Photos

Wikipedia has a very nice article about hummingbirds. Here is the URL: http://en.wikipedia.org/wiki/Hummingbird

For your convenience, I quote several key points here from this article.
(1) Hummingbirds are native to the Americas. Their range extends from southern Alaska to Tierra del Fuego. The majority of species occur in Central and South America.
(2) Hummingbirds can hover in midair by rapidly flapping their wings 12-90 times per second.
(3) Hummingbirds feed on plant nectar and are important pollinators. However, nectar is a poor source of nutrients so they also eat insects and spiders.
(4) Hummingbirds coevolved with ornithophilous flowers. Plants pollinated by hummingbirds produce flowers in shades of red, orange, and bright pink.

In Central America, hummingbirds and Heliconias coevolved. Here is some additional information quoted from this website: http://cloudbridge.or/heliconias.htm

“Heliconias in the tropics rely exclusively on hummingbirds for pollination. This accounts for their bright red, yellow and orange colors, which attract hummingbirds. In addition to their colors, the Heliconias have developed long flower tubes with rich nectar contents. ... The hummingbirds also evolved long curved bills to be able to reach to the bottom of the flower tube to obtain the nectar. Even their tongue is long — twice as long as the bill — so that they can reach even further down the tube.

"Unlike most other flowers, Heliconias have evolved a relationship that gives hummingbirds ‘exclusive’ feeding (and pollination) rights, because neither color nor smell has developed to attract insects. Hummingbirds have no sense of smell. And different species of heliconia uses the birds in different ways. Each species places its pollen on a specific part of a hummingbird’s body to avoid pollen waste and contamination from other Heliconia species in the same region."

I photographed this hummingbird just outside the Monteverde Cloud Forest Nature Reserve close to the continental divide in the mountains of Costa Rica.

I think this is a "Green Violet-Ear" (Colibri thalassinus).