 et 58,8 % de la biomasse ingĂ©rĂ©e et semblaient surtout capturĂ©s lorsque l'occasion s'en prĂ©sentait. Les variations du rĂ©gime alimentaire des deux espĂšces d'un site Ă  l'autre et au cours de l'annĂ©e correspondaient aux disponibilitĂ©s et Ă  la phĂ©nologie locales des proies. Le rĂ©gime alimentaire du HĂ©ron garde-boeufs et celui de la Cigogne blanche Ă©taient trĂšs similaires en ce qui concerne les espĂšces-proies, mais une analyse plus dĂ©taillĂ©e a montrĂ© une nette sĂ©grĂ©gation de ces derniĂšres par la taille, fait souvent rattachĂ© Ă  des diffĂ©rences de morphologie du bec et de la taille entre espĂšces sympatriques. Dans la vallĂ©e du SĂ©baou comme ailleurs, le HĂ©ron garde-boeufs et la Cigogne blanche apparaissent comme des prĂ©dateurs opportunistes qui, lorsque les proies sont abondantes, sĂ©lectionnent celles qui leur conviennent le mieux, mais se contentent de ce qu'elles trouvent lorsque celles-ci sont rares. Ceci explique certainement en grande partie le succĂšs de l'expansion rĂ©cente du Garde-bƓufs en AlgĂ©rie

    MENU TROPHIQUE DU GOÉLAND LEUCOPHÉE LARUS MICHAHELLIS DANS L’ÎLOT AGUÉLI, ZONE HUMIDE DE RÉGHAÏA

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    In Wetland Réghaïa more specifically on the island Agueli 1 km off the beach Réghaïa, we studied the diet of Gull Yellow-legged Larus michahellis during the breeding season. The analysis of 91 balls rejection has allowed us to recognize 52 prey species divided into 8 classes, 25 orders and 30 families. Number of prey fish in 2004 (AR = 33.9%) and birds in 2006 (AR = 21.2%) proved the most consumed. Yellow-legged Gulls in the study area also consumes arthropods, mammals, reptiles, plants and shellfish waste. This Laridé a very diversified diet (E = 0.89) in the wetland Réghaïa

    Disponibilités des ressources alimentaires et leur utilisation par le Héron garde-boeufs Bubulcus ibis en Kabylie, Algérie

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    Cattle Egrets (Bubulcus ibis) living in the SĂ©baou valley, Kabylia, Algeria, have a diet based mainly on insects, which represent 97.1 % of food items and 57.2 % of ingested biomass, calculated after 5 999 prey items recovered from 150 rejection pellets collected in three different colonies. Orthopteran insects in particular account for 47.3 % of the ingested biomass. Vertebrales are few in terms of preys (1.5 %), but represent 42.5 % of the ingested biomass. They seem to be captured when the Egrets get an opportunity to do so, i.e. after crossings of agricultural engines. Variations in the diet of Cattle Egrets from one colon y to the other, as well as variation according to months seem to be correlated to the local availability and phenology of preys. Cattle Egrets in one region visit various biotopes according to prey availability and their own food requirements. ln the SĂ©baou valley as weil as at other places, Cattle Egrets appear to be opportunist feeders which, when preys are abundant, choose the ones fitting best their nutritional requirements, but which can make use of the remaining ones when food becomes scarce. This ability may partly explain the Cattle Egret' s recent, successful range extension in AlgeriaLes HĂ©rons garde-boeufs (Bubulcus ibis) de la vallĂ©e du SĂ©baou, en Kabylie (AlgĂ©rie) ont un rĂ©gime alimentaire fondĂ© sur les insectes, qui reprĂ©sentent 97,1 % des proies et 57,2 % de la biomasse ingĂ©rĂ©e par les oiseaux de trois colonies Ă©tudiĂ©es en 1994-1995. Les OrthoptĂšres en particulier reprĂ©sentent 47,3 % de la biomasse ingĂ©rĂ©e. Les VertĂ©brĂ©s, peu importants en nombre (1,5 % des proies) reprĂ©sentent cependant 42,5 % de la biomasse ingĂ©rĂ©e, et semblent surtout capturĂ©s lorsque l'occasion s'en prĂ©sente, par exemple lors du passage de machines agricoles. Les variations du rĂ©gime alimentaire du HĂ©ron garde-boeufs d'une colonie Ă  l'autre et au cours de l'annĂ©e correspondent aux disponibilitĂ©s et Ă  la phĂ©nologie locales des proies. Les HĂ©rons garde-boeufs frĂ©quentent les divers milieux d'une mĂȘme localitĂ© en fonction de la disponibilitĂ© des proies qui s'y trouvent et de leurs besoins nutritionnels. Dans la vallĂ©e du SĂ©baou comme ailleurs, le Garde-boeuf apparaĂźt comme une espĂšce opportuniste qui, lorsque les proies sont abondantes, sĂ©lectionne celles qui lui conviennent le mieux, mais sait se contenter de ce qu'il trouve lorsqu'elles sont rares. Ceci explique certainement en bonne partie le succĂšs de son expansion rĂ©cente en AlgĂ©rie

