scholarly journals Impact of Mycoplasma ovipneumoniae on juvenile bighorn sheep (Ovis canadensis) survival in the northern Basin and Range ecosystem

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10710
Author(s):  
Robert S. Spaan ◽  
Clinton W. Epps ◽  
Rachel Crowhurst ◽  
Donald Whittaker ◽  
Mike Cox ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Survival Probability ◽  
Population Genetic ◽  
Bighorn Sheep ◽  
Basin And Range ◽  
Ovis Canadensis ◽  
Juvenile Survival ◽  
Adult Females ◽  
Mycoplasma Ovipneumoniae

Determining the demographic impacts of wildlife disease is complex because extrinsic and intrinsic drivers of survival, reproduction, body condition, and other factors that may interact with disease vary widely. Mycoplasma ovipneumoniae infection has been linked to persistent mortality in juvenile bighorn sheep (Ovis canadensis), although mortality appears to vary widely across subspecies, populations, and outbreaks. Hypotheses for that variation range from interactions with nutrition, population density, genetic variation in the pathogen, genetic variation in the host, and other factors. We investigated factors related to survival of juvenile bighorn sheep in reestablished populations in the northern Basin and Range ecosystem, managed as the formerly-recognized California subspecies (hereafter, “California lineage”). We investigated whether survival probability of 4-month juveniles would vary by (1) presence of M. ovipneumoniae-infected or exposed individuals in populations, (2) population genetic diversity, and (3) an index of forage suitability. We monitored 121 juveniles across a 3-year period in 13 populations in southeastern Oregon and northern Nevada. We observed each juvenile and GPS-collared mother semi-monthly and established 4-month capture histories for the juvenile to estimate survival. All collared adult females were PCR-tested at least once for M. ovipneumoniae infection. The presence of M. ovipneumoniae-infected juveniles was determined by observing juvenile behavior and PCR-testing dead juveniles. We used a known-fate model with different time effects to determine if the probability of survival to 4 months varied temporally or was influenced by disease or other factors. We detected dead juveniles infected with M. ovipneumoniae in only two populations. Derived juvenile survival probability at four months in populations where infected juveniles were not detected was more than 20 times higher. Detection of infected adults or adults with antibody levels suggesting prior exposure was less predictive of juvenile survival. Survival varied temporally but was not strongly influenced by population genetic diversity or nutrition, although genetic diversity within most study area populations was very low. We conclude that the presence of M. ovipneumoniae can cause extremely low juvenile survival probability in translocated bighorn populations of the California lineage, but found little influence that genetic diversity or nutrition affect juvenile survival. Yet, after the PCR+ adult female in one population died, subsequent observations found 11 of 14 ( 79%) collared adult females had surviving juveniles at 4-months, suggesting that targeted removals of infected adults should be evaluated as a management strategy.

scholarly journals Desert Bighorn Sheep: Changes in Genetic Variation Over Time and the Impact of Merging Populations

2014 ◽  
Vol 5 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Philip W. Hedrick ◽  
John D. Wehausen
Keyword(s):  
Genetic Variation ◽  
New Mexico ◽  
Monitoring And Evaluation ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Mexican Population ◽  
Desert Bighorn Sheep ◽  
Two Generations ◽  
The Impact ◽  
Over Time

Abstract Founder effects, genetic bottlenecks, and genetic drift in general can lead to low levels of genetic diversity, which can influence the persistence of populations. We examine genetic variation in two populations of desert bighorn sheep Ovis canadensis from New Mexico and Mexico to measure change over time and evaluate the impact of introducing individuals from one population into the other. Over about three generations, the amount of genetic variation in the New Mexico population increased. In contrast, over about two generations the amount of genetic variation in the Mexican population decreased by a great extent compared with an estimate from another Mexican population from which it is primarily descended. The potential reasons for these changes are discussed. In addition, although both populations have low genetic variation, introduction of Mexican rams into the New Mexico population might increase the amount of genetic variation in the New Mexico population. Overall, it appears that management to increase genetic variation might require substantial detailed monitoring and evaluation of ancestry from the different sources and fitness components.

