The red wolf (Canis rufus, formerly Canis lupus rufus) is a North American canid that once roamed throughout the Southeastern United States. Based on fossil and archaeological evidence, the original red wolf range extended throughout the southeast, from the Atlantic and Gulf Coasts, north to the Ohio River Valley and central Pennsylvania, and west to central Texas and southeastern Missouri. Historical habitats included forests, swamps, and coastal prairies, where it was an apex predator. The red wolf is morphologically midway between grey wolves and coyotes, and a 2011 genetic study indicated that it may be a hybrid species between grey wolves and coyotes. Re-analysis of this study coupled with a broader contextual analysis including behavioral, morphological and additional genetic information led to arguments that the red wolf is an independent species but has suffered from significant introgression of coyote genes likely due to decimation of red wolf packs with fragmentation of their social structure from hunting. The most recent comprehensive review (in October 2012) of the genetics studies concluded that the red wolf, eastern wolf, and gray wolf were three distinct species.
The red wolf was thought to be extinct in the wild by 1980. 1987 saw a reintroduction in northeastern North Carolina through a captive breeding program and the animals are considered to be successfully breeding in the wild.
- 1 Physiology
- 2 Ecology
- 3 Life history and behavior
- 4 Conservation
- 5 Cultural reference
- 6 References
- 7 Further reading
- 8 External links
Physiology[edit source | edit]
Species description[edit source | edit]
The red wolf stands about 66–79 cm (26–31 in) at the shoulder. The total length is 111–165 cm (44–65 in) including the tail of 30–43 cm (12–17 in). The body weight can range from 16 to 41 kg (35 to 90 lb) but averages at about 24.5 kg (54 lb). Male red wolves are approximately 10% larger than females. A red wolf's coat is long and coarse; mostly brown and buff colored on the upper part of the body with some black hinted along the backs. Muzzles are long; nose pad wide and black; ears rufous; legs long; tail long, bushy, black tipped. Body is intermediate in size between the gray wolf (Canis lupus) and the coyote (Canis latrans)
General description[edit source | edit]
The red wolf pup begins life with a slate or dark gray pelt with auburn-tinged fur visible on its head (thus its name). As it matures, this color changes color to a mixture of buff, tawny, cinnamon, and brown along the body and a black tipped tail; it often has black guard hairs too and sometimes presents with black or dark bars on its fore-legs. Black or melanistic individuals once occurred; such individuals were more common in Florida and in western areas. The pelt molts once annually in the winter. Its muzzle is white furred around the lips. The red wolf is generally intermediate in size between the coyote and the gray wolf. However, the disproportionately long legs & large ears are two obvious features that separate red wolves from coyotes and gray wolves. Its overall appearance is more slender and graceful looking than that of a grey wolf.
Taxonomy[edit source | edit]
The taxonomy of the red wolf has been debated since before efforts began in 1973 to save it from extinction. In 1971, Atkins and Dillon conducted a study on the brains of canids and confirmed the distinctiveness and primitive characteristics of the red wolf. Many studies throughout the 1970s focused on the morphology of the red wolf came to the conclusion that the red wolf is a distinct species. In 1980, Ferrell et al. found a unique allele in Canis specimens from within the red wolf range, supporting the conclusion that the red wolf is a distinct species. Still, some in the scientific community considered it a subspecies of the grey wolf or a hybrid of the grey wolf and the coyote.
In 1992, the USFWS conducted an exhaustive review of the literature, including their own, and concluded that the red wolf is either a separate species unto itself or a subspecies of the gray wolf. Many agency reports, books and web pages list the red wolf as Canis rufus but genetic research re-opened the debate about the taxonomy of both the red wolf and Canada's eastern wolf (Canis lycaon). Wilson et al. (2000) concluded that the eastern wolf and red wolf should be considered as sister taxa due to a shared common ancestor going back 150,000–300,000 years. In addition, Wilson et al. further stated that they should be recognized as distinct species from other North American canids, and not as subspecies of the gray wolf (Canis lupus). However, these conclusions were disputed, and Mammal Species of the World listed them both in 2005 as subspecies of the gray wolf.
