I always think of hummingbirds as tiny, fast moving birds, ones you can barely see until they stop to slurp some nectar from a flower. I’ve written about the smallest species of hummingbird, the bee hummingbird, but while thinking of an animal for today’s blog, I found myself wondering what the largest species of hummingbird is. Turns out, that honour belongs to the very appropriately named giant hummingbird.
These massive hummingbirds can be found in the Andes of South America, hanging around scrublands and forests. In the summer, the birds live in higher altitude areas, but when things get cool in the winter, the birds migrate down to warmer slopes. Giant hummingbirds are able to cope with some amount of urbanization, as long as there are enough plants to sustain them.
You see, like all hummingbirds, these guys have one primary food source: nectar. They feed on a variety of flowers, including Puya plants and various cacti. Like other hummingbirds, they also supplement their diet with insects to meet mineral and protein needs that nectar alone can’t provide. Female giant hummingbirds snack on tasty things like sand, soil, and wood ash after breeding to replace calcium lost during egg laying.
But the main thing hummingbirds eat is nectar, and there’s a very good reason for that dietary choice. Hummingbirds need a lot of energy, and they need it quickly. Unfortunately for giant hummingbirds, due to their size, their energy requirements are higher than those of smaller hummingbirds, which already require a vast amount of energy to sustain their ridiculous flight and metabolism.
In fact, hummingbirds have the highest basal metabolic rate of any warm-blooded animals, and other than insects, have the highest metabolism of any animal while in flight. Giant hummingbirds have another major energy problem: they live at high altitudes, which means there’s less oxygen in the air, and the thinner air doesn’t generate as much lift for flight. So the giant hummingbird’s size, along with it’s high-altitude habitat, means these birds need to consume huge quantities of nectar. Their energy requirements during flight are estimated to be 4.3 calories per hour.
So just how big are giant hummingbirds? The answer, in the grand scheme of things, is not very. But for hummingbirds, these guys are huge. They weigh a whopping 18-24 g, and measure up to 23 cm in length, with wingspans of around 21 cm. For perspective, these birds are about the size of a starling or cardinal, which really isn’t very large. But they are almost twice the size of the next largest species of hummingbird, and it’s thought that due to their energy requirements, the giant hummingbird is close to the upper bound of how big hummingbirds can get.
I could go on and on about hummingbird physiology, because these birds are truly fascinating. But I think I’ll save that for a post on hummingbirds in general, because there’s lots and lots to say about these amazing birds!