Search

We present the first detailed study of population dynamics, breeding biology and egg measurement of Common Terns. During six years (from 2004 to 2009) of monitoring, from mid-May to mid-August, 74 Common Terns individual were recorded at Laouinet small island, El Tarf, northeast of Algeria, witha finite population growth rate that indicated an alarming population decline(λ = -0.62: Lambda). Sterna hirundo build its nests (n = 37) in the northeast at a mean distance of 7.58 m from the closest edge of rocks. The nests were closed and ovoid, constituted mainly of mussel shells Sandpit, stems and leaves. Incubation was performed by pairs of common tern and lasted 25.5 ±3.4 days. We recorded a clutch size of 1 to 3 eggs with mean clutch size of 2.45±0.65 (41.24±0.83 × 30.46±0.62 mm). The egg parameters (volume, mass, shape index) varied between the six years of the study. The egg volume (19.24±0.87) depended more on egg width (30.46±0.62), however the egg shape (0.73±0.20) depended negatively on the egg length (41.24±0.83) but not on the egg width. Our results also showed a stabilized hatching success and a best estimation of breeding success. The hatching success did not vary between years: 70.5% in 2004, 68.75% in 2005, 71.42% in 2006, 71.42% in 2007, 69.23% in 2008 and 69.23% in 2009. more...

Capsule: Nest site selection of Black-bellied Sandgrouse Pterocles orientalis in an Algerian arid environment is dictated by a combination of topography, human presence, landscape and space.Aims: T... more...

The rapid expansion of urban areas and industrial units has put much strain on natural environments and biodiversity. Quantifying the impact of human pressures on avian biodiversity is vital for the identification, preservation, and restoration of important areas. Here, data collected in 11 coastal Mediterranean oases were used to assess the impact of urban and industrial landscapes and habitat structure on the richness of breeding birds. Results of generalized linear mixed models analyses showed a quadratic effect of distance to the industrial complex on breeding bird richness, being optimal (6.41 ± 0.89) at 24 km. The results also showed a negative effect of the cover of urban areas. Our analysis also emphasized the importance of southern oases for breeding bird richness mostly because of their remoteness from the industrial complex and their significant coverage of fruit trees and natural ground cover. Variation partitioning analysis revealed that the shared fraction of industrial landscape, oasis habitat structure, and space was relevant in explaining the richness of breeding birds. It is highly recommended to (i) uninstall the Gabès industrial complex from this Mediterranean area, (ii) enhance the habitat quality in southern oases by planting other fruit trees, such as pomegranate and olive, and (iii) pursue scientific research in these Mediterranean coastal oases, as they offer a good opportunity for assessment and improvement of knowledge on both the impact of industrialization on quality of habitats and the richness of bird species. more...

The assessment of the impact of urban and industrial landscapes on the occurrence of vulnerable species is one key step in the view to maintaining them in environments that are becoming urbanised. In the present study, we aimed to investigate this issue with regards to the vulnerable European Turtle Dove (TD) (Streptopelia turtur) in the coastal Mediterranean oases. Here, we used data on a series of variables, including microhabitat and urban-industrial landscapes, to identify the best predictors that cause variation in the probability of TD occurrence by means of generalized linear mixed models. The results revealed a significant interaction between the distance to the industrial complex and coverage of fruit trees at the microhabitat scale in explaining this probability (Adj. R2 = 22%; P = 0.001). This probability becomes higher than 0.50 when the distance from the industrial complex is more than 8 km and the cover of fruit trees is above 30%. A high probability of TD occurrence is also recorded in the presence of a very weak cover of urban areas. In the Gabes region, the highest probability of TD occurrence was recorded in the southern oases, thus highlighting their central role in conserving this Columbidae. For the species’ conservation, it is imperative to (i) uninstall the Gabes industrial complex from this coastal Mediterranean area, (ii) protect the southern oases, which constitute important breeding areas for the species in the south-east of Tunisia, (iii) enhance habitat quality in the farthest oases from the industrial complex, and (iv) set up a monitoring system aiming to quantify the impact of urban growth on this North African TD population. more...