Charismatic mega-fauna species such as elephants and rhinos have valuable tusks and horns that are sought after by opportunistic poachers. Poaching also assumes the form of subsistence hunting by households living in and around protected areas. The conservation of endangered animal species is important for the environmental sustainability of natural ecosystems. This dissertation consists of four separate essays on the economics of poaching and protection of endangered species. The first essay examines the labor allocation problem of an opportunistic poacher harvesting an endangered species within a protected area. The labor allocation problem is coupled with the species' population dynamics to estimate how poaching responds to economic parameters over time. The model provides insight into the relationship between species population dynamics, economic parameters, and biological parameters. Interesting and counterintuitive results are observed for a wide range of economic and biological parameters. Civil unrest and political instability have been associated with poaching. In the second essay I examine an empirical data set on rhino poaching in Assam, India. Assam witnessed a prolonged period of civil unrest and political instability during which rhino poaching increased dramatically. The relationship between civil unrest and rhino poaching is identified through an econometric exercise. I factor in the relationship between poaching and other variables associated with it - including blackmarket rhino horn prices, potential size of black markets, and anti-poaching efforts. These variables are seen to have the predicted associations with poaching, and help identify the latter's relationship with civil unrest. International criminal syndicates sponsor elephant poaching in Africa. The third essay develops a dynamic a model of organized criminal poaching. Under plausible conditions poaching is insensitive to black-market price of ivory, but changes dramatically with the probability of interception by anti-poaching patrols. Parameter space is analyzed extensively to ascertain the effect of economic parameters on elephant population sustainability. In the fourth essay I examine the strategic interaction between poachers and anti-poachers in a spatiotemporal setting. A space is conceptualized within which meta-populations of elephants disperse temporally. Optimal locational strategies of poachers and anti-poachers are solved for, and their effects on elephant population dynamics are examined. Keywords: Rhinoceros unicornis; Loxodonta africana; poaching; stochastic population dynamics; bifurcation; deterministic chaos; civil unrest; strategic interaction.