Genetic nature of eastern wolves: Past, present and future

Eastern North American wolves have long been recognized as morphologically distinct from both coyotes and gray wolves. This has led to questions regarding their origins and taxonomic status. Eastern wolves are mainly viewed as: (1) a smaller subspecies of gray wolf (Canis lupus lycaon), potentially the result of historical hybridization between gray wolves (C. lupus) and red wolves (C. rufus), (2) a hybrid, the result of gray wolf (C. lupus) and coyote (C. latrans) interbreeding, or (3) a distinct species, C. lycaon, closely related to the red wolf (C. rufus). Although debate persists, recent molecular studies suggest that the eastern wolf is not a gray wolf subspecies, nor the result of gray wolf/coyote hybridization. Eastern wolves were more likely a distinct species, C. lycaon, prior to the eastward spread of coyotes in the late 1800s. However, contemporary interbreeding exits between C. lycaon to both C. lupus and C. latrans over much of its present range complicating its present taxonomic characterization. While hybridization may be reducing the taxonomic distinctiveness of C. lycaon, it should not necessarily be viewed as negative influence. Hybridization may be enhancing the adaptive potential of eastern wolves, allowing them to more effectively exploit available resources in rapidly changing environments.     

Genic variation in the coyote,Canis latrans,in Tennessee,U.S.A.

Protein variation, levels of heterozygosity, and interlocality gene variation were studied in the coyote, Canis latrans, using starch gel electrophoresis. Canis latrans were obtained from 27 counties in Tennessee. Eleven of 20 loci examined were found to be polymorphic with the remaining nine loci fixed for the same gene in all populations. Mean heterozygosity (\-H) varied from 0.0% to 1.9% with a mean of 0.9%. These values are low for a mammal. Significant heterozygote deficiencies occurred in most groups. Results of F-statistics indicated a significant degree of population differentiation at four loci (Gdh, Idh-1, Mdh-2, 6-Pgd). Rogers' coefficients of genetic similarity ranged from 0.950 to 1.000 and showed C. latrans to be genetically homogenous in that portion of the range investigated.     

Canis accitanus nov. sp., a new small dog (Canidae, Carnivora, Mammalia) from the Fonelas P-1 Plio-Pleistocene site (Guadix basin, Granada, Spain)

This paper reports a new species of dog (Canis accitanus nov. sp.) from the Fonelas P-1 site (dated close to the Plio-Pleistocene boundary) in Granada, Spain. This new taxon shows cranial features more similar to coyote-like dogs (C. lepophagus, C. priscolatrans, C. arnensis or C. latrans) than to wolf-like dogs (C. etruscus, C. mosbachensis or C. lupus), such as a long and narrow muzzle, a little-developed sagittal crest and frontal bones raised only a little above the rostrum. However, it also shows a series of autapomorphic characteristics in its upper dentition, essentially in the first upper molar, which reflects a trophic adaptation towards a more abrasive diet than that eaten by other species of its genus. This new dog is the smallest representative of the genus Canis ever recorded for the European Pliocene or Pleistocene.     

Genetic variation and subspecific status of the grey wolf (Canis lupus) in Saudi Arabia

This work represents the most extensive genetic study of the grey wolf (Canis lupus Linnaeus, 1758) in Arabia and the first considering genetic data from multiple locations within Saudi Arabia. Previous suggestion of the occurrence of two subspecies of wolves in Arabia is not supported by this study. The genetic evidence suggests that the wolves of Saudi Arabia are genetically variable and more closely related to the Eurasian wolf Canis lupus group (dog included) than to the Indian wolf C. l. pallipes. The genetic diversity observed for C. lupus in Saudi Arabia indicates that the subspecific status C. l. arabs should be retained for the Arabian wolf. What remains unclear is the degree to which genetic introgression from domestic dogs has influenced the composition and integrity of C. lupus in Saudi Arabia.     

