The properties of the yellow and colorless modifications of 1,l '-diacetyl-1, 1 ',4,4'-tetrahydro... more The properties of the yellow and colorless modifications of 1,l '-diacetyl-1, 1 ',4,4'-tetrahydro-4,4'-bipyridine (I) have been carefully examined. The colorless form is shown to be pure I, and the yellow form (I-y), a mixture of I and 3-57, of 1,1 '-diacetyl-1,l '-dihydro-4,4'-bipyridine (11). The existence of 1-acetylpyridinyl radicals (V) in samples of the yellow form, postulated by other workers, has been disproved by magnetic susceptibility and e.s.r. spectrum measurements on I-y. The n.m.r. spectrum of I indicates much double bond character in the amide C-N bond. Chemical behavior of 11 has been studied including its facile oxidation to 4,4'-bipyridine. The 1,l '-diacetyl-4,4'-bipyridine radical cation (XIV, green), an unstable intermediate in this oxidation process, has been prepared in solution and characterized by its visible and e.8.r. spectra. Evidence affirming structures I and I1 is presented.
Bis(dimethylamino)-b,4-diphenyl-S-(3-hydroxybulyl)-3pentanol (XIX), prepared from 0.075 mole of X... more Bis(dimethylamino)-b,4-diphenyl-S-(3-hydroxybulyl)-3pentanol (XIX), prepared from 0.075 mole of XIVb and 0.02 mole of lithium aluminum hydride, was a viscous material which could not be distilled or crystallized. The dimethiodide was prepared in methanol; m.p. 248-249' dec. after recrystallization from methanol.
ABSTRACT The conservation of tortoises poses a unique situation because several threatened specie... more ABSTRACT The conservation of tortoises poses a unique situation because several threatened species are commonly kept as pets within their native ranges. Thus, there is potential for captive populations to be a reservoir for repatriation efforts. We assess the utility of captive populations of the threatened Agassiz’s desert tortoise (Gopherus agassizii) for recovery efforts based on genetic affinity to local areas. We collected samples from 130 captive desert tortoises from three desert communities: two in California (Ridgecrest and Joshua Tree) and the Desert Tortoise Conservation Center (Las Vegas) in Nevada. We tested all samples for 25 short tandem repeats and sequenced 1,109 bp of the mitochondrial genome. We compared captive genotypes to a database of 1,258 Gopherus samples, including 657 wild caught G. agassizii spanning the full range of the species. We conducted population assignment tests to determine the genetic origins of the captive individuals. For our total sample set, only 44 % of captive individuals were assigned to local populations based on genetic units derived from the reference database. One individual from Joshua Tree, California, was identified as being a Morafka’s desert tortoise, G. morafkai, a cryptic species which is not native to the Mojave Desert. Our data suggest that captive desert tortoises kept within the native range of G. agassizii cannot be presumed to have a genealogical affiliation to wild tortoises in their geographic proximity. Precautions should be taken before considering the release of captive tortoises into the wild as a management tool for recovery.
We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) ... more We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km 2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/ or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of testpositive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of humanpopulated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
We surveyed an area of ,260 km 2 in the western Mojave Desert to evaluate relationships between c... more We surveyed an area of ,260 km 2 in the western Mojave Desert to evaluate relationships between condition of Agassiz's Desert Tortoise populations (Gopherus agassizii) and habitat on lands that have experienced three different levels of management and protection. We established 240 1-ha plots using random sampling, with 80 plots on each of the three types of managed lands. We conducted surveys in spring 2011 and collected data on live tortoises, shell-skeletal remains, other signs of tortoises, perennial vegetation, predators, and evidence of human use. Throughout the study area and regardless of management area, tortoise abundance was positively associated with one of the more diverse associations of perennial vegetation. The management area with the longest history of protection, a fence, and legal exclusion of livestock and vehicles had significantly more live tortoises and lower death rates than the other two areas. Tortoise presence and abundance in this protected area had no significant positive or negative associations with predators or human-related impacts. In contrast, the management area with a more recent exclusion of livestock, limited vehicular traffic, and with a recent, partial fence had lower tortoise densities and high death rates. Tortoise abundance here was negatively associated with vehicle tracks and positively associated with mammalian predators and debris from firearms. The management area with the least protection-unfenced, with uncontrolled vehicle use, sheep grazing, and high trash counts-also had low tortoise densities and high death rates. Tortoise abundance was negatively associated with sheep grazing and positively associated with trash and mammalian predator scat.
