Fatal neonatal toxoplasmosis in a bobcat (Lynx rufus)

Toxoplasma gondii was found in tissues of a captive 1-week-old bobcat (Lynx rufus) that died of myocarditis, hepatitis and encephalitis. Although infection is common in wild Felidae, clinical toxoplasmosis is rarely seen. In this case, the infection was apparently congenitally acquired.     

Seroprevalence of antibodies to Toxoplasma gondii in the Pennsylvania bobcat (Lynx rufus rufus)

From 2000 to 2002 bobcat blood samples were collected, in association with the Pennsylvania Game Commission, during the recently reactivated bobcat hunting and trapping season. Sex, age, and county/township data were recorded for each animal. Blood was tested for antibodies to Toxoplasma gondii using the modified agglutination test. In the 2-yr study, 131 bobcat samples were collected in 14 Pennsylvania counties and 109 (83%) of these had antibodies to T. gondii (titer>or=25). A two-way Chi-Square test (95% confidence interval) yielded no significance differences in antibody prevalence between males (83%) and females (88%) or adults (83%) and juveniles (77%). All 14 counties had at least one bobcat with antibodies to T. gondii.     

Transient persistence of bobcat (Lynx rufus) occurrence throughout a human-dominated landscape

Human developments have detrimental effects on wildlife populations globally with carnivores being particularly sensitive. The bobcat (Lynx rufus) is often considered an adaptable mesocarnivore that occurs throughout varied landcover types within its wide distribution and may be less susceptible to the negative effects of development. Our objectives were to investigate the landscape occupancy dynamics of bobcats in a highly developed and densely populated region of the northeastern United States to evaluate the sensitivity of bobcat occurrence to natural and anthropogenic landscape features. We established a large-scale camera trapping survey throughout Rhode Island, USA, sampling from 2018 to 2020. Using dynamic occupancy models, we found initial site occupancy was positively influenced by the amount of forested wetland habitat, while increasing road density and shrub cover negatively influenced the probability of site colonization. Surprisingly, we found no hypothesized variables to influence site-level extirpation probability, or any seasonal effects on dynamic parameters. Lastly, we found that forest cover and road density negatively influenced the probability of detection. The probability of occupancy was high, >0.8, throughout much of the study area (49%), but we also found relatively high site transients, with the probability a site would change occurrence status from season to season at ≈0.27 in the majority of the study area (70%). Our results show that although bobcats can persist in human-dominated landscapes, they require contiguous natural areas to do so. Future expansion of road infrastructure may reduce habitat connectivity and increase road mortalities, thus jeopardizing the population.     

Pleistocene and ecological effects on continental-scale genetic differentiation in the bobcat (Lynx rufus)

The potential for widespread, mobile species to exhibit genetic structure without clear geographic barriers is a topic of growing interest. Yet the patterns and mechanisms of structure--particularly over broad spatial scales--remain largely unexplored for these species. Bobcats occur across North America and possess many characteristics expected to promote gene flow. To test whether historical, topographic or ecological factors have influenced genetic differentiation in this species, we analysed 1 kb mtDNA sequence and 15 microsatellite loci from over 1700 samples collected across its range. The primary signature in both marker types involved a longitudinal cline with a sharp transition, or suture zone, occurring along the Great Plains. Thus, the data distinguished bobcats in the eastern USA from those in the western half, with no obvious physical barrier to gene flow. Demographic analyses supported a scenario of expansion from separate Pleistocene refugia, with the Great Plains representing a zone of secondary contact. Substructure within the two main lineages likely reflected founder effects, ecological factors, anthropogenic/topographic effects or a combination of these forces. Two prominent topographic features, the Mississippi River and Rocky Mountains, were not supported as significant genetic barriers. Ecological regions and environmental correlates explained a small but significant proportion of genetic variation. Overall, results implicate historical processes as the primary cause of broad-scale genetic differentiation, but contemporary forces seem to also play a role in promoting and maintaining structure. Despite the bobcat's mobility and broad niche, large-scale landscape changes have contributed to significant and complex patterns of genetic structure.     

Tetranucleotide,trinucleotide, and dinucleotide loci from the bobcat (Lynx rufus)

We describe primers and polymerase chain reaction (PCR) conditions to amplify four dinucleotide, one trinucleotide, and three tetranucleotide microsatellite DNA loci from the bobcat (Lynx rufus). The primers were tested on 22 individuals collected from a population located within southwestern Georgia (USA). The primer pairs developed in this study yielded an average of 7.4 alleles per locus (range four to 10), an average observed heterozygosity of 0.60 (range 0.40 to 0.76), and an average polymorphic information content of 0.70 (range 0.51 to 0.78).     