RAD sequencing and genomic simulations resolve hybrid origins within North American Canis

Top predators are disappearing worldwide, significantly changing ecosystems that depend on top-down regulation. Conflict with humans remains the primary roadblock for large carnivore conservation, but for the eastern wolf (Canis lycaon), disagreement over its evolutionary origins presents a significant barrier to conservation in Canada and has impeded protection for grey wolves (Canis lupus) in the USA. Here, we use 127 235 single-nucleotide polymorphisms (SNPs) identified from restriction-site associated DNA sequencing (RAD-seq) of wolves and coyotes, in combination with genomic simulations, to test hypotheses of hybrid origins of Canis types in eastern North America. A principal components analysis revealed no evidence to support eastern wolves, or any other Canis type, as the product of grey wolf × western coyote hybridization. In contrast, simulations that included eastern wolves as a distinct taxon clarified the hybrid origins of Great Lakes-boreal wolves and eastern coyotes. Our results support the eastern wolf as a distinct genomic cluster in North America and help resolve hybrid origins of Great Lakes wolves and eastern coyotes. The data provide timely information that will shed new light on the debate over wolf conservation in eastern North America.     

Inter-specific territoriality in a Canis hybrid zone: spatial segregation between wolves, coyotes, and hybrids

Gray wolves (Canis lupus) and coyotes (Canis latrans) generally exhibit intraspecific territoriality manifesting in spatial segregation between adjacent packs. However, previous studies have found a high degree of interspecific spatial overlap between sympatric wolves and coyotes. Eastern wolves (Canis lycaon) are the most common wolf in and around Algonquin Provincial Park (APP), Ontario, Canada and hybridize with sympatric gray wolves and coyotes. We hypothesized that all Canis types (wolves, coyotes, and hybrids) exhibit a high degree of spatial segregation due to greater genetic, morphologic, and ecological similarities between wolves and coyotes in this hybrid system compared with western North American ecosystems. We used global positioning system telemetry and probabilistic measures of spatial overlap to investigate spatial segregation between adjacent Canis packs. Our hypothesis was supported as: (1) the probability of locating wolves, coyotes, and hybrids within home ranges ( $\bar{x}$  = 0.05) or core areas ( $\bar{x}$  < 0.01) of adjacent packs was low; and (2) the amount of shared space use was negligible. Spatial segregation did not vary substantially in relation to genotypes of adjacent packs or local environmental conditions (i.e., harvest regulations or road densities). We provide the first telemetry-based demonstration of spatial segregation between wolves and coyotes, highlighting the novel relationships between Canis types in the Ontario hybrid zone relative to areas where wolves and coyotes are reproductively isolated. Territoriality among Canis may increase the likelihood of eastern wolves joining coyote and hybrid packs, facilitate hybridization, and could play a role in limiting expansion of the genetically distinct APP eastern wolf population.     

Genetics and conservation of wolves Canis lupus in Europe

• 1 The wolf Canis lupus, the most widespread of the four species of large carnivores in Europe, after centuries of population decline and eradication, is now recovering in many countries. Wolves contribute to regulating prey–predator dynamics and interact with human activities, mainly livestock farming and ungulate hunting. Although wolves are protected in most European countries, illegal or incidental killing is widespread.
• 2 Wolf populations do not show any apparent phylogeographic structuring worldwide. Molecular and morphological studies of historical samples showed evidence of wolf ecomorph extinctions, coinciding with the great Pleistocene faunal turnover.
• 3 Extant populations show recurrent long‐range dispersal during cycles of expansion and recolonization. Demographically stable populations, in contrast, seem to be characterized by very limited gene flow.
• 4 Despite the potential for dispersal and ecological flexibility, landscape genetic approaches have demonstrated the existence of genetically distinct wolf populations, which originated through habitat and prey specializations.
• 5 Small isolated wolf populations may suffer from inbreeding depression, although selection for heterozygotes and the rescue effect can foster rapid population recovery. Population structure and dynamics is efficiently monitored by non‐invasive genetic methods, which are also useful to identify wolf × dogCanis lupus familiaris hybridization.
• 6 Despite technical advances and a better knowledge of wolf biology, wolf conservation is largely dependent on humans, and on the solution of conflicts with stakeholders.