    RĂ©gime alimentaire de Crocidura pachyura (KĂŒster, 135) (Mammalia, Soricidae) dans plusieurs localitĂ©s d’AlgĂ©rie

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    Le rĂ©gime alimentaire de Crocidura pachyura (KĂŒster, 1835) a Ă©tĂ© Ă©tudiĂ© grĂące Ă  l’analyse des contenus stomacaux de 95 spĂ©cimens collectĂ©s sur le terrain de juin 2007 Ă  septembre 2008 et de mars 2012 Ă  mai 2014. Ces individus ont Ă©tĂ© collectĂ©s au moyen de piĂšges Sherman et de pots-enterrĂ©s dans 8 localitĂ©s d’AlgĂ©rie du Nord et du Centre, du niveau de la mer Ă  1390 m d’altitude (Tigzirt, Boukhalfa, Ouadias, El Misser, Darna, Tala Guilef, Zeralda et Reghaia). On trouve 99 proies diffĂ©rentes distribuĂ©es dans 7 taxons d’invertĂ©brĂ©s (Clitellates, NĂ©matelminthes, Gastropodes, Arachnides, CrustacĂ©s, Myriapodes et Insectes), un vertĂ©brĂ© (Squamate) et des plantes indĂ©terminĂ©es, notamment des graines. Les invertĂ©brĂ©s reprĂ©sentent 77,05 % du rĂ©gime alimentaire et les insectes sont les proies les plus frĂ©quentes avec 54,3 %. Crocidura pachyura se nourrit de petites proies de taille infĂ©rieure Ă  17 mm (moyenne 4 mm) et la diversitĂ© des proies (indice de diversitĂ© de Shannon-Weaver) varie de 1,58 Ă  4,88 (moyenne de 2,4). La comparaison avec les travaux similaires effectuĂ©s en AlgĂ©rie et en Europe sur C. russula montre quelques diffĂ©rences de rĂ©gime, surtout en ce qui concerne les proportions des proies ColeoptĂšres, HymĂ©noptĂšres et DiptĂšres.Ecological information, including food habits, on African shrews is scarce. The aim of this study was to describe the diet of Crocidura pachyura (KĂŒster, 1835) in Algeria. Its diet was studied by analysing stomach contents of 95 shrews collected in pitfall and Sherman traps, from June 2007 to September 2008 and from March 2012 to May 2014, in eight localities of North-Central Algeria, from the sea level until 1390 m (Tigzirt, Boukhalfa, Ouadias, El Misser, Darna, Tala Guilef, Zeralda and Reghaia). The diet was composed of 99 different prey taxa distributed in seven invertebrate classes (Clitellata, Nematelminthes, Gastropoda, Arachnida, Crustacea, Myriapoda and Insecta), one vertebrate (Squamata) and plants, particularly seeds. The most important components of the diet were invertebrates: their contribution was 77.05 % of the overall diet composition. Insects were the most frequent prey with 54.3 %. Crocidura pachyura feeds on small preys lower than 17 mm (average 4 mm) and the diversity index of Shannon-Weaver varied between 1.58 and 4.88 (average 2.4). Comparisons with similar studies in Algeria and Europe for C. russula showed some differences especially for Coleoptera, Hymenoptera and Diptera proportions

