Thursday, June 01, 2006
Asiatic Golden Cat Research
SPATIAL ECOLOGY OF THE ASIATIC GOLDEN CAT
Researchers: Lon Grassman, Jr., Michael Tewes, and Nova Silvy (TAMU)
The Asiatic golden cat is a rare felid occurring in southeast Asia. This cat has never been studied and therefore its ecology is poorly understood. We are conducting the first ecological study of the Asiatic golden cat at the Phu Khieo Wildlife Sanctuary in Thailand. Two golden cats have been captured since the project began. The individuals were adults in good physical condition. They were each fitted with a radio-collar and tracked for several months using radio telemetry. We obtained ecological data on movement, activity patterns, and home range attributes. This baseline information on the Asiatic golden cat will allow us to better understand this species. It will yield knowledge that will be useful in planning future ecological studies of this elusive cat. Our data will also aid the development of effective conservation and management strategies for the Asiatic golden cat in this region.
Researchers: Lon Grassman, Jr., Michael Tewes, and Nova Silvy (TAMU)
The Asiatic golden cat is a rare felid occurring in southeast Asia. This cat has never been studied and therefore its ecology is poorly understood. We are conducting the first ecological study of the Asiatic golden cat at the Phu Khieo Wildlife Sanctuary in Thailand. Two golden cats have been captured since the project began. The individuals were adults in good physical condition. They were each fitted with a radio-collar and tracked for several months using radio telemetry. We obtained ecological data on movement, activity patterns, and home range attributes. This baseline information on the Asiatic golden cat will allow us to better understand this species. It will yield knowledge that will be useful in planning future ecological studies of this elusive cat. Our data will also aid the development of effective conservation and management strategies for the Asiatic golden cat in this region.
Clouded Leopard Research
ECOLOGY OF THE CLOUDED LEOPARD IN THAILAND
Researchers: Lon Grassman, Jr., Sean Austin, Michael Tewes, and Nova Silvy (TAMU)
The clouded leopard is a rare felid occurring in southeast Asia. The ecology of this species is poorly understood as well as its interactions with other felids. We are conducting the first ecological study of clouded leopards. Two study sites are located in Phu Khieo Wildlife Sanctuary and Khao Yai National Park, Thailand. Six clouded leopards have been captured during this project. The cats were aged as adults in good physical condition upon capture. They were fitted with a radio-collar and tracked for several months using radio telemetry.
Radio telemetry locations were used to determine basic natural history information such as movement, activity pattern, and home range attributes. We collected baseline ecological data on this species to better understand the carnivore community dynamics and aid in developing effective conservation and management strategies for clouded leopards in this region. We will also conduct genetic analysis of individuals monitored as well as other clouded leopards. Additionally, we collected ecological information on other species including the Asiatic wild dog, binturong (a tree-dwelling carnivore), and tiger.
This information is critical for developing, prioritizing, and implementing management and conservation strategies. More ecological information will be needed to develop better management and conservation practices in Southeast Asia as human pressures continue to increase and affect carnivores.
Researchers: Lon Grassman, Jr., Sean Austin, Michael Tewes, and Nova Silvy (TAMU)
The clouded leopard is a rare felid occurring in southeast Asia. The ecology of this species is poorly understood as well as its interactions with other felids. We are conducting the first ecological study of clouded leopards. Two study sites are located in Phu Khieo Wildlife Sanctuary and Khao Yai National Park, Thailand. Six clouded leopards have been captured during this project. The cats were aged as adults in good physical condition upon capture. They were fitted with a radio-collar and tracked for several months using radio telemetry.
Radio telemetry locations were used to determine basic natural history information such as movement, activity pattern, and home range attributes. We collected baseline ecological data on this species to better understand the carnivore community dynamics and aid in developing effective conservation and management strategies for clouded leopards in this region. We will also conduct genetic analysis of individuals monitored as well as other clouded leopards. Additionally, we collected ecological information on other species including the Asiatic wild dog, binturong (a tree-dwelling carnivore), and tiger.
This information is critical for developing, prioritizing, and implementing management and conservation strategies. More ecological information will be needed to develop better management and conservation practices in Southeast Asia as human pressures continue to increase and affect carnivores.
Leopard Cat Research
ECOLOGY OF LEOPARD CATS IN THAILAND
Researchers: Lon Grassman, Jr., Sean Austin, Michael Tewes, and Nova Silvy (TAMU)
Little ecological and behavioral information exists on leopard cats. We are studying these wild cats in Khao Yai National Park and Phu Khieo Wildlife Sanctuary. These refuges are located in a tropical evergreen forest and a mixed-evergreen forested plateau in Thailand. Sean Austin and Lon Grassman used radio-telemetry to gather data on home range size, habitat preference and use, activity patterns, and diet.
Our study is providing baseline information for this species. In Phu Khieo Wildlife Sanctuary, Lon Grassman captured, radio-collared, and tracked via radio-telemtry 26 leopard cats. In Khao Yai National Park, Sean Austin captured 16 leopard cats and radio-collared 10 for which he obtained >500 locations. Preliminary data indicate leopard cat home ranges vary 0.9-4.3 mi2. Although activity patterns were irregular, leopard cats were active primarily during daylight. We also analyzed scat composition to identify prey species consumed. We will examine genetic variation in the two study populations to provide information on population structure and geneflow of leopard cat. Microsatellite data will be compared to radio-telemetry data to gain insights into social structure.
This information will make a significant contribution to our knowledge of the species and is critical for developing, prioritizing, and implementing management and conservation strategies. More ecological information is needed to develop better management and conservation practices in Southeast Asia.
Cooperative funding by the Bosack and Kruger Foundation through the Cat Action Treasury, Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, Sierra Endangered Cat Haven, Hexagon Farm, Parco Faunistica La Torbiera, Columbus Zoo, Point Defiance Zoo, and Mountain View Farms Conservation Breeding Centre.
SURVIVAL OF LEOPARD CATS IN THAILAND
Researchers: Lon I. Grassman, Aaron M. Haines, and Michael E. Tewes
The leopard cat (Prionailurus bengalensis) is a relatively common felid found throughout southeast Asia. However, no survival estimates have been developed for this felid. Our objectives were to estimate and contrast annual survival rates for male and female radio-collared leopard cats, and compare our mean annual survival rate to previous studies. From December 1999 to December 2002, we radio-collared leopard cats in Phu Khieo Wildlife Sanctuary, Thailand. We calculated survival rates for leopard cats in 2000, 2001, and 2002. We also calculated survival rates using data from two previous radio-telemetry leopard cat studies in Malaysia and Thailand for comparison.
We found no difference in annual survival between adult male and female leopard cats in our study area. Our estimates of mean annual leopard cat survival on Phu Khieo Wildlife Sanctuary were higher than those calculated for leopard cats in Malaysia and central Thailand. Our high mean annual survival estimate of adult leopard cats may have been related to the remote location of the study area where there were minimal anthropogenic stresses on leopard cats. The two previous studies documented anthropogenic mortalities of leopard cats including hunting and vehicle-collisions. We did not observe any anthropogenic leopard cat mortalities.
