Amphibian and reptile phenology: the end of the warming hiatus and the influence of the NAO in the North Mediterranean.

In the south of France, the so-called climate hiatus from 1998 to 2013 was associated with a late winter cooling which has affected the phenology of several reptiles and amphibian species, delaying their dates of first appearances in spring. This episode has been related to a period of frequently negative values of the North Atlantic Oscillation index (NAOi). The recent increase of this index after this episode marks the end of the "hiatus" and provides an opportunity to verify the impact of the North Atlantic Oscillation (NAO) on the fauna of the North Mediterranean region. Most of the emergence dates of amphibians and reptiles in spring have rapidly advanced from 1983 to 1997 and then receded or stabilized from 1998 to 2010. They began to advance again since 2010. These phenological changes covary with the temperature of February-March in the study area, which is itself related to the variations of the NAO index. These changes confirm the influence of the NAO on the phenology of terrestrial organisms in northern Mediterranean where its influence is sometimes assumed to be attenuated.

A reversal of the shift towards earlier spring phenology in several Mediterranean reptiles and amphibians during the 1998-2013 warming slowdown.

Herps, especially amphibians, are particularly susceptible to climate change, as temperature tightly controls many parameters of their biological cycle-above all, their phenology. The timing of herps' activity or migration period-in particular the dates of their first appearance in spring and first breeding-and the shift to earlier dates in response to warming since the last quarter of the 20th century has often been described up to now as a nearly monotonic trend towards earlier phenological events. In this study, we used citizen science data opportunistically collected on reptiles and amphibians in the northern Mediterranean basin over a period of 32 years to explore temporal variations in herp phenology. For 17 common species, we measured shifts in the date of the species' first spring appearance-which may be the result of current changes in climate-and regressed the first appearance date against temperatures and precipitations. Our results confirmed the expected overall trend towards earlier first spring appearances from 1983 to 1997, and show that the first appearance date of both reptiles and amphibians fits well with the temperature in late winter. However, the trend towards earlier dates was stopped or even reversed in most species between 1998 and 2013. We interpret this reversal as a response to cooling related to the North Atlantic Oscillation (NAO) in the late winter and early spring. During the positive NAO episodes, for certain species only (mainly amphibians), the effect of a warm weather, which tends to advance the phenology, seems to be counterbalanced by the adverse effects of the relative dryness.

Convergent evolution of morphological and ecological traits in the open-habitat chat complex (Aves, Muscicapidae: Saxicolinae).

Open-habitat chats (genera Myrmecocichla, Cercomela, Oenanthe and relative) are a morphologically and ecologically cohesive group of genera with unclear phylogenetic relationships. They are distributed mostly in open, arid and/or rocky habitats of Africa and Eurasia. Here, we present the most comprehensive molecular phylogenetic analysis of this group to date, with a complete taxon sampling at the species level. The analysis, based on a multilocus dataset including three mitochondrial and three nuclear loci, allows us to elucidate the phylogenetic relationships and test the traditional generic limits. All genera are non-monophyletic, suggesting extensive convergence on similar plumage patterns in unrelated species. While the colour pattern appear to be a poor predictor of the phylogenetic relationships, some of the ecological and behavioural traits agree relatively well with the major clades. Following our results, we also propose a revised generic classification for the whole group.

Measuring the postfire resilience of a bird-vegetation system: a 28-year study in a Mediterranean oak woodland.

Despite numerous studies on the response of Mediterranean ecosystems to fire, few have measured the respective resilience of vegetation and fauna compartments. For 28 years, we conducted an annual monitoring of avifauna composition and vegetation structure (cover profile)following a severe wildfire in a holm oak (Quercus ilex) stand in southern France. Our aim was to estimate the time necessary for this bird-vegetation system to return to a state analogous to its pre-fire state. In the burned plots, low herbaceous and shrub layers were gradually replaced by higher, woody layers of vegetation. Neither bird species richness nor inter-annual bird species turnover showed significant differences from one year to the next over the study period. In contrast, bird species composition did change steadily, leading to an almost complete replacement of early-successional species by late-successional ones. Using the first axes of multivariate analyses as 'proxy variables' of vegetation or avifauna recoveries, we estimated by extrapolation the recovery times of these two ecosystem components at ca. 50 and 35 years, respectively. Towards the end of the study period, the rate of change in avifauna composition decreased comparatively to that of vegetation structure. Our results show that holm oak woodlands are highly resilient and seem to tolerate an approximately 50-year fire interval, even if it remains to be assessed how resilient they would be in the case of increased fire frequency. More generally, our multivariate approach, which allows comparative estimations of resilience in different components of an ecosystem using qualitative as wellas quantitative criteria, could be applied to various case studies in disturbance and restoration ecology.

Phylogeny of Palaearctic wheatears (genus Oenanthe)--congruence between morphometric and molecular data.

Wheatears of the genus Oenanthe are birds specialized to desert ecosystems in the Palaearctic region from Morocco to China. Although they have been the subject of many morphological and ecological studies, no molecular data have been used to elucidate their phylogenetic relationships, and, their relationships are still debated. Here we use DNA sequences of 1180 bp of two mitochondrial genes, 16S rRNA and cytochrome oxidase subunit I, from 32 individuals from Middle East and North Africa, and Bayesian methods to derive a phylogeny for 11 species of Oenanthe. The resulting tree supported three major clades: (A) O. alboniger, O. chrysopygia, O. lugens, O. finschii, O. leucopyga, O. picata, O. moesta, (B) O. deserti and O. pleschanka; and (C) O. isabellina and O. oenanthe. These results largely differ from previous hypotheses based on analysis of morphological and chromatic characters. However, the two clades (B) and (C) were also supported by a phenetic analysis of new morphometric data presented here, indicating that characters related to colouration and ecology in Oenanthe are more strongly influenced by homoplasy than those of body shape.