We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) ... more We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km 2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/ or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of testpositive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of humanpopulated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
ABSTRACT Numerous factors have contributed to declines in populations of the federally threatened... more ABSTRACT Numerous factors have contributed to declines in populations of the federally threatened Agassiz's Desert Tortoise (Gopherus agassizii) and continue to limit recovery. In 2010, we surveyed a low-density population on a military test facility in the northwestern Mojave Desert of California, USA, to evaluate population status and identify potential factors contributing to distribution and low densities. Estimated densities of live tortoises ranged spatially from 1.2/km(2) to 15.1/km(2). Although only one death of a breeding-age tortoise was recorded for the 4-yr period prior to the survey, remains of 16 juvenile and immature tortoises were found, and most showed signs of predation by Common Ravens (Corvus corax) and mammals. Predation may have limited recruitment of young tortoises into the adult size classes. To evaluate the relative importance of different types of impacts to tortoises, we developed predictive models for spatially explicit densities of tortoise sign and live tortoises using topography (i.e., slope), predators (Common Raven, signs of mammalian predators), and anthropogenic impacts (distances from paved road and denuded areas, density of ordnance fragments) as covariates. Models suggest that densities of tortoise sign increased with slope and signs of mammalian predators and decreased with Common Ravens, while also varying based on interaction effects involving these predictors as well as distances from paved roads, denuded areas, and ordnance. Similarly, densities of live tortoises varied by interaction effects among distances to denuded areas and paved roads, density of ordnance fragments, and slope. Thus multiple factors predict the densities and distribution of this population.
Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral le... more Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.
Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral le... more Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.
ABSTRACT. – Growth rings of costal scutes were counted using 35 mm photographic slides of 192
d... more ABSTRACT. – Growth rings of costal scutes were counted using 35 mm photographic slides of 192
desert tortoises (Gopherus agassizii) from 11 study sites in the Mojave and Colorado deserts of
California. From 0 to ≥ 3 rings were formed yearly, but subannular rings could not be
distinguished visually from annular rings. Growth ring counts from photographic records of scutes
are not a reliable means of determining absolute age in juvenile and immature desert tortoises
≤ 180 mm in carapace length. Ring count data varied by desert region; mean number of rings
produced yearly varied from 0.86 in the western Mojave to 1.17 in the northeastern Mojave. Mean
numbers of rings formed yearly were significantly different between the western and northeastern
Mojave regions
and western and eastern Mojave regions, but not between the western Mojave region and Colorado
Desert. Grouping data from several study sites and years obscured annual variations, however. At
Goffs in the eastern Mojave Desert, numbers of rings formed annually differed significantly between
1983, 1984, and 1985. Numbers of tortoises producing 2 rings per year declined between 1983 and
1985, whereas numbers of tortoises with 0 rings per year increased in the same interval. At Goffs,
ring formation was positively correlated with annual precipitation, as well as summer and winter
rainfall. Correlations between ring counts and biomass of annual plants used for forage
were
weaker.
Distance, environmental heterogeneity and local adaptation can strongly influence population stru... more Distance, environmental heterogeneity and local adaptation can strongly influence population structure and connectivity. Understanding how these factors shape the genomic landscape of threatened species is a major goal in conservation genomics and wildlife management. Herein, we use thousands (6,859) of single nucleotide polymorphism markers and spatial data from hundreds of individuals (n = 646) to re-evaluate the population structure of Agassiz's desert tortoise (Gopherus agassizii). Analyses resolve from 4 to 8 spatially well-defined clusters across the range. Western, central, and southern populations within the Western Mojave recovery unit are consistent throughout, while analyses sometimes merge other recovery units depending on the level of clustering. Causal modeling consistently associates genetic connectivity with least-cost distance, based on multiple landscape features associated with tortoise habitat, better than geographic distance. Some features include elevation,...
