LE3 .A278 2022

2022

Avery, Trevor
Herman, Tom
Colville, David

Acadia University

Master of Science

Masters

Applied Geomatics

Earth & Environmental Sciences

Eunectes murinus is a large species of aquatic snake from the family Boidae that inhabits the Amazon and Orinoco basins. Most of the information on the species’ ecology is based on studies in Venezuela and northern and eastern Brazil. Descriptions from closed canopy rainforest systems are limited mainly to short notes and sparse observations. Between 2012 and 2021 I aggregated positions of E. murinus data from multiple localities in the Madre de Dios region of Peru. Positions were acquired during periods of intensive surveying, opportunistic encounters, radio telemetry tracking, and analysis of data acquired during other faunal surveys in the region. The information was combined with remotely sensed data products in ArcGIS Pro for spatial analysis and geospatial modelling. In addition to general results pertaining to the ecology of the species, I address two questions about the predatory habits of E murinus: 1) Is the predation behaviour of E. murinus a critical aspect of its conservation? And 2) Does E. murinus target areas of higher prey density and occurrence frequency? During the study 52 individual E. murinus were recorded and four adults were tagged with radio transponders. Snakes were found throughout the study area occupying rivers, small open canopy streams, Maurtia sp. dominated palm swamps, oxbow lakes and human created habitats such as cattle ponds and mining pools. Permanent presence of water and open canopy were determined as two essential variables associated with E. murinus habitat. Results of habitat preference and hydrology mapping were used to produce minimum, maximum and random forest distribution models in the eastern portion of the region. The results from the home range analysis, and a review of individual positions indicate that E. murinus have defined home ranges, and display site fidelity. The activity patterns of snakes in Mauritia palm systems and the affiliation of riverine and stream snakes with mineral licks and game trails demonstrate that E. murinus target areas of higher prey occurrence and are likely more active as predators in these systems than previously described. Several aspects of the results highlight conservation implications for the species in Southeastern Peru and understanding the predation ecology and diet of E. murinus will be essential for addressing the conversation of population in the Madre de Dios region.

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https://scholar.acadiau.ca/islandora/object/theses:3739