     

Boreal predator co‐occurrences reveal shared use of seismic lines in a working landscape

Interspecific interactions are an integral aspect of ecosystem functioning that may be disrupted in an increasingly anthropocentric world. Industrial landscape change creates a novel playing field on which these interactions take place, and a key question for wildlife managers is whether and how species are able to coexist in such working landscapes. Using camera traps deployed in northern Alberta, we surveyed boreal predators to determine whether interspecific interactions affected occurrences of black bears (Ursus americanus), coyotes (Canis latrans), and lynx (Lynx canadensis) within a landscape disturbed by networks of seismic lines (corridors cut for seismic exploration of oil and gas reserves). We tested hypotheses of species interactions across one spatial‐only and two spatiotemporal (daily and weekly) scales. Specifically, we hypothesized that (1) predators avoid competition with the apex predator, gray wolf (Canis lupus), (2) they avoid competition with each other as intraguild competitors, and (3) they overlap with their prey. All three predators overlapped with wolves on at least one scale, although models at the daily and weekly scale had substantial unexplained variance. None of the predators showed avoidance of intraguild competitors or overlap with prey. These results show patterns in predator space use that are consistent with both facilitative interactions or shared responses to unmeasured ecological cues. Our study provides insight into how predator species use the working boreal landscape in relation to each other, and highlights that predator management may indirectly influence multiple species through their interactions.     

Dingo Howls: The Content and Efficacy of a Long‐Range Vocal Signal

Signals are shaped through selective pressures impacting their information content (i.e. ‘what’ is conveyed) and their efficacy (i.e. ‘how’ is it conveyed). In the case of long‐range communication, a signal's structure should both convey information and allow for detection and discrimination despite the effects of environmental variability during propagation. Canid howls are an ideal example of a long‐range communication signal, although research has mostly focused on the relationships between howls’ acoustic characteristics and their potential information content in wolves, Canis lupus spp., and coyotes, Canis latrans. In this study, we quantified these relationships in another canid, the dingo, Canis familiaris dingo, to determine how their howls compare to that of other wild canids. We found that dingoes’ howls are individually distinctive and may convey gender cues. Playback experiments indicate that dingoes can perform class‐level recognition of familiar and unfamiliar individuals on the basis of vocalizations alone. These results mirror findings for other wild canids such as wolves and coyotes. Lastly, propagation experiments demonstrate that this signal's structure can permit long‐distance detectability and discriminability. We discuss our results in relation to the putative functions of canid howls and propose avenues for future research.     

Comparison of Mexican Wolf and Coyote Diets in Arizona and New Mexico

ABSTRACT Interactions between wolves (Canis lupus) and coyotes (C. latrans) can have significant impacts on their distribution and abundance. We compared diets of recently translocated Mexican wolves (C. l. baileyi) with diets of resident coyotes in Arizona and New Mexico, USA. We systematically collected scats during 2000 and 2001. Coyote diet was composed mostly of mammalian species, followed by vegetation and insects. Elk (Cervus elaphus) was the most common item in coyote scats. Mexican wolf diet had a higher proportion of large mammals and fewer small mammals than coyote diet; however, elk was also the most common food item in Mexican wolf scats. Our results suggest that Mexican wolf diet was more similar to coyote diet than previously reported, but coyotes had more seasonal variation. Considering results in other areas, we expect that Mexican wolves will have a negative impact on coyotes through direct mortality and possibly competition. Reintroduction of Mexican wolves may have great impacts on communities by changing relationships among other predators and their prey.     