In May 2011, an analysis of red wolf, Eastern wolf, gray wolf, and dog genomes suggested that the red wolf was 76–80 percent coyote and only 20–24 percent gray wolf, suggesting that the red wolf is actually much more coyote in origin than the Eastern wolf. This study analyzed 48,000 SNP and found no evidence for a unique Eastern wolf or red wolf species. However, X-Ray analysis of the 16 red wolf specimens used in the SNP study were later shown to be wolf-coyote hybrids via cranial morphometric analysis, rendering the finding that the red wolf was a gray wolf-coyote hybrid inaccurate. The U.S. Fish and Wildlife Service (USFWS) still considers the red wolf a valid species (Canis rufus) and plans to make no changes to its recovery program. In 2012, re-analysis of the 2011 SNP study argued that the original SNP study suffered from insufficient sampling and noted that gray wolves do not normally mate with coyotes. However, the statement that grey wolves and coyotes have never hybridized is also false. A study conducted in the Uppsala University detected the presence of coyote haplotypes in some populations of the Mexican grey wolves who are considered a critically endangered subspecies of the grey wolves once nearly hunted to extinction due to being deemed as pest. In addition, Y-chromosomes from the Mexican grey wolves have also been found in some of the male coyotes in Texas. This study suggested that at some point during the aftermath of grey wolf extermination in Mexico and the southern US, female coyotes managed to interbreed with some of the male wolves of the remnant Mexican grey wolf populations with the female hybrid offsprings back-crossing with other male wolves while the hybrid males may have backcrossed with the pure coyotes. . The discovery of grey wolf haplotypes in the Texas coyotes also opens room for speculation that the red wolf population extracted from Texas may have actually been hybrids between coyotes and the extinct Texas grey wolves who were said to be closely related to the Mexican grey wolves and the fact that both subspecies are said to be very genetically distinct from the other North American grey wolf population in the northwest. 
Another Y-chromosome genetic study in 2012 also argued that the eastern wolf and red wolf are not hybrids but rather are a distinct species from the gray wolf, although eastern and red wolves do intermix with coyotes. The same authors have argued that the 2011 SNP study finding that red wolves are not an independent species is flawed and that historical hunting and culling of wolves, leading to invasion of coyotes into eastern North America, has led to introgression of coyote mitochondrial and nuclear DNA into fragmented, decimated eastern wolf packs. They and other authors have postulated that large populations of eastern and red wolves with intact social/pack structures are less likely to interbreed with coyotes. The controversy over the red wolf's species status was the subject of a comprehensive review of the 2011 and 2012 genetics studies, which concluded that there are three separate species of wolf in North America, the red wolf, eastern wolf and gray wolf.
In a pair of 2012 reports, scientists critical of the May 2011 paper outlined three main points of criticism. First, the 2011 paper relied on mtDNA SNPs derived from boxer and poodle genomes (both highly inbred dog breeds) and used these to extrapolate inference about genetic variation within wild canids across the globe. While it is true that many SNPs were examined, it remains unclear whether loci important to red wolf genetic variation were actually identified and analyzed (for example, nuclear DNA was not compared in the SNP analysis). Second, the study sampled modern red wolf specimens, and not historic red wolf specimens from prior to 1900 (when extensive hybridization with coyotes is known to have taken place), which obfuscates the reliability of the study's findings. This is important because using historic red wolf genetic material would have created a baseline genetic profile for the species against which to test the modern captive-bred specimens. (It is common knowledge that the captive-bred red wolves are likely slightly hybridized, but this is a separate issue from interpreting their species origin as due to hybridization.) Third, the authors lumped Eastern wolf specimens (which critics from Trent University warn are of unverified origin) with other Great Lakes wolf specimens, and did not test them separately, which again obfuscated any genetic differences that may have been present. The controversy over the eastern wolf's origins is not considered by the scientific community to be laid to rest, although it may be synonymous with the red wolf.
