In our journey to discover the most interesting articles published on Acta Herpetologica over the years, today we focus on the paper "Age structure of a population of Discoglossus scovazzi Camerano, 1878 (Anura - Discoglossidae) in extreme environmental conditions (High Atlas, Morocco)" by Dr. Mohamed Amine Samlali et al., originally released in 2019.

In the mountainous region of the High Atlas in Morocco, human activities like overgrazing and sand removal have severely damaged natural habitats, especially around rivers and ponds. These actions have harmed several amphibian populations, leading to local extinction of the most vulnerable species. The Moroccan Painted Frog (Discoglossus scovazzi) is relatively common in the area and can tolerate minor modifications to its habitat, but its overall resistance is largely unknown. 

In order to unravel how habitat modification impact on demographic structure, 74 adult frogs were studied between 2016 and 2018, focusing on their breeding sites at their upper altitudinal edge, in the Oukaimeden massif. Each individual was captured, measured and sexed; in addition, the third toe of the left hind leg was clipped. The clipped toe were then used in a skeletocronological study in order to age the frogs and study their growth pattern. 

The authors of the study found that these frogs reach sexual maturity relatively late, at around 3-4 years of age. Interestingly, female frogs were smaller than males, contrary to the usual pattern seen in most frog species. This size difference does not seem to be due to  females maturing earlier than males; rather, it might result from high competition male-male during the mating season, favoring larger individuals over smaller ones. 

The study also revealed that the frogs' growth rate was slow, likely influenced by the challenging alpine environment, including low temperatures and snowfall. Additionally, habitat modifications caused by sand removal and deteriorating water quality due to livestock activities contributed to the frogs' shorter lifespan (around 5-6 years) and reduced reproductive potential (about two years).

The research suggests that these environmental changes, along with potential factors like population instability or the movement of older adults to different sites, have affected the frog population. This study highlights the need for ongoing monitoring to better understand and conserve these amphibians in their changing habitat.

Read the full paper here.