Researchers: Lon Grassman, Jr., Sean Austin, Michael Tewes, and Nova Silvy (TAMU)
Little ecological and behavioral information exists on leopard cats. We are studying these wild cats in Khao Yai National Park and Phu Khieo Wildlife Sanctuary. These refuges are located in a tropical evergreen forest and a mixed-evergreen forested plateau in Thailand. Sean Austin and Lon Grassman used radio-telemetry to gather data on home range size, habitat preference and use, activity patterns, and diet.
Our study is providing baseline information for this species. In Phu Khieo Wildlife Sanctuary, Lon Grassman captured, radio-collared, and tracked via radio-telemtry 26 leopard cats. In Khao Yai National Park, Sean Austin captured 16 leopard cats and radio-collared 10 for which he obtained >500 locations. Preliminary data indicate leopard cat home ranges vary 0.9-4.3 mi2. Although activity patterns were irregular, leopard cats were active primarily during daylight. We also analyzed scat composition to identify prey species consumed. We will examine genetic variation in the two study populations to provide information on population structure and geneflow of leopard cat. Microsatellite data will be compared to radio-telemetry data to gain insights into social structure.
This information will make a significant contribution to our knowledge of the species and is critical for developing, prioritizing, and implementing management and conservation strategies. More ecological information is needed to develop better management and conservation practices in Southeast Asia.
Cooperative funding by the Bosack and Kruger Foundation through the Cat Action Treasury, Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, Sierra Endangered Cat Haven, Hexagon Farm, Parco Faunistica La Torbiera, Columbus Zoo, Point Defiance Zoo, and Mountain View Farms Conservation Breeding Centre.
SURVIVAL OF LEOPARD CATS IN THAILAND
Researchers: Lon I. Grassman, Aaron M. Haines, and Michael E. Tewes
The leopard cat (Prionailurus bengalensis) is a relatively common felid found throughout southeast Asia. However, no survival estimates have been developed for this felid. Our objectives were to estimate and contrast annual survival rates for male and female radio-collared leopard cats, and compare our mean annual survival rate to previous studies. From December 1999 to December 2002, we radio-collared leopard cats in Phu Khieo Wildlife Sanctuary, Thailand. We calculated survival rates for leopard cats in 2000, 2001, and 2002. We also calculated survival rates using data from two previous radio-telemetry leopard cat studies in Malaysia and Thailand for comparison.
We found no difference in annual survival between adult male and female leopard cats in our study area. Our estimates of mean annual leopard cat survival on Phu Khieo Wildlife Sanctuary were higher than those calculated for leopard cats in Malaysia and central Thailand. Our high mean annual survival estimate of adult leopard cats may have been related to the remote location of the study area where there were minimal anthropogenic stresses on leopard cats. The two previous studies documented anthropogenic mortalities of leopard cats including hunting and vehicle-collisions. We did not observe any anthropogenic leopard cat mortalities.
Bobcat Research
KINSHIP AND SOCIAL STRUCTURE OF BOBCATS INFERRED FROM MICROSATELLITE AND RADIO-TELEMETRY DATA
Researchers: Jan Janecka, Terry L. Blankenship (Welder Wildlife Foundation), David Hirth (University of Vermont), C. William Kilpatrick (University of Vermont), and Michael Tewes
The applications of genetics to social structure has received little attention in cat species. We are comparing kinship data from microsatellite genotypes to radio-telemetry data from previous studies to gain insights into social structure of bobcats at the Welder Wildlife Refuge and Aransas National Wildlife Refuge. Genetically identified kinship relationships combined with available radio-telemetry data are being used to reconstruct pedigrees. Family groups are genetically identified from parent-offspring pairs and sibling groups and compared to spatial distribution of the individuals.
To date all parents identified by genetic analysis at the Welder Wildlife Refuge had established home ranges, although low sample size prevents rigorous analysis. Individuals with no distinct home ranges were not genetically observed to have offspring among the bobcats sampled at Welder Wildlife Refuge. This suggests that establishing a home range is necessary for bobcats in order to breed. Juvenile females established home ranges and breed in the vicinity of their mothers. This study is ongoing and as more bobcats in these areas are trapped and collared, we will gain additional insights in to the social structure of bobcats.
Co-operative funding by the Rob and Bessie Welder Wildlife Foundation and the American Museum of Natural History.
DISPERSAL PATTERNS IN BOBCATS
Researcher: Jan Janecka, Terry Blankenship (Welder Wildlife Refuge), David Hirth (University of Vermont), William Kilpatrick (University of Vermont)
Dispersal is a mechanism which has evolved to minimize resource competition and inbreeding. Bobcats exhibit high dispersal rates. However, bobcat dispersal has never been directly studied due to the limitations associated with traditional research methods. In previous studies the limited number of dispersal events observed has prevented a rigorous characterization of dispersal patterns in bobcats.
We examined dispersal patterns in a bobcat population in south Texas using eight variable microsatellites. Relatedness among females (r = -0.013, S.E. = 0.014) was significantly higher than among males (r = -0.077, S.E. = 0.005). The distribution of pair-wise relatedness values in females was significantly different from the expected random distribution and skewed towards first- and second-degree relatives. In contrast, the male distribution of pair-wise relatedness values was not significantly different from the expected random distribution. Genetically identified parent-offspring dyads were also over-represented in females and underrepresented in males. These data provided evidence that the higher group relatedness value in females was due to a greater tendency for females to exhibit philopatric behavior than males (more first-degree relatives among females). The results supported the hypothesis that dispersal in bobcats is male-biased. The patterns of genetic variation were also consistent with observations made during a bobcat radio-telemetry study at the Welder Wildlife Refuge.
Co-operative funding by the Rob and Bessie Welder Wildlife Foundation and the American Museum of Natural History.
MICROSATELLITE ANALYSIS OF POPULATION STRUCTURE OF BOBCATS IN SOUTHERN TEXAS USING SCAT SAMPLES
Researcher: Jan Janecka, David Hirth (University of Vermont), C. William Kilpatrick (University of Vermont), and Michael Tewes
Population genetics can provide important information on population structure and dispersal of bobcats. Advances in genetics have provided methods to extract DNA suitable for population studies from samples such as scat and hair. These methods allow non-invasive sampling of bobcat populations. Obtaining blood samples is difficult due to the time necessary for trapping cats. Collecting scats can provide an efficient method for sampling bobcat populations.
We are using bobcat scat samples for the genetic analysis of population structure in south Texas. The success rate of amplification of microsatellite loci from DNA extracted from scat is low. In preliminary research, seven scat samples were analyzed from the King Ranch (Texas) for the FCA26 microsatellite locus. There were two unique alleles in King Ranch population that were not observed in the Welder Wildlife Refuge population during a previous study. The WWR population also had two rare alleles not observed in the King Ranch population. The observation that the King Ranch population has two unique alleles suggested that the bobcats from WWR and King Ranch may represent two different populations. We are optimizing amplification of other microsatellite loci. Six to eight loci will be required to examine population structure.
Co-operative funding by the Rob and Bessie Welder Wildlife Foundation and the American Museum of Natural History.
EFFECTS OF ROADS ON BOBCAT SPATIAL PATTERNS AND MORTALITY
Researchers: Michael Tewes, Jan Janecka, Stephen Webb, and Rob Hughes
Road development may influence the distribution and population dynamics of species. Developed highways may fragment populations in certain areas. Road accidents are one of the main causes of bobcat mortality in parts of Texas. The objective of this study is to examine the effects of developed roads on bobcat ecology.
