Behaviour and ecology of birds in tropical rain forest canopies

The canopy of rain forests exhibits several distinct features that determin e avian adaptations. Light intensity and colour, wind, and temperature are the most important components of the physical environment. Tree architectur e poses many challenges for the evolution of avian morphological features, and resource availability varies greatly. The canopy is easily accessible f or birds that are equipped to travel over considerable distances. Given the se conditions, high behavioural flexibility, and adaptations in behaviour a nd morphology related to a nomadic life-style, should prevail among canopy birds. The easy access for certain groups of birds also has consequences fo r the historical processes that shape canopy bird communities. Birds may co ntribute greatly to forest dynamics and composition, mainly due to their ro le as seed dispersers. We elaborate on these points with behavioural, morph ological, and ecological data collected at our Neotropical study site in so uthern Venezuela (Surumoni Canopy Crane Project). We discuss how behaviour and morphological features reflect the ecological demands in the canopy. We contrast the specific behavioural and ecological characteristics of canopy birds with those of species found in the other tiers of the rain forest. I t is pointed out that much of our knowledge is biased towards the Neotropic s, and that better knowledge of the larger canopy species is needed for con servation.