When considered as a full species, three subspecies of red wolf were originally recognized by Goldman; two of these subspecies are extinct. The Florida black wolf (Canis rufus floridanus) (Maine to Florida) has been extinct since 1930 and Gregory's wolf (Canis rufus gregoryi) (south-central United States) was declared functionally extinct in the wild by 1980. The Texas red wolf (Canis rufus rufus), the third surviving subspecies, was also functionally extinct in the wild by 1980, although that status was changed to "critically endangered" when captive-bred red wolves from Texas were reintroduced in eastern North Carolina in 1987. The current status of the "non-essential/experimental" population in North Carolina is "endangered" and the population numbers around 100 wild animals. The subspecies designations are essentially moot since two are extinct but the genetic evidence for the three subspecies appears to have been unconvincing anyway.
Fossil and historic record[edit source | edit]
Paleontological evidence has suggested an origin of the red wolf line 1–2 Ma, branching from a wolf-coyote ancestor, which itself appeared about 4.9 Ma. Between 150,000–300,000 years ago, the North American branch evolved into the red wolf, eastern wolf and the coyote. Another wolf-like branch migrated to Eurasia and evolved into the gray wolf, which later migrated to North America. It is thought that its original distribution included much of eastern North America, where red wolves were found from Maine south to Florida and in south central US westward to Texas. Records of bounty payments to Wappinger Indians in New York in the middle 18th century confirm its range at least that far north; it's possible that it could have extended as far as extreme eastern Canada.
Geographic distribution[edit source | edit]
The originally-recognized red wolf range extended throughout the Southeast, from the Atlantic and Gulf Coasts, north to the Ohio River Valley and central Pennsylvania, and west to Central Texas and southeastern Missouri. But research into paleontological, archaeological and historical specimens of red wolves by Ronald Nowak expanded their known range to include land south of the Saint Lawrence River in Canada, along the eastern seaboard, and west to Missouri and mid-Illinois, terminating in the southern latitudes of Central Texas. Since 1987, red wolves (Canis rufus) have been released into northeastern North Carolina where they roam 1.7 million acres. These lands span five counties (Dare, Hyde, Tyrrell, Washington and Beaufort) and include three national wildlife refuges, a U.S. Air Force bombing range, and private land. The red wolf recovery program is unique for a large carnivore reintroduction in that more than half of the land used for reintroduction lies on private property. Approximately 680,000 acres (2,800 km2) are federal and state lands, and 1,002,000 acres (4,050 km2) are private lands. Beginning in 1991, red wolves were also released into the Great Smoky Mountains National Park in eastern Tennessee. However, due to exposure to environmental disease (parvovirus), parasites and competition, (with coyotes as well as intraspecific aggression), the red wolf was unable to successfully establish a wild population in the park. Low prey density was also a problem, forcing the wolves to leave the park boundaries in pursuit of food in lower elevations. Other red wolves have been released on the coastal islands in Florida, Mississippi, and South Carolina as part of the captive breeding management plan. St. Vincent's Island in Florida is currently the only active island propagation site.
Ecology[edit source | edit]
Given their wide historical distribution, red wolves probably utilized a large suite of habitat types at one time. The last naturally occurring population utilized coastal prairie marshes, swamps and agricultural fields used to grow rice and cotton. However, this environment probably does not typify preferred red wolf habitat. There is evidence that the species was found in highest numbers in the once extensive bottom land river forests and swamps of the southeastern United States. Red wolves re-introduced into northeastern North Carolina have utilized habitat types ranging from agricultural lands to forest/wetland mosaics characterized by an over story of pine and an understory of evergreen shrubs. This suggests that red wolves are habitat generalists and can thrive in most settings where prey populations are adequate and persecution by humans is slight.
Life history and behavior[edit source | edit]
Reproduction[edit source | edit]
The red wolf has one estrous cycle per year and typically becomes sexually mature by its second year. Litters average five pups and red wolves live in family units similar to those of gray wolves. Data acquired from the restoration project indicate that the offspring of a breeding pair are tolerated in their natal home range until the onset of sexual maturity.
Behavior[edit source | edit]
The red wolf lives in an extended family unit which includes a dominant breeding pair and young from prior seasons. The red wolf will scent mark territorial boundaries to deter intrusion from other wolf packs. As an apex predator, red wolves have no natural predators, although they may compete for prey with bobcats and coyotes and kills may be stolen by American black bears.