We have home range data from several areas that have road networks. We are examining the avoidance/selection of home range habitat in bobcats based on road density. Results of this study will be used to plan future crossing structures in sensitive areas, as well as to develop alternatives to reduce road impacts on bobcat, and possibly ocelots.
BOBCAT USE OF DENSE THORNSHRUB IN THE TAMAULIPAN BIOTIC PROVINCE
Researchers: Nathan Cook and Michael Tewes
Ocelots prefer dense thornshrub with greater than 95% horizontal canopy cover, whereas bobcats use a variety of cover types with an emphasis on intermediate cover densities. In areas containing both types of cover, ocelot and bobcat home ranges overlapped. This study will determine whether bobcats show a higher competitive potential in areas with large tracts of dense thornshrub.
Our study area is located on private ranches in the Lower Rio Grande Valley containing large tracts of dense thornshrub communities. Although ocelots have been previously documented in our study area, none have been captured during this study. Eight bobcats have been captured and radio-collared, with one adult female lost to a vehicle collision after dispersing over 30 miles. Home range and movement patterns are being established via radio tracking of the collared bobcats. Position information will be added to a GIS database and compared to previous studies of felid use of dense thornshrub communities. Our efforts will lead to a better understanding of bobcat use of large tracts of dense thornshrub communities, and may have management implications for the endangered ocelot.
SPATIAL PATTERNS AND HABITAT USE OF AN UNHARVESTED BOBCAT POPULATION
Researchers: Jennifer M. Mock, John Hitchcock, and Michael E. Tewes
Bobcats are the most adaptable and widest ranging wild cat in North America. They occupy many diverse habitats from northern forests to southern cypress swamps. Historically, the bobcat was harvested and trapped for its spotted pelt throughout its entire range. Although pelt prices have declined over the years reducing fur trade profitability, most bobcat populations across the continent are still harvested. However, an unharvested bobcat population exists on the peninsula of Aransas National Wildlife Refuge. This provides a unique opportunity to study the spatial patterns and habitat use of an unharvested bobcat population.
Thirty-four adult bobcats were trapped and radio-collared in 1995, and tracked via radio-telemetry through October 1996. Bobcat movements were monitored to examine their home range dynamics and habitat use. We are examining the home range dynamics of this protected bobcat population and we will compare them to a harvested bobcat population from previous Feline Research Program studies. We will also contrast spatial patterns and habitat use of these different populations to better understand the spatial differences between bobcat populations and possible effects of harvesting.
Numerous studies have analyzed bobcat survival in temperate regions of North America. This study compared survival and cause-specific mortality rates of resident and transient bobcats in a sub-tropical region of southern Texas in the United States. Our objectives were to estimate seasonal and annual survival rates and cause-specific mortality rates for resident and transient bobcats, and evaluate differences between resident and transient bobcats. We conducted this study on the Welder Wildlife Foundation Refuge in San Patricio County, Texas. We radio-monitored 30 resident (15 F, 15 M) and 23 transient (9 F, 14 M) bobcats from 31 December 1993 through 1 January 2004, with 19 transients being juvenile or subadult bobcats and 26 residents being adult bobcats. Annual (P = 0.09) and seasonal (P > 0.53) survival rates did not differ significantly between male and female resident bobcats. Seasonal survival did not differ for resident (P = 0.64) and transient (P = 0.72) bobcats. Resident bobcats had a higher (P < se =" 0.04)" p =" 0.04)" p =" 0.01)">
Researchers: Jan Janecka, Terry L. Blankenship (Welder Wildlife Foundation), David Hirth (University of Vermont), C. William Kilpatrick (University of Vermont), and Michael Tewes
The applications of genetics to social structure has received little attention in cat species. We are comparing kinship data from microsatellite genotypes to radio-telemetry data from previous studies to gain insights into social structure of bobcats at the Welder Wildlife Refuge and Aransas National Wildlife Refuge. Genetically identified kinship relationships combined with available radio-telemetry data are being used to reconstruct pedigrees. Family groups are genetically identified from parent-offspring pairs and sibling groups and compared to spatial distribution of the individuals.
To date all parents identified by genetic analysis at the Welder Wildlife Refuge had established home ranges, although low sample size prevents rigorous analysis. Individuals with no distinct home ranges were not genetically observed to have offspring among the bobcats sampled at Welder Wildlife Refuge. This suggests that establishing a home range is necessary for bobcats in order to breed. Juvenile females established home ranges and breed in the vicinity of their mothers. This study is ongoing and as more bobcats in these areas are trapped and collared, we will gain additional insights in to the social structure of bobcats.
Co-operative funding by the Rob and Bessie Welder Wildlife Foundation and the American Museum of Natural History.
DISPERSAL PATTERNS IN BOBCATS
Researcher: Jan Janecka, Terry Blankenship (Welder Wildlife Refuge), David Hirth (University of Vermont), William Kilpatrick (University of Vermont)
Dispersal is a mechanism which has evolved to minimize resource competition and inbreeding. Bobcats exhibit high dispersal rates. However, bobcat dispersal has never been directly studied due to the limitations associated with traditional research methods. In previous studies the limited number of dispersal events observed has prevented a rigorous characterization of dispersal patterns in bobcats.
We examined dispersal patterns in a bobcat population in south Texas using eight variable microsatellites. Relatedness among females (r = -0.013, S.E. = 0.014) was significantly higher than among males (r = -0.077, S.E. = 0.005). The distribution of pair-wise relatedness values in females was significantly different from the expected random distribution and skewed towards first- and second-degree relatives. In contrast, the male distribution of pair-wise relatedness values was not significantly different from the expected random distribution. Genetically identified parent-offspring dyads were also over-represented in females and underrepresented in males. These data provided evidence that the higher group relatedness value in females was due to a greater tendency for females to exhibit philopatric behavior than males (more first-degree relatives among females). The results supported the hypothesis that dispersal in bobcats is male-biased. The patterns of genetic variation were also consistent with observations made during a bobcat radio-telemetry study at the Welder Wildlife Refuge.
Co-operative funding by the Rob and Bessie Welder Wildlife Foundation and the American Museum of Natural History.
MICROSATELLITE ANALYSIS OF POPULATION STRUCTURE OF BOBCATS IN SOUTHERN TEXAS USING SCAT SAMPLES
Researcher: Jan Janecka, David Hirth (University of Vermont), C. William Kilpatrick (University of Vermont), and Michael Tewes
Population genetics can provide important information on population structure and dispersal of bobcats. Advances in genetics have provided methods to extract DNA suitable for population studies from samples such as scat and hair. These methods allow non-invasive sampling of bobcat populations. Obtaining blood samples is difficult due to the time necessary for trapping cats. Collecting scats can provide an efficient method for sampling bobcat populations.
We are using bobcat scat samples for the genetic analysis of population structure in south Texas. The success rate of amplification of microsatellite loci from DNA extracted from scat is low. In preliminary research, seven scat samples were analyzed from the King Ranch (Texas) for the FCA26 microsatellite locus. There were two unique alleles in King Ranch population that were not observed in the Welder Wildlife Refuge population during a previous study. The WWR population also had two rare alleles not observed in the King Ranch population. The observation that the King Ranch population has two unique alleles suggested that the bobcats from WWR and King Ranch may represent two different populations. We are optimizing amplification of other microsatellite loci. Six to eight loci will be required to examine population structure.
