The increasing rate of disappearance of carnivores imposes threats to issues such as global biodiversity, top-down synchronization and resilience of the ecosystem (Cahil et al., 2016). According to Rutledge, Devillard, Boone, Hohenlohe and White (2015), such discrepancies have increased the underlying levels of complexity in the processes of illuminating both the origin and the evolutionary mechanisms of the North American Canis. Wilson, Rutledge, Wheeldon, Patterson, and White (2012) explain that while previous controversies were attributed to Canis rufus (red wolf), the polemics have been extended to include Canis lycaon (the eastern wolf). According to Leonard, Echegaray, Randi and Vilà (2014), the two wolf species are genetically unique based on their inherent abilities to crossbreed with coyotes. Therefore, the current study seeks to establish a review of literature on the conservation of North American canids, the conflicting pieces of evidence revealing the existing number of wolf species, evidence supporting and contradicting the history of hybridization among these species and evidence supporting the hybridization of wolves with domestic dogs. Most importantly, the study presents recommendations on the canid species that need to be preserved and the extents to which the experiences in North America will guide the decision making processes in Australia towards protecting the critically endangered taxa.
Conservation of Wild Canids in North America
The conservation initiatives targeting canids in the North American region aim at preserving essential dynamic mechanisms such as evolution. According to Lescureux (2018), the evolutionary processes attributed to wolves in North America have played key roles in altering the static attributes of these creatures. Further, Otis, Thornton, Rutledge and Murray (2017) demystify that while the preservation measures adopted in this region have been met with multiple contradictions such as the supposed role of the local populace in managing their natural settings, the biological significance of invasive species and the value of initiating the conservation processes, Marshall, Langille, Hann and Whitney, (2016) reveal that such efforts have played a crucial role in balancing inconsistent human attributes such as social justice and liberty which may pose threats to the maintenance efforts.
The conservation measures adopted for canids in the North American region are aimed at protecting the wolves from the dangers of extinction and predation. According to Gese and Terletzky (2015) red foxes (Canis vulpes) located in the Eastern states of North America such as Virginia are trapped and shot based on their significant roles as sources of fur. On the other hand, Black, Petty, Radeloff and Pauli (2018) reveal that natural calamities such as spread of rabies epizootics and deterioration of forested land act as key threats to the existence of this species. However, Moehlman and Hayssen (2018) explain that governments have included harvest laws and closed seasons for preservative functions. On the other hand, the swift fox are protected through classification as endangered species. Further, Wilson et al. (2012) reveal that the State of California adopted a law that lists the island grey fox as a threatened species; an aspect that led to the isolation of this animal in the San Clemente and San Nicholas Islands to provide protection through the U.S. Park Service.
Conflicting evidence concerning the number of wolf species
The process of understanding the evolutionary mechanisms and taxonomic attributes of North American canids is faced with multiple controversies. While initial researches were centered on the red wolf (Canis rufus), Cahil et al. (2016) reveal that the inconsistencies have been stretched to include the eastern wolf (Canis lycaon). According to Rutledge et al. (2015), both the red wolf and the eastern wolf show similar characteristics through their inherent abilities to crossbreed with coyotes. On the other hand, Leonard et al. (2014) demystify that historical genetic researches establish the western coyote (Canis latrans) and the gray wolf (Canis lupus) as the hybrid parents of the red and eastern wolves. However, Lescureux (2018) reveals that recent laboratory analyses employed mitochondrial DNA (mtDNA) to support the evolutionary processes of Canis lycaon.
The existing contradictions concerning the number of wolf species in the North American region are heightened by the multiple hybridization scenarios put forth by different scholars. For instance, Otis et al. (2017) reveal that the hybridization mechanisms of North American Canis are partially attributed to the conventional spread of eastern wolves and red wolves that primarily inhabit the eastern side of the Mississippi River. On the other hand, Marshall et al. (2016) link this distribution to the underlying breeding limitations between the gray wolves and coyotes as depicted in the temperate regions. Other contradictions are steered by the existing levels of complexity in the process of analyzing the evolutionary account of North American Canis based on their mtDNA results. According to Gese and Terletzky (2015), there are tendencies that crossbreeding between coyotes and eastern wolves would have resulted into the interrogation of mtDNA sequences that are closely related.
Genome-wide evidence is established by Black et al. (2018) to foster the study of eastern and red wolves. According to Moehlman and Wayssen (2018), previous studies analyzed over 40,000 single-nucleotide polymorphisms (SNPs) in a sample of Canids of North American origin that revealed the possibility of an admixed ancestry for eastern and red wolves. However, Cahill et al. (2016) reveal that contradictions emanate from the reanalysis that demystified the occurrence of genetic clusters that showed the possibilities of ascertainment biases in the previous samples. Further, Black et al. (2018) affirm that simulation of the red wolf and eastern wolf admixtures was not sufficient to explicate the unique positions of these two species.
Evidences supporting and against the history of hybridization between species
The periodic evolution of multiple wolf species supports the premise that hybridization has taken place among different kinds of Canids. Wilson et al. (2012) explain that while the red wolf, gray wolf and coyotes are considered to be the major Canid species dominating the North American region, there is evidence that they dispersed to wider geographical areas in search for mates and prey. On the other hand, Cahill et al. (2016) put forth a two-species evolutionary framework that links Canis lupus (gray wolf) and Canis latrans (coyotes) as the genetic parents of hybrids such as the Great Lakes wolf, the eastern coyotes, the eastern wolf and the red wolf. Further, the researchers establish the proof that he eastern wolf, the western coyote and the gray wolf as distinct hybrid varieties based on a three-species framework. In the latter model, the hybridization of eastern and grey wolves led to the production of the Great Lakes wolf while the eastern coyotes are considered as the hybrid between the western coyotes and the eastern wolves. On the other hand the red wolves are described by Lescureux (2018) to reveal characteristics that are similar to those of the eastern wolf.
