Recently Completed Projects
Ongoing Projects
Estimation
of the Past Effective Population Size in Florida Panthers
Principal
Investigators: Melanie Culver and Phil Hedrick
The
decline of pumas (Puma concolor) began when the Americas were settled by Europeans.
Pumas were aggressively hunted and bounties were offered for their scalps. In
the eastern United States by the late 1920s, pumas were only present in central
and south Florida and possibly along some river drainages in Louisiana (Young
& Goldman 1946). The numbers in Florida continued to decline because of
continued persecution (Tinsley 1970) and in 1967, the Florida panther (P. concolor
coryi) was federally listed as endangered. The number of Florida panthers found
over most of the 1980s and early 1990s was between 30 and 50. In the late 1990s,
the census population number has been estimated at around 70 (Land & Lacy
2000) but the present distribution constitutes less than 5% of the area once
occupied by the Florida panther. Obviously, it is not possible to obtain direct
estimates of the effective population size of the Florida panther during much
of the twentieth century but we can assume that the numbers were fairly large
in the late 1800s, declined throughout much of the 1900s, reaching very low
numbers in the 1960s and 1970s, and have since increased. There are some museum
samples from the 1890s, before much of the decline in numbers. A comparison
of the extent of molecular genetic variation present in these museum samples
to that found in contemporary animals can give an estimate of size and extent
of this bottleneck, i.e., the effective population size necessary to result
in the observed decline in genetic variation.
Use
of Clinch River Mussel Populations to Restore the Powell River Mussel Fauna
Principal
Investigators: Melanie Culver and Dick Neves
The
dMany speices of freshwater mussels in the Clinch River and Powell River watersheds
in Virginia are of concern because of their rarity and endangered status. When
restoration efforts involve translocation of individuals between watersheds
it is imperative to know the evolutionary relationship among populations from
different watersheds. To investigate the relatedness of mussel populations in
the Clinch River and Powell River watersheds, we propose to use both mitochondrial
and nuclear DNA markers. Molecular genetic markers are useful to examine the
evolutionary relationships, as well as quantify the amount of genetic variation.
When utilized together, the nuclear ITS-1 region and the maternally inherited,
rapidly evolving, mitochondrial COI gene should provide independent and informative
markers for robust taxonomic analyses of several mussel species.
Microsatellite
Marker Development in Bald Eagle, Freshwater Mussel and Muskellunge
Principal
Investigator: Melanie Culver
Microsatellite
markers are high resolution genetic loci that can provide useful information
on genetic diversity, paternity/maternity, relatedness, and individual identification
for free-ranging populations. Specifically, the goal of this proposed project
is to develop high-resolution markers for a variety of species, and apply these
markers to specific questions of conservation concern. The species used for
this project include bald eagle (Haliaeetus leucocephalus), tan riffelshell
mussel (Epioblasma capsaeformis), and muskellunge (Esox masquinongy). Microsatellites
for each species of interest will be developed using a capture hybridization
method. The resulting genetic markers will be used for paternity/maternity determination
in bald eagle nestlings, subspecies-level taxonomy in tan riffelshell mussels,
and population differentiation in muskellunge.
Feasibility
of Extracting Florida Panther DNA from Scats
Principal
Investigators: Melanie Culver
Genetic
studies over the past 2 decades have shown Florida panthers to have severely
reduced genetic diversity, compared to other North American pumas. Subsequently,
a recovery plan was developed to restore genetic diversity to Florida panthers
through the introduction of 8 female Texas pumas into the Florida population.
Included in the recovery plan was continued monitoring of genetic characteristics
of the Florida panther population. Our objectives were to evaluate the feasibility
of extracting and analyzing DNA from panther scats. Panther scats could potentially
offer the safest and most cost effective tool for censussing numbers of panthers,
measuring population genetic health, and identifying the origins of puma sign
found outside of core panther areas. We will determine if panther DNA can be
extracted from scats and if this material can then be used to identify individual
panthers, provide a measure of genetic diversity, and indicate the proportion
of alleles originating from Texas versus Florida panther individuals. DNA analysis
from scats could complement or replace handling of live cats depending on specific
goals of the ongoing genetic character assessments.
Conservation
Genetics and Population Dynamics of Black Bears in Arizona
Principal
Investigators: Melanie Culver and Paul Krausman
Graduate
Research Associate: Cora Varas (PhD candidate)
Fragmentation
or perturbation of a species habitat can lead to genetic changes among the separate
populations. Frequently these changes can have adverse implications for the
conservation of the species. There is increasing concern about the long-term
survival of black bear (Ursus americanus) populations in Arizona and the southwest
deserts. In southwest deserts, black bear habitat occurs in mountain “sky
islands” which are separated by a “sea” of desert and grasslands.