Co-operative funding by the Rob and Bessie Welder Wildlife Foundation and the American Museum of Natural History.
EFFECTS OF ROADS ON BOBCAT SPATIAL PATTERNS AND MORTALITY
Researchers: Michael Tewes, Jan Janecka, Stephen Webb, and Rob Hughes
Road development may influence the distribution and population dynamics of species. Developed highways may fragment populations in certain areas. Road accidents are one of the main causes of bobcat mortality in parts of Texas. The objective of this study is to examine the effects of developed roads on bobcat ecology.
We have home range data from several areas that have road networks. We are examining the avoidance/selection of home range habitat in bobcats based on road density. Results of this study will be used to plan future crossing structures in sensitive areas, as well as to develop alternatives to reduce road impacts on bobcat, and possibly ocelots.
BOBCAT USE OF DENSE THORNSHRUB IN THE TAMAULIPAN BIOTIC PROVINCE
Researchers: Nathan Cook and Michael Tewes
Ocelots prefer dense thornshrub with greater than 95% horizontal canopy cover, whereas bobcats use a variety of cover types with an emphasis on intermediate cover densities. In areas containing both types of cover, ocelot and bobcat home ranges overlapped. This study will determine whether bobcats show a higher competitive potential in areas with large tracts of dense thornshrub.
Our study area is located on private ranches in the Lower Rio Grande Valley containing large tracts of dense thornshrub communities. Although ocelots have been previously documented in our study area, none have been captured during this study. Eight bobcats have been captured and radio-collared, with one adult female lost to a vehicle collision after dispersing over 30 miles. Home range and movement patterns are being established via radio tracking of the collared bobcats. Position information will be added to a GIS database and compared to previous studies of felid use of dense thornshrub communities. Our efforts will lead to a better understanding of bobcat use of large tracts of dense thornshrub communities, and may have management implications for the endangered ocelot.
SPATIAL PATTERNS AND HABITAT USE OF AN UNHARVESTED BOBCAT POPULATION
Researchers: Jennifer M. Mock, John Hitchcock, and Michael E. Tewes
Bobcats are the most adaptable and widest ranging wild cat in North America. They occupy many diverse habitats from northern forests to southern cypress swamps. Historically, the bobcat was harvested and trapped for its spotted pelt throughout its entire range. Although pelt prices have declined over the years reducing fur trade profitability, most bobcat populations across the continent are still harvested. However, an unharvested bobcat population exists on the peninsula of Aransas National Wildlife Refuge. This provides a unique opportunity to study the spatial patterns and habitat use of an unharvested bobcat population.
Thirty-four adult bobcats were trapped and radio-collared in 1995, and tracked via radio-telemetry through October 1996. Bobcat movements were monitored to examine their home range dynamics and habitat use. We are examining the home range dynamics of this protected bobcat population and we will compare them to a harvested bobcat population from previous Feline Research Program studies. We will also contrast spatial patterns and habitat use of these different populations to better understand the spatial differences between bobcat populations and possible effects of harvesting.
Numerous studies have analyzed bobcat survival in temperate regions of North America. This study compared survival and cause-specific mortality rates of resident and transient bobcats in a sub-tropical region of southern Texas in the United States. Our objectives were to estimate seasonal and annual survival rates and cause-specific mortality rates for resident and transient bobcats, and evaluate differences between resident and transient bobcats. We conducted this study on the Welder Wildlife Foundation Refuge in San Patricio County, Texas. We radio-monitored 30 resident (15 F, 15 M) and 23 transient (9 F, 14 M) bobcats from 31 December 1993 through 1 January 2004, with 19 transients being juvenile or subadult bobcats and 26 residents being adult bobcats. Annual (P = 0.09) and seasonal (P > 0.53) survival rates did not differ significantly between male and female resident bobcats. Seasonal survival did not differ for resident (P = 0.64) and transient (P = 0.72) bobcats. Resident bobcats had a higher (P < se =" 0.04)" p =" 0.04)" p =" 0.01)">
BOBCAT PREDATION ON QUAIL, BIRDS, AND MESOMAMMALS
Researchers: Michael E. Tewes, Jennifer M. Mock, and John Young (Texas Parks and Wildlife)
The role of bobcat predation on quail is often debated by wildlife managers and hunters. Although researchers have gathered information and performed studies about the predators of specific quail populations, quail were often the research focus while a variety of predators were monitored. Food habit studies focusing on particular predators have often been overlooked by wildlife biologists and managers. One reason is this literature occurs in a variety of sources and under titles exclusive of quail. Consequently, many biologists and managers are unaware of these sources of information.
This study extensively reviews literature and information about the food habits and foraging ecology of bobcats in the United States to determine the relative importance of various quail species in bobcat diets. Also, the use of avian prey was related to mammalian prey to better understand their relative importance in bobcat diets. Mesomammal presence in bobcat scats and stomachs was identified to determine possible interrelationships of mammalian predation on quail.
We surveyed 54 scientific articles about bobcat food habits to determine the occurrence of quail, birds, and mesomammals. Quail were found in 9 diet studies and constituted >3% of the bobcat diet in only 2 of 54 studies. Birds occurred in 47 studies, but were also a minor dietary component in most studies. Mesomammals were infrequently encountered in bobcat diets, and showed regional patterns of occurrence. Bobcats are a minor quail predator, but felid effects on mesomammals and secondary impacts on quail need to be studied.
Ocelot Research
POPULATION GENETICS OF OCELOT IN SOUTHERN TEXAS AND NORTHERN MEXICO
Researchers: Jan Janecka, Linda Laack (USFWS), Rodney Honeycutt (TAMU), Michael Tewes
Wildlife genetics is a quickly growing field because it provides new approaches for studying wildlife biology that can supplement more traditional methods such as radio-telemetry. Genetic variation has important impacts in fitness and adaptability of populations. Genetics variation also provides information on population structure, dynamics, history, and distribution of populations. Previous research has documented reduced ocelot genetic variation in southern Texas. This study will further examine population genetics of ocelot in southern Texas and northern Mexico.
We have collected blood samples from radio-collared ocelots for over 20 years and have the largest collection of ocelot samples from southern Texas. We will use microsatellites and mtDNA markers (control region and cytochrome b) to examine population genetics of ocelot. This study has several main objectives: 1) estimate movement between the two remaining ocelot populations in the United States, 2) examine the rate of genetic erosion and the implications it has on conservation decisions, and 3) examine the effects of reduced genetic variation on fitness, and 4) examine the social structure of ocelot. The reduction in genetic variation has important implications on recovery efforts for the ocelot.
HISTORIC PATTERNS IN GENETIC VARIATION OF OCELOT IN THE TAMAULIPAN BIOTIC PROVINCE
Researchers: Jan Janecka, Rodney Honeycutt (TAMU), Michael Tewes
This research project examines the temporal variation of ocelot in southern Texas and northern Mexico. This study will supplement previous work on ocelot genetics that used samples collected in the 1980’s and early 1990’s. In our previous research we found reduced genetic variation in the remaining ocelot populations of southern Texas. There are several theories that may explain this lack of variation, none of which can be rejected or supported because we have no data on historic genetic variation of ocelot in this region.
