Two central ideas of the Convention on Biological Diversity (UNEP 1992) are (1) the sustainable use of natural resources and (2) the implementation of environmental impact assessments. These are precisely the precepts of Integrated Conservation and Development Projects (ICDPs) such as CARE Ecuador´s Sustainable Use of Biological Resources (SUBIR) Project. Although any project proposing the use of natural resources may have adverse effects on biodiversity, environmental assessment is an important instrument to avoid or at least reduce such results. In this context, recent and accurate biological diversity data are critical, for they are exactly what allow us to determine the ecological sustainability and environmental impact of a proposed project. Unfortunately, such environmental assessment is often limited by time and money, which makes the availability of effective and affordable rapid assessment methods imperative. The Multi Time-Window Transect Mapping (MTW) method was developed explicitly to meet this need in assessing tropical bird communities. In this paper I discuss how MTW data on threatened bird species improved the conservation efforts in SUBIR´s pilot Community Forest Management Plan, which was developed in the community of Playa de Oro. Furthermore, I present a scheme for the integration of avifaunistic data into conservation and development projects.