| nitrogen requirements of an old world nectarivore, the orange-tufted sunbird nectarinia osea. | nectarivorous birds are represented by three major radiations: honeyeaters and sunbirds in the old world and hummingbirds in the new world. costa's hummingbirds and new holland honeyeaters have unusually low nitrogen requirements, which have been related to the species' low-protein, high-sugar diets. therefore, we hypothesised that orange-tufted sunbirds (nectarinia osea) would likewise have low-maintenance nitrogen requirements and low rates of endogenous nitrogen loss. to test this hypothesis, ... | 2013 | 11073800 |