There is debate as to the implications reductions in genetic variation have on fitness and dynamics of a population. Loss of variation may cause significant reductions in fitness that may lead to extinction of small populations. Also, there is contradictory evidence that any negative effects of genetic depletion are significantly less important than demographic variables. As populations of endangered species become more reduced and isolated, it is important to determine if genetic factors limit the recovery of these species. The ocelot population in southern Texas is among the highest conservation priorities in the United States. Therefore it is important to determine the loss of genetic variation and its effects on the conservation of this species.
We are using microsatellite and mtDNA markers to examine the effects population reductions since turn of the century have had on the genetic variation of ocelot in south Texas. We will compare predicted rates of loss of variation to the genetic depletion observed. Also, we will examine the historic connectivity of ocelot populations in northern Mexico and southern Texas in order to guide any future population supplementation projects.
EVALUATING RECOVERY STRATEGIES FOR AN OCELOT POPULATION IN THE UNITED STATES
Aaron M. Haines, Michael E. Tewes, Linda L. Laack, and William E. Grant
The ocelot (Leopardus pardalis) population in the United States was listed as endangered in 1982, with only two known isolated breeding populations occurring in southern Texas. Conservation concerns for ocelots include loss of dense thornshrub habitat, mortality from ocelot-vehicle collisions, and genetic erosion. In this study, we used a population viability analysis (PVA) to evaluate three recovery strategies (i.e., habitat protection and restoration, road culvert construction, and supplementation of additional ocelots) for ocelot conservation management. We used the VORTEX (Version 9.42) program to conduct our PVA for an ocelot population located in Cameron County, Texas. Each scenario was simulated 500 times over 100 years. We compared the effectiveness of recovery strategies and combinations thereof with estimates of extinction probability. Model scenarios with no recovery strategies predicted an extinction probability of 0.65 to 0.98 for the Cameron population of ocelots over 100 years. The protection and restoration of thornshrub habitat was the most effective recovery strategy, followed by construction of culverts, and supplementation of ocelots being the least effective strategy. Preferred scenarios that reduced ocelot extinction probability to ≤0.01 over 100 years included habitat protection and restoration used simultaneously with construction of culverts, as well as all three recovery strategies used simultaneously. Protection and restoration of ocelot habitat cannot be accomplished without the participation of private landowners. Using an adaptive management approach, future actions need to be taken to monitor ocelot populations and habitats and help reduce the high probability of extinction predicted in our PVA for the ocelot population in Cameron County.
SURVIVAL AND CAUSE-SPECIFIC MORTALITY OF OCELOTS IN SOUTH TEXAS
Researchers: Aaron M. Haines, Michael E. Tewes, and Linda L. Laack
Survival and cause-specific mortality estimates are needed to develop effective conservation strategies for the ocelot in the United States. We analyzed seasonal and annual survival and cause-specific mortality rates of ocelots. We found that survival of resident ocelots was higher than of transient ocelots. Sex-specific annual survival was similar between resident ocelots and transient ocelots. Majority of mortalities observed were human caused, primarily ocelot-vehicle collisions. Transient ocelots suffered from higher natural mortality rates (disease, intraspecific mortality) than resident ocelots. Resident ocelots had higher mortality due to unidentified causes than transient ocelots.
Human population expansion within the Lower Rio Grande Valley of southern Texas will increase transportation related effects and possibly decrease the quantity of ocelot habitat. This expansion could lead to increased ocelot-vehicle collisions and possibly cause more transient behavior within ocelots, thus significantly lowering ocelot survival. Conservation strategies are needed to mitigate these impacts, and the implementation of a population viability analysis will address these concerns.
REPRODUCTIVE ECOLOGY OF OCELOT IN SOUTHERN TEXAS
Researchers: Linda Laack (USFWS), Michael Tewes, Aaron Haines, John Rappole
Data on ocelot reproductive biology is needed to develop models of population viability. The objective of this study was to gather preliminary data on ocelot parturition, fecundity, sex ratios, den characteristics and first year survival for ocelots in south Texas. Adult female resident ocelots were radio-collared and monitored to study their reproductive ecology.
Eight parturition dates ranging from mid-May to late December were observed for 6 female ocelots. Litters consisted of 1-2 kittens with a mean litter size of 1.4. Cumulative sex ratio from this study and historical observations of ocelots in southern Texas was dominated by females 1:2.2 . Six den sites were found in the study. All den sites were in close proximity to (≤ 10 m) to thorn shrub. Adult female ocelots used 2-4 den sites per litter with distance between consecutively occupied den sites ranging from 110-280 m. Ocelots aged ≤ 3 months old had a lower survival than ocelots aged 6-11 months old. Ocelots were shown to have short inter-parturition periods if a litter failed and evidence suggest that ocelots may breed more than once every other year. Results from this study provide preliminary ocelot reproduction estimates to be used in population modeling.
OCELOT SPATIAL PATTERNS RELATIVE TO ROADS IN SOUTHERN TEXAS
Researchers: Jan Janecka, Stephen Webb, Linda Laack (USFWS), Michael Tewes
One of two known ocelot populations occurs in the eastern portion of Cameron County, Texas. The road network in this area is one of the primary mortality threats to ocelots. Road development often leads to increases in human activity, habitat alterations, and road mortality. Consequently, we are exploring the distribution of ocelot home ranges relative to the road density in eastern Cameron County.
We analyzed telemetry locations of 28 ocelots (14 males, 14 females) in southern Texas and classified roads into secondary highway, hard surface, and other roads. We are examining road densities and proximity of telemetry locations to roads. Preliminary analysis suggests that ocelot home ranges have lower secondary highway mean density than the study area and greater hard surface road and other road mean densities. Ocelot locations are at greater distances from secondary roads than from hard surface roads. We are also comparing road ecology patterns in ocelot to bobcat.
Understanding the relationship between road development and ocelot distribution is important in the conservation of ocelot. We will work with U. S. Fish and Wildlife Service, Texas Department of Transportation, and Texas Parks and Wildlife to design management policies that minimize road mortality.
Cooperative funding by the Texas Department of Transportation.
IMPORTANCE OF ROAD ECOLOGY FOR OCELOT
Researchers: Jan Janecka, Michael E. Tewes, Stephen Webb, and Robert Hughes
The reduction of ocelot mortality due to automobile collisions is a priority in management of this endangered species. The primary source of documented mortality for ocelots in Texas is vehicle collisions. A proposed method to minimize the danger of road crossings has been to construct "cat underpasses" in critical areas. The Texas Department of Transportation installed 5 ocelot-crossing structures in Cameron County in an effort to reduce vehicle related deaths of ocelots. Barrier fencing was erected at 4 of the 5 crossing structures in an effort to guide the cats into the structures. The objective of this study was to monitor the use of these structures by mammals with emphasis on possible ocelot usage.
Remote infrared-triggered camera systems were placed at each of these culverts to monitor use by ocelot. Data recorded from the camera systems included date, time and species of animal using the crossing structure. Although no ocelots have been documented in over 700 trap-nights, multiple bobcats and feral house cats have been observed utilizing these structures. Results of this study will be used to plan future crossing structures in sensitive areas, as well as to develop alternatives to reduce road impacts on ocelots.
Cooperative funding by Texas Department of Transportation.
