Owl or Eagle?

by Patricia J. Knobloch (4/2006)

Return to Bird Identification: Harpy Eagle

The Pucara style bird image was first identified as a possible owl (Franquemont 1967:14, fig. 24a, 1990:8, fig. 81) and more specifically as the Great Horned Owl (Bubo virginianus) (Chavéz 1992:229). drawing The two tri-partite appendages above the bird’s head as possible long feathers or “ear-tufts”, indeed, limit the choice of possible birds. Only a few genuses of owls or Strigidae can be candidates such as: Megascops, Asio and Bubo.

The Megascops genus is a large category of “Screech Owls”. Duncan (2003: 79) presents the most recent DNA analysis that establishes the New World taxanomic change from the genus Otus (as used in König, et al.) to the current Megascops. Those species with the easily observable ear-tufts are: (1) “Tropical Schreech Owl” or Megascops choliba, subspecies surutus (König, Weick and Becking 1999: 259-261, no images); and, (2) “Rio Napo Screech Owl” or Megascops napensis, subspecies bolivianus (König, Weick and Becking 1999: 277-278, Plate 22, fig. 83a). These Megascops prefer warm climates, normally stay below 1500 m. and are relatively small birds between 20 to 23 cm in length. Therefore, I do not suggest that they are candidates for the image.

The Asio clamator or “Striped Owl” has three subspecies with ear tufts: (1) clamator, (2) forbesi, (3) midas. The A. c. midas is known from Bolivia, Paraguay, northern and central Argentina to Uruguay and southeast Brazil (König, Weick and Becking 1999: 428-429, Plate 64, fig. 210b) but only up to 1600 m. and therefore not considered a candidate.

The Asio stygius or “Stygian Owl” also has three subspecies with ear tufts: (1) stygius or barberoi, (2) robustus or lambi, (3) siguapa or noctipetens. Only the A. s. stygius is known from Colombia, Venezuela and Ecuador through Peru, Bolivia and central Brazil to northern Argentina and southeast Brazil (König, Weick and Becking 1999: 423-424, Plate 63, fig. 206a), and is found in mountainous terrain up to 3000 m. Pucara is located at 3900 m so it may have been a possible reference though its current mapping places it in eastern Bolivia.

The Bubo virginianus or “Great Horned Owl” has many subspecies and some identities may be due only to individual variations. Though Chavéz (1992:229) suggested the nigrescens subspecies (Fjeldså and Krabbe 1990: 226, Plate XXVI 3b), König, Weick and Becking (1999: 289-290, Plate 26, figs. 94f) describe B. v. nigrescen’s habitat location as Ecuador and Colombia and as the darkest subspecies. Alternatively, the habitat description for the subspecies, nacurutu, is a more likely candidate as being east of the Andes in northwest Venezuela, Guyana, then Peru through Bolivia though absent in Amazon area, and from Paraguay to central Argentina and Uruguay (IBID: fig. 94g) up to 4000 m, sometimes higher. The Bubo virginianus nacurutu’s common name is Magellan’s Eagle Owl. However, König, et al. remark that the horned owl of the Andes observed from Peru, south is not the Great Horned Owl species at all because of its different vocalization from observed horned owls in this area. They suggest that the large, though slightly smaller, horned owl of the altiplano is the Bubo magellanicus or Magellanic Owl. From the altiplano south through Chile, the Magellanic Owl dominates and has a habitat that overlaps with Magellan’s Eagle Owl in its northern extents. Of interest here is the tendency for the Magellanic Owl to dominate the rocky ravines and areas above the timberline of 3,000 – 4,000 m. Whereas, Magellan’s Eagle Owl occupies the lowlands and foothills of the eastern Andes (König, Weick and Becking 1999: 290-292, Plate 26, fig. 95). This distribution pattern would suggest that the Bubo owl most likely viewed by Pucara people in their immediate homeland would be the Magellanic Owl.

Size may have been a factor in dedicating iconic significance to this bird’s imagery and their lengths indicate that they are quite large: (1) Asio stygius stygius is 38-46 cm; and, (2) Bubo magellanicus is 45 cm.

