The global decline of amphibians and reptiles continues unabated, with a significant portion of species facing extinction due to different factors such as habitat loss, pollution, and spreading of pathogens. Additionally, limited funding for conservation efforts exacerbates the challenge of protecting biodiversity. To address these issues, it is crucial to employ effective monitoring and conservation strategies. Traditional methods like capture-mark-recapture (CMR) can be resource-intensive and impractical for elusive species. Hierarchical Models (HMs), including N-mixture and occupancy models, offer a cost-effective alternative by utilizing repeated count data to estimate population size and other demographic parameters. These approaches have been successfully applied in herpetological studies and can be extended to other taxa, providing valuable insights into population dynamics and informing conservation efforts. This thesis explores the application of CMR methods for guiding conservation activities and demonstrates the utility of HMs in investigating the demography, ecology, and interactions of amphibian and reptile communities. Overall, embracing diverse methodologies and expanding the scope of study to include various taxa can enhance our understanding of population dynamics and facilitate more effective conservation and management strategies in the face of the biodiversity crisis.