PRELIMINARY ECOLOGICAL STUDIES

Dr.Jafer Palot, Zoological Survey of India , Kozhikode. (Published in Vembanad Water Bird Count 2006 report)

PRELIMINARY ECOLOGICAL STUDIES ON THE PATHIRAMANAL ISLAND , ALAPPUZHA DISTRICT, KERALA

....Preliminary ecological studies on the biodiversity rich Pathiramanal island in Alappuzha district, Kerala by the research team of Kottayam Nature Society and Malabar Natural History Society, Kozhikode reveal that the area is rich in diversity of flora and fauna which called for urgent conservation measures to protect the area from further deterioration. The study reveals that the area support a rich assemblage of faunal elements that are as given below.

Diversity of Dragonflies and Damselflies (Odonata: Insecta)

....24 species of Odonates (dragonflies & damselflies) belong to 4 families and 18 genera were recorded from the Pathiramanal area of Alappuzha district. Of these, 7 species are damselflies (Zygoptera) and 17 species are dragonflies (Anisoptera). Among the dragonflies Rhyothemis variega ta was the most abundant species followed by Brachythemis contaminata and Neurothemis tullia. Damselflies were dominated with Ceriagrion coromandelianum and Agriocnemis pygmaea. Agriocnemis keralaensis, hitherto known only from its type locality at Karamana, Thiruvananthapuram district (Peters, 1981) has now been rediscovered from Pathiramanal after its original description in 1981. A checklist of Odonates recorded from Pathiramanal area is given below.

1 Ceriagrion coromandelianum 2 Ceriagrion cerinorubellum 3 Pseudagrion microcephalum 4 Ischnura aurora 5 Agriocnemis pygmaea 6 Agriocnemis keralaensis 7 Agriocnemis pieris 8 Ictinogomphus rapax 9 Acisoma panorpoides 10 Brachythemis contaminata 11 Brachydiplax sobrina 12 Brachydiplax chalybea 13 Diplacodes trivialis 14 Neurothemis tullia 15 Orthetrum chrysis 16 Orthetrum sabina 17 Pantala flavescens 18 Potamarcha congener 19 Tholymis tillarga 20 Tramea limbata 21 Trithemis pallidinervis 22 Aethrimantha brevipennis 23 Urothemis signata 24 Rhyothemis variegata.

....Because of the rich diversity of these Odonata fauna, the magnificent creatures of these island ecosystem, this treasure trove of biodiversity can also be declared as the first and foremost ‘Dragonfly Park' in our country, as the initial step taken for the conservation of these attractive flies.

Spider diversity:

....This small island also harbours more than 23 species of spiders including Argiope aemula, Argiope anasuja, Gasteracantha geminata . A rare and endemic Thomasid spider, Thomisus andamanensis , reported only from Andaman & Nicobar Islands in 1980 (Tikader, 1980) was recorded from Pathiramanal area.

Butterflies:

....34 species of butterflies were recorded from the area including 4 species protected under various schedules of Indian Wildlife (Protection) Act, 1972. Rare and endangered species like Southern Birdwing , Crimson Rose, Common Silverline, etc were also recorded fairly in good numbers in the locality. The abundance of butterfly species mentioned above shows the presence of larger number of depended larval food plants in the region.

Birds:

....Birds are the most visible fauna of the area evidenced by 88 species of birds. A rare winter visitor, Red-winged Crested cuckoo, Clamator coromandus was reported from the area during January 2006. This island acts as a roosting place for many waterfowls including Little Cormorant, Indian Shag, Oriental Darter, Little Egret,Pond Heron and Night Heron.

Fishes:

....58 species of fishes were recorded from in and around the Island . The fringe of the Island acts as a hatchery for the fishes of the Vembanad Lake.

Mammals:

....A refuge for Smooth coated Otter, Lutra perspicillata, an endangered aquatic mammal species. Many sightings of this animal from the area, Adult animal with young ones were also observed during January 2005 (S. Jayachandran, Pers. Commn.).

Reptiles:

....7 species of snakes were observed during the survey. The Indian Rock Python, listed in the Schedule I of Indian Wildlife (Protection) Act, 1972 was frequently reported from the island. Other reptiles like Indian Monitor Lizard ( Varanus benghalensis ), Southern Green Calotes ( Calotes calotes ), Indian Pond Terrapin (Melanochelys trijuga ), Southern Flapshell Turtle ( Lissemys punctata ), etc were also sighted from the area.