scholarly journals Effects of anthropogenic mortality on Critically Endangered red wolf Canis rufus breeding pairs: implications for red wolf recovery

Oryx ◽  
2015 ◽  
Vol 51 (1) ◽  
pp. 174-181 ◽  
Author(s):  
Joseph W. Hinton ◽  
Kristin E. Brzeski ◽  
David R. Rabon ◽  
Michael J. Chamberlain
Keyword(s):  
North Carolina ◽  
Critically Endangered ◽  
Population Declines ◽  
Canis Rufus ◽  
Red Wolf ◽  
Management Actions ◽  
Control Programmes ◽  
Negative Effect ◽  
Eastern North Carolina ◽  
Red Wolves

AbstractFollowing precipitous population declines as a result of intensive hunting and 20th century predator-control programmes, hybridization of the Critically Endangered red wolf Canis rufus with coyotes Canis latrans posed a significant challenge for red wolf recovery efforts. Anthropogenic mortality and hybridization continue to pose challenges; the increasing number of wolf deaths caused by humans has limited wolf population growth, facilitated the encroachment of coyotes into eastern North Carolina, and affected the formation and disbandment of breeding pairs. We assessed the effects of anthropogenic mortality on Canis breeding units during a 22-year period (1991–2013). Our results show that deaths caused by people accounted for 40.6% of breeding pair disbandment, and gunshots were the primary cause of mortality. Red wolves replaced congeneric breeding pairs > 75% of the time when pairs disbanded under natural conditions or as a result of management actions. Since the mid 2000s anthropogenic mortality has caused annual preservation rates of red wolf breeding pairs to decline by 34%, and replacement of Canis breeders by red wolves to decline by 30%. Our results demonstrate that human-caused mortality, specifically by gunshots, had a strong negative effect on the longevity of red wolf pairs, which may benefit coyotes indirectly by removing their primary competitor. Coyotes are exacerbating the decline of red wolves by pair-bonding with resident wolves whose mates have been killed.

scholarly journals Wild red wolf Canis rufus poaching risk

2020 ◽  
Author(s):  
Suzanne W. Agan ◽  
Adrian Treves ◽  
Lisabeth Willey
Keyword(s):  
North Carolina ◽  
Causes Of Death ◽  
Hunting Season ◽  
Canis Rufus ◽  
Red Wolf ◽  
In The Wild ◽  
Endangered Population ◽  
Red Wolves ◽  
Mean Time ◽  
Future Population

AbstractThe reintroduced red wolf population in northeastern North Carolina declined to 7 known wolves by October 2020. Poaching (illegal killing) is the major component of verified anthropogenic mortality in this and many other carnivore populations, but it is still not well understood. Poaching is often underestimated, partly as a result of cryptic poaching, when poachers conceal evidence. Cryptic poaching inhibits our understanding of the causes and consequences of anthropogenic mortality which is important to conservation as it can inform us about future population patterns within changing political and human landscapes. We estimate risk for marked adult red wolves of 5 causes of death (COD: legal, nonhuman, unknown, vehicle and poached) and disappearance, describe variation in COD in relation to hunting season, and compare time to disappearance or death. We include unknown fates in our risk estimates. We found that anthropogenic COD accounted for 0.724 – 0.787, including cryptic and reported poaching estimated at 0.510 – 0.635 of 508 marked animals. Risk of poaching and disappearance was significantly higher during hunting season. Mean time from collaring until nonhuman COD averaged 376 days longer than time until reported poached and 642 days longer than time until disappearance. Our estimates of risk differed from prior published estimates, as expected by accounting for unknown fates explicitly. We quantify the effects on risk for three scenarios for disappearances, which span conservative to most likely COD. Implementing proven practices that prevent poaching or hasten successful reintroduction may reverse the decline to extinction in the wild of this critically endangered population. Our findings add to a growing literature on endangered species protections and enhancing the science used to measure poaching worldwide.

scholarly journals Rediscovery of Red Wolf Ghost Alleles in a Canid Population Along the American Gulf Coast

