Birds
Sword-billed Hummingbird
Ensifera ensifera · also called sword-billed hummingbird
The sword-billed hummingbird holds a record no other bird comes close to — its bill is longer than its entire body. That bill unlocks nectar buried at the bottom of flowers no other hummingbird can reach, but it is so unwieldy that the bird perches with its head tipped almost straight up and preens with its feet.
Overview
Sword-billed hummingbirds live in cloud forest and forest edge along the Andes, from Venezuela to Bolivia, at roughly 1,700 to 3,500 metres. The body is about 14 cm, with a straight black bill of 9–11 cm, and they drink nectar from long tubular flowers, especially passionflowers.
A bill longer than the bird
Its bill exceeds the combined length of head, body, and tail — the only bird with this proportion, an extreme feeding specialisation.
An awkward tool
Too heavy to hold level at rest, the bill forces the bird to perch with its head angled skyward, and it must preen with its feet since the bill cannot reach its own body.
Status
The sword-billed hummingbird is Least Concern, widespread along the Andes but dependent on the long-tubed flowers it alone can pollinate.
Sword-billed Hummingbird: common questions
Is the sword-billed hummingbird's bill really longer than its body?
Yes. Its straight bill is about 9 to 11 centimetres long, which exceeds the combined length of the bird's head, body, and tail, making it the only bird species in the world with a bill longer than the rest of its body. This is an extreme case of an evolutionary trend seen more modestly in many hummingbirds, where bill length is matched to the flowers a species feeds from, and it gives the sword-billed hummingbird a genuinely one-of-a-kind silhouette in flight.
What is the long bill actually for?
The bill, together with a tongue that can be extended even further, lets the sword-billed hummingbird feed on nectar held deep at the base of very long tubular flowers, especially certain passionflowers whose floral tubes can be around 10 centimetres or more. These flowers are effectively inaccessible to other hummingbirds, so the sword-billed hummingbird has that rich nectar source largely to itself, and in return it is often the sole effective pollinator of those plants, brushing pollen between flowers as it feeds. The bill also allows it to probe flowers from a hovering distance without its wings striking the plant.
How does the sword-billed hummingbird cope with such an awkward bill?
The bill is too long and heavy to hold out horizontally when the bird is not flying, so a perched sword-billed hummingbird tilts its head and bill sharply upward, sometimes to nearly vertical, to balance the weight and reduce strain. It also cannot use its bill for preening the way other birds do, because the bill cannot reach most of its own plumage, so it preens with its feet instead, scratching and combing its feathers. In flight the long bill is less of a problem, and the bird is a capable, agile flier despite the unusual load out front.
What does coevolution mean in the case of the sword-billed hummingbird?
Coevolution describes a process in which two species act as agents of natural selection on each other, so that changes in one drive changes in the other over evolutionary time. In the case of the sword-billed hummingbird and its passionflowers, the idea is that flowers with slightly longer tubes forced the bird's pollinators to have longer bills to reach the nectar, while birds with longer bills in turn favoured, through more effective pollination, plants with longer tubes, and this reciprocal pressure ratcheted both traits to their current extremes. The relationship is a textbook example used to illustrate how specialised partnerships between plants and pollinators can arise.