This report presents consensus recommendations from a group of independent scientists 1 to the Re... more This report presents consensus recommendations from a group of independent scientists 1 to the Renewable Energy Action Team (REAT) 2 for the California Desert Renewable Energy Conservation Plan (DRECP). DRECP is intended to be a Natural Community Conservation Plan (NCCP) under California's NCCP Act of 2003 and will be the primary vehicle for obtaining authorizations to "take" or harm some state or federally listed Threatened or Endangered species incidental to constructing and managing renewable energy projects. The Act requires NCCP plans to obtain independent scientific input to guide Plan decisions. The DRECP science advisors include experts in desert ecology, wildlife biology, botany, hydrogeology, and other fields pertinent to the conservation of desert species and natural communities.
... MU HA,^ AND KRISTIN HIGHBERG BERRY' Chemistry Division, US Naval Ordnance Test Stati... more ... MU HA,^ AND KRISTIN HIGHBERG BERRY' Chemistry Division, US Naval Ordnance Test Station, China Lake, Califvrnia, and Analytical Research Division, Esso Research and Engineering Company, Linden, New Jersey Received January 80, 1964 ...
The properties of the yellow and colorless modifications of 1,l '-diacetyl-1, 1 ',4,4'-tetrahydro... more The properties of the yellow and colorless modifications of 1,l '-diacetyl-1, 1 ',4,4'-tetrahydro-4,4'-bipyridine (I) have been carefully examined. The colorless form is shown to be pure I, and the yellow form (I-y), a mixture of I and 3-57, of 1,1 '-diacetyl-1,l '-dihydro-4,4'-bipyridine (11). The existence of 1-acetylpyridinyl radicals (V) in samples of the yellow form, postulated by other workers, has been disproved by magnetic susceptibility and e.s.r. spectrum measurements on I-y. The n.m.r. spectrum of I indicates much double bond character in the amide C-N bond. Chemical behavior of 11 has been studied including its facile oxidation to 4,4'-bipyridine. The 1,l '-diacetyl-4,4'-bipyridine radical cation (XIV, green), an unstable intermediate in this oxidation process, has been prepared in solution and characterized by its visible and e.8.r. spectra. Evidence affirming structures I and I1 is presented.
Bis(dimethylamino)-b,4-diphenyl-S-(3-hydroxybulyl)-3pentanol (XIX), prepared from 0.075 mole of X... more Bis(dimethylamino)-b,4-diphenyl-S-(3-hydroxybulyl)-3pentanol (XIX), prepared from 0.075 mole of XIVb and 0.02 mole of lithium aluminum hydride, was a viscous material which could not be distilled or crystallized. The dimethiodide was prepared in methanol; m.p. 248-249' dec. after recrystallization from methanol.
ABSTRACT The conservation of tortoises poses a unique situation because several threatened specie... more ABSTRACT The conservation of tortoises poses a unique situation because several threatened species are commonly kept as pets within their native ranges. Thus, there is potential for captive populations to be a reservoir for repatriation efforts. We assess the utility of captive populations of the threatened Agassiz’s desert tortoise (Gopherus agassizii) for recovery efforts based on genetic affinity to local areas. We collected samples from 130 captive desert tortoises from three desert communities: two in California (Ridgecrest and Joshua Tree) and the Desert Tortoise Conservation Center (Las Vegas) in Nevada. We tested all samples for 25 short tandem repeats and sequenced 1,109 bp of the mitochondrial genome. We compared captive genotypes to a database of 1,258 Gopherus samples, including 657 wild caught G. agassizii spanning the full range of the species. We conducted population assignment tests to determine the genetic origins of the captive individuals. For our total sample set, only 44 % of captive individuals were assigned to local populations based on genetic units derived from the reference database. One individual from Joshua Tree, California, was identified as being a Morafka’s desert tortoise, G. morafkai, a cryptic species which is not native to the Mojave Desert. Our data suggest that captive desert tortoises kept within the native range of G. agassizii cannot be presumed to have a genealogical affiliation to wild tortoises in their geographic proximity. Precautions should be taken before considering the release of captive tortoises into the wild as a management tool for recovery.
