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1.
The results of a parasitological survey carried out on 116 cats found dead in Bologna, Firenze and Milano was reported. The parasites identified were: Toxocara cati (49.1%); Toxascaris leonina (3.4%); Ancylostoma tubaeforme (9.5%); Ollulanus tricuspis (3.4%); Dipylidium caninum (41.4%); Taenia taeniaeformis (11.2%); Mesocestoides lineatus (1.7%); Spirometra sp. (0.9%); Coccidia (12.9%). The autopsies' results were compared with coprological ones in order to assess their reliability.  相似文献   

2.
Piroplasms, morphologically indistinguishable from Cytauxzoon felis, previously were detected in 36% of cougars in Florida. We utilized a nested 18S rRNA assay, which amplifies DNA from all piroplasms, to screen blood samples collected from 41 cougars from Florida (39 native Florida panthers [Puma concolor coryi] and two translocated Texas cougars [P. c. stanleyana]) from 1989-2005. Thirty-nine of the 41 cougars (95%) were positive for piroplasms; however, sequence analysis and restriction enzyme digestion revealed that only five were positive for C. felis. Samples from 32 cougars were positive for a Babesia sp. Two cougars were co-infected with both C. felis and the Babesia sp. Phylogenetic analysis of 18S rRNA gene sequence indicated that the Florida panther Babesia sp. was most closely related to a Babesia sp. reported from Ixodes ovatus from Japan, Babesia divergens, and Babesia odocoilei. This study indicates that Florida panthers harbor two distinct piroplasms, C. felis and a Babesia sp., and that some individuals are infected with both organisms. The infectivity and pathogenicity of this Babesia sp. for domestic cats is unknown. This represents the first report of a feline Babesia sp. in North America.  相似文献   

3.
Several phorid fly species were introduced to the southern United States for biological control of the invasive imported fire ants, Solenopsis richteri (Black), Solenopsis invicta (Red), and their Hybrid S. richteri×S. invicta (Hybrid). It has been previously reported that the Jaguariuna biotype of Pseudacteon tricuspis and the Formosan biotype of Pseudacteon curvatus could distinguish among the three fire ant species with greater preference for Hybrid and Red fire ants. We hypothesized that phorid flies might use host derived chemical cues to differentiate ant species. To determine possible differential olfactory sensitivity of phorid fly species to different fire ant species, we compared electroantennogram (EAG) and behavioral responses of both sexes of P. tricuspis and P. curvatus to body extracts of Black, Red and Hybrid fire ants. As worker sizes of Black and Hybrid fire ants used in this study were much larger than that of Red fire ant (the average weight for Black, Red and Hybrid workers was 1.707, 0.863, 1.223mg per ants, respectively), at doses of 0.01, 0.1, 1 worker equivalent, body extracts of Black and Hybrid fire ant elicited significantly greater EAG response in both sexes of P. tricuspis than that of Red fire ant. Similarly, the EAG response in female P. curvatus to body extract of Black fire ant was significantly greater than to body extract of Red fire ant. To eliminate worker size influence on EAG response in phorid flies, we conducted a second EAG study using a dose of 1mg ant equivalent (body extract from 1mg of worker). No difference in EAG responses was recorded to body extract obtained from the same amount of workers among the three fire ant species (we consider viable Hybrid fire ant as a species in this paper), suggesting that worker size differences contributed to difference in EAG response in the first EAG study. In both EAG studies, male P. tricuspis showed significantly greater EAG responses than male P. curvatus to all three fire ant species. In four-way olfactometer bioassay, worker body extracts of all three fire ant species were equally attractive to P. tricuspis and P. curvatus (i.e. both phorid fly species did not show any preferences among the three fire ant species). Together, the results of the EAG and behavior studies suggest that parasitic phorid flies utilize host derived non-polar compounds from worker ants extracted out by hexane for host location but not for host preference, since both fly species are not able to distinguish among the body extracts of the three fire ant species. Future study will investigate possible involvement of polar compounds and/or non-chemical cues in mediating host preference by phorid flies.  相似文献   