    Trophic ecology of the Spotted Flycatcher Muscicapa striata during the breeding period in Algeria

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    The diet of the Spotted Flycatcher Muscicapa striata, a breeding migratory species in Algeria, was studied from May to October 1994 and from May to September 1995 at El Harrach, a locality south-east of Algiers. It was based mainly on insects, which represented 95.8% of the 1889 food items recovered from 356 faeces. 196 taxa were identified at different taxonomic levels, from order to species. Arachnida, Gastropoda, Crustacea and Myriapoda were only occasionally captured and hence slightly represented. Hymenoptera dominated (48.3% of individual insects, 25.6% being ants), followed by Coleoptera (17.5%), Diptera (12.5%) and Hemiptera (11.4%). Other orders were few in terms of preys. They seemed to be captured when the Spotted Flycatcher got an opportunity to do so. This study shows annual and monthly variations of the species consumed, indicating a high-level of plasticity in the diet. These variations correspond to the local availability and phenology of preys. In the suburban area of Algiers like elsewhere, the Spotted Flycatcher appears to be an opportunist feeder which, when preys are abundant, selects those that best fit its nutritional requirements, but which can use others and become more eclectic when food becomes scarce.Écologie trophique du Gobemouche gris Muscicapa striata en pĂ©riode de reproduction en AlgĂ©rie. L’étude du rĂ©gime alimentaire du Gobemouche gris Muscicapa striata, visiteur d’étĂ© nicheur en AlgĂ©rie, a Ă©tĂ© conduite de mai Ă  octobre 1994 et de mai Ă  septembre 1995 Ă  El Harrach, au sud-est d’Alger, Ă  partir de l’analyse de 356 fientes. Au total, 1889 proies appartenant Ă  197 taxons ont Ă©tĂ© identifiĂ©es Ă  divers niveaux taxinomiques, variant de l’ordre Ă  l’espĂšce. Le rĂ©gime alimentaire est fondĂ© sur les insectes, qui ont reprĂ©sentĂ© en moyenne 95,8 % des proies ingĂ©rĂ©es par les oiseaux durant les deux saisons de reproduction 1994-1995. Les arachnides, gastropodes, crustacĂ©s et myriapodes n’ont Ă©tĂ© capturĂ©s qu’occasionnellement, et de ce fait reprĂ©sentĂ©s par des effectifs nĂ©gligeables. Parmi les Insectes, les HymĂ©noptĂšres reprĂ©sentaient 48,3 % des proies, dont 25,6 % de fourmis. Avec respectivement 17,5, 12,5 et 11,4 % des proies, les ColĂ©optĂšres, DiptĂšres et HĂ©miptĂšres occupaient une place secondaire. Les autres groupes taxinomiques n’étaient que trĂšs faiblement reprĂ©sentĂ©s et capturĂ©s occasionnellement. Les espĂšces consommĂ©es diffĂ©raient selon les saisons et les annĂ©es, selon la disponibilitĂ© et la phĂ©nologie locales des proies. Dans la rĂ©gion d’Alger comme ailleurs, le Gobemouche gris apparaĂźt comme une espĂšce assez opportuniste qui, lorsque les proies sont abondantes, sĂ©lectionne certaines, mais sait les remplacer par d’autres lorsqu’elles sont rares.Boukhemza-Zemmouri Nabila, Belhamra Mohamed, Boukhemza Mohamed, Doumandji Salaheddine, Voisin Jean-François. Trophic ecology of the Spotted Flycatcher Muscicapa striata during the breeding period in Algeria. In: Revue d'Écologie (La Terre et La Vie), tome 66, n°2, 2011. pp. 183-194

    Écologie trophique de la Cigogne blanche (Ciconia ciconia) et du HĂ©ron garde-boeufs (Bubulcus ibis) en Kabylie (AlgĂ©rie)

