Saturday, 13 June 2015

Humming with Iridescence

Last time I revelled (as I hope you did) in some birds that flaunt iridescent colours - colours that flash with light, and even change with the angle of viewing. I won't repeat the details of how it works here, but now I want to dedicate this entire post to just one family of birds, the fabulous hummingbirds, a South American group which has spread into North America in relatively recent times. Hummers seem to specialise in iridescence, with rich layers of cells that reinforce reflected and refracted light to magnificent effect.

It's probably a cheek for someone from this side of the Pacific (and with a non-spectacular camera) to be featuring hummers, but I am such a fan that I can't help myself. Hopefully some of these will give you pleasure too. I think these little gems can speak for themselves throughout this post for the most part.

Amethyst-throated Sunangel Heliangelus amethysticollis, Inca Track near Machu Picchu, Peru.
Andean Emerald Agyrtria franciae, Alandbi Lodge north-west of Quito, Ecuador.
Common in the northern Andes, but always exquisite.
Blue-mantled Thornbill Chalcostigma stanleyi, El Cajas NP, southern Ecuador.
A mostly high-altitude bird which shines all over!
Buff-tailed Coronet Boissonneaua flavescens, Bellavista Lodge, north-west of Quito.
A relatively unassuming hummer - until it catches the light.
White-necked Jacobin Florisuga mellivora male, Alanbi Lodge, north-west of Quito.
Collared Inca Coeligena torquata female, Bellavista Lodge, north-west Ecuador cloud forests.

Golden-tailed Sapphire Chrysuronia oenone, Wild Sumaco Lodge, north-eastern Andes, Ecuador.
Some of these birds really have big names to live up to, but they seem to manage with ease...
Green Violetear Colibri thalassinus near Cusco, Peruvian Andes.
A widespread beauty.

Green-crowned Brilliant Heliodoxa jacula, Mirador Rio Blanco, north-west of Quito, Ecuador.
A relatively big hummer, and brilliant indeed.

Green-crowned Woodnymph Thalurania colombica, Alanbi Lodge.
Surely one of the most stunning in the glittering constellation of hummers.
Long-tailed Sylph Aglaiocercus kingii, San Isidro Lodge, Ecuador (above)
and Violet-tailed Sylph A. coelestis, Sachatamia Lodge, north-west of Quito.
This stunning species pair evolved on opposite sides of the Andes, east and west respectively, from a common ancestor; this phenomenon is one reason that the northern Andean countries
are so fabulously rich in natural diversity.

Purple-bibbed Whitetip Urosticte benjamini, Alanbir Lodge, is limited to the northern Andes.

Rufous-tailed Hummingbird Amazilia tzacatl, also at Alanbi.
A very common hummingbird from Mexico to southern Ecuador, but who could ever tire of them?
Velvet-purple Coronet Boissonneaua jardini, Sachatamia Lodge, north-west of Quito, above and below.
This is one of the most iridescent of all hummers - a big claim, and not really borne out by these photos
taken on a dull wet day. But compare the wing edges and thighs in the two photos to see how the iridescence
'switches on and off'.


Violet-bellied Hummingbird Juliamyia julie, Umbrellabird Lodge, southern Ecuador.
There is no bad way to end a posting on either iridescence or hummers
and I reckon this bird emphasises that. Wow!
Thanks for staying with me through a fairly self-indulgent post and one without a lot of extra information - this cast doesn't need help though.

Next time I'll finish this mini-series by looking at iridescence in other animals, mostly invertebrates.



1hummer said...

Ian, The picture of the Collared Inca (male) is actually a White-necked Jacobin

Rick Greenspun

Ian Fraser said...

Oops, that's embarrassing! Thanks for taking the trouble to correct me Rick, I appreciate it.