Dietary habits[edit source | edit]
Prior to extinction in the wild, the red wolf diet consisted of nutria, rabbits and rodents. In contrast, the red wolves from the restored population rely on white-tailed deer, raccoon, nutria and rabbits. It should be noted, however, that white-tailed deer were largely absent from the last wild refuge of red wolves on the Gulf Coast between Texas and Louisiana (where specimens were trapped from the last wild population for captive breeding), which likely accounts for the discrepancy in their dietary habits listed here. Historical accounts of wolves in the southeast by early explorers such as William Hilton, who sailed along the Cape Fear River in what is now North Carolina in 1644, also note that they ate deer.
Conservation[edit source | edit]
Captive breeding and reintroduction[edit source | edit]
Formal efforts backed by the U.S. Fish and Wildlife Service began to save the red wolf from extinction in 1973 when a captive breeding program was established at the Point Defiance Zoological Gardens, Tacoma, Washington. Four hundred animals were captured from southwestern Louisiana and southeastern Texas from 1973 to 1980 by the US Fish and Wildlife Service. Measurements, vocalization analyses, and skull X-rays were used to distinguish red wolves from coyotes and red wolf-coyote hybrids. Of the 400 animals captured, only 43 were believed to be red wolves and sent to the breeding facility. The first litters were produced in captivity in May 1977. Some of the pups were determined to be hybrids, and they and their parents were removed from the captive breeding program. Of the original 43 animals, only 17 were considered pure red wolves and since three were unable to breed, 14 became the breeding stock for the captive breeding program. These 14 were so closely related that they had the genetic effect of being only eight individuals.
In Dec. 1976, two wolves were released onto Cape Romain National Wildlife Refuge's Bulls Island in South Carolina with the intent of testing and honing reintroduction methods. They were not released with the intent of beginning a permanent population on the island. The first experimental trans location lasted for 11 days, during which a mated pair of red wolves were monitored day and night with remote telemetry. A second experimental trans location was tried in 1978 with a different mated pair, and they were allowed to remain on the island for close to nine months. After that, a larger project was executed in 1987 to reintroduce a permanent population of red wolves back to the wild in the Alligator River National Wildlife Refuge (ARNWR) on the eastern coast of North Carolina. Also in 1987, Bulls Island became the first island breeding site. Pups were raised on the island and relocated to North Carolina until 2005.
In September 1987, four male-female pairs of red wolves were released in Alligator River National Wildlife Refuge in northeastern North Carolina and designated as an experimental population. Since then, the experimental population has grown and the recovery area expanded to include four national wildlife refuges, a Department of Defense bombing range, state-owned lands, and private lands, encompassing about 1,700,000 acres (6,900 km2).
In 1989, the second island propagation project was initiated with release of a population on Horn Island off the Mississippi coast. This population was removed in 1998 because of a likelihood of encounters with humans. The third island propagation project introduced a population on St. Vincent Island, Florida offshore between Cape San Blas and Apalachicola, Florida in 1990, and in 1997 the fourth island propagation program introduced a population to Cape St. George Island, Florida south of Apalachicola, Florida.
In 1991, two pairs were reintroduced into the Great Smoky Mountains National Park, where the last known red wolf was killed in 1905. Despite some early success, the wolves were relocated to North Carolina in 1998, ending the effort to reintroduce the species to the Park.
In 2007, the US Fish and Wildlife Service estimated that there were 300 red wolves remaining in the world, with 207 of those in captivity.
According to the latest Red Wolf Recovery Program First Quarter Report (October–December 2010), the US Fish and Wildlife Service estimates that there are currently 110-130 red wolves in the Red Wolf Recovery Area in North Carolina, however, since not all of the newly bred in the wild red wolves have radio collars, they can only confirm a total of 70 "known" individuals, 26 packs, 11 breeding pairs, and 9 additional individuals not associated with a pack.
Interbreeding with the coyote (a species not native to North Carolina) has been recognized as a threat affecting the restoration of red wolves. Currently, adaptive management efforts are making progress in reducing the threat of coyotes to the red wolf population in northeastern North Carolina. Other threats, such as habitat fragmentation, disease, and anthropogenic mortality, are of concern in the restoration of red wolves. Efforts to reduce the threats are presently being explored.