HELMINTH PARASITES OF OCELOTS FROM SOUTHERN TEXAS
Michael Tewes (professor) handling a sedated ocelot.
Researchers: Danny Pence (Texas Tech), Michael Tewes, and Linda Laack (USFW)
In order to recover ocelots, it is imperative we identify potential limiting factors that may negatively affect the population. Large populations of helminth parasites, such as hookworms and ascarid nematodes, could be pathogenic to wild ocelots. Our objective is to identify parasitism occurring in ocelots from southern Texas.
Helminth parasites collected from live-trapped ocelots will be examined for species identification. We have also examined 14 adult ocelots that died from various causes. These parasites are common species found in other wild and domestic felids in southern Texas and could be pathogenic if present in large numbers. To date, none of the adult ocelots examined have been heavily infected with helminth parasites. In fact, all of the ocelots had extremely low numbers of helminth species and individuals. Preliminary results suggest that the adult ocelot population is at little pathogenic risk by helminth parasites. However, since young animals are at higher risk for heavy ascarid infections and other potentially pathogenic helminth species, ocelot kittens and juveniles must be examined to assess the effects of helminth infections and their potential negative effects.
Researchers: Jan Janecka, Linda Laack (USFWS), Rodney Honeycutt (TAMU), Michael Tewes
Wildlife genetics is a quickly growing field because it provides new approaches for studying wildlife biology that can supplement more traditional methods such as radio-telemetry. Genetic variation has important impacts in fitness and adaptability of populations. Genetics variation also provides information on population structure, dynamics, history, and distribution of populations. Previous research has documented reduced ocelot genetic variation in southern Texas. This study will further examine population genetics of ocelot in southern Texas and northern Mexico.
We have collected blood samples from radio-collared ocelots for over 20 years and have the largest collection of ocelot samples from southern Texas. We will use microsatellites and mtDNA markers (control region and cytochrome b) to examine population genetics of ocelot. This study has several main objectives: 1) estimate movement between the two remaining ocelot populations in the United States, 2) examine the rate of genetic erosion and the implications it has on conservation decisions, and 3) examine the effects of reduced genetic variation on fitness, and 4) examine the social structure of ocelot. The reduction in genetic variation has important implications on recovery efforts for the ocelot.
HISTORIC PATTERNS IN GENETIC VARIATION OF OCELOT IN THE TAMAULIPAN BIOTIC PROVINCE
Researchers: Jan Janecka, Rodney Honeycutt (TAMU), Michael Tewes
This research project examines the temporal variation of ocelot in southern Texas and northern Mexico. This study will supplement previous work on ocelot genetics that used samples collected in the 1980’s and early 1990’s. In our previous research we found reduced genetic variation in the remaining ocelot populations of southern Texas. There are several theories that may explain this lack of variation, none of which can be rejected or supported because we have no data on historic genetic variation of ocelot in this region.
There is debate as to the implications reductions in genetic variation have on fitness and dynamics of a population. Loss of variation may cause significant reductions in fitness that may lead to extinction of small populations. Also, there is contradictory evidence that any negative effects of genetic depletion are significantly less important than demographic variables. As populations of endangered species become more reduced and isolated, it is important to determine if genetic factors limit the recovery of these species. The ocelot population in southern Texas is among the highest conservation priorities in the United States. Therefore it is important to determine the loss of genetic variation and its effects on the conservation of this species.
We are using microsatellite and mtDNA markers to examine the effects population reductions since turn of the century have had on the genetic variation of ocelot in south Texas. We will compare predicted rates of loss of variation to the genetic depletion observed. Also, we will examine the historic connectivity of ocelot populations in northern Mexico and southern Texas in order to guide any future population supplementation projects.
EVALUATING RECOVERY STRATEGIES FOR AN OCELOT POPULATION IN THE UNITED STATES
Aaron M. Haines, Michael E. Tewes, Linda L. Laack, and William E. Grant
The ocelot (Leopardus pardalis) population in the United States was listed as endangered in 1982, with only two known isolated breeding populations occurring in southern Texas. Conservation concerns for ocelots include loss of dense thornshrub habitat, mortality from ocelot-vehicle collisions, and genetic erosion. In this study, we used a population viability analysis (PVA) to evaluate three recovery strategies (i.e., habitat protection and restoration, road culvert construction, and supplementation of additional ocelots) for ocelot conservation management. We used the VORTEX (Version 9.42) program to conduct our PVA for an ocelot population located in Cameron County, Texas. Each scenario was simulated 500 times over 100 years. We compared the effectiveness of recovery strategies and combinations thereof with estimates of extinction probability. Model scenarios with no recovery strategies predicted an extinction probability of 0.65 to 0.98 for the Cameron population of ocelots over 100 years. The protection and restoration of thornshrub habitat was the most effective recovery strategy, followed by construction of culverts, and supplementation of ocelots being the least effective strategy. Preferred scenarios that reduced ocelot extinction probability to ≤0.01 over 100 years included habitat protection and restoration used simultaneously with construction of culverts, as well as all three recovery strategies used simultaneously. Protection and restoration of ocelot habitat cannot be accomplished without the participation of private landowners. Using an adaptive management approach, future actions need to be taken to monitor ocelot populations and habitats and help reduce the high probability of extinction predicted in our PVA for the ocelot population in Cameron County.
SURVIVAL AND CAUSE-SPECIFIC MORTALITY OF OCELOTS IN SOUTH TEXAS
Researchers: Aaron M. Haines, Michael E. Tewes, and Linda L. Laack
Survival and cause-specific mortality estimates are needed to develop effective conservation strategies for the ocelot in the United States. We analyzed seasonal and annual survival and cause-specific mortality rates of ocelots. We found that survival of resident ocelots was higher than of transient ocelots. Sex-specific annual survival was similar between resident ocelots and transient ocelots. Majority of mortalities observed were human caused, primarily ocelot-vehicle collisions. Transient ocelots suffered from higher natural mortality rates (disease, intraspecific mortality) than resident ocelots. Resident ocelots had higher mortality due to unidentified causes than transient ocelots.
Human population expansion within the Lower Rio Grande Valley of southern Texas will increase transportation related effects and possibly decrease the quantity of ocelot habitat. This expansion could lead to increased ocelot-vehicle collisions and possibly cause more transient behavior within ocelots, thus significantly lowering ocelot survival. Conservation strategies are needed to mitigate these impacts, and the implementation of a population viability analysis will address these concerns.
REPRODUCTIVE ECOLOGY OF OCELOT IN SOUTHERN TEXAS
Researchers: Linda Laack (USFWS), Michael Tewes, Aaron Haines, John Rappole
Data on ocelot reproductive biology is needed to develop models of population viability. The objective of this study was to gather preliminary data on ocelot parturition, fecundity, sex ratios, den characteristics and first year survival for ocelots in south Texas. Adult female resident ocelots were radio-collared and monitored to study their reproductive ecology.
Eight parturition dates ranging from mid-May to late December were observed for 6 female ocelots. Litters consisted of 1-2 kittens with a mean litter size of 1.4. Cumulative sex ratio from this study and historical observations of ocelots in southern Texas was dominated by females 1:2.2 . Six den sites were found in the study. All den sites were in close proximity to (≤ 10 m) to thorn shrub. Adult female ocelots used 2-4 den sites per litter with distance between consecutively occupied den sites ranging from 110-280 m. Ocelots aged ≤ 3 months old had a lower survival than ocelots aged 6-11 months old. Ocelots were shown to have short inter-parturition periods if a litter failed and evidence suggest that ocelots may breed more than once every other year. Results from this study provide preliminary ocelot reproduction estimates to be used in population modeling.
