Diversity of Butterflies (Lepidoptera: Papilionoidea) in Three Distinct Locations in Central Panama during an El Niño Period

Panama's rich butterfly diversity, owing to its position as a biological bridge between North America and South America, remains insufficiently documented. To address this, we conducted a noninvasive modified Pollard walk survey over 20 days, between May 20 and June 14, 2023, focusing on central Panama: Panama City (high urbanization, low elevation), Cerro Azul (moderate urbanization, high elevation), and Gamboa (low urbanization, low elevation). This study aimed to assess butterfly diversity in natural habitats across these three distinct locations. We identified 310 species from all papilionoid families except Hedylidae, recording 1,803 individuals. The abundance was relatively low, potentially due to the impact of El Niño conditions. Panama City yielded 137 species and 474 individuals (8 days), Cerro Azul yielded 58 species and 221 individuals (4 days), and Gamboa yielded 220 species and 1,108 individuals (8 days). The Shannon index was highest for Gamboa (4.59) and lowest for Cerro Azul (3.59), whereas Pielou’s evenness index was slightly greater for Cerro Azul (0.88) than for Gamboa and Panama City (0.85). Rarefaction analysis revealed that Gamboa had the highest diversity in terms of species richness (q = 0), Shannon diversity (q = 1), and Simpson’s diversity (q = 1), followed by Panama City and Cerro Azul, emphasizing that species diversity tends to be greater at lower elevations and in less urbanized areas. This study provides valuable insights into the butterfly fauna of central Panama, contributing to understanding biodiversity and highlighting the need for long-term research and conservation.