RESEARCH ARTICLE

POPULATION DYNAMICS OF AN Acavus POPULATION IN A HOME GARDEN IN KANDY DISTRICT SRI LANKA

Abstract

Sri Lanka is an island with a rich diversity of land snails characterized by both terrestrial and arboreal species. Arboreal Acavus is one of the five endemic land snail genera recorded in the island. It is mainly found in both natural forests and home gardens in the wet zone of Sri Lanka. Healthy populations survive in both rural and suburban home gardens. Home garden populations are not only threatened by natural factors like predation but also by anthropogenic activities. Despite all these stresses Acavus populations thrive in home gardens. However, proper attention has not been paid on these populations. The objective of this study was to identify the population dynamics of a population of Acavus phoenix found in a home garden in Dodamwala Kandy district Sri Lanka. Snails were sampled monthly using markedrecapture method (Jolly-Seber method was used) from June 2000 to January 2002. Thirteen samples were taken during the study. Mean population size of Acavus phoenix in the home garden was 20 individuals. The highest population size (45 individuals) was recorded in April 2001 while the lowest population size (3 individuals) was recorded in November 2001. The highest number of the marked individuals (25 individuals) was recorded in January 2001. The mean values of probability of survival and the number of individuals joined the population (recruitment) were 0.83 and 2.08 respectively. Mean shell height and width of adult Acavus phoenix were 48.93mm and 55.10mm respectively. It was apparent that home garden population fluctuated drastically and it can be due to various reasons like local weather patterns, micro habitats, food sources, predators and anthropogenic activities. Though there are fluctuations, home garden population progresses over time and the Jolly-Seber method is a successful marked-recapture method to estimate Acavus population size in open systems like home gardens. These estimates can be used to monitor home garden Acavus populations over time, compare home garden Acavus populations with one another and to identify the suitability of home gardens for the survival of Acavus populations.

Keywords: Home Gardens, Individuals, Snail, Survival, Population

How to Cite: Bandara,A.M.R.S, Ranawana,K.B, (2016). POPULATION DYNAMICS OF AN Acavus POPULATION IN A HOME GARDEN IN KANDY DISTRICT SRI LANKA.WILDLANKA, 4(1):Pages 001-006

Published On:2016-03-30

Download