Assessing the extinction risk of the great bustard Otis tarda in Africa

Palacín, C., Martín, B., Onrubia, A. & Alonso, J. C. 2016. Assessing the extinction risk of the great bustard Otis tarda in Africa. Endang Species Res 30: 73–82. doi: 10.3354/esr00726 (Open Access)

Abstract:

We studied the dynamics and trend of the last extant population of great bustards Otis tarda in Africa. Moroccan great bustards are the southernmost population of this species, and thus show the characteristics of a peripheral population: small size, isolation and low gene flow. Available counts indicate a severe population decline (62% in the last 15 yr), as well as a contraction of the species’ distribution. We used a population viability analysis (PVA) to evaluate the quasi-extinction risk and to identify the most important threats. The estimated geometric growth rate of the more realistic of a set of possible scenarios was 0.87 (95% CI: 0.85, 0.89). This implies a 13% annual decline over 50 yr. However, projections derived from these results should be interpreted with caution, because models have a great deal of uncertainty and vital rates from Iberian populations may be different from those of the Moroccan population. PVA showed the negative consequence of human-induced mortality. According to the model that best fits our census data and if present threats remain in the coming years, this peripheral population could go extinct in ca. 20 yr. Agricultural intensification, infrastructure developments and new power lines in rural areas where the species occurs are causing habitat destruction and fragmentation and increasing artificial mortality. Urgent conservation measures, especially to reduce human-induced mortality, are needed to save African great bustards from extinction. We suggest that these findings can be generalized to other peripheral great bustard populations living in highly humanized landscapes.

Great Bustard (Otis tarda): a vulnerable species
Great Bustard (Otis tarda): a vulnerable species (Andrej Chudý, via Wikipedia Commons)

Nesting ecology of Ferruginous Duck (Aythya nyroca) in north-eastern Algeria

Fouzari, A., Samraoui, F., Alfarhan, A. H. & Samraoui, B. (2015). Nesting ecology of Ferruginous Duck Aythya nyroca in north-eastern Algeria. African Zoology 50: 299–305. doi: 10.1080/15627020.2015.1108165
PDF in ResearchGate.net

Abstract:

The status of waterbirds breeding in protected areas in North Africa needs constant monitoring because of a naturally fluctuating environment and permissive attitudes towards illegal activities likely to negatively affect population dynamics of threatened species. We present the results of a study conducted at a protected site, Lake Tonga, north-eastern Algeria, on a breeding population of Ferruginous Duck Aythya nyroca, a Near-Threatened duck subjected to considerable pressure from egg-pilfering and illegal hunting. Two distinct habitats within the lake were used by Ferruginous Duck: an Alder carr (Alnus glutinosa) and floating islets across the lake. The mean clutch size was 9.51±1.84 eggs (N = 51 clutches) with hatching rate of 80.7% for successful clutches. Breeding success was low (37%) with predation (33%) and clutch desertion (17%) accounting for the majority of failed nests. The probabilities of nest failure and nest desertion increased with a delayed onset of egg laying. Predation was not significantly associated with egg laying date and vegetation cover, but late breeders nesting in dense vegetation seemed to suffer less predation. Conspecific brood parasitism was positively associated with nest size, whereas interspecific brood parasitism was marginally associated with water depth. We discuss different hypotheses concerning nest desertion, and argue that illegal hunting and disturbance may best explain why birds desert their nests.

Ferruginous Duck (Aythya nyroca)

Ferruginous Duck Aythya nyroca (photo: Tony Smith, in flickr CC BY)

 

Le retour du Fuligule milouin (Aythya ferina) nicheur dans la réserve naturelle du Lac de Réghaia, Algérie

Lardjane-Hamiti, A., Metna, F., Sayaud, M. S., Boukhemza, M. & Houhamdi, M. 2014. Le retour du Fuligule milouin Aythya ferina nicheur dans la réserve naturelle du Lac de Réghaia (Alger, Algérie). In: Feltrup-Azafzaf, C., Dain, M., Brochet, A.L., Defos du Rau, P., Mondain-Monval, J.Y. & Azafzaf, H. (eds.). Bulletin of the network “Mediterranean Waterbirds”, No. 2. AAO, ONCFS, Tour du Valat. pp: 42-43. PDF

Common Pochard Aythya ferina breeding back in the Réghaia Lake nature reserve (Alger, Algeria).

Extrait du texte:

“Les derniers cas de nidification du Fuligule milouin (Aythya ferina) rapportés en Algérie ont été signalés par Heim de Balsac et Mayaud en 1962 au niveau du Lac Fetzara (Annaba) et au Lac Tonga (Parc National d‘El-Kala)……

C’est en avril 2009 que le groupe ornithologique du centre cynégétique de Réghaia a signalé la présence des nids de cette espèce. L’Algérie représente donc une nouvelle zone de reproduction pour le Fuligule milouin. L’étude de l’écologie de la reproduction de six nids installés durant l’année 2010 a révélé une taille de ponte moyenne avoisinant 8,16 œufs/nid. Les nids sont installés dans les touffes de Massettes à feuilles étroites Typha angustifolia…….”.

Voir aussi:

Lardjane-Hamiti, A., Metna, F., Sayaud, M.-S., Guelmi, M., Boukhemza, M. & Houhamdi, M. 2012. Le Fuligule milouin Aythya ferina nicheur dans la réserve naturelle du Lac de Réghaia (Alger, Algérie). Alauda 80: 151–152.  PDF

Abstract:

Breeding evidence of Common Pochard Aythya ferina at Lake Réghaia (North Algeria).

