Using citizen science to protect threatened amphibian populations in urban spaces: ecology, life history, and conservation of green toads and fire salamanders in Jerusalem and Haifa

Abstract

The rapid urbanization processes occurring worldwide are amongst the main factors driving the current biodiversity crisis. In particular, a third of known amphibian species are directly threatened by urbanization. The negation of this threat will require conservation efforts aimed at sustaining viable amphibian populations within the urban landscape, which must be informed by a deep understanding of the way amphibian populations are affected by the unique risk factors of the urban environment. To address this need for four populations of amphibians in Israel, we performed a capture-recapture analysis on two datasets. The larger of the two datasets is the result of a multi-year citizen science program focused on two Salamandra infraimmaculata populations within the city of Haifa, Israel. The second dataset is the result of one year of survey following a similar protocol that we performed on two Bufotes variabilis populations within the city of Jerusalem and at a nature reserve near it. Individuals of both species have unique and recognizable dorsal spot patterns, which allowed for noninvasive recapture identification. The results of our analysis provide insights that can guide future conservation of the specific studied population, but our conclusions have wider implications, regarding both the ecology of the studied species and applied conservation science: using the salamander dataset, we developed a method of length-based age estimations for this species and found that the studied salamanders have a prolonged period of increased vulnerability throughout their first years of life, even after reaching sexual maturity. Additionally, the shared conclusions from the two case studies indicate that the creation of fish-containing artificial water bodies in Mediterranean habitats can have detrimental impacts on the resident amphibian populations. Synthesis and implications: The significance and extent of our results demonstrate the effectiveness of citizen science as a tool for research and conservation in the urban environment. Our findings call for the implementation of management practices that prioritize the protection of urban amphibians and their habitats. By identifying the vulnerability of amphibians during critical life stages and highlighting the negative impacts of fish-containing water bodies, our study contributes to the development of informed conservation policies with implications for urban planning, habitat management, and biodiversity conservation strategies.