Evidence of Hybridization with Domestic dogs
Otis et al. (2017) reveal that domestic dogs (Canis lupus familiaris) were hybridized from gray wolves about 20,000 years ago. On the other hand, Leonard et al. (2014) explain that most of the exiosting wolf populations present genetic evidences to support the premise that they might have evolved from similar parents at the same period as domestic dogs. Consequently, Black et al. (2018) demystify that the genetic study of the mtDNA of prehistoric dogs reveals that most of these animals were reared and bred from Eurasian wolves. Further, Rutledge et al. (2015) demystify that most of the antediluvian domestic dogs shared similar mitochondrial haplotypes with North American wolves. By implication, Marshall et al. (2016) reveal that this premise provides a clear platform to prove the existence admixtures between dogs and wolves in the pre-domestication era.
Genes controlling the digestion of starch in human beings show multiple similarities in wolves and domesticated dogs. For instance, Leonard et al. (2014) demystify that while wolves depict two copies of the gene that codes the enzyme alpha-2b-amylase, dogs have about 30 copies of this gene. Lescureux (2018) reveals that the variation could have emanated from the evolutionary process of dogs since they were domesticated prior to the inception of crop farming. Similarly, Wilson et al. (2012) reveal that the variations depicted by the brain cells play a crucial role in fostering the comparison between wolves and dogs; an aspect that reveals the genetic basis of the behavioral variations associated with the two kinds of canids.
Recommendations on the Canids to be Preserved
There is need for governmental authorities and other stakeholders in the wildlife sector to come up with the efforts aimed at fostering the conservation of coyotes (Canis latrans). According to Otis et al. (2012), coyotes are heavily hunted for commercial purposes, sporting activities and attempts to reduce their predatory effects on poultry and livestock. While the population of coyotes continues to increase, governments need to come up with proper strategies of instilling hunting seasons to control their numbers while protecting them from extinction.
Further, there is need for inclusion of proper measures aimed at conserving the raccoon dog. According to Leonard et al. (2014), over 70,000 raccoon dogs are hunted on an annual basis. On the other hand, the species is highly vulnerable to rabies and the effects of urbanization. Therefore, the concerned agencies need to implement proper education campaigns aimed at preserving the raccoon dogs.
Lessons from the North American Scenario
The conservation measures adopted in North America play act as crucial sources of information on the most effective ways of preserving critically endangered species in Australia. While the canids pose threats to the existence of poultry and livestock, the authorities in Australia are challenged to adopt proper measures of educating the populace on the importance of coexisting with these animals. Further, the efforts adopted in North America inform the Australian authorities on the importance of implementing voluntary vaccination programs as a way of protecting the endangered species from extinction.
Black, K. L., Petty, S. K., Radeloff, V. C., & Pauli, J. N. (2018). The Great Lakes Region is a melting pot for vicariant red fox (Vulpes vulpes) populations. Journal of Mammalogy.
Cahill, J. A., Fan, Z., Gronau, I., Robinson, J., Pollinger, J. P., Shapiro, B., ... & Wayne, R. K. (2016). Whole-genome sequence analysis shows that two endemic species of North American wolf are admixtures of the coyote and gray wolf. Science Advances, 2(7), e1501714.
Gese, E. M., & Terletzky, P. A. (2015). Using the “placeholder” concept to reduce genetic introgression of an endangered carnivore. Biological Conservation, 192, 11-19.
Leonard, J. A., Echegaray, J., Randi, E., & Vilà, C. (2014). Impact of hybridization with domestic dogs on the conservation of wild canids. Free-ranging dogs and wildlife conservation. Oxford University Press, Oxford, 170-185.
Lescureux, N. (2018). Beyond wild and domestic: human complex relationships with dogs, wolves, and wolf-dog hybrids. In Hybrid Communities (pp. 83-98). Routledge.
Marshall, H. D., Langille, B. L., Hann, C. A., & Whitney, H. G. (2016). Patterns of MHC-DRB1 polymorphism in a post-glacial island canid, the Newfoundland red fox (Vulpes vulpes deletrix), suggest balancing selection at species and population timescales. Immunogenetics, 68(5), 381-389.
Moehlman, P. D., & Hayssen, V. (2018). Canis aureus (Carnivore: Canidae). Mammalian Species, 50(957), 14-25.
Otis, J. A., Thornton, D., Rutledge, L., & Murray, D. L. (2017). Ecological niche differentiation across a wolf?coyote hybrid zone in eastern North America. Diversity and Distributions, 23(5), 529-539.
Rutledge, L. Y., Devillard, S., Boone, J. Q., Hohenlohe, P. A., & White, B. N. (2015). RAD sequencing and genomic simulations resolve hybrid origins within North American Canis. Biology letters, 11(7), 20150303.
Wilson, P. J., Rutledge, L. Y., Wheeldon, T. J., Patterson, B. R., & White, B. N. (2012). Y?chromosome evidence supports widespread signatures of three?species Canis hybridization in eastern North America. Ecology and evolution, 2(9), 2325-2332.