Home range scaling: intraspecific and comparative trends

Summary Intraspecific and intrasexual variation in home range size, body mass and ecological productivity is examined in three selected species of Carnivora (Felis rufus: Canis latrans; Ursus americanus), reflecting different diets. We then compare the intraspecific results with prior cross-species studies. Home range size and body mass inFelis rufus are positively and significantly correlated, similar to other comparative studies. For both intraspecific and intrasexual analyses of all three species, home range size and latitude are strongly correlated. Home range size scales with latitude more steeply as the proportion of meat increases in the diet of each species. That is, the slope of home range size on latitude is greatest in the meat-eatingFelis rufus followed by a shallower slope in the omnivorousCanis latrans and the most shallow slope in the frugivorous/folivorousUrsus americanus. These differences in slope are consistent with models of trophic level biomass change with variation in productivity, and parallel the dietary differences observed in cross-species differences in home range.     

Canid hybridization: contemporary evolution in human‐modified landscapes

Contemporary evolution through human‐induced hybridization occurs throughout the taxonomic range. Formerly allopatric species appear especially susceptible to hybridization. Consequently, hybridization is expected to be more common in regions with recent sympatry owing to human activity than in areas of historical range overlap. Coyotes ( Canis latrans) and gray wolves ( C. lupus) are historically sympatric in western North America. Following European settlement gray wolf range contracted, whereas coyote range expanded to include eastern North America. Furthermore, wolves with New World (NW) mitochondrial DNA (mtDNA) haplotypes now extend from Manitoba to Québec in Canada and hybridize with gray wolves and coyotes. Using mtDNA and 12 microsatellite markers, we evaluated levels of wolf‐coyote hybridization in regions where coyotes were present (the Canadian Prairies, n = 109 samples) and absent historically (Québec, n = 154). Wolves with NW mtDNA extended from central Saskatchewan (51°N, 69°W) to northeastern Québec (54°N, 108°W). On the Prairies, 6.3% of coyotes and 9.2% of wolves had genetic profiles suggesting wolf‐coyote hybridization. In contrast, 12.6% of coyotes and 37.4% of wolves in Québec had profiles indicating hybrid origin. Wolves with NW and Old World ( C. lupus) mtDNA appear to form integrated populations in both regions. Our results suggest that hybridization is more frequent in historically allopatric populations. Range shifts, now expected across taxa following climate change and other human influence on the environment, might therefore promote contemporary evolution by hybridization.     

Ecological Changes in Coyotes (Canis latrans) in Response to the Ice Age Megafaunal Extinctions

Coyotes (Canis latrans) are an important species in human-inhabited areas. They control pests and are the apex predators in many ecosystems. Because of their importance it is imperative to understand how environmental change will affect this species. The end of the Pleistocene Ice Age brought with it many ecological changes for coyotes and here we statistically determine the changes that occurred in coyotes, when these changes occurred, and what the ecological consequences were of these changes. We examined the mandibles of three coyote populations: Pleistocene Rancho La Brean (13–29 Ka), earliest Holocene Rancho La Brean (8–10 Ka), and Recent from North America, using 2D geometric morphometrics to determine the morphological differences among them. Our results show that these three populations were morphologically distinct. The Pleistocene coyotes had an overall robust mandible with an increased shearing arcade and a decreased grinding arcade, adapted for carnivory and killing larger prey; whereas the modern populations show a gracile morphology with a tendency toward omnivory or grinding. The earliest Holocene populations are intermediate in morphology and smallest in size. These findings indicate that a niche shift occurred in coyotes at the Pleistocene/Holocene boundary – from a hunter of large prey to a small prey/more omnivorous animal. Species interactions between Canis were the most likely cause of this transition. This study shows that the Pleistocene extinction event affected species that did not go extinct as well as those that did.     

Re-Defining <Emphasis Type="Italic">Canis etruscus</Emphasis> (Canidae,Mammalia): A New Look into the Evolutionary History of Early Pleistocene Dogs Resulting from the Outstanding Fossil Record from Pantalla (Italy)

