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1

Egg size variation and breeding characteristics of the Black-winged Stilt Himantopus himantopus in a Saharan oasis

100%
Adamou A.-E., Kouidri M., Chabi Y., Skwarska J., Banbura J.
Acta Ornithologica
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2009
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tom 44
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nr 1
Different aspects of the breeding biology of the Black-winged Shit were studied in a natural oasis wetland area in the Sahara Desert, the Chott of Aïn El Beïda, near Ouargla, E Algeria in 2004-2007. In this wetland the water level is independent of rainfall and Stilts start egg laying when average daily temperature increases to ca. 15°C, mostly in April-May, with no significant differences between years. Complete clutches usually consist of 4 eggs but 3 egg clutches happen with low frequency (2.9-5.6%). Egg size traits (mass, length, breadth and volume) tended to decrease from 2004 to 2007, probably due to deteriorating hydrological conditions of the wetland. Within-clutch variability showed both significant repeatability and laying-sequence-dependent differences among eggs, with the final egg being smaller than the clutch mean value. We found that all egg traits studied showed a negative correlation with the date of laying, which seems to be a phenomenon analogous to the seasonal decrease in clutch size, typical of birds with more variable clutch sizes. Hatching tended to be asynchronous, with average clutch hatching time being 1.84 days. The small final egg and hatching asynchrony are typical components of the adaptive brood reduction, the phenomenon not being recorded so far and remaining for future studies on the Black-winged Stilt. These are the first published data on breeding characteristics for any N African population of the Black-winged stilt.
2

Variation in the timing of reproduction and clutch size of Afrocanarian blue tits Cyanistes teneriffae ultramarinus in the Saharan Atlas of Algeria

86%
Adamou A.-E., Kouidri M., Banbura A., Ouakid M. L., Chabi Y., Banbura J.
Polish Journal of Ecology
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2015
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tom 63
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nr 4
We examined the variation in the date of the onset of egg laying and clutch size in three peripheral populations of the Afrocanarian Blue Tits Cyanistes teneriffae ultramarinus at the edge of the species and subspecies geographic range. This study was carried out in three study sites, 130–290 km apart, in similar geographic conditions of the South Border Range of the Saharan Atlas in Algeria. Mean altitudes of nesting territories were between 1327 and 1437 m a.s.l. Habitats of the study sites were covered by the secondary, human-modified vegetation, ranging from a maquis shrubland, with the Holm oak Quercus ilex shrubs to woodlands dominated by the Atlas cedar Cedrus atlantica or by the Aleppo pine Pinus halepensis. 169 wooden nest-boxes were monitored for breeding parameters (laying dates and clutch sizes) during the breeding seasons 2007–2009 and 2011–2013. The timing of egg laying was relatively late for the latitude of the study sites, with overall mean laying dates varying between the study sites from 4 to 13 May. The laying date was influenced by the altitude of nesting sites, with the dates being delayed with increasing altitude. Overall mean clutch size differed between the study sites from 5.91 at Djelfa to 8.43 at Aflou. Clutch size tended to decrease with the advance of the breeding season. Because the study populations inhabit areas of similar physical conditions (climate and altitude), the main inter-population source of variation in the breeding parameters studied was probably variation in habitat quality.
3

High egg size variation in African Blue Tits Cyanistes caeruleus ultramarinus on the periphery of species range

86%
Kouidri M., Adamou A.-E., Banbura A., Ouakid M. L., Chabi Y., Banbura J.
Acta Ornithologica
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2015
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tom 50
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nr 2
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