Glaucidium Brasilianum

The ferruginous pygmy owl (''Glaucidium brasilianum'') is a small owl that breeds in south-central Arizona and southern Texas in the United States, south through Mexico and Central America, to South America into Brazil, Bolivia, Paraguay and Argentina.

In Central America and South America, it is the most widely distributed pygmy owl and is probably one of the most numerous owl species in those areas. It is found in a wide range of semi-open wooded habitats.

Taxonomy

The ferruginous pygmy owl was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's ''Systema Naturae''. He placed it with all the other owls in the genus ''Strix'' and coined the binomial name ''Strix brasiliana''. Although not cited directly, Gmelin's description was ultimately based on the "Cabure" that had been described in 1648 by the German naturalist Georg Marcgrave in his '' Historia Naturalis Brasiliae''. The ferruginous pygmy owl is now placed with 28 other small owls in the genus '' Glaucidium'' that was introduced in 1826 by the German zoologist Friedrich Boie. The genus name is from Ancient Greek ''glaukidion'' meaning "little owl" or "owlet". It is diminutive of ''glaux'' meaning "owl".

Thirteen subspecies are recognised:

* ''G. b. cactorum'' Van Rossem, 1937 – south Arizona (USA) to Sonora to north Nayarit (west Mexico)
* ''G. b. intermedium'' Phillips, AR, 1966 – south Nayarit to Oaxaca (west Mexico)
* ''G. b. ridgwayi'' Sharpe, 1875 – south Texas (central south USA) to west Panama
* ''G. b. medianum'' Todd, 1916 – north Colombia
* ''G. b. margaritae'' Phelps, WH & Phelps, WH Jr, 1951 – Margarita Island (off Venezuela)
* ''G. b. phaloenoides'' ( Daudin, 1800) – north, east Venezuela, Trinidad and the Guianas
* ''G. b. duidae'' Chapman, 1929 – Cerro Duida (south Venezuela)
* ''G. b. olivaceum'' Chapman, 1939 – Auyán Tepui (southeast Venezuela)
* ''G. b. ucayalae'' Chapman, 1929 – Amazonia
* ''G. b. brasilianum'' (Gmelin, JF, 1788) – east Brazil to northeast Argentina
* ''G. b. pallens'' Brodkorb, 1938 – east Bolivia, west Paraguay and north Argentina
* ''G. b. stranecki'' König, C & Wink, 1995 – central Argentina to south Uruguay
* ''G. b. tucumanum'' Chapman, 1922 – west Argentina

Trinidad, as well as other localities, have endemic subspecies of the ''Glaucidium brasilianum'' owl. Recent genetics work has found substantial differences in ferruginous pygmy owls from different regions and members of the northern ''ridgwayi'' group are sometimes considered a separate species, Ridgway's pygmy-owl (''Glaucidium ridgwayi'').

Description

The ferruginous pygmy owl is small, typically , and stocky with disproportionately large feet and talons. The crown has elongated white/ buff streaks, the wing coverts have white spots, and the underparts are heavily streaked white. There are prominent white supercilia above the facial disc. There are two dark spots on the nape, often termed "false eyes" by birders. Otherwise, its overall color is highly variable, ranging from grey-brown with a black-and-white barred tail to rich rufous with a uniform rufous tail. Sexes are similar with females slightly larger and often more reddish. The flight is often undulating in motion, similar to that of many woodpecker species.

Call

The call is a whistled ''hoo-hoo-hoo-hoo'', usually in E flat. It is easily imitated, and is used by birdwatchers to attract small birds intent on mobbing the pygmy owls.

Behavior and ecology

It can be readily located by the small birds that mob it while it is perched in a tree (up to 40 birds of 11 species have been recorded mobbing one owl).

Food and feeding

This species is crepuscular, but often hunts by day. It hunts a variety of birds, lizards, other reptiles, amphibians, mammals, and insects. Specific examples of what these owls feed on include grasshoppers, crickets, scorpions, six-lined racerunners, four-lined skinks, Texas spotted whiptails, creamy-bellied thrushes, pale-breasted thrushes, eared doves, and mice.

Breeding

The breeding season is from late winter to early spring. It is a cavity nesting bird (tree and columnar cactus cavities), laying one to seven white eggs. Incubation is 28 days, with 27 to 30 days to fledging.

Status and conservation

The northernmost subspecies, ''G. b. cactorum'', commonly called the cactus ferruginous pygmy owl, was a listed Endangered species under the U.S. Endangered Species Act. It This protected it in south-central Arizona from loss of habitat and buffel grass fires. Buffel grass catches fire very easily, which spreads to cacti, burning the owl's primary habitat. Its range extends over the border into Sonora, Mexico. ''G. b. cactorum'' was delisted in 2006. It was also considered to be an ''Imperiled Subspecies'' by NatureServe, with the species as a whole considered ''Secure''.

References

External links

Ferruginous Pygmy Owl - ''Glaucidium brasilianum''
- USGS Patuxent Bird Identification InfoCenter
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Cactus Ferruginous Pygmy Owl information and Photos



Ferruginous Pygmy Owl Photos
at peter-haefele.de
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Birds described in 1788, ferruginous pygmy owl
Birds of Central America
Birds of Mexico
Birds of the Tepuis
Birds of Trinidad and Tobago
Fauna of the Sonoran Desert
Glaucidium (owl)
Native birds of the Southwestern United States
Owls of South America
ferruginous pygmy owl