The Amazon rainforest is perhaps the most famous of them all. The enormity of the Amazon is unparalleled with any other, extending over Brazil, Peru, Columbia, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. Superlatives are synonymous with the Amazon, the largest tropical rainforest by area, the biggest drainage basin, the longest river, the greatest biodiversity and home to the heaviest snake with the anaconda. Spend any time in a tropical rainforest and your senses are awakened to a cacophony of sounds. From the evening chorus of toads and cicadas to the morning calls of macaws and howler monkeys. There is an astonishing array of colours in the sky, lakes, rivers and forest and the irritation of the mosquitoes is only amplified by the stifling humidity.
On the western edges of this huge rainforest is the Pacaya-Samiria National Reserve, one of the largest protected areas in Peru. The reserve extends over 2,080,000 ha and is located between two rivers the Ucayali and Marañon which come together to form the Amazon at the vibrant city of Iquitos. These two rivers have meandered and changed pathways to leave behind old channels; the Pacaya a previous channel of the Ucayali and the Samiria of the Marañon. Over 170 settlements can be found within the boundaries of the reserve, reliant on subsistence production and the extraction of resources. With the ever increasing exploitation of petroleum within the Peruvian Amazon it is imperative that the reserve is managed in a manner that protects both the needs of indigenous people and the conservation of the flora and fauna found within the rainforest.
Success in conservation management relies on understanding the population dynamics over time of those species trying to conserve. From 2008 to 2011 I led scientific surveys, completed over 6 week summer expeditions, for the British Exploring Society. Various surveys were completed on a number of key indicator species to form an annual population analysis for the reserve. When compared with data collected in previous years, these surveys aid in monitoring recovering populations, increase our understanding of interactions between populations, provide an indication of the health of the rainforest and can be used to assess the impacts of hunting and to set harvest limits.
Objectives of the expedition were to survey the following:
- Primate species, ungulates and game birds. Such species are important sources of bush meat. Monitoring densities of these populations helps to determine the impact on hunting and the effectiveness of sustainable hunting models.
- Macaws. The mobility of macaws will quickly indicate the general health of the rainforest. Numbers will rise or fall as they enter or leave the reserve depending on the availability of roosts in the palm swamps and fruit in the forest.
- Pink and grey river dolphins. By looking at current and past population densities an assessment can be made on the quality of the aquatic system and links can be made to changes in the abundance of particular fish species.
- Fish. Monitoring the abundance, diversity and composition of fish allows any impact made by local fisheries to be assessed.
- Caiman. Primarily surveys were completed to assess the impact of the recovery of the previously overhunted black caiman on populations of common caiman.
- Yellow Spotted River Turtle. Turtle eggs are considered a delicacy and are subject to intensive poaching during the laying season. The impact of poaching on turtles is compounded by the fact it takes 8 years for a turtle to reach a reproductive age. The head start programme involves removing turtle eggs to a safe beach for incubation and releasing the hatchlings from the beach they were taken from.
Demand for natural resources, be it hunting pressure or petroleum extraction, is unlikely to fall in the coming years. Compounded with the as yet unknown effects that climate change may bring upon the Peruvian rainforests, continued monitoring of wildlife populations will prove crucial for the successful conservation of biodiversity and the preservation of the socio-economic value of this rainforest ecosystem.