Solitary : Possible in Texas? By William S. Clark northern extent of the Sierra Madre Oriental. It is a mounted specimen in the Museo de las Aves de México in Saltillo, Coahuila, Mexico. Additionally, there are at least three sight records of eagles in the last five years by Bonnie McKinney and colleagues (but no details) from the nearby Sierra de Carmen, which is even closer to the US border. Further, eagles have been reported nesting in the Sierra Madre Occidental of Chihuahua by parrot researchers (Pers. Comm. Adrian Ganen Sada), and egg and specimen records from southern Sonora (van Rossem 1948, Harrison and Kiff 1977). Both of these loca- tions are west and north of the Big Bend area of Texas. Finally, south of Texas, near El Cielo in southern Tamaulipas in the Sierra Madre Oriental, a perched immature Solitary was recently photographed.

Figure 1. Adult perched. (Peru. Feb. 2007. W. S. Clark)

The Solitary Eagle ( solitar- ius) is a large raptor that is closely related and similar in adult and immature plumages to the black-hawks ( ) (Lerner and Mindell 2005, Howell and Webb 1995). It is an extremely rare and local Figure 2. Adult resident in a variety of wet and dry forested Solitary Eagle in hills and highlands from northern Mexico to flight. (Ecuador, Jan. 2007. Brian northern Argentina (del Hoyo et al. 1994, Sullivan) Ferguson-Lees and Christie 2001). Aldegunda Garza de Leon collected an adult specimen in December, 1979 in the Serranías del Burro in the northern part of Coahuila, less than 150 km from the Rio Grande border with Texas. This area is the

16 TEXAS ANNUAL 2007 Figure 4. Adult in flight. (Panama, Oct. 2002. W. S. Clark)

Could a Solitary Eagle or two have flown across the Rio Grande River into the United States in recent years? Big Bend National Park is less than 200 km from both of these Coahuilan locations, and mountains extend northwestward to the Davis Mountains and the Chinatí Mountains in Texas. This raptor has a huge range, but occurs at an extremely low density. Thus of necessity they must wander far afield to find a mate and a breeding niche. It is not too far fetched to imagine that one or more of these eagles, either immatures or non-breeding adults, Figure 3. Immature Solitary Eagle could easily have flown the short distances perched. Mexico, Feb. 2006. from these two Coahuila locations north and Photo by Rick Cech

Figure 5. Mounted adult Solitary Eagle. Collected in northern Coauila, Mexico. See text for details. Photo by W. S. Clark VOLUME 3 17 Figure 6. Map of northern Mexico. Solitary Eagle locations. 1. Sierrana del Burro, where Figure 5 was collected. 2. Sierra del Carmen sightings. 3. Chihuahua sightings. 4. Sonora specimens, nest, and eggs. 5. Tamaulipas location for Figure 3. west into the United States. Is it also not too 2001. Raptors of the World. Christopher preposterous that individuals from areas of Helm, London. Mexico south or west of Big Bend could have del Hoyo, J., A. Elliott, and J. Sargatal passed over Texas? (eds) 1994. Handbook of the Birds of the Because of the paucity of birders in this World. Vol 2. Lynx edicions, Barcelona. area of Texas, the extreme rarity of the eagle, Harrison, E. N., and L. F. Kiff. 1977. The and the previous lack of information of how nest and egg of the Black Solitary Eagle. to distinguish it from the Common Black- Condor 79:132–133. hawk, an uncommon resident in the Davis Howell, S. N. G., and S. Webb. 1995. A Mountains, no Solitary Eagles have been Guide to the Birds of Mexico and Northern reported from Texas. However, nowadays, the Central America. Oxford Univ. Press, Oxford. recent article on field ID of this eagle (Clark Lerner, H. R. L., and D. P. Mindell. 2005. et al. 2005), will enable birders to identify Phylogeny of eagles, Old World vultures, and any such eagle seen in Texas (and elsewhere) other based on nuclear and with certainty. mitochondrial DNA. Molecular Phylogenetics and Evolution 37:327–346. Literature Cited van Rossem, A. J. 1948. A race of Clark, W. S., H. L. Jones, C. Benesh, and Urubitornis soloitaria from northwestern N. J. Schmitt. 2006. Field identification of Mexico. Proc. Biol. Soc. Wash. 61:67–68. the Solitary Eagle. Birding 38(6):66–74. William S. Clark, Ferguson-Lees, J., and D. A. Christie. E-mail: [email protected]

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