Responses of a transplanted troop of Japanese macaques (Macaca fuscata) to bobcat (Lynx rufus) predation

A series of encounters between a transplanted troop of Japanese monkeys (Macaca fuscata) and one or more bobcats (Lynx rufus) is described. One incident of predation was observed and four additional cases assumed. Reactions of identified individuals and groups of monkeys as well as general troop reactions are noted. The effects of breeding season behavior, troop size, differences in mother care, behavior of the bobcat, and the structure of the south Texas environment are explored. After the observed predation incident, intervention by the researchers affected the behavior of the monkeys and the bobcat, and reduced encounters.     

Helminth species diversity and biology in the bobcat, Lynx rufus (Schreber), from Nebraska

Cestodes of 4 species and nematodes of 9 species were collected from 75 bobcats, Lynx rufus (Schreber), in Nebraska from 1977 to 1979. Of these 75, 11 were trapped from 6 border counties in 3 border states: South Dakota, 7 carcasses/3 counties; Kansas, 3/2; and Wyoming, 1/1. Helminths recovered included: Mesocestoides corti Hoeppli, 1925 (15% prevalence), Taenia rileyi Loewen, 1929 (67%), Taenia pisiformis (Bloch, 1780) Gmelin, 1790 (27%), Taenia macrocystis (Diesing, 1850) Lühe, 1910 (19%), Physaloptera praeputialis von Linstow, 1889 (55%), Physaloptera rara Hall and Wigdor, 1918 (32%), Toxascaris leonina (von Linstow, 1902) Leiper, 1907 (31%), Toxocara cati (Schrank, 1780) (39%), Ancylostoma tubaeforme (Zeder, 1800) von Linstow, 1885 (5%), Pterygodermatites (Multipectines) cahirensis (J?gerski?ld, 1909) Quentin, 1969 (1%), Vogeloides felis (Vogel, 1928) Davtian, 1933 (7%), Cylicospirura felineus (Chandler, 1925) Sandground, 1932 (12%), and Capillaria aerophila (Creplin, 1839) (4%). One bobcat was not infected; 74 had 1 to 7 species (means = 3). Simpson's index for helminth species was moderately low (0.12), indicating a relatively diverse helminth fauna. Mean levels of infection between prominent species pairs and within each species were compared with bobcat sex and age differences using Student's t-test. Mean intensity of Physaloptera praeputialis was significantly (P less than 0.01) greater than that of Toxocara cati; mean intensity of Mesocestoides corti was significantly (P less than 0.01) greater than that of all other prominent species. No significant intensity differences were indicated among bobcat sex and age categories. G-tests computed for prevalence of prominent species with bobcat age indicated no significance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sarcocysts in the Florida bobcat (Felis rufus floridanus).

Sarcocysts were found in the tongue, diaphragm, heart, intestinal tunica muscularis, and skeletal muscle of bobcats (Felis rufus floridanus) collected in Florida (USA). The tongue was found to be the best indicator tissue for sarcocysts (P less than 0.005). Thirty of 60 bobcats screened were found to contain sarcocysts in at least one of the muscle tissues examined. Of the positive bobcats, 28 of 28 tongues contained sarcocysts, while only 10 of 27 (37%), and 8 of 26 (31%) contained sarcocysts in the diaphragm or cardiac muscle, respectively. Although immune suppression has been suggested as a possible reason for formation of sarcocysts in some carnivores, no such correlation was evident in the bobcats. Comparisons of prey species taken by the panther and bobcat, and overlap of geographical range by the two species leave questions as to the source of infection, and the species of Sarcocystis that is infecting both felids.     

Gene flow and pathogen transmission among bobcats (Lynx rufus) in a fragmented urban landscape

Urbanization can result in the fragmentation of once contiguous natural landscapes into a patchy habitat interspersed within a growing urban matrix. Animals living in fragmented landscapes often have reduced movement among habitat patches because of avoidance of intervening human development, which potentially leads to both reduced gene flow and pathogen transmission between patches. Mammalian carnivores with large home ranges, such as bobcats (Lynx rufus), may be particularly sensitive to habitat fragmentation. We performed genetic analyses on bobcats and their directly transmitted viral pathogen, feline immunodeficiency virus (FIV), to investigate the effects of urbanization on bobcat movement. We predicted that urban development, including major freeways, would limit bobcat movement and result in genetically structured host and pathogen populations. We analysed molecular markers from 106 bobcats and 19 FIV isolates from seropositive animals in urban southern California. Our findings indicate that reduced gene flow between two primary habitat patches has resulted in genetically distinct bobcat subpopulations separated by urban development including a major highway. However, the distribution of genetic diversity among FIV isolates determined through phylogenetic analyses indicates that pathogen genotypes are less spatially structured-exhibiting a more even distribution between habitat fragments. We conclude that the types of movement and contact sufficient for disease transmission occur with enough frequency to preclude structuring among the viral population, but that the bobcat population is structured owing to low levels of effective bobcat migration resulting in gene flow. We illustrate the utility in using multiple molecular markers that differentially detect movement and gene flow between subpopulations when assessing connectivity.     

