Sunday, January 8, 2017

A Few Southern Owls

This post celebrates some of the southernmost owl species in the Americas from Chile and Argentina as seen on a very short trip there. Each species is introduced in red text:

Austral Pygmy-Owl (Glaucidium nana), Valle de las Trancas, Bío-Bío, Chile, © Christian Artuso.
I had a very hard time choosing from amongst my photos of Austral Pygmy-Owl so I decided to share nine images of this species. The Austral Pygmy-Owl is similar to Ferruginous Pygmy-owl and they were formerly considered conspecific. This species is only found in southern Chile and southwestern Argentina. It is partially an austral migrant with southern breeding populations migrating north in the austral winter. All of these images are cropped except for the habitat photo and all were taken at sites in the Valle de las Trancas area.

The nine photos show:
1.  A cropped portrait of the owl looking downward showing the crown pattern.
2.  A cropped portrait of the owl with the snow-covered mountains in the background.
3.  A cropped portrait of the owl against a greener background showing most of the features. including the barred undertail and the throat while the owl is singing.
4.  A cropped portrait of the owl showing the false face (turned 180 degrees).
5.  A cropped portrait of the owl in foliage and the feathers of the throat while singing.
6.  A cropped portrait of the owl with more of the underparts and the wing pattern visible, as well as a good look at the sparse feathering on the toes, and with the throat feathers pushed out as the owl is singing.
7.  A cropped horizontal format image of the owl standing on one leg with the tail turned sideways and caught in a “wink” (i.e. eyes closed).
8.  A horizontal habitat photo showing the owl being mobbed by a Common Diuca Finch and a White-browed Ground-Tyrant and with the mountains and the valley (Valle de las Trancas) in the background. Note that this species is thought to prey primarily on birds!
9.  A more reddish individual (although interestingly the back is still rather brownish)

Rufous-legged Owl (Strix rufipes), Bío-Bío, Chile, © Christian Artuso.
The beautiful Rufous-legged Owl has the southernmost distributions of any Strix owl, occurring in the southernmost Andes and Pacific Coastal Range from central Chile south to Tierra del Fuego. It occurs only in Chile and Argentina (small portion of its range in the latter). It probably forms a superspecies cluster with Rusty-barred Owl and Chaco Owl (also from southern South America).  The Rufous-legged Owl is a denizen of old-growth forests, especially the tall Nothofagus forests, and some other forest types including Podocarpus and Araucaria.  The first two photos were taken in dense fog in the spectacular, coastal monkey-puzzle tree (Araucaria araucana) forest at the Refugio Entre Araucarias in southern Chile. Although the fog robs the photo of colour, it does give a sense of some of the mystique of this poorly known owl species. The next three photos were taken in Nosthofagus forests in the Valle de las Trancas, also in the Bío-Bío, region. Very few nests of this species have ever been found but the majority of those few nests have been in cavities of the large Magellanic Woodpecker (Campephilus magellanicus), a southern relative of Ivory-billed Woodpecker. I highly recommend listening to the song of this owl, which sounds like the maniacal laughter of a warlock and sent a shutter down my spine as I stood in the darkness of the tall, dense, moss-dripping old growth forests in the still of the night (e.g.

Magellanic Horned Owl (Bubo magellanicus), Bío-Bío, Chile, © Christian Artuso
The Magellanic Horned Owl (also known as the Lesser Horned Owl) is sometimes considered a subspecies of Great Horned Owl (e.g. following Clements); however, numerous taxonomic authorities including the IOC now treat it as a full species. The voice, genetics and morphology (smaller size overall, small ear-tufts, less powerful feet and possibly some differences in facial rim and narrowness of underpart barring according to Handbook of Birds of the World) all differ from the Great Horned Owl. It is found from Peru to southern Chile and southwestern Argentina, in both the high Andes (approximately 2500 – 4500 m ASL) and in the lowlands of Patagonia.  This individual was found roosting near the Pacific coast of central Chile just before sunset. I pasted these two photo into a collage to give you a sense of the owl’s camouflage in its natural habitat and the field marks as visible in the cropped portrait.

Montane-forest Screech-Owl (Megascops hoyi), La Cornisa, Jujuy, Argentina, © Christian Artuso.
Also known as Yungas Screech-Owl or Hoy’s Screech-Owl, the Montane-forest Screech-Owl is endemic to the mid elevation (1,000 – 2,500 m ASL), moist Yungas forest of northern Argentina and southern Bolivia. This individual (presumed to be male based on voice) was singing with a beetle larva dangling from his beak. I found the warm plumage colour of this bird also interesting. I am not sure if it is red enough to be considered a rufous morph or rather an intermediate. 



Buff-fronted Owl (Aegolius harrisii), Calilegua National Park, Jujuy, Argentina, © Christian Artuso.
There are only four extant species in the genus Aegolius. Three of these are confined to the Americas: the Buff-fronted Owl from South America, the Unspotted Saw-whet Owl from Central America and the Northern Saw-whet Owl from North America. The fourth species is the Boreal Owl, also known as Tengmalm’s Owl, which has a Holarctic distribution (across the boreal/taiga region of North America and Eurasia). I have long held a fascination for this genus of enigmatic owls and the Buff-fronted Owl, one of the most secretive species in the Americas, was a bird I dreamed of seeing for many years until I finally managed to photograph one in Brazil with the help of Cal Martins. My second chance to photograph a Buff-fronted Owl came very recently when I heard one call shortly after dusk in Calilegua National Park, Argentina. It was quite a moment of exhilaration when, after waking my sleeping travel companion, we carefully scampered down a steep bank to enable a viewpoint into the subcanopy of the tree I believed the owl to be calling from and found this little gem perched on a beautiful mossy branch. This was at approximately 2000 m ASL in the moist Yungas forest of the eastern Andes. In addition to the exquisite plumage colouration, you can see just a little of the pale blue eyelids of this species in the first photo. The second photo shows the eyelids better (this photo caught the owl in a wink it seems). The third photo shows the black cap to best effect.

Burrowing Owl (Athene cunicularia), Dique Campo Alegre, Salta, Argentina, © Christian Artuso
The Burrowing Owl is very common in parts of South America. I only wish I could say the same for the North American Great Plains where they are disappearing rapidly! These two photos show some of the habitat they are found in and also one individual with a very dark face. I am not sure what the first individual has in its bill (at first I thought it was dung).

Barn Owl (Tyto alba), Calilegua National Park, Jujuy, Argentina, © Christian Artuso
Not matter how common and cosmopolitan the Barn Owl may be, I still find this owl takes my breath away every time I see one. Just look at the glistening golden mantle of this individual from northern Argentina!The second photo is a composite that shows preening behaviour.


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