Population Variation and Food Habits of Ranid Frogs in the Rice-Based Cropping System in Gujranwala Region,Pakistan

摘要

The current study aims to investigate the population variation and food habits of ranid frogs in the rice-based cropping system in District Gujranwala,Pakistan.The population in the study area was estimated using capture,mark and release method whereas food habits of the species were studied by analysis of stomach contents.The results showed the highest average population was found during August 2009(93.10±18.64/ha) while the lowest from December 2008 to February 2009.Maximum seasonal populations existed in summer 2009,whereas winter 2008 sizes were at a minimum.Stomach content analysis of the species revealed percent frequency(% F) of occurrence of insects(80.3),earthworms(28.5),whole frogs(15.8),bone pieces(22.5),rodents(1.66),vegetation(5.0),soil particles(13.3) and some unidentified material(7.5) in all the stomach samples.Most frequently consumed prey items were insects(30% by volume),although frogs also preyed upon conspecifics and rodents.Insects recovered from the stomach contents were identified as belonging to Orthoptera,Lepidoptera,Coleoptera,Diptera,Odonata and Homoptera as well as the class Archnida.Insects recovered from the stomach contents were compared to those captured from the study area.