After an absence of nearly 50 years, breeding was again assessed for the Common Pochard in Algeria. Nesting was found in 2009 and 2010 at Lake Réghaia. The six nests found in 2010 showed a mean clutch size of 8.16 eggs/nest. The first hatching occurred in May and the last one in the first week of July. Hatching success was of 66.66 %. The main causes of hatching failure were predation and egg abandonment. Nests are made of Typha and Phragmites leaves.

Femelle avec poussins du Fuligule milouin (Aythya ferina), Lac de Réghaia, Algérie.

Fuligule milouin (Aythya ferina – Common Pochard): une femelle avec ses poussins dans le Lac de Réghaia, Algérie. (photo: Mohamed-Samir Sayaud).

Nid du Fuligule milouin (Aythya ferina), Lac de Réghaia, Algérie.

Nid du Fuligule milouin (Aythya ferina), installé dans les touffes de Typha angustifolia, Lac de Réghaia, Algérie. (photo: Aicha Lardjane-Hamiti).

Breeding ecology of the Marbled Duck Marmaronetta angustirostris at Boussedra march (Annaba, Northeast of Algeria)

Aberkane, M., Chettibi, F., Bakhouche, B., Draidi, K., Bouslama, Z. & Houhamdi, M. 2013. Breeding ecology of the Marbled Duck Marmaronetta angustirostris at Boussedra march (Annaba, Northeast of Algeria). Annals of Biological Research 4 (10): 103-107.  PDF

Abstract:

Marbled duck Marmaronetta angustirostris (Anatidae) nested for three consecutive years (2011, 2012 and 2013) in the marais de Boussedra (North-East of Algeria): a much polluted site. Nests are built on Scolymus hispanicus and Innula graveloens (Asteraceae). In water, the nests are built in clusters of Typha angustifolia (Typhaceae). Nesting occurs between mid-May and mid-June of each year. The eggs have a mean weight of 32.61g and a volume of 26.51 cm3. The hatching rate recorded is 40.40% and the causes of failure are many and the most important are predation by the White Stork Ciconia ciconia, the rodents and the dogs.

Chicks of the Marbled Duck (Marmaronetta angustirostris) after hatching

Chicks of the Marbled Duck (Marmaronetta angustirostris) after hatching (M. Abdekane)

Entre mer et terre : le peuplement d’oiseaux d’eau de l’Oued Boukhmira

Touati, L. & Samraoui, B. (2013). Entre mer et terre : le peuplement d’oiseaux d’eau de l’Oued Boukhmira. In: Azafzaf, H., Brochet, A.L., Deschamps, C., Defos du Rau, P., Feltrup-Azafzaf, C. & Mondain-Monval, J.Y. (eds). Bulletin of the network “Mediterranean Waterbirds”, No. 1. AAO, ONCFS, Tour du Valat. pp: 17-22. PDF

Résumé :

Le suivi de l’avifaune aquatique de l’embouchure de l’Oued Boukhmira durant la période novembre 2005-mars 2006 a révélé la présence de 12 familles d’oiseaux d’eau représentées par 33 espèces. Cette population est composée d’individus hivernants, résidents ou de passage. La présente étude explore la dynamique du peuplement aviaire du site et sa structure spatio-temporelle. Malgré sa richesse ornithologique et son rôle de refuge, l’Oued Boukhmira est soumis à une forte pression anthropique et des mesures urgentes sont nécessaires pour garantir son avenir de sanctuaire ornithologique.

Between sea and land: the waterbird population of Oued Boukhmira.

Abstract:

Waterbird monitoring at the mouth of the wadi Oued Boukhmira during the period November 2005-March 2006 revealed the presence of 12 families of waterbirds represented by 33 species. This population is composed of wintering, resident and migratory individuals. This study explores the dynamics of the avian population of the site and its spatio-temporal structure. Despite its rich birdlife and its role as a safe refuge, Boukhmira Wadi is subject to heavy anthropogenic pressure and urgent measures are needed to ensure the future of the bird sanctuary.

Related paper:

Ornithological values of wetlands in Guerbes-Sanhadja eco-complex (Algeria)

Embourchure de l’Oued Boukhmira, Annnaba, Nord-Est algérien

Embourchure de l’Oued Boukhmira, Annnaba, Nord-Est algérien (B. Samraoui)

Effects of human disturbance on nest placement of the Woodpigeon in Morocco

Hanane, S. 2014. Effects of human disturbance on nest placement of the woodpigeon (Columba palumbus): a case study from the Middle Atlas, Morocco. Integrative Zoology 9: 349–359.  doi: 10.1111/1749-4877.12078

Abstract:

The Woodpigeon (Columba palumbus) is a common and widespread bird in Morocco (North Africa). I examined, over two years (2010 and 2011), the breeding density and nest placement of this game species in relation to nest-site habitat and degree of human disturbance. The study area was in the Middle Atlas Tighboula mountain forest, Morocco, in a disturbed and an undisturbed site. Using data collected in the two study sites, I aimed to identify the factors influencing the placement of nests within Holm oak trees (Quercus rotundifolia) and their densities. I found that habitat structures, influenced by grazing disturbance, have affected nesting density and location of nests of this species. Woodpigeons place their nests in a higher position (3.42 ± 0.19 m) when disturbance intensity is high and lower (1.68 ± 0.1 m) when it is low and showed higher nesting density in less disturbed zone (3.1 ± 0.4 nests/ha) than in high disturbed one (1.4 ± 0.2 nests/ha). Grazing disturbance could pose a threat to population persistence at a broader scale and could potentially contribute to reduce the abundance of this species by altering the composition and the structure of the forest nesting habitat. Further multi-scale studies are needed to assess the effects of different levels of grazing disturbance on Woodpigeon nest density and placement and to enhance our knowledge on breeding behaviour of this game species under variable environments.

Woodpigeon (Columba palumbus) on nest

Woodpigeon Columba palumbus. (Photo by flickr member gynti_46, licence CC-by-nc-sa)