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 618 ◽  
Author(s):  
Elizabeth Heppenheimer ◽  
Kristin Brzeski ◽  
Ron Wooten ◽  
William Waddell ◽  
Linda Rutledge ◽  
...  
Keyword(s):  
North Carolina ◽  
Gulf Coast ◽  
Nucleotide Polymorphisms ◽  
Conservation Action ◽  
Single Nucleotide ◽  
Red Wolf ◽  
Reintroduced Population ◽  
Coastal Louisiana ◽  
Red Wolves ◽  
Bayesian Cluster

Rediscovering species once thought to be extinct or on the edge of extinction is rare. Red wolves have been extinct along the American Gulf Coast since 1980, with their last populations found in coastal Louisiana and Texas. We report the rediscovery of red wolf ghost alleles in a canid population on Galveston Island, Texas. We analyzed over 7000 single nucleotide polymorphisms (SNPs) in 60 canid representatives from all legally recognized North American Canis species and two phenotypically ambiguous canids from Galveston Island. We found notably high Bayesian cluster assignments of the Galveston canids to captive red wolves with extensive sharing of red wolf private alleles. Today, the only known extant wild red wolves persist in a reintroduced population in North Carolina, which is dwindling amongst political and taxonomic controversy. Our rediscovery of red wolf ancestry after almost 40 years introduces both positive opportunities for additional conservation action and difficult policy challenges.

DNA profiles of the eastern Canadian wolf and the red wolf provide evidence for a common evolutionary history independent of the gray wolf

2000 ◽  
Vol 78 (12) ◽  
pp. 2156-2166 ◽  
Author(s):  
Paul J Wilson ◽  
Sonya Grewal ◽  
Ian D Lawford ◽  
Jennifer NM Heal ◽  
Angela G Granacki ◽  
...  
Keyword(s):  
Genetic Material ◽  
Gray Wolf ◽  
Canis Rufus ◽  
Red Wolf ◽  
The Subject ◽  
The 1960S ◽  
Original Species ◽  
Dna Profiles ◽  
Microsatellite Alleles ◽  
Red Wolves

The origin and taxonomy of the red wolf (Canis rufus) have been the subject of considerable debate and it has been suggested that this taxon was recently formed as a result of hybridization between the coyote and gray wolf. Like the red wolf, the eastern Canadian wolf has been characterized as a small "deer-eating" wolf that hybridizes with coyotes (Canis latrans). While studying the population of eastern Canadian wolves in Algonquin Provincial Park we recognized similarities to the red wolf, based on DNA profiles at 8 microsatellite loci. We examined whether this relationship was due to similar levels of introgressed coyote genetic material by comparing the microsatellite alleles with those of other North American populations of wolves and coyotes. These analyses indicated that it was not coyote genetic material which led to the close genetic affinity between red wolves and eastern Canadian wolves. We then examined the control region of the mitochondrial DNA (mtDNA) and confirmed the presence of coyote sequences in both. However, we also found sequences in both that diverged by 150 000 - 300 000 years from sequences found in coyotes. None of the red wolves or eastern Canadian wolf samples from the 1960s contained gray wolf (Canis lupus) mtDNA sequences. The data are not consistent with the hypothesis that the eastern Canadian wolf is a subspecies of gray wolf as it is presently designated. We suggest that both the red wolf and the eastern Canadian wolf evolved in North America sharing a common lineage with the coyote until 150 000 - 300 000 years ago. We propose that it retain its original species designation, Canis lycaon.

scholarly journals Cross-fostering as a conservation tool to augment endangered carnivore populations

2018 ◽  
Vol 99 (5) ◽  
pp. 1033-1041
Author(s):  
Eric M Gese ◽  
William T Waddell ◽  
Patricia A Terletzky ◽  
Chris F Lucash ◽  
Scott R McLellan ◽  
...  
Keyword(s):  
Life Span ◽  
Litter Size ◽  
Average Life ◽  
Canis Rufus ◽  
Average Life Span ◽  
Red Wolf ◽  
In The Wild ◽  
Red Wolves ◽  
Cross Fostering