An outstanding sample of Canis etruscus has been found within the faunal assemblage from the early Pleistocene site of Pantalla (Italy), which is referred to the early late Villafranchian. Canis etruscus appeared in Europe about 2 Ma ago. It is regarded as an important taxon for biochronology, as its first occurrence (the “wolf event”) has been used to define one of the Villafranchian faunal turnovers. The discovery of four crania from Pantalla prompted a revision of C. etruscus, in order to better describe its cranial morphology. Since early studies, the distinction between C. etruscus and the coeval C. arnensis has been based mainly on mandibular traits. For this reason, our study is aimed at highlighting differences in craniodental characters between the two species. Canis arnensis has been conventionally considered a jackal-like dog, while C. etruscus is regarded as a wolf-like dog. Consequently, we decided to use jackals for comparison, in addition to C. lupus. Although the jackal group has been traditionally considered as quite homogenous (different species are partially sympatric and similar in both size and ecology), recent genetic studies demonstrate that jackals are not monophyletic. Considering the model offered by extant species, our goal is to delineate the degree of intra- and interspecific variability among the basal forms of the genus Canis.     

Rodent foraging is affected by indirect, but not by direct, cues of predation risk

We used foraging trays to determine whether oldfield mice, Peromyscuspolionotus, altered foraging in response to direct cues of predationrisk (urine of native and nonnative predators) and indirectcues of predation risk (foraging microhabitat, precipitation,and moon illumination). The proportion of seeds remaining ineach tray (a measure of the giving-up density [GUD]) was usedto measure risk perceived by mice. Mice did not alter theirGUD when presented with cues of native predators (bobcats, Lynxrufus, and red foxes, Vulpes vulpes), recently introduced predators(coyotes, Canis latrans), nonnative predators (ocelots, Leoparduspardalis), a native herbivore (white-tailed deer, Odocoileusvirginianus), or a water control. Rather, GUD was related tomicrohabitat: rodents removed more seeds from foraging trayssheltered beneath vegetative cover compared with exposed traysoutside of cover. Rodents also removed more seeds during nightswith precipitation and when moon illumination was low. Our resultssuggest that P. polionotus used indirect cues rather than directcues to assess risk of vertebrate predation. Indirect cues maybe more reliable than are direct scent cues for estimating riskfrom multiple vertebrate predators that present the most riskin open environments.     

Genetic and morphometric analysis of sixteenth century <Emphasis Type="Italic">Canis</Emphasis> skull fragments: implications for historic eastern and gray wolf distribution in North America

Resolving the taxonomy and historic ranges of species are essential to recovery plans for species at risk and conservation programs that aim to restore extirpated populations. In eastern North America, planning for wolf population restoration is complicated by the disputed historic distributions of two wolf species: the Old World-evolved gray wolf (Canis lupus) and the New World-evolved eastern wolf (C. lycaon). We used genetic and morphometric data from 4- to 500-year-old Canis samples excavated in London, Ontario, Canada to help clarify the historic range of these two wolf species in the eastern temperate forests of North America. We isolated DNA and sequenced the mitochondrial control region and found that none of the samples were of gray wolf origin. Two of the DNA sequences corresponded to those found in present day coyotes (C. latrans), but morphometric comparisons show an eastern wolf, not coyote, origin. The remaining two sequences matched ancient domestic dog haplotypes. These results suggest that the New World-evolved eastern wolf, not the gray wolf, occupied this region prior to the arrival of European settlers, although eastern-gray wolf hybrids cannot be ruled out. Furthermore, our data support the idea of a shared common ancestry between eastern wolves and western coyotes, and that the distribution of gray wolves at this time probably did not include the eastern temperate forests of North America.     

Tracking of food quantity by coyotes (Canis latrans)

Previous studies have demonstrated that Weber's Law mediates quantitative discrimination abilities across various species. Here, we tested coyotes’ (Canis latrans) ability to discriminate between various quantities of food and investigated whether this ability conforms to predictions of Weber's Law. We demonstrate herein that coyotes are capable of reliably discriminating large versus small quantities of discrete food items. As predicted by Weber's Law, coyotes’ quantitative discrimination abilities are mediated by the ratio between the large and small quantities of food and exhibit scalar variability. Furthermore, in this task coyotes were not discriminating large versus small quantities based on olfactory cues alone.     