4.
As human populations continue to expand across the world, the need to understand and manage wildlife populations within the wildland – urban interface is becoming commonplace. This is especially true for large carnivores as these species are not always tolerated by the public and can pose a risk to human safety. Unfortunately, information on wildlife species within the wildland – urban interface is sparse, and knowledge from wildland ecosystems does not always translate well to human‐dominated systems. Across western North America, cougars (Puma concolor) are routinely utilizing wildland – urban habitats while human use of these areas for homes and recreation is increasing. From 2007 to 2015, we studied cougar resource selection, human–cougar interaction, and cougar conflict management within the wildland – urban landscape of the northern Front Range in Colorado, USA. Resource selection of cougars within this landscape was typical of cougars in more remote settings but cougar interactions with humans tended to occur in locations cougars typically selected against, especially those in proximity to human structures. Within higher housing density areas, 83% of cougar use occurred at night, suggesting cougars generally avoided human activity by partitioning time. Only 24% of monitored cougars were reported for some type of conflict behavior but 39% of cougars sampled during feeding site investigations of GPS collar data were found to consume domestic prey items. Aversive conditioning was difficult to implement and generally ineffective for altering cougar behaviors but was thought to potentially have long‐term benefits of reinforcing fear of humans in cougars within human‐dominated areas experiencing little cougar hunting pressure. Cougars are able to exploit wildland – urban landscapes effectively, and conflict is relatively uncommon compared with the proportion of cougar use. Individual characteristics and behaviors of cougars within these areas are highly varied; therefore, conflict management is unique to each situation and should target individual behaviors. The ability of individual cougars to learn to exploit these environments with minimal human–cougar interactions suggests that maintaining older age structures, especially females, and providing a matrix of habitats, including large connected open‐space areas, would be beneficial to cougars and effectively reduce the potential for conflict.  相似文献   

5.
Aims To examine the spatio‐temporal co‐occurrence of cougars (Felis concolor), wolves (Canis lupus), and their prey during winter using monthly (November–March) species–environment relationship models. In addition, to contrast predictions across two methods: logistic regression and Geographic Information System (GIS) image correlation. Location The eastern front ranges of the Canadian Rocky Mountains (south‐central Alberta), approximately 100 km west of Calgary, including portions of Banff National Park and Kananaskis Country. Methods Snow‐tracking data were collected simultaneously for cougars, wolves, elk (Cervus elaphus), and deer (Odocoileus virginianus and O. hemionus) between November and March, 1997–2000. Track data were synthesized in a GIS. Logistic regression and Akaike's information criterion (AIC) were used to select optimal environmental relationship models for each species. We first examined co‐occurrence by iteratively using each species as a dependent variable (presence/absence) in a logistic regression analysis and using all other species track‐density estimates as independent variables. We built predictive surfaces in a GIS using the exponent form of the logistic regression models, and assessed model accuracy with a receiver operating characteristic curve. We then re‐examined co‐occurrence using pairwise correlations of species probability surfaces by month. The correlation results were compared with logistic regression results to illuminate mechanisms of co‐occurrence and to investigate predictive consistency across the two methods. Results Cougars showed a trend in distribution from higher elevation and less rugged terrain in December, to lower elevation and more rugged terrain in March. This trend differed from that for wolves, which showed a more stable affinity for low elevation and less rugged valley bottoms across all months. The logistic regression models indicated variable positive and negative associations of cougars with wolves by month, and changes in prey associations over time. Notably, there was a shift in co‐occurrence for both predators from elk to deer in March. We found high predictive accuracy for all probability surfaces, except for the month of January. Our image comparison showed that spatial co‐occurrence amongst all species increased over winter, except that wolves and cougars were negatively correlated in February. Combining the results of each approach we found that cougars and wolves converged spatially over winter at the landscape scale (i.e. the valley), while showing more discrete use of that space over time and by habitat attributes (e.g. forest cover, topographic complexity, and prey track density). Main conclusions In the Rocky Mountains, the spatial distributions of cougars and wolves converged into the valley floor as winter progressed. Cougars were distinct from wolves and prey in the intensity of this shift. We determined that a comparison of predictive surfaces alone fails to explain species co‐occurrence. The surfaces must be coupled with investigation of respective species–environment models to account for temporal changes in associations. We suggest that the two approaches represent different ecological scales: image comparison may be best for landscape‐ (valley) level analysis, while logistic regression is best for site‐level analysis. Ultimately, both approaches were critical to our analysis. Finally, the variability observed over time suggested that annual and seasonal models may obscure important ecological patterns and processes, especially for cougars.  相似文献   

