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Dynamique de la population de la cigogne blanche (Ciconia ciconia) en Algérie depuis 1995
Abstract
Ce travail porte sur l'analyse des paramètres démographiques de la cigogne blanche en lgérie, à partir des données de trois ecensements nationaux effectués en 1995, 1998 et 001. Un délai de trois années entre un recensement et un autre a été dopté pour voir par apport à la tendance évolutive des effectifs des couples nicheurs si des possibilités de ecrutement par les eunes nés trois années auparavant pouvaient avoir lieu. Le nombre de ouples reproducteurs a doublé entre l'année 1995 et 'année 2001. Dans la majorité des olonies, les augmentations sont assez importantes. En tenant compte de ces données et es corrélations positives trouvées entre l'effectif des jeunes nés (JZg) en 1995 et l'effectif es couples nicheurs (HPm) ecensés durant l'année 1998 (r = 0.88, p < 0.05) et aussi 'effectif es jeunes nés en 1998 et l'effectif des couples nicheurs ecensés durant l'année 2001(r = .98, p < 0.05), nous supposons que l'augmentation des effectifs de cigognes blanches en lgérie ne pouvait pas provenir uniquement d'une immigration des cigognes des autres pays ais des recrutements locaux sachant qu'une démographie importante de ces dernières nnées est enregistrée un peu partout dans toute son aire de répartition omme en Espagne ù l'effectif des couples nicheurs est passé de 91 416 en 1996 à 113 006 en 1998, en France e 315 n 1995 à 641 en 2000 et en Tunisie de 231 nids recensés en 1998, l'effectif est passé 303 nids en 1999.
In this study, we analyse the demographic parameters of the white stork in Algeria from three census years (1995, 1998 and 2001). An interval of three years between each census was adopted to see whether the trends in numbers of nesting pairs was due to the recruitment of young hatched three years previously. The number of nesting pairs doubled between 1995 and 2001. In the majority of colonies the increases were quite large. Taking into consideration these data and the positive correlations found between the numbers of young hatched (JZg) in 1995 and the number of nesting pairs (HPm) counted during 1998 (r = 0.88, p < 0.05) and also the numbers of young hatched in 1998 and the number of nesting pairs counted during 2001 (r = 0.98, p < 0.05), we assume that the increase in numbers of the white stork in Algeria cannot be solely due to immigration from other countries, but from local recruitment, although we know that an important increase has been recorded in the last few years almost throughout the species' range, such as in Spain where numbers of nesting pairs increased from 91 416 in 1996 to 113 006 in 1998; in France from 315 in 1995 to 641 in 2000; while in Tunisia the total number of nests counted went up from 213 nests in 1998 to 303 nests in 1999.
Ostrich2007, 78(2): 291–293
In this study, we analyse the demographic parameters of the white stork in Algeria from three census years (1995, 1998 and 2001). An interval of three years between each census was adopted to see whether the trends in numbers of nesting pairs was due to the recruitment of young hatched three years previously. The number of nesting pairs doubled between 1995 and 2001. In the majority of colonies the increases were quite large. Taking into consideration these data and the positive correlations found between the numbers of young hatched (JZg) in 1995 and the number of nesting pairs (HPm) counted during 1998 (r = 0.88, p < 0.05) and also the numbers of young hatched in 1998 and the number of nesting pairs counted during 2001 (r = 0.98, p < 0.05), we assume that the increase in numbers of the white stork in Algeria cannot be solely due to immigration from other countries, but from local recruitment, although we know that an important increase has been recorded in the last few years almost throughout the species' range, such as in Spain where numbers of nesting pairs increased from 91 416 in 1996 to 113 006 in 1998; in France from 315 in 1995 to 641 in 2000; while in Tunisia the total number of nests counted went up from 213 nests in 1998 to 303 nests in 1999.
Ostrich2007, 78(2): 291–293