Cultural reference[edit source | edit]
On July 1, 1976, the red wolf became the official mascot of the United States Navy's premier Naval Special Warfare Support Helicopter Squadron, HAL-4. Today, they are known as HSC-84 and fly the HH-60H Rescue Hawk.
On January 1, 2008, Arkansas State University’s Mascot Selection Steering Committee decided to use the Wolves as a mascot. The Red Wolves were officially approved by the university board of trustees on March 7, 2008. The ceremony and unveiling of the new Red Wolves logo was held on March 13, 2008.
On April 30, 2008, Indiana University East revealed the Red Wolves to be the new mascot for the campus.
The chorus of the song "Coyotes" (written by Bob McDill, re-popularized by Don Edwards's performance in the documentary Grizzly Man) states that "the red wolf is gone." The line is an allusion to the cowboy's vanishing way of life.
Red Wolf is a Native-American superhero in Marvel comic books. He made his first appearance in 1971 in the issue Marvel Spotlight #1. Red Wolf has super human strength, senses, and fighting abilities, and has a pet wolf named Lobo.
References[edit source | edit]
- Chambers SM, Fain SR, Fazio B, Amaral M (2012). "An account of the taxonomy of North American wolves from morphological and genetic analyses". North American Fauna 77: 1–67. Retrieved 2013-07-02.
- Kelly BT, Beyer A & Phillips MK (2008). Canis rufus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 2008-10-23. Database entry includes justification for why this species is critically endangered.
- Audubon, J. and J.Bachman.1851.The quadrupeds of North America, Volume 2.New York, NY.p.334.
- Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Reich, D.E., R.K. Wayne, and D.B. Goldstein. (1999) Genetic evidence for a recent origin by hybridization of red wolves. Molecular Ecology 8:139-144.
- VonHolt, BM; et al (12 May 2011). "A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids". Genome Res 21 (8): 1294–305. doi:10.1101/gr.116301.110. PMC 3149496. PMID 21566151.
- Linda Y. Rutledge, Paul J. Wilson, Cornelya F.C. Klütsch, Brent R. Patterson, Bradley N. White (2012). "Conservation genomics in perspective: A holistic approach to understanding Canis evolution in North America". Biological Conservation 155: 186–192. Retrieved 2013-07-01.
- U.S. Fish and Wildlife Service.1997.Endangered Red Wolves. http://library.fws.gov/Pubs4/endangered_red_wolves.pdf:1-3.
- Red Wolf Species Profile (2011).
- Alden,P. and Nelson, G.2010.National Adubon Society Field Guide to the Southeastern States.p.365
- Alderon, David. Foxes, Wolves, and Wild Dogs of the World. London: Blandford. 1998.p117
- Nowak, R. 2003.Wolf Evolution and Taxonomy. ‘’In’’ Wolves, Behavior, Ecology and Conservation. Edited by Mech, D and Boitain, L.,University of Chicago Press, University of Chicago Press.
- Atkins, D. and L.Dillon. 1971. Evolution of the cerebellum in the genus Canis. J. Mammal. 52:96-97.
- Ferrell et al. 1980. Biochemical markers in species endangered by introgression: The red wolf. Biochem. Genet. 18:39-49.
- Lawrence,B. and W. Bossert. 1975. Relationships of North American Canis shown by a multiple character analysis of selected populations. P. 73-86 in M.W. Fox, ed., The wild canids: Their systematic, behavioral ecology, and evolution. Van Nostrand Reinhold, New York.
- Mech, L.1970. The wolf: The ecology and behavior of an endangered species. Natural History Press, Garden City, NY.
- Wayne, R. and S.Jenks. 1991. Mitochondrial DNA analysis supports extensive hybridization of the endangered red wolf (Canis rufus). Nature 351:565-68.
- Phillips, M. & Henry, V. (1992). Comments on red wolf taxonomy. Conservation Biology, 6:596–599.
- Nowak, R. (1992). The red wolf is not a hybrid. Conservation Biology, 6:593–595.