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    The various habitats attended by the white Stork (Ciconia ciconia) from January to August 1995 and the Cattle Egret (Bubulcus ibis) from November 1994 to October 1995 in the valley of SĂ©baou were highlighted by frequentation indexes. Direct observations on the hunting and feeding activities of these two species from March to July 1995 were also carried out. We distinguished several categories of preys according to the occupied habitats. In addition, a quantitative approach of the diet and feeding activity of these wading birds was also approached according to the seasons and of the attended trophic habitats. Within locality, the frequentation indexes of the habitats by these two species varied from one season to another according to food availability, which was function of the biological cycle of preys. The species were both very highly attracted by plowed fields. Insects largely dominated all other animal classes in the diet of both birds, but accounted only for a small part of biomass intake. Although represented by small numbers, Vertebrates represented most of all the consumed biomass. The temporal variation of the feeding effort parameters showed the highest intake values during April, nesting and breeding period for the young. These values dropped at the time when the young become independent from their parents. Feeding activity, expressed in numbers of steps, was also maximum in April, then dropped therafter. Hunting efficiency, expressed in terms of failure percentage, was maximum in summer. The variations of the feeding effort parameters according to habitats show that energy intake was highest in plowlands, and least in the mown meadows and wetland. Feeding activity, expressed in step numbers, was maximum in waste lands. Hunting efficiency, expressed in failure percentage, was maximum in ploughings and minimal in the wetlands.Les divers milieux frĂ©quentĂ©s par la Cigogne blanche (Ciconia ciconia) de janvier Ă  aoĂ»t 1995 et le HĂ©ron garde-boeufs (Bubulcus ibis) de novembre 1994 Ă  octobre 1995 dans la vallĂ©e du SĂ©baou ont Ă©tĂ© caractĂ©risĂ©s par des indices de frĂ©quentation. L’activitĂ© de chasse et d’alimentation de ces deux espĂšces a Ă©tĂ© suivie par observation directe de mars Ă  juillet 1995, et leurs proies ont Ă©tĂ© classĂ©es en catĂ©gories selon les habitats occupĂ©s. Une approche quantitative du rĂ©gime et de l’activitĂ© alimentaire (nombre de pas) de ces deux espĂšces a Ă©tĂ© Ă©galement abordĂ©e en fonction des saisons et des milieux trophiques frĂ©quentĂ©s. Pour ces deux espĂšces et en une mĂȘme localitĂ©, les indices de frĂ©quentation des milieux varient d’une saison Ă  l’autre en fonction des disponibilitĂ©s alimentaires, qui sont elles-mĂȘmes fonction du cycle biologique des proies. L’attractivitĂ© des champs labourĂ©s est toujours trĂšs forte. Dans les deux cas, les insectes dominent largement en effectifs toutes les autres classes animales consommĂ©es. Du point de vue biomasse, ils n’occupent qu’une petite partie du poids ingĂ©rĂ©. Les vertĂ©brĂ©s, bien que faiblement reprĂ©sentĂ©s en nombre, reprĂ©sentent Ă  eux seuls la quasi-totalitĂ© de la biomasse ingĂ©rĂ©e. Les variations temporelles des diffĂ©rents paramĂštres de l’effort de capture montrent que ses proportions sont les plus Ă©levĂ©es pendant le mois d’avril, pĂ©riode de nidification et d’élevage des jeunes, donc de forte activitĂ©. Ces valeurs baissent quand les jeunes prennent leur indĂ©pendance. L’activitĂ© alimentaire, exprimĂ©e en nombre de pas, est Ă©galement maximum durant le mois d’avril, puis baisse. L’efficacitĂ© de chasse exprimĂ©e par le pourcentage d’échecs est maximale en Ă©tĂ©. Les variations des diffĂ©rents paramĂštres de l’effort de capture en fonction des biotopes montrent que ses proportions sont les plus Ă©levĂ©es dans les labours, et les plus basses dans les terrains fauchĂ©s et les milieux humides. L’activitĂ© alimentaire est maximum dans les friches. L’efficacitĂ© de chasse exprimĂ©e est maximum dans les labours et minimum dans les milieux humides.Boukhemza Mohamed, Boukhemza-Zemmouri Nabila, Voisin Jean-François, Baziz Belkacem. Écologie trophique de la Cigogne blanche (Ciconia ciconia) et du HĂ©ron garde-boeufs (Bubulcus ibis) en Kabylie (AlgĂ©rie). In: Ecologia mediterranea, tome 32,2006. pp. 15-28

    Breeding Biology of Booted Eagle Hieraaetus Pennatus (Gmelin, Jf, 1788): The First Study in North Africa