In terms of coloration and artistic attributes of the Pucara rendition, the use of alternating spotting of feathers, red markings and the chevron pattern of raptor tail feathers provide other attributes that may narrow the choice. The Pucara image includes red coloration that is most likely a limitation of color choices and represents natural coloration of the bird such as brown. Both owls have some brown coloration with the Asio most dominantly brown. The alternations of colored feathers indicate the spotting of the Pucara image. Another design trait in the image is the number of bands in the tail feathers. The Pucara image indicates two zigzags and one straight black banding of the tail feathers ending in white tips. The Asio has at least 6 bands and the Bubo has at least 5. The presence of this inconsistency and others discussed below suggests that the Pucara image may be indicating a totally different bird family of raptors with fewer black tail feather bands. Thus the candidates for owl imagery based on the presence of ear tufts, size and coloration are Asio stygius stygius and Bubo magellanicus, but on habitation the latter is most likely. The Owl Pages website provides genus and species imagery, but not subspecies. Clements and Shany (2001) and Duncan (2003) also provide only genus/species data and imagery.

I suggest that the bird image represents the “Harpy Eagle” or Harpia harpyja. (see: http://www.iwokrama.org/forest/animals/harpyeagle.htm). Though the Pucara image has the distinctive round head and ear-tufts of the owls, the Harpy Eagle also displays a round face and has dominate, elongated feathers above the forehead that are forked and can appear like ear-tufts. Also the owl’s round crown encircling its face is interrupted by the eyebrow and tuft feathers as well as the beak and chin area, whereas the eagle’s eyes and beak are completely and continuously encircled by its feathered corona (see: http://www.iwokrama.org/forest/images/Harpy%20Eagle.jpg ). The eagle’s tail feathers display the 3 black bands ending in the white tips that match the Pucara image (see: http://kawa3104.at.infoseek.co.jp/ougiwasi.JPG).

The most distinctive attribute that correlates the image with the Harpy Eagle is the overall stance with the robust body with prominent, round breast held high above the legs and feet. The owl body is well rounded and settles over the legs with slight exposure of the feet. Owl claws have a third front toe that rotates to the back allowing them to grasp with two toes in front and two in back. The eagle can hold its body high, almost horizontal to the ground, with long exposed legs. The three toes are always to the front with one in back. The Pucara image indicates a three-toed bird and thus the artist did not discern the rear toe at all. The owl legs and tarsus are completely covered in feathers. The Harpy Eagle has feathers down the leg, but the tarsus is bare with typical “scaly” plates. The significance of this distinction is the observation by Chavéz (1992:227-228, figs. 197, 198) that the tarsus area of the legs on the two vessel examples of the bird has a “curious” or “unusual post-fire scratching or scraping made by a hard implement extending from the red ankle band onto the nearby portion of the foot.” This scratching may indicate the artist’s attempt to represent the scaly appearance of the eagle’s tarsus. The modeling of the beak on the Pucara vessels indicates an extension that is more horizontal like the eagle than the downward curving beak of the owl (Chavéz 1992:227-228, figs. 197b; Franquemont 1990: fig. 81a). The Pucara images have a circled dot on the breast that may be an artistic convention or may be indicating the white feathers in the center area of black feathers on the eagle’s collar (see: http://www.junglephotos.com/amazon/amanimals/ambirds/harpyeagle.shtml). In any of these observations, this analysis relies on the accuracy of drawings by Chavéz (no photos are currently available) and assumed accuracy of observation by the Pucara artist in discerning each bird’s attributes. Both owl and eagle do not appear to have black tear bands and only on juvenile Harpy Eagle does one see a mottling of feathers on the breast.

Book References:

Chávez, Sergio J.

1992 The conventionalized rules in Pucara pottery technology and iconography: Implications for socio-political developments in the northern Lake Titicaca basin. Unpublished PhD dissertation. Michigan State University, Department of Anthropology.

Clements, James F. and Noam Shany

2001 A Field Guide to the Birds of Peru. Ibis Publishing, Temecula, CA.

Duncan, James R.

2003 Owls of the World: Their Lives, Behavior and Survival. Firefly Books, Buffalo.

Fjeldså, Jon and Niels Krabbe

1990 Birds of the High Andes: A Manual to the Birds of the Temperate Zone of the Andes and Patagonia, South America. University of Copenhagen and Apollo Books, Svendborg, Denmark.

Franquemont, Edward M.

1967 The Ancient Pottery from Pucara, Peru. Revised version of Senior Honors Thesis, Department of Anthropology, Harvard University. Cambridge.

1990. The Ancient Pottery from Pucara, Peru. Ñawpa Pacha 24(1986): 1-30.

König, Claus, Friedhelm Weick and Jan-Hendrik Becking

1999 Owls: A Guide to the Owls of the World. Yale University Press, New Haven.

Weick, Friedhelm

1980 Birds of Prey of the World: A coloured guide to identification of all the diurnal species order Falconiformes. Verlag Paul Parey, Hamburg und Berlin.