- Nowak et al. (1995). Another look at wolf taxonomy. pp 375–397 In L.N. Carbyn, S.H. Fritts, and D.R. Seip, eds. Ecology and conservation of wolves in a changing world. Canadian Circumpolar Institute, Edmonton, Alberta.
- Koblmuller, S., Nord, M., Wayne, R. K. and J. Leonard. (2009). Origin and Status of the Great Lakes wolf. Molecular Ecology, 18:2313–2326.
- Nowak, R. M. (2002). The original status of Wolves in Eastern North America. Southeastern Naturalist, 1:95–130
- T. DeLene Beeland (2013). The Secret World of Red Wolves. Chapel Hill, NC: University of North Carolina Press. ISBN 9781469601991.
- "US Fish and Wildlife Species Profile". USFWS. Retrieved 2013-07-08.
- Esch, Mary. "Study: Eastern wolves are hybrids with coyotes". AP News. Retrieved 1 June 2011.
- Paul J. Wilson, Linda Y. Rutledge, Tyler J. Wheeldon, Brent R. Patterson & Bradley N. White (2012). "Y-chromosome evidence supports widespread signatures of three-species Canis hybridization in eastern North America". Ecology and Evolution 2 (9): 2325–2332. Retrieved 2013-07-01.
- Astrid V. Stronen, Nathalie Tessier, Hélène Jolicoeur, Paul C. Paquet, Michel Hénault, Mario Villemure, Brent R. Patterson, Tim Sallows, Gloria Goulet and François-Joseph Lapointe (2012). "Canid hybridization: contemporary evolution in human-modified landscapes". Ecology and Evolution 2 (9): 2128–2140. Retrieved 2013-07-01.
- E.A. Goldman. (1937). The wolves of North America. Journal of Mammology, 18:37–45.
- "Red Wolf Recovery Program". U.S. Fish and Wildlife Program. Retrieved 2013-07-02.
- W. W. Dalquest and G. E. Schultz 1992. Ice Age mammals of northwestern Texas
- B. Kurten and E. Anderson. 1980. Pleistocene mammals of North America 1-442
- Wilson, P.J., S. Grewal, I.D. Lawford, J.N.M. Heal, A.G. Granacki, D. Pennock, J.B. Theberge, M.T. Theberge, D.R. Voigt, W. Waddell, R.E.Chambers, P.C. Paquet, G. Goulet, D. Cluff, and B.N. White. 2000. DNA profiles of the eastern Canadian wolf and the red wolf provide evidence for a common evolutionary history independent of the gray wolf. Canadian Journal of Zoology 78:2156 - 2166.
- J. Michael Smith: The Highland King Nimhammaw and the Native Indian Proprietors of Land in Dutchess County, NY: 1712-1765. Hudson River Valley Review
- Wolves of Algonquin Provincial Park
- U.S. Fish and Wildlife Service.1997. Endangered Red Wolves. http://library.fws.gov/Pubs4/endangered_red_wolves.pdf:p7.
- Nowak, R. M. (2002). The original status of wolves in eastern North America. Southeastern Naturalist, 1(2), 95-130.
- "Current Red Wolf Facts," found on the Red Wolf Recovery web page, http://www.fws.gov/redwolf/index.html, accessed on July 5, 2011.
- Phillips et al.2003. Restoration of the Red Wolf ‘’In’’Wolves, Behavior, Ecology and Conservation. Edited by Mech, D and Boitain, L.,University of Chicago Press, University of Chicago Press.
- Powell, W. S. (1973). Creatures of North Carolina from Roanoke Island to Purgatory Mountain. North Carolina Historical Review, 50 (2 ), 121-168.
- Carley,C.1975.Activities and findings of the red wolf recovery program from late 1973 to July 1, 1975. U.S. Fish and Wildlife Service, Albuquerque,NM.
- McCarley,H. and J. Carley. 1979. Recent changes in distribution and status of red wolves (Canis rufus) Endangered Species Report no.4. U.S. Fish and Wildlife Service, Albuquerque, NM.
- Carley, Curtis J. 1979. "Report on the Successful Trans location Experiment of Red Wolves (Canis rufus) to Bulls Island, S.C." Presentation at the Portland Wolf Symposium, Lewis and Clark College, Portland, Oregon, August 13–17, 1979.