Bobcat (Lynx rufus) Breeding in Captivity: The Importance of Environmental Enrichment

Environmental enrichment is an improvement in the biological functioning of nonhuman animals in captivity resulting from modifications to their environment; however, specifying appropriate and practical measures of enrichment is problematic. This study analyzes the behavior of 4 bobcats (Lynx rufus) in the Jerez Zoo before and after the application of a global program of environmental enrichment that included (a) changes in the size and complexity of their installations, (b) the introduction of new objects into compounds, (c) changes in diet, and (d) modifications in the grouping of animals. A factorial correspondence analysis showed a highly significant relationship among individual animals, behavior, and experimental design. Behaviors such as locomotion, repeated pacing, vigilance, and grooming more often occurred before enrichment, whereas exploratory and food behaviors were more often associated with the enrichment phase. After the implementation of the enrichment program, the bobcats bred successfully for the first time since their arrival in the zoo.     

Bobcat (Lynx rufus) breeding in captivity: the importance of environmental enrichment

Environmental enrichment is an improvement in the biological functioning of nonhuman animals in captivity resulting from modifications to their environment; however, specifying appropriate and practical measures of enrichment is problematic. This study analyzes the behavior of 4 bobcats (Lynx rufus) in the Jerez Zoo before and after the application of a global program of environmental enrichment that included (a) changes in the size and complexity of their installations, (b) the introduction of new objects into compounds, (c) changes in diet, and (d) modifications in the grouping of animals. A factorial correspondence analysis showed a highly significant relationship among individual animals, behavior, and experimental design. Behaviors such as locomotion, repeated pacing, vigilance, and grooming more often occurred before enrichment, whereas exploratory and food behaviors were more often associated with the enrichment phase. After the implementation of the enrichment program, the bobcats bred successfully for the first time since their arrival in the zoo.     

Seroprevalence of antibodies to Toxoplasma gondii in lynx (Lynx canadensis) and bobcats (Lynx rufus) from Québec, Canada.

The seroprevalence of antibodies to Toxoplasma gondii was investigated in trapped lynx (Lynx canadensis) and bobcats (Lynx rufus) from Québec, Canada. Forty-seven of 106 (44%) lynx and 4 of 10 (40%) bobcats had positive titers for T. gondii (> or = 25) by means of the modified agglutination test incorporating mercaptoethanol and formalin-fixed tachyzoites. Seroprevalence was significantly higher (P < 0.0001) in adult lynx than in juvenile lynx. The presence of antibodies to T. gondii in lynx and bobcats suggests that this organism is widespread in the wild and that exposure to wild felids and game animals from Québec may represent a potential source of infection for humans.     

Testosterone production and spermatogenesis in free-ranging Eurasian lynx (Lynx lynx) throughout the year

Seasonal variation in reproduction is common in mammals as an adaptation to annual changes in the habitat. In lynx, male reproduction activity is of special interest because female lynxes are monoestric with an unusual narrow (about 1 month) breeding season. In Eurasian lynx, mating occurs between January and April depending on the latitude. To characterize the seasonal pattern of sperm and testosterone production in free-ranging Eurasian lynxes, long-term frozen-stored testis material obtained postmortem from 74 hunted or road-killed lynxes in Sweden was used to analyze annual changes in testis mass, testicular testosterone content, and spermatogenetic activity. Values of most gonadal parameters obtained in subadult lynxes were significantly different from the values observed in adult males. In adult lynxes, a moderate annual fluctuation of gonadal parameters was found which was most profound for testis weight and testicular testosterone concentration reaching highest values in March (median of 2.18 g and 2.67 μg/g tissue respectively). Grouping the data of pre-/breeding (January–April) and postbreeding season (May–September) revealed significant changes in testis weight and testosterone concentration. The relative spermatogenetic activity remained high in postbreeding testes. However, net sperm production decreased according to reduction of testis mass and a tendency to lower cauda epididymal sperm numbers in the postbreeding period was observed. Our results demonstrate that it is possible to analyze the gonadal activity of frozen testis/epididymis tissue postmortem and that male Eurasian lynxes show—opposite to the females—only moderate seasonal changes in their reproductive capacity.     