6.
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.  相似文献   

7.
We studied how the behavior and performance of Pseudacteon tricuspis Borgmeier varies with the social form of its host Solenopsis invicta Buren, in its native range in Argentina where monogyne colonies are more abundant than polygynes (approximately 75 vs. 25%). Female, P. tricuspis took 44% less time (50 vs. 89 s) to attack monogyne than polygyne ants, but oviposition attempts were similar (23 vs. 18 attacks). The presence of the parasitoid affected the average size of foragers on the trail, with the proportion of minor workers increasing on both social forms. In the laboratory, P. tricuspis selected similar host sizes, although pupal survival was 25% higher on monogynes than on polygynes. Developmental times of both genders were similar (33-35 d), although larger females emerged from bigger hosts. The sex ratio of P. tricuspis was more male biased when exploiting polygyne ants. Intraspecific competition significantly affected parasitoid reproductive success, being significantly higher for a solitary female than when three females were present, although the size of workers selected did not vary. The male:female ratio also changed, being 1:1 without competition but 2:1 with competition. We demonstrated for the first time the consequences of interference competition among P. tricuspis females, a common behavior observed in others parasitoids. We discuss why P. tricuspis sex ratios are always biased toward males in both social forms and suggest that similar studies of interference competition within and between already naturalized Pseudacteon species in the United States could help predict establishment patterns.  相似文献   

8.
Sarcocysts of Sarcocystis sp. were found in the striated muscles from 11 of 14 wild Florida panthers (Felis concolor coryi) and four of four cougars (two wild F. concolor stanleyana and two captive F. concolor of undetermined subspecies). The common occurrence of sarcocysts in muscles of top carnivores such panthers and cougars is unexplained. This stage of the life cycle is normally confined to the muscles of the prey species. Because large felids are rarely preyed upon, it is unlikely that a species of Sarcocystis has evolved using large cats as intermediate hosts. Therefore, the presence of these sarcocysts might be an indication of immune compromise in these felids, enabling the atypical development of the sarcocysts.  相似文献   

9.
四川菊科植物新记录   总被引:1,自引:1,他引:0  
报道四川菊科植物分布新记录15种,即白山蒿、韦谷草白背变种、百能葳、小一点红、异羽千里光、无毛蟹甲草、黑紫橐吾、蒜叶婆罗门参、华北鸦葱、毛柄蒲儿根、三尖千里光、华麻花头、棉头风毛菊、灰白风毛菊、丽江蓟。列出这些种的标本引证、地理分布和近缘种的区别等。  相似文献   

10.
The geography of the Black Hills region of South Dakota and Wyoming may limit connectivity for many species. For species with large energetic demands and large home ranges or species at low densities this can create viability concerns. Carnivores in this region, such as cougars (Puma concolor), have the additive effect of natural and human-induced mortality; this may act to decrease long-term viability. In this study we set out to explore genetic diversity among cougar populations in the Black Hills and surrounding areas. Specifically, our objectives were to first compare genetic variation and effective number of breeders of cougars in the Black Hills during three harvest regimes: pre (2003–2006), moderate (2007–2010), and heavy (2011–2013), to determine if harvest impacted genetic variation. Second, we compared genetic structure of the Black Hills cougar population with cougar populations in neighboring eastern Wyoming and North Dakota. Using 20 microsatellite loci, we conducted genetic analysis on DNA samples from cougars in the Black Hills (n = 675), North Dakota (n = 113), and eastern Wyoming (n = 62) collected from 2001–2013. Here we report that the Black Hills cougar population maintained genetic variation over the three time periods. Our substructure analysis suggests that the maintenance of genetic variation was due to immigration from eastern Wyoming and possibly North Dakota.  相似文献   