OCELOT SPATIAL PATTERNS RELATIVE TO ROADS IN SOUTHERN TEXAS
Researchers: Jan Janecka, Stephen Webb, Linda Laack (USFWS), Michael Tewes
One of two known ocelot populations occurs in the eastern portion of Cameron County, Texas. The road network in this area is one of the primary mortality threats to ocelots. Road development often leads to increases in human activity, habitat alterations, and road mortality. Consequently, we are exploring the distribution of ocelot home ranges relative to the road density in eastern Cameron County.
We analyzed telemetry locations of 28 ocelots (14 males, 14 females) in southern Texas and classified roads into secondary highway, hard surface, and other roads. We are examining road densities and proximity of telemetry locations to roads. Preliminary analysis suggests that ocelot home ranges have lower secondary highway mean density than the study area and greater hard surface road and other road mean densities. Ocelot locations are at greater distances from secondary roads than from hard surface roads. We are also comparing road ecology patterns in ocelot to bobcat.
Understanding the relationship between road development and ocelot distribution is important in the conservation of ocelot. We will work with U. S. Fish and Wildlife Service, Texas Department of Transportation, and Texas Parks and Wildlife to design management policies that minimize road mortality.
Cooperative funding by the Texas Department of Transportation.
IMPORTANCE OF ROAD ECOLOGY FOR OCELOT
Researchers: Jan Janecka, Michael E. Tewes, Stephen Webb, and Robert Hughes
The reduction of ocelot mortality due to automobile collisions is a priority in management of this endangered species. The primary source of documented mortality for ocelots in Texas is vehicle collisions. A proposed method to minimize the danger of road crossings has been to construct "cat underpasses" in critical areas. The Texas Department of Transportation installed 5 ocelot-crossing structures in Cameron County in an effort to reduce vehicle related deaths of ocelots. Barrier fencing was erected at 4 of the 5 crossing structures in an effort to guide the cats into the structures. The objective of this study was to monitor the use of these structures by mammals with emphasis on possible ocelot usage.
Remote infrared-triggered camera systems were placed at each of these culverts to monitor use by ocelot. Data recorded from the camera systems included date, time and species of animal using the crossing structure. Although no ocelots have been documented in over 700 trap-nights, multiple bobcats and feral house cats have been observed utilizing these structures. Results of this study will be used to plan future crossing structures in sensitive areas, as well as to develop alternatives to reduce road impacts on ocelots.
Cooperative funding by Texas Department of Transportation.
HELMINTH PARASITES OF OCELOTS FROM SOUTHERN TEXAS
Michael Tewes (professor) handling a sedated ocelot.
Researchers: Danny Pence (Texas Tech), Michael Tewes, and Linda Laack (USFW)
In order to recover ocelots, it is imperative we identify potential limiting factors that may negatively affect the population. Large populations of helminth parasites, such as hookworms and ascarid nematodes, could be pathogenic to wild ocelots. Our objective is to identify parasitism occurring in ocelots from southern Texas.
Helminth parasites collected from live-trapped ocelots will be examined for species identification. We have also examined 14 adult ocelots that died from various causes. These parasites are common species found in other wild and domestic felids in southern Texas and could be pathogenic if present in large numbers. To date, none of the adult ocelots examined have been heavily infected with helminth parasites. In fact, all of the ocelots had extremely low numbers of helminth species and individuals. Preliminary results suggest that the adult ocelot population is at little pathogenic risk by helminth parasites. However, since young animals are at higher risk for heavy ascarid infections and other potentially pathogenic helminth species, ocelot kittens and juveniles must be examined to assess the effects of helminth infections and their potential negative effects.
Molecular Genetics Research
APPLYING MOLECULAR MARKERS TO ECOLOGY, BEHAVIOR, AND POPULATION HISTORY OF WILD CATS IN TEXAS
Researchers: Jan E. Janecka, Michael Tewes, John Young (TPWD), Linda Laack (USFWS), Rodney Honeycutt (TAMU)
Bobcat, ocelot, jaguarundi, and mountain lion are four species of felids present in Texas. Bobcats are abundant throughout the United States and Texas. Mountain lions are distributed throughout the western United States and western and southern Texas. In contrast, ocelots are primarily found in Central and South America and southern Texas. Although jaguarundis are found in Central and South America, their presence in Texas is doubtful. In Texas, the majority of the studies on these cats have focused on habitat use, activity, and diet. There have been few studies on population genetics of these species. Two of the most recent projects were conducted by Chris Walker on ocelot and bobcat (at Texas A&M University with Drs. Tewes and Honeycutt) and Jan Janecka on bobcat (at University of Vermont with Drs. Hirth and Kilpatrick).
We have been collecting scat samples from throughout this region for over 20 years and have a large number of ocelot, bobcat, and mountain lion samples. We are continuing to collect samples with the cooperation of Texas Parks and Wildlife, Wildlife Services, U. S. Fish and Wildlife Service, Welder Wildlife Foundation, and private landowners. This study will examine genetic variation of wild cats in Texas using both microsatellites and mtDNA. We will compare differences in genetic variation, geneflow, and dispersal between the cat species and relate them to known differences in ecology and behavior. This study has four main emphases: 1) examine population structure and patterns in genetic variation, 2) estimate recent fluctuations in population size, 3) combine genetic data with radio-telemetry to examine dispersal and social structure, and 4) compare the differences and similarities between these four cat species.
CONSERVATION GENETICS OF WILD AND CAPTIVE CATS IN THAILAND
Researchers: Jan E. Janecka, Lon I. Grassman, Dr. Whichan Eiadthong (Department of Forest Biology, Kasetsart University, Thailand), Michael Tewes
Population genetics has become an important tool for wildlife conservation and captive breeding programs. The application of genetics to conservation biology has provided critical insight into the status, history, and conservation of threatened populations and captive breeding programs. There is extremely limited ecological information on the clouded leopard, Asiatic golden cat, marbled cat, and leopard cat and no knowledge on population genetics of these species. In addition, Thailand Zoological Parks Organization has clouded leopards, Asiatic golden cats, marbled cats, fishing cats, and leopard cats that have not been genetically analyzed.
Our field research of wild cats in Thailand has resulted in a unique opportunity to examine samples valuable for the study and conservation of these species both in the wild and in captivity. We have also recently approached Thailand Zoological Parks Organization to obtain access to samples from captive cats maintained in membership zoos. We will use microsatellite loci and mitochondrial DNA sequences to: (1) examine genetic erosion that may have occurred in wild and captive clouded leopard and leopard cat due to fragmentation and reductions in population size, (2) provide baseline data on genetic variation of clouded leopard, Asiatic golden cat, marbled cat, and leopard cat in wild and captive populations in Thailand, (3) provide genetic information on captive populations that will be pertinent to breeding and zoo exchange strategies, (4) estimate the level of dispersal and geneflow between Phu Khieo Wildlife Sanctuary and Khao Yai National Park, (5) estimate long-term effective population size (Ne) and recent reductions/expansions of leopard cat, and (6) support and expand a wildlife genetics laboratory at Kasetsart University (Bangkok, Thailand).