scholarly journals Linking population performance to nutritional condition in an alpine ungulate

2020 ◽  
Vol 101 (5) ◽  
pp. 1244-1256 ◽  
Author(s):  
Thomas R Stephenson ◽  
David W German ◽  
E Frances Cassirer ◽  
Daniel P Walsh ◽  
Marcus E Blum ◽  
...  
Keyword(s):  
Body Fat ◽  
Bighorn Sheep ◽  
Nutritional Condition ◽  
Ovis Canadensis ◽  
Population Increase ◽  
Overwinter Survival ◽  
Fat Reserves ◽  
Adult Females ◽  
Free Body

Abstract Bighorn sheep (Ovis canadensis) can live in extremely harsh environments and subsist on submaintenance diets for much of the year. Under these conditions, energy stored as body fat serves as an essential reserve for supplementing dietary intake to meet metabolic demands of survival and reproduction. We developed equations to predict ingesta-free body fat in bighorn sheep using ultrasonography and condition scores in vivo and carcass measurements postmortem. We then used in vivo equations to investigate the relationships between body fat, pregnancy, overwinter survival, and population growth in free-ranging bighorn sheep in California and Nevada. Among 11 subpopulations that included alpine winter residents and migrants, mean ingesta-free body fat of lactating adult females during autumn ranged between 8.8% and 15.0%; mean body fat for nonlactating females ranged from 16.4% to 20.9%. In adult females, ingesta-free body fat > 7.7% during January (early in the second trimester) corresponded with a > 90% probability of pregnancy and ingesta-free body fat > 13.5% during autumn yielded a probability of overwinter survival > 90%. Mean ingesta-free body fat of lactating females in autumn was positively associated with finite rate of population increase (λ) over the subsequent year in bighorn sheep subpopulations that wintered in alpine landscapes. Bighorn sheep with ingesta-free body fat of 26% in autumn and living in alpine environments possess energy reserves sufficient to meet resting metabolism for 83 days on fat reserves alone. We demonstrated that nutritional condition can be a pervasive mechanism underlying demography in bighorn sheep and characterizes the nutritional value of their occupied ranges. Mountain sheep are capital survivors in addition to being capital breeders, and because they inhabit landscapes with extreme seasonal forage scarcity, they also can be fat reserve obligates. Quantifying nutritional condition is essential for understanding the quality of habitats, how it underpins demography, and the proximity of a population to a nutritional threshold.

Genetic diversity and differentiation in populations of invasive Eurasian (Myriophyllum spicatum) and hybrid (Myriophyllum spicatum × Myriophyllum sibiricum) watermilfoil

2020 ◽  
Vol 13 (2) ◽  
pp. 59-67
Author(s):  
Ryan A. Thum ◽  
Gregory M. Chorak ◽  
Raymond M. Newman ◽  
Jasmine A. Eltawely ◽  
Jo Latimore ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Myriophyllum Spicatum ◽  
Population Variation ◽  
Efficacy Evaluation ◽  
Submerged Aquatic Plant ◽  
Myriophyllum Sibiricum ◽  
Control Response ◽  
Herbicide Response

AbstractPopulation genetic studies of within- and among-population genetic variability are still lacking for managed submerged aquatic plant species, and such studies could provide important information for managers. For example, the extent of within-population genetic variation may influence the potential for managed populations to locally adapt to environmental conditions and control tactics. Similarly, among-population variation may influence whether specific control tactics work equally effectively in different locations. In the case of invasive Eurasian watermilfoil (Myriophyllum spicatum L.), including interspecific hybrids with native northern watermilfoil (Myriophyllum sibiricum Kom.), managers recognize that there is genetic variation for growth and herbicide response. However, it is unclear how much overall genetic variation there is, and how it is structured within and among populations. Here, we studied patterns of within- and among-lake genetic variation in 41 lakes in Michigan and 62 lakes in Minnesota using microsatellite markers. We found that within-lake genetic diversity was generally low, and among-lake genetic diversity was relatively high. However, some lakes were genetically diverse, and some genotypes were shared across multiple lakes. For genetically diverse lakes, managers should explicitly recognize the potential for genotypes to differ in control response and should account for this in monitoring and efficacy evaluation and using pretreatment herbicide screens to predict efficacy. Similarly, managers should consider differences in genetic composition among lakes as a source of variation in the growth and herbicide response of lakes with similar control tactics. Finally, laboratory or field information on control efficacy from one lake may be applied to other lakes where genotypes are shared among lakes.