Abstract Cross-fostering offspring with nonbiological parents could prove useful to augment populations of endangered carnivores. We used cross-fostering to augment captive-born and wild-born litters for the endangered red wolf (Canis rufus). Between 1987 and 2016, 23 cross-fostering events occurred involving captive-born pups fostered into captive litters (n = 8 events) and captive-born pups fostered into wild recipient litters (n = 15 events). Percentage of pups surviving 3 and 12 months was 91.7% for captive-born pups fostered into captive recipient litters. For pups fostered into wild litters, percentage of pups surviving 5 months was > 94% among fostered pups (pups fostered into a wild red wolf litter or replaced a hybrid litter), pups in recipient litters (wild-born litters receiving fostered pups), and pups in control litters (wild-born litters not in a fostering event) when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 5 months was > 54% among fostered pups, pups in recipient litters, and pups in control litters. Among wild litters, percentage of pups surviving 12 months was > 82% among fostered pups, pups in recipient litters, and pups in control litters when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 12 months was > 48% among fostered pups, pups in recipient litters, and pups in control litters. Although survival to 12 months was similar among the groups, average life span was different with pups in control litters living 3.3 years, pups in recipient litters living 4.6 years, and fostered pups living 5.6 years. Of fostered pups surviving > 12 months in the wild, 9 animals whelped or sired 26 litters. Cross-fostering was successful at augmenting litter size for red wolves without any deleterious effects on recipient litters, illustrating fostering as a tool for increasing populations of endangered carnivores.

scholarly journals Describing a developing hybrid zone between red wolves and coyotes in eastern North Carolina, USA

2016 ◽  
Vol 9 (6) ◽  
pp. 791-804 ◽  
Author(s):  
Justin H. Bohling ◽  
Justin Dellinger ◽  
Justin M. McVey ◽  
David T. Cobb ◽  
Christopher E. Moorman ◽  
...  
Keyword(s):  
North Carolina ◽  
Hybrid Zone ◽  
Eastern North Carolina ◽  
Red Wolves

Using policy goals to evaluate red wolf reintroduction in eastern North Carolina

2018 ◽  
Vol 23 (4) ◽  
pp. 359-374 ◽  
Author(s):  
Christopher Serenari ◽  
David T Cobb ◽  
Deidre M Peroff
Keyword(s):  
North Carolina ◽  
Red Wolf ◽  
Policy Goals ◽  
Eastern North Carolina

Effects of age and experience on reproductive performance of captive red wolves (Canis rufus)

2014 ◽  
Vol 92 (3) ◽  
pp. 251-258 ◽  
Author(s):  
David R. Rabon
Keyword(s):  
Reproductive Success ◽  
Sex Ratio ◽  
Litter Size ◽  
Sexual Experience ◽  
Canis Rufus ◽  
Breeding Experience ◽  
Offspring Production ◽  
Pup Survival ◽  
Negative Effect ◽  
Red Wolves

Propagation programs contribute to the conservation of a species by preserving genetic and demographic stock that may be used to reinforce or re-establish wild populations. Identifying traits that affect reproductive success is essential to achieve this goal. Longitudinal reproductive events of the captive population of endangered red wolves (Canis rufus Audubon and Bachman, 1851) were investigated to determine whether parental age, breeding experience, and rearing type were factors in reproduction, litter size, and sex ratio, as well as viability of offspring. Younger wolves were more likely to reproduce and produce larger litters than were older individuals. The age of the female, but not the male, had a negative effect on pup survival. Wolves that had prior experience in offspring production were more likely to reproduce again than were individuals that had no prior reproductive success, but prior sexual experience alone was not a factor in offspring production. Parental breeding experience had a negative effect on pup survival, but no apparent relationships with litter size or sex ratio. Declines in reproduction, fitness, and survival with advancing age suggest the effect is due to senescence, the onset of which occurs at 8 years of age in females. The results are consistent with the breeding-experience hypothesis.

scholarly journals Investigating media that support red wolf (Canis rufus) sperm viability and capacitation in vitro

2020 ◽  
Vol 1 (1) ◽  
pp. 83-92
Author(s):  
Jennifer B Nagashima ◽  
Marcia de Almeida Monteiro Melo Ferraz ◽  
Sarah H Kamen ◽  
Nucharin Songsasen
Keyword(s):  
Tyrosine Phosphorylation ◽  
Sperm Motility ◽  
Assisted Reproductive Technologies ◽  
Culture Media ◽  
Reproductive Technologies ◽  
Critically Endangered ◽  
Sperm Viability ◽  
Canis Rufus ◽  
Red Wolf