ESTIMATING EFFECTIVE POPULATION SIZE USING GENETIC METHODS
Researchers: Jan Janecka, Michael Tewes, John Young (TPWD), Rodney Honeycutt (TAMU)
It is important to monitor effective population size (Ne) because it has a strong effect on genetic variation. Analysis of Ne provides insights into the stability and viability of a population. The Ne of a population is defined as the size of an ideal population that has the same genetic behavior as the study population. Wild populations often violate assumptions made in many genetic models. For example, only a portion of all individuals breed and mating is not random. Due to these violations, Ne is always lower than the actual census population size. Because Ne has predictable effects on genetic variation it can be estimated from genetic data (although estimation can be problematic).
We will use several different models to estimate Ne of mountain lion, bobcat, and ocelot in Texas. Different models will be tested for biologically meaningful estimates against each other. The confidence intervals of different models will be compared. The effects of sample size, number of molecular markers, and types of molecular markers used on different models will also be tested. The goal of this project will be to design methods for estimating Ne of wild cats that is biologically meaningful and informative for management purposes. This project will be done in close cooperation with Texas Parks and Wildlife.
ANALYSIS OF SCAT SAMPLES USING MICROSATELLITES AND MtDNA MARKERS
Researchers: Jan E. Janecka, Michael Tewes, Rodney Honeycutt (TAMU)
Studies on elusive species (such as felids) are often limited by small sample sizes. The time and financial cost of obtaining a large sample is often prohibitive. Invasive studies may also be complicated by the interference effects of capturing animals. However, non-invasive sampling such as collecting scat or hair samples is in some cases a simple and efficient way to obtain wildlife samples. For some cat species such as bobcat, scat is often visible and easy to find, providing researchers with a large sample per unit effort.
Successful genetic analyses have been done on DNA extracted from scat samples. However, several factors complicate DNA analysis of scat. These factors include DNA degradation due to the harsh environment of the digestive track, low amounts of target DNA, and allele drop-out. Despite these difficulties, other researchers have amplified DNA from scat from various species including grey seals (Halichoerus grypus), harbor seals (Phoca vitulina), bears (Ursidae), mountain lions (Puma concolor), and bobcats (Lynx rufus).
This study has several objectives: 1) develop an easily assayed species specific genetic marker for differentiating ocelot, bobcat, jaguarundi, and mountain lion that is efficiently amplified in scat, and 2) identify microsatellites that will provide efficient genotyping of scat samples for mark-recapture or rarefaction estimates of population size. In some areas this may eliminate the need to capture felids for the purpose of obtaining DNA, saving significant amounts of time and financial expenditures.
ESTIMATING POPULATION SIZE AND DISTRIBUTION USING SCAT SURVEYS
Researchers: Jan Janecka, John Young (TPWD), Michael Tewes, Rodney Honeycutt (TAMU)
It is very difficult to estimate population size of elusive carnivores that occur at low densities, such as mountain lion and ocelot. Yet these species are a high management priority in Texas. The size and distribution of populations has to be accurately described to make good management decisions. The latest methods for estimating population size utilize survey schemes that non-invasively sample populations, then use genetic markers to identify individuals, and finally estimate population size from the data using mark-recapture or rarefaction models.
In this project, we will develop scat collection schemes that will effectively sample a population in a representative area. A portion of the cytochrome b sequence will be used for species identification of questionable scat. Individuals sampled will be identified by genotyping scat using a sufficient number of microsatellite loci. Population size will be estimated for the study area using either the rarefaction or mark-recapture model (depending on the survey method). We will test the applicability of this method for estimating population size of mountain lion, ocelot, and bobcat.
HISTORIC GENETIC VARIATION OF WILD CATS IN TEXAS
Researchers: Jan E. Janecka, Michael Tewes, Rodney Honeycutt (TAMU)
Genetic factors must be taken into account for long-term management of threatened populations. To provide more detailed information on population genetics of ocelot and bobcat, this study will examine the temporal continuity of these cats in Texas. We will examine the patterns in genetic variation of historic populations by analyzing museum specimens and compare them to current populations. The effects that population fluctuations in the 20th century have had on genetic variation will be studied.
Ocelot and bobcat museum specimens collected around 1900 will represent historic populations. Samples collected in the 1990's will represent current populations. We will use microsatellite, control region, cytochrome b, and Major Histocompatibility Complex (MHC) markers to address the following objectives: 1) compare historic and current genetic variation, 2) examine the geographic origin of current populations in southern Texas, 3) compare the differences in genetic erosion between neutral markers (microsatellites and mtDNA) and adaptive loci (MHC). We will generate historic baseline data on genetic variation for future studies and monitoring of ocelot and bobcat in southern Texas.
The contradictory evidence and the lack of understanding of the effects of genetic depletion on fitness in wild populations are partly due to the limited number of studies conducted that compare current variation to historic variation. Genetic data from this study will increase our understanding of temporal changes in genetic variation and make an important contribution towards testing current hypotheses on conservation biology and genetics.
Mountain Lion Research
POPULATION GENETICS OF MOUNTAIN LION IN TEXAS
Researchers: Jan Janecka, John Young (Texas Parks and Wildlife), Michael Tewes
Several important population parameters that must be taken into consideration for management of mountain lions in Texas are the stability and size of the population and population structure. The goal of this project is to examine population genetics of mountain lions in Texas. This study will provide information on population subdivision, gene flow, and population history that will be useful for management decisions. This project is being conduct with support and funding from the Texas Parks and Wildlife Department.
In a previous study, Walker et al. (2000) found evidence that mountain lions in Texas have reduced genetic variation compared to other regions of the country. In addition, they found that mountain lions from south and west Texas regions represent two subpopulations with reduced gene flow. However, due to the limited sample size they were unable to make clear management recommendations.
We will use microsatellite loci to examine population parameters and structure of mountain lions in Texas. We will address the following objectives: (1) characterize population structure in Texas, (2) estimate the level of geneflow between metapopulations, and (3) examine if the mountain lion population has recently expanded or been reduced.
Interspecific competition between jaguars and pumas: A REVIEW
Aaron M. Haines
The jaguar (Panthera onca) and puma (Puma Concolor) are both large high trophic level carnivores that coexist throughout Central and most of South America. Many studies have been conducted that have theorized about methods of coexistence exhibited by sympatric jaguars and pumas. By reviewing the literature, I assessed if habitat and/or prey are partitioned between jaguars and pumas. Many studies support the concept of prey portioning between pumas and jaguars where the species are sympatric. In addition, it is hypothesized that pumas in the tropics have a smaller body size to select smaller prey items to minimize competition with jaguars. However, evidence may suggest that puma size throughout its range may simply reflect the fact that they have evolved to concentrate on various prey species regardless of competition with jaguars. However, current anthropogenic effects can potentially cause changes between jaguar and puma coexistence. Jaguars may suffer more from declining prey populations caused by man because of predator/prey relationships in Neotropical environments, and the jaguar’s dependence on diverse Neotropical prey species. However, the more adaptable puma may fair better under current anthropogenic effects being more a generalist and able to adapt quicker by sustaining itself on smaller and more diverse prey species.
