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We analyzed the body length, age structure, and age at sexual maturity of the invasive Asian common toad Duttaphrynus melanostictus from different sites in Toamasina, east Madagascar. We used skeletochronology as a proxy for age estimation, while gonads were histologically analyzed to determine the age of sexual maturity. The analysis of pooled age data from three sites investigated in 2016 showed that both sexes were larger, although not older, than those of native populations. For the individuals from Madagascar, the males were significantly smaller and younger (mean ± SD, SVL: 71.4 ± 1.6 mm; age: 1.8 ± 0.7 years) than the females (SVL: 78.42 ± 1.9 mm; age: 2.7 ± 1.3 years), when the data were pooled, but when the data were analyzed separately for each of the three sites, similar results were obtained only for one site. The oldest recorded male and female were 3 and 6 years old, respectively. Gonadal histology showed that the males and females reach sexual maturity after the first and second years of age, respectively. Further studies are needed to understand if the larger size and faster growth rates observed in the invasive population of D. melanostictus in Madagascar are a consequence of more favorable environmental conditions with respect to the native range (e.g., the availability of larger trophic niches, a lack of competitors, and lower predatory pressure), and we suggest to extend the monitoring of these life history traits to understand how they might influence the invasion.

International audience; To contain the spread of the COVID-19 outbreak, the French government ordered a national lockdown from March 17th to May 10th 2020. At the beginning of the spring, French people thus experienced a strict limitation of their movement in public places, with very limited access to nature. Between April 22nd and May, 11rst, we realized an online survey to question the effects of this unprecedented situation on both the people’s relationship with the nearby nature and their representations of environmental issues. Indeed, crisis and environmental sociologies question how environmental issues are requalified by individuals (Chateauraynaud, 2017) in relation with unevenly distributed resources and experiences. The inquiry focused on the sociodemographic characteristics of participants; their lockdown experience ; their environmental behaviours and daily relationship with nature before and during lockdown; and “opinion about how this crisis could transform how environment issues would be collectively engaged in the short and long terms. This study gathered in three weeks 1,200 responses, nationally, with various sociodemographic characteristics. This contribution will explore how, in times of a global pandemic, people build different and competing framings (Gusfield, 1981) of the environmental issues, with various understandings of the causal relationships between the environmental crisis and the COVID-19 outbreak. It will then examine how this is related to individual socioeconomic characteristics and material conditions of lockdown experience. Also, it will question the capacity of questionnaire-based surveys to capture how the cognitive categories used to frame environmental issues are transformed in times of crisis.

The Asian toad, Duttaphrynus melanostictus, was accidentally introduced to Toamasina (eastern Madagascar) around 2010, and since then has spread at a substantial rate across a larger area. This study documents the expansion of the invasive range of this species, calculates the invasion spread rate, and provides estimates of toad abundance and habitat preferences. Updates of the distribution range revealed a fivefold increase of the invaded area over 3 years, and a doubling of the rate of spread, showing a shift of the invasion towards the North-West, most probably because of the absence of ecological barriers. We used N-mixture models to estimate toad abundance on the basis of repeated count data of six areas in Toamasina and its surrounding countryside. Toad distribution shows heterogeneous density across the distribution range, with an average abundance of 184 toads ha−1 (95% CI 132–263). The toad’s abundance was highest in sites with the presence of organic waste, and was negatively related to the density of road networks in the proximity of study sites. The rapid expansion of the Asian toad in the Toamasina region suggests that this toad is an increasing threat for Madagascar. We propose immediate management actions that could limit the spread of alien toads in this megadiverse country.

51 páginas, incluye 5 figuras y 2 tablas, Lataste's viper (Vipera latastei) is a venomous European viper endemic to the Iberian Peninsula, recognised as medically important by the World Health Organization. To date, no comprehensive characterisation of this species' venom has been reported. Here, we analysed the venoms of juvenile and adult specimens of V. latastei from two environmentally different populations from northern Portugal. Using bottom-up venomics, we produced six venom proteomes (three per population) from vipers belonging to both age classes (i.e., two juveniles and four adults), and RP-HPLC profiles of 54 venoms collected from wild specimens. Venoms from juveniles and adults differed in their chromatographic profiles and relative abundances of their toxins, suggesting the occurrence of ontogenetic changes in venom composition. Specifically, snake venom metalloproteinase (SVMP) was the most abundant toxin family in juvenile venoms, while snake venom serine proteinases (SVSPs), phospholipases A2 (PLA2s), and C-type lectin-like (CTLs) proteins were the main toxins comprising adult venoms. The RP-HPLC venom profiles were found to vary significantly between the two sampled localities, indicating geographic variability. Furthermore, the presence/absence of certain peaks in the venom chromatographic profiles appeared to be significantly correlated also to factors like body size and sex of the vipers. Our findings show that V. latastei venom is a variable phenotype. The intraspecific differences we detected in its composition likely mirror changes in the feeding ecology of this species, taking place during different life stages and under different environmental pressures. SIGNIFICANCE: Lataste's viper (Vipera latastei) is a medically important viper endemic to the Iberian Peninsula, inhabiting different habitats and undergoing a marked ontogenetic dietary shift. In the current study, we report the first proteomic analysis of V. latastei venom from two environmentally different localities in northern Portugal. Our bottom-up venomic analyses show that snake venom serine proteinases (SVSPs), phospholipases A2 (PLA2s), and C-type lectin-like (CTLs) proteins are the major components of adult V. latastei venom. The comparative analysis of young and adult venoms suggests the occurrence of ontogenetic shift in toxin abundances, with snake venom metalloproteinases (SVMPs) being the predominant toxins in juvenile venoms. Moreover, geographic venom variation between the two studied populations is also detected, with our statistical analyses suggesting that factors like body size and sex of the vipers are possibly at play in its determination. Our work represents the first assessment of the composition of V. latastei venom, and the first step towards a better understanding of the drivers behind its variability., IA, FL, and FM-F are supported by FCT - Fundação para a Ciência e a Tecnologia, Portugal (ref. SFRH/BD/137797/2018, SFRH/BD/131722/2017, and DL57/2016/CP1440/CT0010, respectively). Analyses at the Evolutionary and Translational Venomics Laboratory of the Institute of Biomedicine of Valencia were partially financed by Ministerio de Ciencia e Innovación, Spain (grant BFU2020_PID2020-119593GB-I00).

In 2014, an invasive population of the Asian common toad Duttaphrynus melanostictus was reported in Toamasina, the major seaport town of Madagascar. This species is poisonous, generalist, highly fecund and is rapidly spreading across the lowland habitats of eastern Madagascar. The success of future management strategies will depend on research, public awareness and financial and political support as well as on the feasibility of the methodology to be put in place. Here we present an overview of the Asian toad invasion in Madagascar, tracing the activities undertaken within the framework of the invasion risk assessment in the past 6 years and outlining what needs to be done in the near future to contain the threats to Madagascar’s unique biodiversity.