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.