The purpose of the report was to generate an interest among amateur naturalists to further take up studies on these fascinating and elusive animals and give them much needed recognition in conservation issues - something that has, at least in India, been sadly neglected. The report also includes detailed photographs and sketches, serving as a useful resource for species identification.

EXCERPTS FROM THE REPORT

GUINDY NATIONAL PARK (GNP) AND ITS ENVIRONS

The Guindy National Park has the unique distinction of being the only forest to be located within a metropolitan city. Like all National Parks today, the Guindy Park was originally a game reserve. It was in 1958 that the area of 400 hectares was handed to the Tamilnadu Forest Department. With Educational Institutions and Memorials taking up land, the National Park now has only 270.57 hectares remaining. The biodiversity within the Guindy National Park is quite amazing, despite the fact that it is a very small area surrounded by concrete jungles and human habitation. All these exert intense pressure directly and indirectly. The ecological significance of Guindy National Park for Chennai is immense- infact it has been called "The Lung of Chennai City".

The Guindy National Park (GNP) is a tropical dry evergreen type of forest, one of last homes of the typical Carnatic coastal or tropical dry vegetation. So far over 350 species of plants have been found including trees, shrubs, climbers, herbs and grasses. Large portions are under mixed dry deciduous scrub jungle. The entire vegetation looks dry during summer months but acquires a verdant look with the onset of monsoons. GNP abounds in Chital and Blackbuck and an open grassland on the northern edge of the park creates an ideal habitat for them. Nocturnal animals include the toddy cat, civets, jungle cat, pangolin, hedgehog, shrew and the blacknaped hare. The vast plant biodiversity of dense forests, open scrub, grasslands and waterbodies cater to the habitat needs of nearly 130 species of birds, some not seen anywhere else in Chennai. Apart from snakes, GNP is also home to certain species of tortoises and turtles, lizards, geckos, chameleons and the common Indian monitor lizard.

For the past several years, a number of studies on different flora and fauna of Guindy National Park have been conducted. Booklets and monographs have been produced at regular intervals. The invertebrate population, which includes important predators like spiders, scorpions, wasps, pseudoscorpions among others, make up more than 90% of the fauna found in Guindy National Park. Unfortunately, previous researchers have not attempted studies on their ecological significance in GNP. Besides, several visitors to the National Park are unaware of the importance of this small patch of forest area within the metropolis and that it supports animal and plant life no other city can boast of.

OBJECTIVES OF THE STUDY

To carry out an exploratory survey of spider species richness / diversity in a small reserve forest area, Guindy National Park, Chennai, which includes recording of -

• Species occurences in pre-monsoon / monsoon and post-monsoon periods and comparisons.
• Behaviour and habitat associations of different species of spiders and
  photo-documentation of the same.

PERIOD OF STUDY

Pre-monsoon / Monsoon
Last week of October 1998 - Middle of December 1998
Last week of January 1999 (6 weeks)

Post -Monsoon / Summer
May - June 1999 (6 weeks)

HABITS AND MICRO-HABITAT ASSOCIATION

Recording of behaviour and micro habitat associations of different species were an important aspect of this study. While spiders can be broadly classified as web-builders or hunters, each have their own unique hunting method and niche. Hunting spiders may either be ground-dwellers inside burrows or may wait inside crevices for prey, or may be found on vegetation (including barks of trees, where they are usually camouflaged to escape predation). Leaf litter on the forest floor is another habitat preferred by many spiders. Similarly, many web-building spiders have devised numerous web variations, to increase predatory success. Some prefer building their webs in lower areas while some construct their webs only at an angle and at certain heights. These microhabitat preferences were recorded and the details have been appended in the species-wise descriptions.

RESULTS AND DISCUSSION

Certain species were found to be seasonal, and since the study period covered the monsoon and post monsoon months from November - January and April - June, a Monsoon and Post-monsoon record of occurances of different families was maintained.

Certain species are nocturnal, hence they would not have been represented during the study. 2 night walks inside the National Park, during the study period, added to the species list.

GNP being in the heart of the city, is highly vulnerable to outside interference and this was evident in certain areas of the National Park, especially near the boundaries. Places of worship are also present within the park and during the festive season, these areas sometimes are host to a number of people. This leads to accumulation of garbage, and though regularily cleaned these areas suffer due to constant human interference and disturbance. These areas were classified as disturbed areas. When these areas were sampled, it was found that there was a sharp decrease in species richness and abundance. There were also areas where vegetation was cleared to make way for pipelines, during the study period. A species which was under observation (Portia sp.) which may have been a first record in South India was found on that vegetation which was cleared, and after than there has been no trace of it. Spider juveniles can disperse very easily, but the larger the spider, the more difficult it is to disperse. Therefore intact habitat areas are very essential. If vegetation is cleared, it can be kept in the vicinity for sometime, to allow species to rehabilitate.

Shrubs like Clausena dentata and Glycosmis cochinsinensis seem to harbour a wide variety of species. Thorny bushes like the Randia dumetorium, Carissa spinarum abundant within the National Park harbour spiders belonging to Family - Stegodyphus, Lycosidae and Araneidae, which have been found to devour a wide variety of insects.

The association between the Jatropha plant and the green lynx spider (Peucetia viridans) has still not been studied. This spider was almost all the time spotted only on this plant. This has been observed even outside the National Park. The family to which it belongs (Family : Oxyopidae) are very useful predators especially in agroecosystems where there have been observed feeding on a variety of crop pests. They can feed on pests sometimes almost ten times their size.

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