A continuous and careful monitoring of connectivity among sky islands and management
units is important to ensure the black bear’s continued existence in the
southwest deserts of North America (including Arizona, New Mexico, Utah, Colorado,
and Mexico). We will examine the historical and current population structure,
genetic variability, and bear movements to document how these factors have changed
over time. Historical black bear samples will be collected from specimens located
in North American museums and current samples will be provided from several
sources (Arizona Game and Fish Department, hunters, field collections from different
bear management units in Arizona, and field collaborators in Mexico). Molecular
markers (mitochondrial DNA and microsatellites) will be used to execute the
genetic analyses on the black bear samples. These molecular markers can determine
the amount of gene flow, as well as estimate the genetic variability, population
size, amount of inbreeding and pairwise genetic distances among populations.
This analysis of genetic structure of southwestern bear populations, from historical
times through current populations, will be used to understand the ecological
factors that may be influencing the long-term survival of black bears in the
southwest desert habitats, and aid resource agencies to improve black bear population
management.
Carnivore
Composition and Abundance in Grand Canyon and other Southwestern National Parks
Principal
Investigator: Melanie Culver and Elaine Leslie
There
is a lack of quantitative information regarding the species composition and
population size for carnivores in National Parks of Arizona and New Mexico.
Non-invasive samples (hair and scat) are being collected from several National
Parks in Arizona and New Mexico and these samples will be subjected to a series
of genetic tests. First, species ID will be performed using mitochondrial DNA
sequence data from the 16S rRNA gene. If species ID indicates that the sample
was obtained from a felid, then sex determination will be performed using a
felid Y-chromosome gene (ZFY) and individual identification will be performed
using 10 felid microsatellite loci. These highly polymorphic microsatellite
markers are able to distinguish unique individuals, therefore, a minimum number
of individuals can be determined for the samples analyzed. Final results will
indicate the carnivore composition in several southwestern National Parks, and
for felids, will indicate the sex ratio and minimum population size for each
species. In addition, the resulting data will be provide an estimate of the
amount of gene flow (migration) occurring among these parks, for felid species.
DNA
sequence variation in the 12S Mitochondrial gene in the eastern Salamanders
of the Genus Plethodon
Principal
Investigator: Melanie Culver and Richard Highton
Hypothesis
on the evolutionary relationships of salamanders of the woodland salamander
genus Plethodon, based on previous morphological, allozyme, immunological, and
DNA hybridization studies, have largely been in agreement. There are two major
divisions in the genus: eastern and western clades, each with four species groups,
and 53 currently recognized species. However, detailed studies of the eastern
species groups have revealed that there are numerous cryptic species present
in the genus. In order to investigate further the phylogenetic relationships
among the species of eastern Plethodon, 360 base pairs of the 12s ribosomal
RNA mitochondrial gene have been sequenced in 44 species of eastern Plethodon.
The results were compared to those of previous allozyme and morphological studies.
The results will attempt to resolve evolutionary relationships among some of
these cryptic species of eastern Plethodon.
Genetic
Differentiation of Water Shrews in Arizona and the Southern Rocky Mountains
Principal
Investigator: Melanie Culver
Graduate
Research Associate: Tracy Scheinkman (PhD candidate)
This
preliminary study proposes to examine mitochondrial molecular genetic markers
in Sorex palustris navigator from Arizona, New Mexico, Colorado, and Utah, for
evidence of genetic differentiation between Arizona and the others. Mirochondrial
DNA sequence, from regions previously used to study shrew species (ND4, Cyt
B, 12S, and D-Loop) will be utilized. In Arizona the water shrew is listed as
a wildlife species of special concern. The Arizona water shrew population which
occurs in the White Mountains, is disjunct from the other nearby populations,
therefore may be genetically differentiated. Wildlife managers in Arizona, both
at the state and federal level, are concerned about the subspecies status of
the White Mountains population since its occurrence in Arizona may be in jeopardy
due to its rarity. This study can help resolve a subspecies-level taxonomic
uncertainty as well as provide important information to wildlife managers.
Genetic
Identification of Fish Species Found in Stomachs of Crayfish in the Verde River
Principal
Investigator: Scott Bonar, Melanie Culver
Undergraduate
Research Associate: Didio Martinez
Crayfish
masticate their food to the extent that their stomach contents are devoid of
any morphological traits to utilize for species identification of what they
eat. Crayfish may be consuming potentially endangered native fish species as
part of their diet. This preliminary study will examine the feasibility of using
stomach contents as a source of DNA for identification of fish species consumed
by crayfish. The mitochondrial cytochrome b gene was selected as an appropriate
genetic marker because it is the most common DNA sequence found in the genetic
database of Arizona native fish species. It would be useful for fisheries managers
to know what species are being consumed by the non-native crayfish living in
the Verde River.