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.巴拿马作为连接南北美洲的生物桥梁，拥有极为丰富的蝴蝶多样性，但相关研究记录仍较为匮乏。为填补这一空白，我们于2023年5月20日至6月14日期间开展了为期20天的非侵入式改良Pollard步道调查（Pollard walk），调查区域聚焦巴拿马中部的三个典型点位：巴拿马城（高城市化水平、低海拔）、阿苏尔山（Cerro Azul，中等城市化水平、高海拔）与甘博阿（Gamboa，低城市化水平、低海拔）。本研究旨在评估这三个不同区位的自然生境中的蝴蝶多样性，共记录到除蛾蝶科（Hedylidae）外的所有凤蝶总科类群，总计310个物种、1803只个体。种群丰度相对偏低，这可能与厄尔尼诺（El Niño）气候条件的影响有关。其中巴拿马城（累计调查8天）记录到137个物种、474只个体，阿苏尔山（累计调查4天）记录到58个物种、221只个体，甘博阿（累计调查8天）则记录到220个物种、1108只个体。香农-威纳指数（Shannon index）以甘博阿最高（4.59），阿苏尔山最低（3.59）；而皮卢均匀度指数（Pielou’s evenness index）则以阿苏尔山略高（0.88），略高于甘博阿与巴拿马城（0.85）。物种稀化分析（rarefaction analysis）结果显示，在物种丰富度（q=0）、香农多样性（q=1）与辛普森多样性（q=1）三个维度上，甘博阿的多样性水平均为最高，其次依次为巴拿马城与阿苏尔山，这一发现印证了物种多样性通常在低海拔、低城市化程度的区域更高。本研究为巴拿马中部的蝴蝶区系提供了宝贵的基础数据与研究见解，有助于深化对区域生物多样性的认知，并凸显了长期生态监测与物种保护研究的必要性。