Assessing The Effectiveness of Rainwater Harvesting Systems In Improving Wintering Bird Richness In Pre-Saharan Tunisia.

The impact of rainwater harvesting systems on biodiversity in hyperarid North African areas has not been assessed to date despite its demonstrated usefulness. The present study investigated this impact by considering the richness of wintering birds (RWB) in the Tataouine region (pre-Saharan Tunisia). We used data from three sets of variables-rainwater harvesting system type, microhabitat conditions, and topography-to determine the best predictors causing variation in the RWB by means of generalized linear mixed models. Our results show that the jessour system is the most attractive for the wintering bird species, followed by the tabia system, and lastly by the control areas. In the jessour system, RWB is influenced positively by slope and shrub cover and quadratically by tree cover, whereas this richness is affected positively by the extent of the herbaceous layer in the tabia system. In the control areas, RWB is negatively affected by elevation and quadratically affected by tree cover. Variation partitioning (VP) analysis reveals that (i) space is the most robust factor explaining the RWB in control areas (adj. R2 = 0.15, p = 0.001), (ii) microhabitat is central in the tabia system (adj. R2 = 0.10, p = 0.001), and (iii) the shared fraction between microhabitat and space is relevant in the jessour systems (adj. R2 = 0.20). Specific management actions, especially preserving, maintaining, and promoting these traditional systems, are suggested to improve the attraction of wintering bird species to the Tataouine region. The implementation of a scientific watch system is recommended to understand how changes take place in such an arid environment.

Spatio-temporal pattern of latrine distribution in reintroduced Cuvier's gazelles (Gazella cuvieri): an assessment in a Mediterranean forest reserve.

Knowledge about the factors affecting the number of active latrines (NAL) of reintroduced Cuvier's gazelles (Gazella cuvieri Ogilby, 1841) is of a crucial step aiming at understanding their distributional dynamics and their habitats preference. Here, we used six random 500-m transects to assess the effect of season, microhabitat, and management variables on the spatio-temporal pattern of latrines in the Tergou forest reserve (TFR). Our results showed that, in this reserve, NAL is mainly governed by the interaction between season and distance to the nearest developed runway, being higher at the farthest distances from the runway in autumn and the closest distances to it in summer and winter. Variation partitioning analysis confirmed this pattern as the interaction between season and distance to the nearest developed runway explains 82% (p = 0.001) of the total variance in NAL. The distance to the nearest fence also contributes, but marginally, in influencing the NAL in this forest enclosure. For the species' management and conservation, it is recommended to dispose of sandy open ground areas especially in forest reserves to ensure ideal conditions for reintroduced gazelles. The pursuit of monitoring is necessary to understand mechanisms governing the distributional dynamics of Cuvier's gazelles more deeply. As any enclosure, the TFR would offer a good opportunity for consolidating and improving the knowledge on this vulnerable mammal species in the view of a successful release in the wild.

Seasonal pattern in browsing trees and shrubs by reintroduced Cuvier's gazelles: a study in Morocco with management implications.

Cuvier's gazelle (Gazella cuvieri) was reintroduced in Tergou reserve (TR) in 2018-2019 to help restore its population at the Moroccan Central Plateau. A study on browsing trees and shrubs was conducted in this reserve to identify (i) the seasonal pattern of this activity and (ii) the most solicited tree and shrub species. Here, we used six random 500-m transects to collect, each month and at each transect, the number of fresh browsing traces of each encountered tree and shrub species. We used principal component analysis (PCA) and linear regression model (LM) to test seasonal variation of the composition of trees and shrubs browsed. Our results showed that, in this reserve, Olea europaea, Quercus ilex, Cistus salviifolius, and Cistus creticus are mostly browsed during winter, whereas Tetraclinis articulata and Ruta angustifolia are mainly used during spring. This information is useful to the managers of the TR not only to consider the importance of the aforementioned trees and shrubs for reintroduced gazelles but also to take the necessary measures so that the forest stand of this reserve is maintained at an appropriate level. Thus, the pursuit of monitoring is necessary to understand the bio-ecology of this semi-captive population more deeply. For this reason, the TR remains a useful and appropriate reference framework offering the opportunity for consolidating and improving the knowledge on this vulnerable mammal species in the view of a future successful release in the wild.

Sex-linked genetic diversity and differentiation in a globally distributed avian species complex.

Sex chromosomes often bear distinct patterns of genetic variation due to unique patterns of inheritance and demography. The processes of mutation, recombination, genetic drift and selection also influence rates of evolution on sex chromosomes differently than autosomes. Measuring such differences provides information about how these processes shape genomic variation and their roles in the origin of species. To test hypotheses and predictions about patterns of autosomal and sex-linked genomic diversity and differentiation, we measured population genetic statistics within and between populations and subspecies of the barn swallow (Hirundo rustica) and performed explicit comparisons between autosomal and Z-linked genomic regions. We first tested for evidence of low Z-linked genetic diversity and high Z-linked population differentiation relative to autosomes, then for evidence that the Z chromosome bears greater ancestry information due to faster lineage sorting. Finally, we investigated geographical clines across hybrid zones for evidence that the Z chromosome is resistant to introgression due to selection against hybrids. We found evidence that the barn swallow mating system, demographic history and linked selection each contribute to low Z-linked diversity and high Z-linked differentiation. While incomplete lineage sorting is rampant across the genome, our results indicate faster sorting of ancestral polymorphism on the Z. Finally, hybrid zone analyses indicate barriers to introgression on the Z chromosome, suggesting that sex-linked traits are important in reproductive isolation, especially in migratory divide regions. Our study highlights how selection, gene flow and demography shape sex-linked genetic diversity and underlines the relevance of the Z chromosome in speciation.

Effects of human disturbance on nest placement of the woodpigeon (Columba palumbus): a case study from the Middle Atlas, Morocco.

The woodpigeon (Columba palumbus) is a common and widespread bird in Morocco (North Africa). I examined, over 2 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 2 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 the 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 disturbance intensity is low, and show higher nesting density in less disturbed zone (3.1 ± 0.4 nests/ha) than in highly disturbed zones (1.4 ± 0.2 nests/ha). Grazing disturbance could pose a threat to population persistence at a broader scale and could potentially 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 of the breeding behavior of this game species under variable environments.