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    Knowledge and study of breeding birds’ biology is essential to understand the dynamic, assess productivity and identify threats. The population of booted eagles (Hieraaetus pennatus) was studied during three consecutive breeding seasons (2013−2015) in the Chettabah forest. Each year, arrivals of Booted eagles are recorded during March (15 individuals in 2013, 12 in 2014 and 11 in 2015). For the three years of study, the mean breeding pair’s density was 1.23 ± 0.153/km2, incubation period ranged from 33 to 38 days, whilst the frequency distribution of clutch size was 67.6% for 2 eggs, 27% for 1 and 5.4% for 3. Amongst the 63 eggs monitored, 55 hatched. No significant variation in hatching rate was observed during the 3 years (90% in 2013, 76.19% in 2014 and 84% in 2015). The comparison of breeding parameters with those reported in Spain showed a noticeable similarity. Further investigations should be conducted to improve the provision of information to support sound management interventions of this North African population

    Comparative utilization pattern of trophic resources by White Storks Ciconia ciconia and Cattle Egret Bubulcus ibis in Kabylia (Algeria)

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    The diets of White Storks and Cattle Egrets were studied by analysis of rejection pellets in the SĂ©baou valley, Kabylia, Algeria. 150 pellets from each species were collected, from April to August 1995 for the White Stork and from November 1994 to October 1995 for the Cattle Egret. Insects predominated in similar proportions in the diet of the two species, and represented respectively 97.1 and 92.7% in prey number as well as 57.2 and 67.4% in biomass. Coleopterans were the most numerous prey, but were only 7.1 and 8.2% in biomass. Orthopterans were 47.3% of the biomass ingested by the White Stork, and 58.8% of that ingested by the Cattle Egret, and seemed to be captured opportunistically, when human activities disturbed them. Variations in the diet of the two species, between colonies and during the course of the year, corresponded to the local availability and phenology of prey. The diets of the White Stork and Cattle Egret were very similar in terms of prey species, but differed sharply in prey size, which may be related to the birds’ different body size and bill morphology. As elsewhere, Cattle Egrets and White Storks in the SĂ©baou valley are opportunist predators which, when prey is abundant, select those items which suit them best, but can live on what they find when prey becomes scarce. This may largely explain the successful recent range expansion of the Cattle Egret in Algeria.Les rĂ©gimes alimentaires ont Ă©tĂ© Ă©tudiĂ©s par l’analyse de 150 pelotes de rĂ©jection fraĂźchement rĂ©coltĂ©es d’avril Ă  aoĂ»t 1995 pour la Cigogne blanche et 150 autres de novembre 1994 Ă  octobre 1995 pour le HĂ©ron garde-boeufs. Dans la vallĂ©e du SĂ©baou, en Kabylie (AlgĂ©rie), les insectes dominaient tant dans le rĂ©gime alimentaire du HĂ©ron garde-boeufs que dans celui de la Cigogne blanche et reprĂ©sentaient respectivement 97,1 et 92,7 % du nombre de proies, ainsi que 57,2 et 67,4 % de la biomasse. Les colĂ©optĂšres furent les plus nombreux, mais ne reprĂ©sentaient que 7,1 et 8,2 % de la biomasse ingĂ©rĂ©e. Les orthoptĂšres reprĂ©sentaient respectivement 47,3 et 58,8 % de la biomasse ingĂ©rĂ©e et semblaient surtout capturĂ©s lorsque l’occasion s’en prĂ©sentait. Les variations du rĂ©gime alimentaire des deux espĂšces d’un site Ă  l’autre et au cours de l’annĂ©e correspondaient aux disponibilitĂ©s et Ă  la phĂ©nologie locales des proies. Le rĂ©gime alimentaire du HĂ©ron garde-boeufs et celui de la Cigogne blanche Ă©taient trĂšs similaires en ce qui concerne les espĂšces-proies, mais une analyse plus dĂ©taillĂ©e a montrĂ© une nette sĂ©grĂ©gation de ces derniĂšres par la taille, fait souvent rattachĂ© Ă  des diffĂ©rences de morphologie du bec et de la taille entre espĂšces sympatriques. Dans la vallĂ©e du SĂ©baou comme ailleurs, le HĂ©ron garde-boeufs et la Cigogne blanche apparaissent comme des prĂ©dateurs opportunistes qui, lorsque les proies sont abondantes, sĂ©lectionnent celles qui leur conviennent le mieux, mais se contentent de ce qu’elles trouvent lorsque celles-ci sont rares. Ceci explique certainement en grande partie le succĂšs de l’expansion rĂ©cente du Garde-boeufs en AlgĂ©rie.Boukhemza Mohamed, Doumandji Salaheddine, Voisin Claire, Voisin Jean-François. Comparative utilization pattern of trophic resources by White Storks Ciconia ciconia and Cattle Egret Bubulcus ibis in Kabylia (Algeria). In: Revue d'Écologie (La Terre et La Vie), tome 59, n°4, 2004. pp. 559-580

