In 1996, a floral and faunal inventory of the southeastern slopes of the Marojejy Massif, which falls in a protected area known as the Parc national de Marojejy, was conducted in an ascending series of altitudinal transect zones. The 1996 research team worked in five altitudinal zones (referred to as transect zones). Between 3 October and 15 November 2021, a floral and faunal inventory was completed, replicating the locations surveyed in 1996 and closely the dates. Detected bird species were analyzed for changes in elevational distribution between 1996 and 2021. Birds were divided into three feeding behavior groups and tolerance to forest habitat degradation was considered.