Factors affecting nesting success in the Great-crested Grebe Podiceps cristatus at Lake Tonga, north-east Algeria

Cheriet, S., Samraoui, F., Alfarhan, A. H. & Samraoui, B. (2015). Factors affecting nesting success in the Great-crested Grebe Podiceps cristatus at Lake Tonga, north-east Algeria. Ostrich 86(3): 239-245.      doi: 10.2989/00306525.2015.1067932
PDF in ResearchGate.net

Abstract:

The breeding ecology of the Great-crested Grebe Podiceps cristatus was investigated over four consecutive years (2009-2012) at Lake Tonga, north-east Algeria. In all four years, the egg-laying period was relatively short, spanning two months (end of March to end of May), and bimodal. Nests were mainly located in Phragmites australis, over water of substantial depth (178 ± 43 cm, N=209), far from the shore and in habitat with low vegetation cover (12.37 ± 7.67%, N=209). The overall clutch size was 3.73 ± 0.92 eggs (N=127) and it decreased marginally over time. The overall nesting success was 70.4% (N=209), with nest failure caused mainly by predation (65%) and flooding (23%). Breeding outcome was significantly and positively related to nest size, with bigger nests conferring better survival to eggs and young probably through affording better protection during spells of adverse weather. However, the benefits of bigger nests may be confounded by the age or intrinsic quality of birds. The location of nests in P. australis, rather than other vegetation types, increased nesting success marginally but significantly. Two cases of interspecific mixed clutches involving the Great-crested Grebe were recorded.

Great-crested Grebe (Podiceps cristatus) and chicks

Great-crested Grebe (Podiceps cristatus) and chicks (Michael Brace, flickr)

Factors influencing species-richness of breeding waterbirds in Moroccan IBA and Ramsar wetlands

Cherkaoui, S. I., Hanane, S., Magri, N., El Agbani, M.-A. & Dakki, M. (2015). Factors influencing species-richness of breeding waterbirds in Moroccan IBA and Ramsar wetlands: a macroecological approach. Wetlands 35(5): 913–922.
doi: 10.1007/s13157-015-0682-y

Abstract:

Since 2005, Morocco has designated 28 Important Bird Areas (IBA) and Ramsar wetlands for waterbirds, yet little is known about how waterbird communities are changing over time and space, within and between sites. We assessed the relationships between species numbers of overall breeding waterbirds, as well as those of Anatidae, Rallidae and Podicipedidae, and geographical, topographical and macrohabitat factors. Species richness of overall waterbirds and Anatidae were positively correlated with: (i) extent of emergent vegetation, (ii) number of plant species present, and (iii) altitude. Species richness of Rallidae was positively correlated with: (i) latitude, and (ii) different beds of emergent vegetation, while that of Podicipedidae was exclusively correlated with altitude. These results suggest that breeding waterfowl are significantly related to habitat characteristics, most importantly vegetation structure, and altitude. Our findings give support to the idea that large mountain wetlands protected areas provide valuable habitat to breeding waterbirds in this region, by providing larger buffer zones with fewer human activities, such as hunting, urbanization and tourism disturbance. This study provides a platform from which we can advance the scientific research on Moroccan IBA and Ramsar wetlands.

Nest-site selection and reproductive success of the Little Grebe (Tachybaptus ruficollis) in Northeast Algeria

Athamnia, M., Samraoui, F., Kelailia, B., Rouabah, A., Alfarhan, A. H. & Samraoui, B. (2015). Nest-site selection and reproductive success of the Little Grebe Tachybaptus ruficollis in Northeast Algeria. Ardeola 62: 113–124.
doi: 10.13157/arla.62.1.2015.113
PDF in ResearchGate.net

Summary:

We studied the phenology, habitat selection, and interannual and seasonal changes in breeding performance of the little grebe Tachybaptus ruficollis in relation to the spatial structure of a shallow lake during three breeding seasons (2010–2012). Nests were mostly located in shallow waters, close to the shore (98.3 ± 37.9 cm), in vegetation dominated by Scirpus lacustris. The egg-laying period started at the end of March and extended for four months until the end of July. Overall, the mean clutch size was 4.7 ± 1.1 (N = 154) with a modal clutch of 5. There was a seasonal decline in both egg volume and clutch size. The overall nesting success was 60% and the chief causes of nest failure were predation (52%) and adverse weather (20%). Breeding outcome was influenced by water depth, nest size and year of breeding. Predation and nest flooding markedly varied between years. Larger nests had a higher nesting success than smaller ones. Likewise, nests located at greater water depth (further from the shore) succeeded better than ones located in shallower water. As the little grebe forages preferentially in shallow waters, these results suggest that optimal nesting locations may be the result of a trade-off between conflicting selection pressures such as foraging efficiency (better in shallow waters) and nest predation risk (greater in shallow waters).

Little Grebe (Tachybaptus ruficollis) nest with eggs

Little Grebe (Tachybaptus ruficollis) nest with eggs (Sébastien Bertru, wikipedia)

Black-necked Grebe: an expanding species in the Middle Atlas wetlands, Morocco

Cherkaoui, I., Bouajaja, A., Elbanak, A., Lahrouz, S. & Hanane 2014. The Black-necked Grebe (Podiceps nigricollis): an expanding species in the Middle Atlas wetlands, MoroccoWetlands Ecology and Management 22: 93-98. doi: 10.1007/s11273-013-9321-7
PDF in ResearchGate.net

Abstract:

The present study investigates the population trends of Black-necked Grebe Podiceps nigricollis (Podicipedidae: Podicidae) over 5 years (2009–2013) in three Middle Atlas wetlands (Aguelmam Afennourir, Dayet Aoua and Dayet Ifrah). Using generalized linear models with a Poisson distribution, we demonstrated that the number of Black-necked Grebe breeding pairs has varied significantly and positively over the 5 years and between the three study wetlands. The annual population growth rate of the three colonies was 0.48 (±0.01). This positive trend is consistent with the current Least Concern conservation status of the IUCN Red List. Further more detailed studies are, however, needed to improve our understanding on the mechanisms driving the population increase in this part of North Africa. This remains a prerequisite for proper population conservation and management.

Black-necked Grebe (Podiceps nigricollis)

Black-necked Grebe Podiceps nigricollis (Alan Vernon, flickr)