We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) ... more We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km 2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/ or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of testpositive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of humanpopulated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
We surveyed an area of ,260 km 2 in the western Mojave Desert to evaluate relationships between c... more We surveyed an area of ,260 km 2 in the western Mojave Desert to evaluate relationships between condition of Agassiz's Desert Tortoise populations (Gopherus agassizii) and habitat on lands that have experienced three different levels of management and protection. We established 240 1-ha plots using random sampling, with 80 plots on each of the three types of managed lands. We conducted surveys in spring 2011 and collected data on live tortoises, shell-skeletal remains, other signs of tortoises, perennial vegetation, predators, and evidence of human use. Throughout the study area and regardless of management area, tortoise abundance was positively associated with one of the more diverse associations of perennial vegetation. The management area with the longest history of protection, a fence, and legal exclusion of livestock and vehicles had significantly more live tortoises and lower death rates than the other two areas. Tortoise presence and abundance in this protected area had no significant positive or negative associations with predators or human-related impacts. In contrast, the management area with a more recent exclusion of livestock, limited vehicular traffic, and with a recent, partial fence had lower tortoise densities and high death rates. Tortoise abundance here was negatively associated with vehicle tracks and positively associated with mammalian predators and debris from firearms. The management area with the least protection-unfenced, with uncontrolled vehicle use, sheep grazing, and high trash counts-also had low tortoise densities and high death rates. Tortoise abundance was negatively associated with sheep grazing and positively associated with trash and mammalian predator scat.
We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) ... more We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km 2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/ or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of testpositive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of humanpopulated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
ABSTRACT Numerous factors have contributed to declines in populations of the federally threatened... more ABSTRACT Numerous factors have contributed to declines in populations of the federally threatened Agassiz's Desert Tortoise (Gopherus agassizii) and continue to limit recovery. In 2010, we surveyed a low-density population on a military test facility in the northwestern Mojave Desert of California, USA, to evaluate population status and identify potential factors contributing to distribution and low densities. Estimated densities of live tortoises ranged spatially from 1.2/km(2) to 15.1/km(2). Although only one death of a breeding-age tortoise was recorded for the 4-yr period prior to the survey, remains of 16 juvenile and immature tortoises were found, and most showed signs of predation by Common Ravens (Corvus corax) and mammals. Predation may have limited recruitment of young tortoises into the adult size classes. To evaluate the relative importance of different types of impacts to tortoises, we developed predictive models for spatially explicit densities of tortoise sign and live tortoises using topography (i.e., slope), predators (Common Raven, signs of mammalian predators), and anthropogenic impacts (distances from paved road and denuded areas, density of ordnance fragments) as covariates. Models suggest that densities of tortoise sign increased with slope and signs of mammalian predators and decreased with Common Ravens, while also varying based on interaction effects involving these predictors as well as distances from paved roads, denuded areas, and ordnance. Similarly, densities of live tortoises varied by interaction effects among distances to denuded areas and paved roads, density of ordnance fragments, and slope. Thus multiple factors predict the densities and distribution of this population.
Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral le... more Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.
Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral le... more Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.
ABSTRACT. – Growth rings of costal scutes were counted using 35 mm photographic slides of 192
d... more ABSTRACT. – Growth rings of costal scutes were counted using 35 mm photographic slides of 192
desert tortoises (Gopherus agassizii) from 11 study sites in the Mojave and Colorado deserts of
California. From 0 to ≥ 3 rings were formed yearly, but subannular rings could not be
distinguished visually from annular rings. Growth ring counts from photographic records of scutes
are not a reliable means of determining absolute age in juvenile and immature desert tortoises
≤ 180 mm in carapace length. Ring count data varied by desert region; mean number of rings
produced yearly varied from 0.86 in the western Mojave to 1.17 in the northeastern Mojave. Mean
numbers of rings formed yearly were significantly different between the western and northeastern
Mojave regions
and western and eastern Mojave regions, but not between the western Mojave region and Colorado
Desert. Grouping data from several study sites and years obscured annual variations, however. At
Goffs in the eastern Mojave Desert, numbers of rings formed annually differed significantly between
1983, 1984, and 1985. Numbers of tortoises producing 2 rings per year declined between 1983 and
1985, whereas numbers of tortoises with 0 rings per year increased in the same interval. At Goffs,
ring formation was positively correlated with annual precipitation, as well as summer and winter
rainfall. Correlations between ring counts and biomass of annual plants used for forage
were
weaker.