- U.S. Fish and Wildlife Service Cape Romain NWR, red wolf web page
- USFWS.2010. Red Wolf Recovery Program, 1st Quarter Report, October–December 2010, Manteco, NC.
- U.S. Fish and Wildlife Service. 2007. Red Wolf (Canis rufus) 5-Year Status Review: Summary and Evaluation.
Further reading[edit source | edit]
- Beeland, T. D. (2013). The Secret World of Red Wolves: The Fight to Save America's Other Wolf. 256 pages. Chapel Hill: University of North Carolina Press.
- Chambers, S. M., Fain, S. .R, Fazio, B., & Amaral, M. (2012). An account of the taxonomy of North American wolves from morphological and genetic analyses. North American Fauna, 77, 1–67.
- Nowak, R. M. (2003). Chapter 9: Wolf evolution and taxonomy. In D. Mech & L. Boitani (Eds.), Wolves: Behavior, Ecology, and Conservation (pp. 239–258). Chicago: University of Chicago Press.
- Philips, M. K., Kelly, B., & Henry, G. (2003). Restoration of the red wolf In D. Mech & L. Boitani (Eds.), "Wolves: Behavior, Ecology, and Conservation (pp. 272–288). Chicago: University of Chicago Press.
- Nowak, R. M. (2002). The original status of wolves in eastern North America. Southeastern Naturalist, 1(2), 95-130.
- Wilson, P. J., Grewal, S., Lawford, I. D., Heal, J. N. M., Granacki, A. G., Pennock, D., et al. (2000). DNA profiles of the eastern Canadian wolf and the red wolf provide evidence for a common evolutionary history independent of the gray wolf Canadian Journal of Zoology, 78, 2156–2166.
- ^ Roy, M.S., Geffen, E., Smith, D., Ostrander, E.A. & Wayne, R.K. (1994). "Patterns of differentiation and hybridization in North American wolflike canids, revealed by analysis of micro satellite loci.". Molecular Biology and Evolution 11 : 553–570.
- ^ Roy, M.S., Girman, D.G., Taylor, A.C. & Wayne, R.K. (1994). "The use of museum specimens to reconstruct the genetic variability and relationships of extinct populations.". Experientia 50 : 551-557.
- ^ Wayne, R.K. & Jenks, S.M. (1991). "Mitochondrial DNA analysis implying extensive hybridization of the endangered red wolf Canis rufus". Nature 351 : 565-568.
- ^ Wayne, R.K., Lehman, N., Allard, M.W. & Honeycutt, R.L. (1992). "Mitochondrial DNA variability of the grey wolf - genetic consequences of population decline and habitat fragmentation". Conservation Biology 6 : 559-569.
- ^ R. Nowak, R.M. (1992). "The red wolf is not a hybrid.". Conservation Biology 6 : 593-595.
- ^ Silverstein, A., Silverstein, V. B. & Silverstein, R. A. (1994). "The Red wolf: endangered in America.". Brookfield: Conn. Millbrook Press.
- Nowak, R. M. (1979). North American Quaternary Canis. Unpublished Monograph, University of Kansas Hays.
|Wikispecies has information related to: Canis rufus|
|Wikimedia Commons has media related to: Canis rufus|
Suggested reading for related issue of Eastern wolf:
- Rutledge, L. Y., Bos, K. I., Pearce, R. J., & White, B. N. (2010). Genetic and morphometric analysis of sixteenth century Canis skull fragments: implications for historic eastern and gray wolf distribution in North America. Conservation Genetics, 11(4), 1273-1281.
- Wilson, P. J., Grewal, S. K., Mallory, F. F., & White, B. N. (2009). Genetic Characterization of Hybrid Wolves across Ontario. Journal of Heredity, 100(1), 80-89.
- Wilson, P. J., Grewal, S., McFadden, T., Chambers, R. C., & White, B. N. (2003). Mitochondrial DNA extracted from eastern North American wolves killed in the 1800s is not of gray wolf origin. Canadian Journal of Zoology, 81, 936-940.