Genetic variation in the greater bilby (Macrotis lagotis)

1994 ◽  
Vol 1 (1) ◽  
pp. 46 ◽  
Author(s):  
Richard Southgate ◽  
Mark Adams
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Population Genetic ◽  
Taxonomic Status ◽  
Biological Species ◽  
Significant Loss ◽  
Allozyme Electrophoresis ◽  
Allozyme Data ◽  
Data Support

The taxonomic status of and genetic diversity amongst extant populations of the greater bilby, Macrotis lagotis, were assessed using allozyme electrophoresis. A total of 47 bilbies sampled from three geographic areas and two captive colonies were screened for 42 loci, six of which were polymorphic. The results are consistent with the view that all extant populations represent a single biological species. All populations were genetically very similar (Nei D's 0.000 to 0.004) and overall levels of within-population genetic variability were low (Ho 0.004 � 0.004 to 0.0026 � 0.017). The allozyme data support the hypothesis that there has been no significant loss of variability in the captive colonies when compared to the species as a whole.

Genetic Diversity and Population Genetic Structure in the Rare Chittering Grass Wattle, Acacia anomala Court

1988 ◽  
Vol 36 (3) ◽  
pp. 273 ◽  
Author(s):  
DJ Coates
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Genetic System ◽  
Small Population ◽  
Vegetative Multiplication ◽  
The Mean ◽  
Allozyme Loci

There are 10 known populations of Acacia anomala occurring in two small disjunct groups some 30 km apart. The Chittering populations reproduce sexually whereas the Kalamunda populations appear to reproduce almost exclusively by vegetative multiplication. The level and distribution of genetic variation were studied at 15 allozyme loci. Two loci were monomorphic in all populations. In the Chittering populations the mean number of alleles per locus was 2.0 and the expected panmictic heterozygosity (genetic diversity) 0.209. In the Kalamunda populations the mean number of alleles per locus was 1.15 and the expected panmictic heterozygosity 0.079, although the observed heterozygosity of 0.150 was only marginally less than the Chittering populations (0.177). These data support the contention that the Chittering populations are primarily outcrossing whereas the Kalamunda populations are clonal, with each population consisting of individuals with identical and, in three of the four populations, heterozygous, multilocus genotypes. The level of genetic diversity within the Chittering populations is high for plants in general even though most populations are relatively smsll and isolated. It is proposed that either the length of time these populations have been reduced in size and isolated is insufficient for genetic diversity to be reduced or the genetic system of this species is adapted to small population conditions. Strategies for the adequate conservation of the genetic resources of Acacia anomala are discussed.

scholarly journals Survival of Bighorn Sheep (Ovis canadensis) Commingled with Domestic Sheep (Ovis aries) in the Absence of Mycoplasma ovipneumoniae

2012 ◽  
Vol 48 (1) ◽  
pp. 168-172 ◽  
Author(s):  
Thomas E. Besser ◽  
E. Frances Cassirer ◽  
Catherine Yamada ◽  
Kathleen A. Potter ◽  
Caroline Herndon ◽  
...  
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Mycoplasma Ovipneumoniae

scholarly journals Phylogeographic and population genetic structure of bighorn sheep (Ovis canadensis) in North American deserts