11.
Pseudacteon flies, parasitoids of worker ants, are being intensively studied as potentially effective agents in the biological control of the invasive pest fire ant genus Solenopsis (Hymenoptera: Formicidae). This is the first attempt to describe the karyotype of P. curvatus Borgmeier, P. nocens Borgmeier and P. tricuspis Borgmeier. The three species possess 2n = 6; chromosomes I and II were metacentric in the three species, but chromosome pair III was subtelocentric in P. curvatus and P. tricuspis, and telocentric in P. nocens. All three species possess a C positive band in chromosome II, lack C positive heterochromatin on chromosome I, and are mostly differentiated with respect to chromosome III. P. curvatus and P. tricuspis possess a C positive band, but at different locations, whereas this band is absent in P. nocens. Heterochromatic bands are neither AT nor GC rich as revealed by fluorescent banding. In situ hybridization with an 18S rDNA probe revealed a signal on chromosome II in a similar location to the C positive band in the three species. The apparent lack of morphologically distinct sex chromosomes is consistent with proposals of environmental sex determination in the genus. Small differences detected in chromosome length and morphology suggests that chromosomes have been highly conserved during the evolutionary radiation of Pseudacteon. Possible mechanisms of karyotype evolution in the three species are suggested.  相似文献   

12.
Estimates of cougar (Puma concolor) density are among the least available of any big game species in North America because of monetary and logistical challenges. Thus, wildlife managers identify cougar density estimates as a high priority need for population estimation, developing harvest guidelines, and evaluating management objectives. Cougar densities range from <1 to almost 7 cougars/100 km2; however, the magnitude of spatial and temporal variation associated with these estimates is difficult to assess because this range of densities could potentially be reported for any given population using different demographic, temporal, durational, and analytical approaches. We used long-term global positioning system (GPS) data from collared cougars across 5 diverse study areas in Washington, USA, as the basis for calculating multiple annual independent-aged (≥18 months) cougar densities, using consistent methods, and conducted a meta-analysis to assist with statewide harvest guidelines. To generate specific harvest guidelines for unobserved populations at the management unit scale, we employed a Bayesian decision-theoretic approach that minimizes statistical risk of failing to achieve a defined harvest rate. For the 16-year field effort, we calculated 24 annual densities for independent-aged cougars. Average annual densities ranged from 1.55 ± 0.44 (SD) cougars/100 km2 (n = 5 years) to 2.79 ± 0.35 cougars/100 km2 (n = 5 years) among the 5 study areas. Explicit delineation of the cougar population demonstrated that contribution to density can vary considerably by sex and age class. Application of a 12–16% harvest rate within the risk analysis framework yielded a potential annual harvest of 249 cougars over 91,000 km2 of cougar habitat in Washington. Given the importance of density for establishing harvest guidelines, and the degree of uncertainty in projecting derived densities to future years and unstudied management units, our approach may lessen the ambiguity of extrapolations and increase the longevity of research results. Our risk analysis can be used for a diverse array of species and management objectives and be incorporated into an adaptive management framework for minimizing management risk. Our recommendations can improve standardization in reporting and interpretation of cougar density comparisons and bring clarity to the sources of variability observed in cougar populations. © 2021 The Wildlife Society.  相似文献   

