Population Dynamics and Behavioral Pattern of Marsh Crocodile (Crocodylus palustris Lesson, 1831) – A Dimensional Analogy between Hydro-Chemical Physiognomies and Species Richness
The study aims population dynamics and behavioral pattern of Marsh Crocodile (Crocodylus palustris Lesson, 1831) in two palustrine rural habitats of Central Gujarat, India at four sampling points (Site-I) and two stations (Site-II) from January to April, 2021 to delineate population count, behavioral pattern and scat analysis of Marsh Crocodile (MC) associated with hydro-chemical physiognomies. Prior to commencement of the study, hypothesis about effects of water quality on species richness of MC was proposed. Outcomes of study reflect high population density of MC (60) at Point-3, followed by Point-1 (34), Point-4 (32) and Point-2 (12) at Site-I (N=138). Behavioral pattern of MC was more intense in Floating (71), followed by Basking (40) and Swimming (19) (N=130, 94.20%). Population peak of MC was noted at Point-2 (75), compared to Point-1 (53) at Site-II (N=128). Here, behavioral pattern of MC was more accentuated in Basking (75), followed by Floating (24) and Yawning (14) (N=113, 88.28%). Comparatively, Site-I exhibited more richness (N=138, 51.88%) than Site-II (N=128, 48.12%), making an aggregate of 266 individuals. Comparing mean values of hydro-chemical parameters of two observation areas, void difference was observed in Temperature (18 degree Celsius each). Mean concentration of pH, Chloride, Phosphate and Nitrate was intense at Site-I compared to Site-II (8.41, 500.55 mg/L, 4.76 mg/L, 2.54 mg/L, respectively) with a disparity of 0.71, 325.78 mg/L, 2.25 mg/L and 0.05 mg/L of pH, Chloride, Phosphate, and Nitrate, respectively. Conversely, Sulphate contents was more in hydrological regime at Site-II (64.64 mg/L) compared to Site-I (12.38 mg/L) with a noteworthy discrepancy (-52.26 mg/L). Correlation between hydro-chemical parameters and species richness of MC revealed that population of MC was highly affected positively by gradient contents of Nitrate (0.929) and inversely affected by Phosphate (0.182) at Site-I. However, pH was found affecting more species richness of MC (1.293) against fewer population by Temperature (0.563) at Site-II. Findings of present study evidently proved hypothesis with appropriate adequacy in term of effects of water quality on species richness of Marsh Crocodile. Scat analysis of MC revealed higher contents of TOM (366.35%) and TOC (212.50%), followed by Nitrate (1.990 mg/gm), Sulphur (0.314 mg/gm) and Phosphorus (0.014 mg/gm). Considering above facts, it is suggested that water quality of both studied palustrine habitats should be maintained by adding up selective enrichment factors (e.g. Nitrate and pH) as a management perspectives and implicative measures. Moreover, as crocodilian scat is very rich in Organic Carbon and Organic Matter, native farmers should use it commercially (cost-benefit factors) to augment fertility and productivity of desired crop yields. Above suggestions would unfailingly be aiding tools to sustain prevailing population of Marsh Crocodiles in Central Gujarat, India.