Distance, environmental heterogeneity and local adaptation can strongly influence population stru... more Distance, environmental heterogeneity and local adaptation can strongly influence population structure and connectivity. Understanding how these factors shape the genomic landscape of threatened species is a major goal in conservation genomics and wildlife management. Herein, we use thousands (6,859) of single nucleotide polymorphism markers and spatial data from hundreds of individuals (n = 646) to re-evaluate the population structure of Agassiz's desert tortoise (Gopherus agassizii). Analyses resolve from 4 to 8 spatially well-defined clusters across the range. Western, central, and southern populations within the Western Mojave recovery unit are consistent throughout, while analyses sometimes merge other recovery units depending on the level of clustering. Causal modeling consistently associates genetic connectivity with least-cost distance, based on multiple landscape features associated with tortoise habitat, better than geographic distance. Some features include elevation,...
This report presents consensus recommendations from a group of independent scientists 1 to the Re... more This report presents consensus recommendations from a group of independent scientists 1 to the Renewable Energy Action Team (REAT) 2 for the California Desert Renewable Energy Conservation Plan (DRECP). DRECP is intended to be a Natural Community Conservation Plan (NCCP) under California's NCCP Act of 2003 and will be the primary vehicle for obtaining authorizations to "take" or harm some state or federally listed Threatened or Endangered species incidental to constructing and managing renewable energy projects. The Act requires NCCP plans to obtain independent scientific input to guide Plan decisions. The DRECP science advisors include experts in desert ecology, wildlife biology, botany, hydrogeology, and other fields pertinent to the conservation of desert species and natural communities.
... MU HA,^ AND KRISTIN HIGHBERG BERRY' Chemistry Division, US Naval Ordnance Test Stati... more ... MU HA,^ AND KRISTIN HIGHBERG BERRY' Chemistry Division, US Naval Ordnance Test Station, China Lake, Califvrnia, and Analytical Research Division, Esso Research and Engineering Company, Linden, New Jersey Received January 80, 1964 ...
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Papers by Kristin Berry
desert tortoises (Gopherus agassizii) from 11 study sites in the Mojave and Colorado deserts of
California. From 0 to ≥ 3 rings were formed yearly, but subannular rings could not be
distinguished visually from annular rings. Growth ring counts from photographic records of scutes
are not a reliable means of determining absolute age in juvenile and immature desert tortoises
≤ 180 mm in carapace length. Ring count data varied by desert region; mean number of rings
produced yearly varied from 0.86 in the western Mojave to 1.17 in the northeastern Mojave. Mean
numbers of rings formed yearly were significantly different between the western and northeastern
Mojave regions
and western and eastern Mojave regions, but not between the western Mojave region and Colorado
Desert. Grouping data from several study sites and years obscured annual variations, however. At
Goffs in the eastern Mojave Desert, numbers of rings formed annually differed significantly between
1983, 1984, and 1985. Numbers of tortoises producing 2 rings per year declined between 1983 and
1985, whereas numbers of tortoises with 0 rings per year increased in the same interval. At Goffs,
ring formation was positively correlated with annual precipitation, as well as summer and winter
rainfall. Correlations between ring counts and biomass of annual plants used for forage
were
weaker.
desert tortoises (Gopherus agassizii) from 11 study sites in the Mojave and Colorado deserts of
California. From 0 to ≥ 3 rings were formed yearly, but subannular rings could not be
distinguished visually from annular rings. Growth ring counts from photographic records of scutes
are not a reliable means of determining absolute age in juvenile and immature desert tortoises
≤ 180 mm in carapace length. Ring count data varied by desert region; mean number of rings
produced yearly varied from 0.86 in the western Mojave to 1.17 in the northeastern Mojave. Mean
numbers of rings formed yearly were significantly different between the western and northeastern
Mojave regions
and western and eastern Mojave regions, but not between the western Mojave region and Colorado
Desert. Grouping data from several study sites and years obscured annual variations, however. At
Goffs in the eastern Mojave Desert, numbers of rings formed annually differed significantly between
1983, 1984, and 1985. Numbers of tortoises producing 2 rings per year declined between 1983 and
1985, whereas numbers of tortoises with 0 rings per year increased in the same interval. At Goffs,
ring formation was positively correlated with annual precipitation, as well as summer and winter
rainfall. Correlations between ring counts and biomass of annual plants used for forage
were
weaker.