Intergeneric and Interspecific Relationships in Araceae tribe Caladieae and Development of Molecular Markers using Amplified Fragment Length Polymorphism (AFLP)

Since amplified fragment length polymorphism (AFLP) analysishas proved useful in distinguishing cultivars of Caladium, itwas used to assess the status of species of Caladium vs. Xanthosoma,both in tribe the Caladieae, and to reassess the position ofHapaline in the same tribe. AFLP analysis using three primercombinations was carried out on four species of Caladium(C.bicolor, C. humboldtii, C. lindenii and C. schomburgkii). Resultsshowed that AFLP can distinguish between the different speciesby their unique and different banding patterns. AFLP analysisconfirmed that C. humboldtii is a species distinct from C. bicolorand that C. lindenii is a true Caladium species and does notbelong to Xanthosoma. UPGMA cluster analysis showed that C.bicolor and C. schomburgkii are most similar and that C. humboldtiiis closer to the C. bicolor / C. schomburgkii cluster comparedwith C. lindenii. Genetic relationships between Caladium, Xanthosoma,Hapaline, Alocasia and Protarum were also examined by AFLP analysisusing eight primer combinations. Several useful molecular markerswere specific either to Caladium orXanthosoma , so that AFLPcan be used to distinguish species of these two genera. Geneticanalysis of the genera examined confirms that the Caladieaeand Colocasieae tribes are distinct and that Hapaline fallswithin the tribe Caladieae and that Protarum is most distantfrom all the genera examined. Copyright 2000 Annals of BotanyCompany Araceae, Caladium, Xanthosoma, Hapaline, Alocasia, Protarum, AFLP DNA fingerprinting, diversity, AFLP markers     

Ageing and environmental factors affect PCR success in wolf (Canis lupus) excremental DNA samples

Individual genotypes determined from noninvasive DNA samples (typically extracted from shed hairs or scats) are used to estimate population size in monitoring projects of elusive species. However, polymerase chain reaction (PCR) success rates usually are lower, and genotyping errors higher than in standard population genetic surveys, due to DNA degradation or contamination in aged field samples. In this study, we evaluate the results of common garden experiments showing that DNA degradation is significant in wolf (Canis lupus) scats older than 3 days, and it is enhanced in scats in direct contact with soil. A storage test showed that samples kept frozen in 95% ethanol performed better compared to other methods. However, variance of PCR success among samples was high, independent on sample age or storage condition. The detrimental consequences of DNA degradation can be avoided by collecting scat samples as fresh as possible, and implementing efficient multitube procedures and stringent quality control of the laboratory results. Efficient multitube procedures can produce reliable data, like in this study, which showed that the consensus genotypes obtained from excremental DNA exactly matched distinct reference genotypes obtained from wolf blood samples.     

Predator densities and white-tailed deer fawn survival

Predation is the dominant source of mortality for white-tailed deer (Odocoileus virginianus) <6 months old throughout North America. Yet, few white-tailed deer fawn survival studies have occurred in areas with 4 predator species or have considered concurrent densities of deer and predator species. We monitored survival and cause-specific mortality from birth to 6 months for 100 neonatal fawns during 2013–2015 in the Upper Peninsula of Michigan, USA, while simultaneously estimating population densities of deer, American black bear (Ursus americanus), coyote (Canis latrans), bobcat (Lynx rufus), and gray wolf (Canis lupus). We estimated fawn predation risk in response to sex, birth mass, and date of birth. Six-month fawn survival pooled among years was 36%, and fawn mortality risk was not related to birth mass, date of birth, or sex. Estimated mean annual deer and predator densities were 334 fawns/100 km², 25.9 black bear/100 km², 23.8 coyotes/100 km², 3.8 bobcat/100 km², and 2.8 wolves/100 km². Despite lower estimated per-individual kill rates, coyotes and black bears were the leading sources of fawn mortality because they had greater densities relative to bobcats and wolves. Our results indicate that the presence of more predator species in a system is not entirely additive in its effect on fawn survival. © The Wildlife Society, 2019