Traditional agroecological calendar, phenology, and biotic indicators among the Lepchas of Sikkim, Eastern Himalaya

Traditional ecological knowledge plays a crucial role in understanding ecological processes, seasonal forecasting, and sustainable agroecosystem management among indigenous communities.The present study documents and analyzes the traditional agroecological calendar and biotic ecological indicators used by the Lepcha community of Sikkim in the Eastern Himalaya.Field investigations were conducted during 2024 in Lepcha-dominated areas of Pakyong district, Sikkim, using unstructured interviews, participant observations, and focused group discussions with knowledgeable community elders and local practitioners.The study primarily examined traditional seasonal calendars, floral and faunal indicators, insect activity, climatic observations, hydrological cues, and agricultural practices associated with seasonal transitions.The study documented twelve traditional Lepcha months synchronized with ecological rhythms rather than fixed calendrical systems.Seasonal progression and agricultural operations were regulated through detailed observations of flowering phenology, bird behaviour, insect emergence, amphibian vocalization, fish migration, atmospheric conditions, hydrological changes, and indigenous acoustic cues.Important floral indicators included Bombax ceiba, Rhododendron arboreum, Clerodendrum infortunatum, Rosa macrophylla, Luculia gratissima, and Erythrina arborescens, while faunal and insect indicators involved migratory birds, cicada choruses, frog breeding calls, dragonfly activity, moth swarming, and fish movements.Agricultural activities such as sowing, harvesting, food gathering, mushroom collection, honey harvesting, and tuber extraction were closely synchronized with these ecological indicators and seasonal environmental conditions.The findings reveal that the Lepcha seasonal calendar represents a highly integrated indigenous agroecological forecasting system developed through longterm interaction with Himalayan ecosystems.The study further highlights the ecological and cultural significance of indigenous phenological knowledge, soundscape ecology, and biotic forecasting systems in regulating traditional agricultural practices and livelihood adaptation.In the context of rapid socio-cultural transformation, biodiversity loss, and climate change, documentation of such indigenous ecological knowledge systems is essential for cultural preservation, biodiversity conservation, and sustainable mountain agroecosystem management in the Eastern Himalaya.