Global environmental transformation has triggered well-studied impacts on ecological interactions and biodiversity but the effects of damaged ecosystems and diminished access to natural resources on human health is less understood. Mammalian wildlife not only influences ecological systems but also serves as a primary source of meat to hundreds of millions of people throughout the developing world. The consumption of animal-source foods is important in providing essential micronutrients to humans in bioavailable forms. Thus, loss of access to wildlife may have powerful and far-reaching effects on the health of human populations that rely on bushmeat. In this dissertation, I evaluated the provisioning service value of wildlife populations to human health and livelihoods, using methods from ecology, economics and epidemiology.
Ecosystem service valuations are useful to conservation and development practitioners for calculating the total value of benefits from ecosystems, choosing between alternative land use or management scenarios, ascertaining the distribution of the costs and benefits of services to users, and identifying or developing financing mechanisms for ecosystem services. I use the case of wildlife harvest and consumption in northeastern Madagascar to identify the distribution of these benefits to further understanding of local incentives for conservation promotion and conservation rule-breaking. Through my analysis of the disproportionate benefits of these services to local people, conservation practitioners may better understand the heterogeneity of local people's incentives for conservation. These fine-scale differences between communities and households can also be used to create frameworks for policy linkages so that public health and development initiatives can best allocate sparse funds to support regions, households or individuals most vulnerable to changes in access to wildlife. This valuation framework highlights the local importance of this service, but still ignores the cultural, ecological and health value of wildlife and wild meat to local people, and the existence value of this biodiversity to the global community.
Despite widespread human reliance on wildlife for food, the impact of wildlife depletion on human health remains poorly understood. I studied a longitudinal cohort of 77 pre-adolescent children in Madagascar and show that consuming more wildlife was associated with significantly higher hemoglobin concentrations. My empirical models demonstrate that removing access to wildlife would induce a 29% increase in the numbers of children suffering from anemia and a tripling of anemia cases among children in the poorest households. This research quantifies costs of reduced access to wildlife for rural communities in Madagascar and provides evidence linking global trends in biodiversity loss to declines in childhood health.
This study linking anemia to wildlife availability and access seeks to provide an improved understanding of the ultimate determinants of anemia, a widespread and critically important nutritional disorder. Anemia is a disease characterized by a deficiency in red blood cells, hemoglobin (an iron-containing protein whose main function is oxygen transportation in humans) or both. Although there are multiple etiologies, the majority of anemia cases worldwide are a result of iron deficiency, and this is the most common nutritional disease globally affecting one-fourth of the world's population. Because of the critical role of iron in metabolic processes, reductions in hemoglobin on an individual and population level may induce a breadth of health sequelae from nearly all health domains. I use results from a systematic review of the literature to describe the potential short- and long-term effects of iron-deficiency anemia in two ways: 1) by linking shifts in hemoglobin to dose-response health effects using previously published studies and then 2) demonstrating the impact on health and economies of predicted increases in the future prevalence of anemia in my study population.