The red wolf is a critically endangered canid, with ~250 and ~20 individuals in the ex situ and reintroduced wild populations, respectively. Assisted reproductive technologies such as sperm cryopreservation and in vitro fertilization therefore represent critically-needed tools to manage these populations. However, the motility of post-thaw red wolf sperm rapidly declines during in vitro incubation, hindering the ability to develop these technologies. In this study, we evaluated the influence of several culture media (a modified canine capacitation medium (mCCM), a modified North Carolina State University-23 medium (mNCSU-23), a synthetic oviductal fluid (SOF), a fertilization Tyrode’s medium base or Fert-TALP (FERT), and a TRIS-based buffer (TRIS)) on the survival and capacitation of red wolf sperm during extended (18 h) incubation at 38.5°C and 5% CO2. Red wolf sperm motility averaged (±s.e.m.) 73.8 ± 7.1% at the time of collection, and was better maintained over 4 h incubation in mCCM (55.0 ± 9.8%) and mNCSU-23 (54.7 ± 10.4), compared to mSOF (43.8 ± 8.3%), FERT (30 ± 10.5), and TRIS (16.4 ± 4.1%) solutions. Patterns of tyrosine phosphorylation signal, as assessed via immunocytochemistry, indicated induction of capacitation between 2 and 4 h in vitro culture. Tyrosine phosphorylation signal was particularly robust in mCCM and mNCSU-23 incubated sperm, although significant acrosome exocytosis was not observed in response to progesterone supplementation after 3 h incubation in any of the media. In sum, results indicate mCCM and mNCSU-23 are promising base media for the in vitro incubation and capacitation of red wolf sperm, for assisted reproduction applications. Lay summary Development of assisted reproductive technologies such as in vitro fertilization and artificial insemination is of high importance to the genetic management of critically endangered species such as the red wolf (Canis rufus). However, these technologies require the ability to maintain sperm viability and function during extended incubation, which has not been successful for the red wolf thus far. In this study, various culture media developed for sperm/egg/embryo culture in large mammalian species were evaluated for their ability to maintain red wolf sperm motility under physiological incubation conditions. Media and conditions previously utilized for domestic dog sperm were found to best support sperm incubation and capacitation (process of becoming competent to fertilize an egg) in the red wolf, representing a key step for future development of assisted reproductive technologies for the species.

scholarly journals Managing hybridization of a recovering endangered species: The red wolf Canis rufus as a case study

2015 ◽  
Vol 61 (1) ◽  
pp. 191-205 ◽  
Author(s):  
Eric M. Gese ◽  
Fred F. Knowlton ◽  
Jennifer R. Adams ◽  
Karen Beck ◽  
Todd K. Fuller ◽  
...  
Keyword(s):  
Endangered Species ◽  
Adaptive Management ◽  
Social Groups ◽  
Management Plan ◽  
Wolf Population ◽  
Canis Rufus ◽  
Unique Challenge ◽  
Species Recovery ◽  
Red Wolf ◽  
Red Wolves

Abstract Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered species recovery effort for the red wolf Canis rufus is a classic system for understanding and addressing the challenges of hybridization. From 1987?1993, 63 red wolves were released from captivity in eastern North Carolina, USA, to establish a free-ranging, non-essential experimental population. By 1999, managers recognized hybridization with invasive coyotes Canis latrans was the single greatest threat to successful recovery, and an adaptive management plan was adopted with innovative approaches for managing the threat of hybridization. Here we review the application and results of the adaptive management efforts from 1993 to 2013 by comparing: (1) the numbers of wolves, coyotes, and hybrids captured, (2) the numbers of territorial social groups with presumed breeding capabilities, (3) the number of red wolf and hybrid litters documented each year and (4) the degree of coyote introgression into the wild red wolf gene pool. We documented substantial increases in the number of known red wolves and red wolf social groups from 1987–2004 followed by a plateau and slight decline by 2013.The number of red wolf litters exceeded hybrid litters each year and the proportion of hybrid litters per year averaged 21%. The genetic composition of the wild red wolf population is estimated to include < 4% coyote ancestry from recent introgression since reintroduction. We conclude that the adaptive management plan was effective at reducing the introgression of coyote genes into the red wolf population, but population recovery of red wolves will require continuation of the current management plan, or alternative approaches, for the foreseeable future. More broadly, we discuss the lessons learned from red wolf adaptive management that could assist other endangered species recovery efforts facing the challenge of minimizing hybridization.

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