2016 ◽  
Vol 97 (3) ◽  
pp. 823-838 ◽  
Author(s):  
Michael R. Buchalski ◽  
Benjamin N. Sacks ◽  
Daphne A. Gille ◽  
Maria Cecilia T. Penedo ◽  
Holly B. Ernest ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
North American ◽  
Population Genetic ◽  
Bighorn Sheep ◽  
Ovis Canadensis

RAPD analysis on genetic diversity of typical tea populations in Hunan Province

2008 ◽  
Vol 5 (1) ◽  
pp. 67-72
Author(s):  
Shen Cheng-Wen ◽  
Huang Yi-Huan ◽  
Huang Jian-An ◽  
Luo Jun-Wu ◽  
Liu Chun-Lin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Diversity Index ◽  
Gene Diversity ◽  
Population Variation ◽  
Hunan Province ◽  
Rapid Amplification ◽  
Population Genetic Variation ◽  
Shannon’S Diversity Index

AbstractGenetic diversity and genetic variation of 240 adult plants of four tea populations in Hunan – Camellia sinensis var. sinensis, C. sinensis var. assamica cv. Duntsa, C. ptilophylla and C. sinensis var. assamica cv. Jianghua – were studied by rapid amplification of polymorphic DNA (RAPD) markers. The results showed 226 loci using 21 random primers (10 bp), of which 201 (88.9%) were polymorphic. The genetic diversity analysis indicated that Shannon's index was 0.43; 74.7% of which was within-population genetic diversity while 25.3% was among-population variation. The gene diversity indexes of total populations (HT), within populations (HS) and among populations (HST) were, respectively, 0.37, 0.28 and 0.09. The coefficient of gene differentiation (GST) among populations was 0.23, indicating a 76.7% variation within populations and 23.3% among populations. These results displayed a rich within-population genetic variation, as in Shannon's diversity index. Interpopulation gene flow (Nm) was 0.74, which indicates the limited genetic exchange between populations.

scholarly journals Analysis of genetic diversity of bighorn sheep (Ovis canadensis) from Mexican populations

2015 ◽  
Vol 96 (3) ◽  
pp. 473-480 ◽  
Author(s):  
Marco A. Rodríguez-Rodríguez ◽  
Jaime Gasca-Pineda ◽  
Rodrigo A. Medellín ◽  
Luis E. Eguiarte
Keyword(s):  
Genetic Diversity ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Mexican Populations

High resolution DNA fingerprinting by AFLP to study the genetic variation amongOesophagostomum bifurcum(Nematoda) from human and non-human primates from Ghana

Parasitology ◽  
2004 ◽  
Vol 130 (2) ◽  
pp. 229-237 ◽  
Author(s):  
J. M. DE GRUIJTER ◽  
R. B. GASSER ◽  
A. M. POLDERMAN ◽  
V. ASIGRI ◽  
LENIE DIJKSHOORN
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Rapd Analysis ◽  
Restriction Enzymes ◽  
Parasitic Nematodes ◽  
Patas Monkey ◽  
Olive Baboon ◽  
Geographical Regions ◽  
Mona Monkey

An AFLP approach was established to investigate genetic diversity withinOesophagostomum bifurcum(order Strongylida) from human and non-human primates. Evaluation of different combinations of restriction enzymes (n=8) and primers (n=29) demonstrated that the use ofHindIII/BglII digested templates and primers with the selective nucleotides +AG/+AC, respectively, was the most effective for the analysis ofO. bifurcumDNA. A total of 63O. bifurcumadults from human, Patas monkey, Mona monkey and Olive baboon hosts from different geographical regions in Ghana were subjected to analysis using this method. Cluster analysis revealed 4 genetically distinct groups, namelyO. bifurcumfrom the Patas monkey (I), from the Mona monkey (II), from humans (III) and from the Olive baboon (IV). These findings were concordant with those achieved previously using RAPD analysis and supports population genetic substructuring withinO. bifurcumaccording to host species. The results demonstrated the effectiveness of the present AFLP method for establishing genetic variation withinO. bifurcum, and indicates its applicability to other parasitic nematodes of human and/or veterinary health importance.

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