Vol. 32 – 2006 - Ecologia Mediterranea
Vol. 32 – 2006 - Ecologia Mediterranea
Vol. 32 – 2006 - Ecologia Mediterranea
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MOHAMED BOUKHEMZA, NABILA BOUKHEMZA-ZEMMOURI, JEAN-FRANÇOIS VOISIN, BELKACEM BAZIZ<br />
16<br />
Sébaou were highlighted by frequentation<br />
indexes. Direct observations on the hunting and<br />
feeding activities of these two species from<br />
March to July 1995 were also carried out. We<br />
distinguished several categories of preys according<br />
to the occupied habitats. In addition, a<br />
quantitative approach of the diet and feeding<br />
activity of these wading birds was also<br />
approached according to the seasons and of the<br />
attended trophic habitats.<br />
Within locality, the frequentation indexes of the<br />
habitats by these two species varied from one<br />
season to another according to food availability,<br />
which was function of the biological cycle of<br />
preys. The species were both very highly<br />
attracted by plowed fields. Insects largely dominated<br />
all other animal classes in the diet of<br />
both birds, but accounted only for a small part<br />
of biomass intake. Although represented by<br />
small numbers, Vertebrates represented most of<br />
all the consumed biomass. The temporal variation<br />
of the feeding effort parameters showed<br />
the highest intake values during April, nesting<br />
and breeding period for the young. These values<br />
dropped at the time when the young<br />
become independent from their parents. Feeding<br />
activity, expressed in numbers of steps, was<br />
also maximum in April, then dropped therafter.<br />
Hunting efficiency, expressed in terms of failure<br />
percentage, was maximum in summer. The variations<br />
of the feeding effort parameters according<br />
to habitats show that energy intake was<br />
highest in plowlands, and least in the mown<br />
meadows and wetland. Feeding activity,<br />
expressed in step numbers, was maximum in<br />
waste lands. Hunting efficiency, expressed in<br />
failure percentage, was maximum in ploughings<br />
and minimal in the wetlands.<br />
Abriged english version<br />
In Algeria, Cattle Egret Bubulcus ibis lives in<br />
almost all the tellian area. In the <strong>Mediterranea</strong>n<br />
region, except for of Franchimont’s<br />
work in 1986b, few data are available about<br />
the food locations from which the successfully<br />
reproduction of Cattle Egret depends,<br />
contrary to what occurs for nesting sites (Bredin<br />
1981, 1983; Hafner & Fasola 1992). The<br />
white Stork Ciconia ciconia, is considered as<br />
a one of the declining species in the Western<br />
part of its distribution area (Reinwald et al.<br />
1989). In Europe, several works on feeding<br />
ecology have been carried out (e.g. Pinowska<br />
& Pinowski 1989; Dziewiaty 1992; Thomsen<br />
& Struwe 1994). In Algeria, many studies<br />
were undertaken (Boukhemza et al. 1997;<br />
Boukhemza 2001; Boukhemza et al. 2004),<br />
but there is a lack of quantitative data on feeding<br />
activity. The White stork and Cattle<br />
Egret live together in the Sébaou valley. It<br />
seemed convenient enough to see how these<br />
two species, the one (Cattle Egret) which is<br />
described as ubiquist and the other being rare<br />
and in the regression phase, do share food<br />
space and resources during their annual cycle,<br />
from the expenditure and energy profits points<br />
of vues.<br />
The various habitats attended by the white<br />
Stork (Ciconia ciconia) from January to<br />
August 1995 and the Cattle Egret (Bubulcus<br />
ibis) from November 1994 to October 1995<br />
in the Sébaou valley were highlighted by frequentation<br />
indexes. Direct observations on the<br />
hunting and feeding activities of these two<br />
species from March to July 1995 were also<br />
carried out. We distinguished several categories<br />
of preys according to the places of capture.<br />
In addition, a quantitative approach of<br />
the diet and feeding activity of these wading<br />
birds was also achieved during the same period.<br />
It related to the relative estimation of the<br />
expenditure and energy contributions through<br />
some parameters according to seasons and<br />
attended trophic habitats.<br />
In the same area, the frequentation indexes of<br />
the habitats by these two species fluctuated<br />
from one season to the other depending on<br />
food availability, this was function of the<br />
preys biological cycle. In both cases, it is<br />
mostly in June, which corresponds to the takeoff<br />
time of the young generation that the frequentation<br />
indices are highest. It is also at that<br />
time of the year that the most significant activity<br />
of these birds is observed.<br />
The white Stork finds most of its food in the<br />
temporary meadows, the ponds, the ploughed<br />
grounds and the cultures which it attends all<br />
the year. The other habitats, like the refuse<br />
tips, are frequented only in winter. Ploughed<br />
fields were always very highly attractive. This<br />
diagram of frequentation is found in the European<br />
countries such as Denmark, Spain and<br />
Germany (Skov 1991; Coppa 1991; Lestan<br />
1991; Thomsen 1995; Thomsen & Struwe<br />
1994; Marchamaldo de Blas 1995). These<br />
choices of frequentation seem to be dictated<br />
by good conditions such as the preys detection<br />
along with the possibility of moving<br />
without being stopped by the vegetation.<br />
In Kabylie, the Cattle Egret all along the year<br />
attend ploughings, the meadows, the low cultures,<br />
the wetlands and the temporary ponds.<br />
In the Camargue, it is also present all along<br />
the year in the marshes (Voisin 1991), and the<br />
other habitats such as the discharges are frequented<br />
only in periods of food (Hafner 1977;<br />
ecologia mediterranea <strong>–</strong> <strong>Vol</strong>. <strong>32</strong> <strong>–</strong> <strong>2006</strong>