Monitoring urban biodiversity with reference to butterflies in Thevara, Kochi

Cities and small to median towns in Kerala are on the fast move to urbanization; Kochi is not an exception. If proper strategies are not implemented the green spaces and the wet lands now exist here, may alarmingly shrink in size or even vanish in the near future. An inventory of today’s biodiversity of this area is essential and justifiable at this juncture because urbanization is a major threat to biodiversity. There are no many reports particular to urban biodiversity assessments from Kerala. In an attempt to assess the urban biodiversity, a nine month long monitoring of biodiversity with special focus on butterflies; an indicator of urban biodiversity was conducted in Thevara, a densely populated area in the city of Kochi which is under severe pressure of urbanization. The vast marshy lands with abundant growth of mangroves once existed here were largely modified for human habitation. Large number of high-rise buildings emerging here drastically change the topography of this area. Butterflies are good representatives of urban fauna because they survive well even in small patches of urban vegetation as in forests and hilly areas. So monitoring them provides valuable insights on urban biodiversity. For the present work four widely separated regions were selected in the study area and sampling was carried out at each region by line transect method during February 2013 to October 2013, once in a month. Butterflies observed were identified with standard field guides and recorded. The study provided a total of 44 species of butterflies belonging to 36 genera and 5 families. Various indices of biodiversity were calculated to analyze the result. A checklist of butterflies recorded was prepared. From the result it can be concluded that the study area harbours a modest number of butterflies indicating the richness of biodiversity. (In S. Thomas & G. K. Joseph (Eds.), Invertebrates - Systematics and Biology: Proceedings of the National Seminar on Invertebrate Taxonomy (pp. 94-101). Muvattupuzha, Kerala: Nirmala Academic & Research Publications. ISBN: 978-81-929844-0-7.)喀拉拉邦的城市及中小城镇正快速推进城市化进程，科钦（Kochi）也不例外。若不采取恰当的应对策略，当前该区域现存的绿地与湿地或将在不久的将来令人担忧地大幅缩减，甚至彻底消失。在此关键节点，对该区域当下的生物多样性进行清查不仅十分必要，且具备充分合理性——因为城市化是生物多样性面临的主要威胁之一。目前针对喀拉拉邦城市生物多样性评估的专项研究报告较为匮乏。 为评估城市生物多样性，研究团队于科钦市人口稠密、承受着严峻城市化压力的特瓦拉（Thevara）区域，开展了为期九个月的生物多样性监测工作，重点关注作为城市生物多样性指示物的蝴蝶。该区域曾拥有大片生长着茂密红树林的沼泽湿地，如今大多已被改造为人类聚居用地；大量高层建筑的拔地而起，极大地改变了该区域的地形地貌。 蝴蝶是城市动物区系的优良指示类群，即便在城市植被的小型斑块生境中（如同森林与丘陵地带），它们也能良好存活。因此，对蝴蝶的监测能够为城市生物多样性研究提供极具价值的视角。本研究在研究区域内选取了四处相距较远的样区，于2013年2月至2013年10月期间，每月一次采用样线法对各区域开展采样工作。观测到的蝴蝶通过标准野外图鉴进行鉴定并记录。 本研究共计记录到隶属于5科36属的44种蝴蝶。研究人员计算了多项生物多样性指数以对实验结果进行分析，并编制了所记录蝴蝶的物种名录。从结果可以看出，研究区域内孕育了数量可观的蝴蝶类群，表明该区域具备丰富的生物多样性。 （收录于S. Thomas与G. K. Joseph主编：《无脊椎动物——系统分类与生物学：全国无脊椎动物分类学研讨会论文集》，第94-101页，喀拉拉邦穆瓦特普扎：奈尔玛拉学术与研究出版社，ISBN：978-81-929844-0-7。）