How much nectar does a hummingbird consume?

Hummingbirds drink more than their weight in nectar each day. This requires hundreds of visits to flowers. If they are deprived of nectar for just a few hours they are in danger of starving. This high rate of consumption is required because they have the highest recorded metabolic rate of any vertebrate, both while resting and during activity. This high rate of metabolism is due to several factors: their massive flight muscles, which make up 30% of their body weight and their tiny size, which causes them lose heat more rapidly than a larger bird does.