Kinship and social structure of bobcats (Lynx rufus) inferred from microsatellite and radio-telemetry data

Kinship analysis using 12 microsatellites was compared with radio-telemetry data to examine the social structure of bobcats Lynx rufus in southern Texas. Genetically identified kinship relationships combined with capture data were used to reconstruct pedigrees. Three family groups were constructed from parent/offspring pairs identified from shared alleles. All parents identified by genetic analysis had established home ranges. Individuals with no distinct home ranges were not genetically observed to have offspring among the bobcats sampled. This suggests that establishing a home range is necessary for bobcats to breed. Of three identified male offspring and three identified female offspring, two female offspring were philopatric. These females became a part of the breeding population in their natal area. Among sibling pairs that included nine female and four male individuals, four females and one male were residents suggesting male-biased dispersal.     

Cylicospirura species (Nematoda: Spirocercidae) and stomach nodules in cougars (Puma concolor) and bobcats (Lynx rufus) in Oregon

The stomachs and proximal duodena of 160 cougars (Puma concolor) and 17 bobcats (Lynx rufus), obtained throughout Oregon during 7 yr, were examined for Cylicospirura spp. and associated lesions. Prevalence in cougars was 73%, with a range in intensity of 1-562 worms. The mean diameter of nodules was 1.2 cm (SD=0.5), and many extended through the submucosa to the muscularis. About 83% of cougars had nodules; most nodules contained worms, but 14% of the smaller nodules (<0.2 cm) contained porcupine (Erethizon dorsatum) quills. A mean of 12.4 worms/nodule (SD=34.1) was observed, with a maximum of 340 worms/nodule. Prevalence in bobcats was 53%, with an intensity of 1-25 worms. About 65% of bobcats had nodules, which were slightly smaller than those in cougars but appeared to involve similar layers of gastrointestinal tissue. One to 25 Cylicospirura sp. were found in all but two small nodules in bobcats. Cougars killed for livestock damage or safety concerns had a significantly higher median worm intensity than did those that died of other causes. Also, the median worm intensity of older cougars was higher than that of younger lions. There were more males than females killed for livestock damage or safety concerns. The cylicospirurid from cougars was Cylicospirura subaequalis, and that of bobcats was Cylicospirura felineus. These two similar species were separated morphologically by differences in tooth and sex organ morphology. They were also differentiated by DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1). Worm sequences from cougars differed from those from bobcats by 11%, whereas essentially no difference was found among worms from the same host. Phylogenetic analysis showed that within the order Spirurida, both cylicospirurids were most closely related to Spirocerca lupi, based on this gene sequence.     

Serological survey of Toxoplasma gondii infection in free-ranging Eurasian lynx (Lynx lynx) from Sweden

To investigate the prevalence of Toxoplasma gondii infection in free-ranging Eurasian lynx (Lynx lynx) in Sweden, serosanguinous fluids and feces were collected from 207 carcasses of lynx killed or found dead from 1996 to 1998. Sera were tested for antibodies against T. gondii by the direct agglutination test, and 156 (75.4%) of the sera tested positive at antibody titers>or=40. Antibody prevalence was significantly lower in lynx originating from the northern parts of Sweden than in lynx from the more southern regions that are more densely populated by humans. Age-related differences also were found, with a significantly lower prevalence (55%) in juvenile (<1-yr-old) than in subadult and adult animals (82%). There was no significant difference in seroprevalence between males and females. Oocysts typical of T. gondii were not detected in any of the fecal samples.     

Urbanization reduces genetic connectivity in bobcats (Lynx rufus) at both intra– and interpopulation spatial scales

Urbanization is a major factor driving habitat fragmentation and connectivity loss in wildlife. However, the impacts of urbanization on connectivity can vary among species and even populations due to differences in local landscape characteristics, and our ability to detect these relationships may depend on the spatial scale at which they are measured. Bobcats (Lynx rufus) are relatively sensitive to urbanization and the status of bobcat populations is an important indicator of connectivity in urban coastal southern California. We genotyped 271 bobcats at 13,520 SNP loci to conduct a replicated landscape resistance analysis in five genetically distinct populations. We tested urban and natural factors potentially influencing individual connectivity in each population separately, as well as study–wide. Overall, landscape genomic effects were most frequently detected at the study–wide spatial scale, with urban land cover (measured as impervious surface) having negative effects and topographic roughness having positive effects on gene flow. The negative effect of urban land cover on connectivity was also evident when populations were analyzed separately despite varying substantially in spatial area and the proportion of urban development, confirming a pervasive impact of urbanization largely independent of spatial scale. The effect of urban development was strongest in one population where stream habitat had been lost to development, suggesting that riparian corridors may help mitigate reduced connectivity in urbanizing areas. Our results demonstrate the importance of replicating landscape genetic analyses across populations and considering how landscape genetic effects may vary with spatial scale and local landscape structure.