Pete Oxford / Sparkling violetear hummingbird (Colibri coruscans) at base of Chimborazo Volcano (Highest mountain in Ecuador), Andes, Ecuador, South America

B&S Draker / Three Black-chinned Hummingbird (Archilochus alexandri) females feeding on Texas thistle (Cirsium texanum). Sinton, Corpus Christi, Coastal Bend, Texas, USA, May.

Rolf Nussbaumer / Ruby-throated Hummingbird (Archilochus colubris), male in flight feeding on flower. Hill Country, Central Texas, USA, August.

Bence Mate / Green crowned brilliant hummingbird (Heliodoxa jacula) male taking off to feed at feeder in garden, another waiting perched on lichen covered branch, Costa Rica, January. Winner, Eric Hosking award at...

Pete Oxford / Sword-billed Hummingbird (Ensifera ensifera), the only species of bird to have a bill longer than the rest of its body, approaching a flower. Yanacocha Reserve, Ecuador.

Pete Oxford / Silhouette of a Sword-billed Hummingbird (Ensifera ensifera), the only species of bird to have a bill longer than the rest of its body. Yanacocha Reserve cloud forest, Ecuador.

Diane McAllister / Male Anna's hummingbird (Calypte anna) hovers in mid-air looking at the camera in a backyard in Reno. Nevada, USA, August

Diane McAllister / Rufous hummingbird (Selasphorus rufus) drinking nectar from an Agastache bloom in a backyard in Reno. Nevada, USA, August

Chris Shields / Illustration of wildlife of the Andes: South America Alpaca (Vicugna pacos),centre; Cougar / Puma / Mountain lion / Mountain cat / Catamount / Panther (Puma concolor),left; Spectacled / Andean bear (...

Mary McDonald / Violet Sabrewing Hummingbird (Campylopterus hemileucurus) male hovering at feeder, Bosque de Paz, Costa Rica, Central America.

Nick Garbutt / Sword-billed Hummingbird (Ensifera ensifera). Yanacocha montane forest, Ecuador. May.

Shattil & Rozinski / Broad-tailed hummingbird (Selasphorus platycercus) hovering over Rocky Mountain Irises (Iris missouriensis) flowering in pasture, Wyoming, USA, North America