23 research outputs found
Local Extinction and Unintentional Rewilding of Bighorn Sheep (Ovis canadensis) on a Desert Island
Bighorn sheep ( Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476-1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ∼1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
Recommended from our members
Local Extinction and Unintentional Rewilding of Bighorn Sheep (Ovis canadensis) on a Desert Island
Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and
Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable
island population of ~500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican
mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet
Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal
pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA
and control regions. The fossil dung was ¹⁴C-dated to 1476–1632 calendar years before present and was confirmed as
bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known
bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep
populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón
population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene,
when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ~1500 years,
probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced
population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn
sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding,
defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
History, Commemoration, and Belief: Abraham Lincoln in American Memory, 1945-2001
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91765/1/Schuman-History_Commemoration_Belief.pd
Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis) on a desert island.
Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476-1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ∼1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
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EppsClintonFisheriesWildlifeLocalExtinctionUnintentional.pdf
Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and
Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable
island population of ~500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican
mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet
Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal
pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA
and control regions. The fossil dung was ¹⁴C-dated to 1476–1632 calendar years before present and was confirmed as
bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known
bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep
populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón
population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene,
when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ~1500 years,
probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced
population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn
sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding,
defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
Recommended from our members
EppsClintonFisheriesWildlifeLocalExtinctionUnintentional_SupportingInformation.zip
Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and
Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable
island population of ~500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican
mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet
Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal
pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA
and control regions. The fossil dung was ¹⁴C-dated to 1476–1632 calendar years before present and was confirmed as
bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known
bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep
populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón
population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene,
when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ~1500 years,
probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced
population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn
sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding,
defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
Isla Tiburón <i>a</i>DNA and Sonoran Desert ungulate sequences.
<p>Partial sequences of the 12S ribosomal RNA subunit of the mitochondrial genome for the Isla Tiburón <i>a</i>DNA sample and published sequences from all ungulate species thought to have existed in the area since the start of the Holocene, with GenBank accession numbers. Open box denotes primer region, dot indicates identical bases between sequences, N indicates unknown base. Sequence position numbers are derived from <i>O. c. canadensis</i> haplotype (GenBank Accession NC015889).</p