Nesting dynamics of the scarlet Ibis (Eudocimus ruber ) in Trinidad, West Indies

The effect of human disturbance on colonial waterbirds is a global issue. Many colonial waterbirds are migratory, and their protection depends on balancing conservation of their habitats and habits across many regions. Such protection is critical given the economic benefits that come from a growing ecotourism industry, involving bird watching and other recreational activities. This thesis begins with a review of the literature available via Web of Science and Jstor, to determine whether the effects of human disturbance on the habit, behaviour, and physiological characteristics may differ with biome, migratory habit and functional group.;Scarlet Ibis (Eudocimus ruber) is a significant species of colonial waterbirds in Trinidad, West Indies, whose management is hampered by limited information on its life history. Although a keystone species in the tourism industry, it is under increasing pressure caused by poaching, human disturbance and habitat destruction. The nesting pattern of the Scarlet Ibis in the Caroni Swamp, a traditional breeding area in Trinidad, was studied during the 2008 breeding season, in order to determine factors that may have an influence on its reproductive success.;Observation of key spatial variables in the nesting site such as distance of neighbouring nests, number of nests per tree, nest cover, distance to the water edge, diameter of nesting tree and number of egrets present, was undertaken and related to clutch size, hatching success and fledging success. The number of nests per tree, distance to the water's edge and distance of the neighbouring nests were the most significant factors that influenced breeding success in any or the three measures. Nesting pattern appear to follow the "selfish herd hypothesis" described for the Scarlet Ibis in Brazil by Olmos (2003). Nesting aggregation is one strategy used by birds to reduce the chances of predation.;Key Words: breeding biology, Caroni swamp, ciconiiformes, colonial waterbirds, Eudocimus ruber, human disturbance, Scarlet Ibis, Trinidad, West Indies;Waterbirds throughout the world suffer from similar effects of human disturbance such as increased vigilance, reduction in feeding rates, lower reproductive success and greater energetic loss caused by destruction and manipulation of habitats. Acclimation to human disturbance can also cause birds to increase their feeding efficiency and tolerate or habituate to such disturbances. Such acclimation may result in positive outcomes. The classification of colonial waterbirds according to biome, habit and functional group is helpful, because food and nesting sites vary, the energy requirement based on habits vary and body size and structure of species differ. Based on the literature reviewed, studies on colonial waterbirds in tropical regions are limited and available research is limited to their wintering or summer home range. Additional research should include the effects of human disturbance in order to understand how it affects the behaviour, physical fitness and physiological characteristics of waterbirds.