Order: Passeriformes Family: Corvidae Genus: Corvus Species: Corvus brachyrhynchos
Introduction
At 17.5’ (L) x 39” (ws) and at 1 lb, (Sibley 2003), the American crow is a coomon medium to large sized corvid found throughout North America (Verbeek and Caffrey 2002). Known for its distinctive vocalizations and entirely black plumage, the crow is seemingly ever present near human civilization, and it is one of the most recognizable birds on the continent (Sibley 2003).
Widespread and common throughout the United States and up into Canada, the American crow can likely be sighted in open areas of varying geographical features (Sibley 2003).
Within the Evergreen State College campus, the most common viewing places to observe these animals include the Red Square and the soccer fields, though they have been known to frequent the campus’s organic farm and private beach as well (Anderson, Stromsdorfer pers. obs.).
The American crow is omnivorous, and has been known to have a diverse diet. Recent analysis of crow pellets revealed diets consisting of grit, various seeds, vegetation, and small mammals in American Crowsof Lancaster, Pennsylvania (Annala et. al 2012). The American crow is also thought to prey upon other birds’ offspring, such as piping plover (Charadrius melodus) fledglings (Ivan and Murphy 2005).
American Crow Vocalizations (Winter 2014)
Crows are considered to be very complex behaviorally (Powell and Kelly 1977, Caffrey 2000, Caffrey 2001, Marzluff et. al 2010, Clucas et. al 2013, Mukherjee et. al 2013, Langley 2014). Crows are very perceptive to humans and have been observed using the human gaze as a visual cue when deciding how to react in the event of being approached by a person (Clucas et. al 2013). The American Crow has also been observed using tools (Powell and Kelly 1977, Caffrey 2000) and objects for goal-directed use (Caffrey 2001). Additionally, American crows have been found to be able to detect directionality of an oncoming vehicle and effectively evade the threat based on a basal comprehension of traffic movement (Mukherjee et. al 2013). It has also been hypothesized that nightly roosts serve as informational centers in which information is exchanged between birds about potential foraging sites (Langley 2014). Furthermore, crows have shown that they are able to not only recognize the face of a person who has threatened them, but be able to retain that recognition for at least 2.7 years (Marzluff et. al 2010).
Though the species is extremely susceptible to West Nile Virus (Wheeler et. al 2014), the species has responded positively to various types of vaccinations cultivated for particular strains of the virus (Bunning et. al 2007) and has been known to show a decreasing mortality rate following a transmission season (Reed et. al 2009). The American crow has also been recorded to be carriers of various types of parasites (Morgan and Waller 1941). Despite these setbacks, the American Crow is an abundant species in North America and is considered to be neither threatened nor endangered in any of its chosen ranges (Verbeek 2002).
Annala, M., Tillman, E., Backus, G., Keacher, K., & Avery, M. (2012). Crow Pellets from Winter Roosts in Lancaster, Pennsylvania. Northeastern Naturalist, 19(3), 527-532.
Bunning, M., Fox, P., Bowen, R., Komar, N., Chen, G., Speaker, T., … Turell, M. (2007). DNA Vaccination of the American Crow (Corvus brachyrhynchos) Provides Partial Protection Against Lethal Challenge with West Nile Virus. Avian Diseases, 51(2), 573-577.
Caffrey, C. (2000). Tool Modification and Use by an American Crow. The Wilson Bulletin, Vol. 112(2), 283-284. Retrieved December 6, 2014, from http://www.jstor.org/stable/pdfplus/4164211.pdf?acceptTC=true
Caffrey, C. (2001). Goal-Directed Use of Objects by American Crows. The Wilson Bulletin, 113(1), 114-115. Retrieved December 6, 2014, from http://www.jstor.org/stable/pdfplus/4164315.pdf
Clucas, B., Marzluff, J., Mackovjak, D., & Palmquist, I. (2013). Do American Crows Pay Attention to Human Gaze and Facial Expressions? Ethology, 296-302. Retrieved from http://www.sefs.washington.edu/research.acl/Crows_and_Other_Corvids/clucas_etal_crow_gaze.pdf
Gorenzel, W., Blackwell, B., Simmons, G., Salmon, T., & Dolbeer, R. (2002). Evaluation of lasers to disperse American crows, Corvus brachyrhynchos, from urban night roosts. International Journal of Pest Management, 327-331.
Ivan, J., & Murphy, R. (2005). What preys on piping plover eggs and chicks? Wildlife Society Bulletin, 33, 113-119. Retrieved December 2, 2014, from http://www.bioone.org/doi/pdf/10.2193/0091-7648(2005)33[113:WPOPPE]2.0.CO;2
Langley, W. (2014). Effect of Food Patch Discovery on the Number of American Crows (Corvus brachyrhynchos) Using a Flight Lane. THE CANADiAN FiELD-NATURALiST, 128(2), 195-199.
Marzluff, J., Walls, J., Cornell, H., Withey, J., & Craig, D. (2010). Lasting Recognition Of Threatening People By Wild American Crows. Animal Behaviour, 79(699-707), 699-707.
Morgan, B., & Waller, E. (1941). Some Parasites of the Eastern Crow (Corvus brachyrhynchos brachyrhynchos Brehm).Bird-Banding, 12(1), 16-22.
Mukherjee, S., Ray-Mukherjee, J., & Sarabia, R. (2013). Behavior of American Crows (Corvus brachyrhnchos) when Encountering an Oncoming Vehicle. The Canadian Field-Naturalist, 127(3), 229-233. Retrieved December 1, 2014, from http://www.canadianfieldnaturalist.ca/cfn/index.php/cfn/article/view/1488/1508
Powell, R., & Kelly, W. (1977). Tool use in captive crows. Bulletin of the Psychonomic Society, Vol. 10(6), 481-483. Retrieved December 2, 2014, from http://link.springer.com/article/10.3758/BF03337704
Reed, L., Johansson, M., Panella, N., Mclean, R., Creekmore, T., Puelle, R., & Komar, N. (2009). Declining Mortality in American Crow (Corvus brachyrhynchos) Following Natural West Nile Virus Infection.Avian Diseases, 53(458-461), 458-461.
Sibley, D. 2003. The Sibley field guide to birds of western North America. New York: Knopf.
Townsend AK, Barker CM (2014) Plastic and the Nest Entanglement of Urban and Agricultural Crows. PLoS ONE 9(1): e88006. doi:10.1371/
Verbeek, N. A. and C. Caffrey. 2002. American Crow (Corvus brachyrhynchos), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/647
Wheeler, S., Woods, L., Boyce, W., Eckstrand, C., Langevin, S., Reisen, W., & Townsend, A. (2014). West Nile Virus and Non-West Nile Virus Mortality and Coinfection of American Crows (Corvus brachyrhynchos) in California. Avian Diseases, 58(2), 255-261. Retrieved December 1, 2014, from http://www.bioone.org/doi/pdf/10.1637/10691-101413-Reg.1
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