Wildlife responses to anthropogenic disturbance in Amazonian forests

Abrahams, Mark (2016) Wildlife responses to anthropogenic disturbance in Amazonian forests. Doctoral thesis, University of East Anglia.

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Abstract

Legally inhabited indigenous, extractive and sustainable use tropical forest reserves, have been lauded as a solution to the intractable problem of how to assure the welfare and secure livelihoods of the world’s diverse forest-dependent people, whilst conserving the world’s most biodiverse terrestrial ecosystems. This strategy has been critiqued by human rights advocates, who assert that legally inhabited reserves paternalistically restrict the livelihood choices and development aspirations of forest-dwellers, and by conservationists, who argue that sustained human presence and resource extraction erodes tropical forest biodiversity. This thesis examines both the anthropogenic impacts on tropical forests at the regional, landscape and household scales and the livelihood challenges faced by semi-subsistence local communities in the Brazilian Amazon. A spatially explicit dataset of 633,721 rural Amazonian households and an array of anthropogenic and environmental variables were used to examine the extent and distribution of structural (deforestation) and non-structural (hunting) human disturbance adjacent to 45 cul-de-sac rivers across the Brazilian states of Amazonas and Pará. At the landscape and household scales, a total of 383 camera trap deployments, 157 quantitative interviews and 164 GPS deployments were made in the agricultural mosaics and forest areas controlled by 63 semi-subsistence communities in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia, in order to quantify and explicate the (i) livelihood costs incurred through the raiding of staple crops by terrestrial forest vertebrates, (ii) degree of depletion that communities exert upon the assemblage of forest vertebrates and (iii) spatial behaviour of hunting dogs and their masters during simulated hunts. Our results indicate that at the regional scale, accessibility, fluvial or otherwise, modulated the drivers, spatial distribution and amount of anthropogenic forest disturbance. Rural household density was highest in the most accessible portions of rivers and adjacent to rivers close to large urban centres. Unlike the low unipolar disturbance evident adjacent to roadless rivers, road-intersected rivers exhibited higher disturbance at multiple loci. At the household and landscape scales semi-subsistence agriculturalists lost 5.5% of their staple crop annually to crop raiders and invested significant resources in lethal and non-lethal strategies to suppress crop raiders, and to avoid losses an order of magnitude higher. Crop raiding was heightened in sparsely settled areas, compounding the economic hardship faced by communities already disadvantaged by isolation from urban centres. A select few harvest-sensitive species were either repelled or depleted by human communities. Diurnal species were detected relatively less frequently in disturbed areas close to communities, but individual species did not shift their activity patterns. Aggregate species biomass was depressed near urban areas rather than communities. Depletion was predicated upon species traits, with large-bodied large-group-living species the worst impacted. Hunting dogs travelled only ~ 13% farther than their masters. Urban hunters travel significantly farther than rural hunters. Hunting dogs were recognised to have deleterious impacts on wildlife, but were commonly used to defend against crop raiders.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Environmental Sciences
Depositing User:	Users 4971 not found.
Date Deposited:	04 Jul 2017 14:08
Last Modified:	30 Jun 2018 00:38
URI:	https://ueaeprints.uea.ac.uk/id/eprint/64005
DOI:

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