    DisponibilitĂ©s des ressources alimentaires et leur utilisation par le HĂ©ron garde-bƓufs Bubulcus ibis en Kabylie, AlgĂ©rie

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    Cattle Egrets (Bubulcus ibis) living in the SĂ©baou valley, Kabylia, Algeria, have a diet based mainly on insects, which represent 97. 1 % of food items and 57.2 % of ingested biomass, calculated after 5 999 prey items recovered from 150 rejection pellets collected in three different colonies. Orthopteran insects in particular account for 47.3 % of the ingested biomass. Vertebrates are few in terms of preys (1.5 %), but represent 42.5 % of the ingested biomass. They seem to be captured when the Egrets get an opportunity to do so, i.e. after crossings of agricultural engines. Variations in the diet of Cattle Egrets from one colony to the other, as well as variation according to months seem to be correlated to the local availability and phenology of preys. Cattle Egrets in one region visit various biotopes according to prey availability and their own food requirements. In the SĂ©baou valley as well as at other places, Cattle Egrets appear to be opportunist feeders which, when preys are abundant, choose the ones fitting best their nutritional requirements, but which can make use of the remaining ones when food becomes scarce. This ability may partly explain the Cattle Egret’s recent, successful range extension in Algeria.Les HĂ©rons garde-bƓufs (Bubulcus ibis) de la vallĂ©e du SĂ©baou, en Kabylie (AlgĂ©rie) ont un rĂ©gime alimentaire fondĂ© sur les insectes, qui reprĂ©sentent 97,1 % des proies et 57,2 % de la biomasse ingĂ©rĂ©e par les oiseaux de trois colonies Ă©tudiĂ©es en 1994-1995. Les OrthoptĂšres en particulier reprĂ©sentent 47,3 % de la biomasse ingĂ©rĂ©e. Les VertĂ©brĂ©s, peu importants en nombre (1,5 % des proies) reprĂ©sentent cependant 42,5 % de la biomasse ingĂ©rĂ©e, et semblent surtout capturĂ©s lorsque l’occasion s’en prĂ©sente, par exemple lors du passage de machines agricoles. Les variations du rĂ©gime alimentaire du HĂ©ron garde-bƓufs d’une colonie Ă  l’autre et au cours de l'annĂ©e correspondent aux disponibilitĂ©s et Ă  la phĂ©nologie locales des proies. Les HĂ©rons garde-bƓufs frĂ©quentent les divers milieux d’une mĂȘme localitĂ© en fonction de la disponibilitĂ© des proies qui s’y trouvent et de leurs besoins nutritionnels. Dans la vallĂ©e du SĂ©baou comme ailleurs, le Garde-bƓuf apparaĂźt comme une espĂšce opportuniste qui, lorsque les proies sont abondantes, sĂ©lectionne celles qui lui conviennent le mieux, mais sait se contenter de ce qu’il trouve lorsqu’elles sont rares. Ceci explique certainement en bonne partie le succĂšs de son expansion rĂ©cente en AlgĂ©rie.Boukhemza Mohamed, Doumandji Salaheddine, Voisin Claire, Voisin Jean-François. DisponibilitĂ©s des ressources alimentaires et leur utilisation par le HĂ©ron garde-bƓufs Bubulcus ibis en Kabylie, AlgĂ©rie. In: Revue d'Écologie (La Terre et La Vie), tome 55, n°4, 2000. pp. 361-381
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