13.
Natural controls on the distribution, abundance, or growth rates of exotic species are a desirable mode of intervention because of lower costs compared to anthropogenic controls and greater social acceptance. In the Great Basin, cougars (Puma concolor) are the most widely distributed carnivore capable of killing large ungulate prey. Populations of feral horses (Equus ferus) are widely distributed throughout the Great Basin and can grow at rates up to 20%/year. Although cougars exhibit distributional overlap with horses, it has been assumed that predation is minimal because of differences in habitat use and body-size limitations. To evaluate this hypothesis, we monitored the diets of 21 global positioning system (GPS)-collared cougars in the western Great Basin (5 males, 8 females) and eastern Sierra Nevada (2 males, 6 females) from 2009–2012. We investigated 1,310 potential kill sites and located prey remains of 820 predation events. We compared prey composition and kill rates of cougars inhabiting the Sierra Nevada and Great Basin, and among male and female cougars across seasons. We used generalized linear mixed models (GLMMs) to examine the effects of prey availability and habitat characteristics on the probability of predation on horses by cougars. Mule deer (Odocoileus hemionus) comprised 91% of prey items killed on the Sierra Nevada reference site but only comprised 29% of prey items in the Great Basin study area. Average annual kill rates for deer differed between the Sierra Nevada ( = 0.85 deer/week, range = 0.44–1.3) and Great Basin ( = 0.21 deer/week, range = 0.00–0.43). Diets of cougars in the Great Basin were composed predominantly of horses (59.6%, n = 460 prey items; 13 individuals). Ten cougars regularly consumed horses, and horses were the most abundant prey in the diet of 8 additional individuals in the Great Basin. Cougars on average killed 0.38 horses/week in the Great Basin (range=0.00–0.94 horses/week). Differences in predation on horses between the sexes of cougars were striking; Great Basin females incorporated more horses across all age classes year-round, whereas male cougars tended to exploit neonatal young during spring and summer before switching to deer during winter. Within GLMM models, the probability of predation on horses compared to other prey species increased with elevation, horse density, and decreasing density of mule deer on the landscape, and was more likely to occur in sagebrush (Artemesia spp.) than in pinyon (Pinus monophylla)–juniper (Juniperus osteosperma) forests. Behavior of individual cougars accounted for more than a third of the variation explained by our top models predicting predation on horses in the Great Basin. At landscape scales, cougar predation is unlikely to limit the growth of feral horse populations. In the Great Basin ecosystem, however, cougars of both sexes successfully preyed on horses of all age classes. Moreover, some reproductive, female cougars were almost entirely dependent on feral horses year-round. Taken together, our data suggest that cougars may be an effective predator of feral horses, and that some of our previous assumptions about this relationship should be reevaluated and integrated into management and planning. © 2021 The Wildlife Society.  相似文献   

14.
We examined flight activity patterns for a guild of fire ant parasitoids in western Argentina in relationship to their host's location (mound/foraging trail) and light condition (full sun/partial sun/full shade) at different scales, from the individually sampled mound to the full day's summation for each species. We asked first whether taxa showed preferences among these conditions, and second, whether certain species and sexes might be found together more frequently than expected to by chance. All species, except the P. obtusus species complex, were significantly more likely to be found attacking ants at disturbed mounds than at paired foraging trails. The P. nocens complex and P. litoralis were more likely to be in the shade when temperatures were above the overall mean of the study (28.3 degrees C), whereas others, such as the P. obtusus complex and P. tricuspis, were more likely to be in full sun under these same conditions. Our analyses indicated that a limited set of species, particularly P. nocens with P. litoralis, and males with female P. obtusus and P. tricuspis, were more likely to be found together than expected. We also found decreasing proportions of males with increasing time of analysis. We discuss the implications of host location, metereological conditions, and sex ratios in relationship to ongoing classical biological control efforts using species of these phorids.  相似文献   

15.
Male and female predators are often assumed to have the same effects on prey. Because of differences in body size and behavior, however, male and female predators may use different species, sexes, and ages of prey, which could have important implications for wildlife conservation and management. We tested for differential prey use by male and female cougars (Puma concolor) from 2003 to 2008 in Washington State. We predicted that male cougars would kill a greater proportion of larger and older prey (i.e., adult elk [Cervus elaphus]), whereas females would kill smaller and younger prey (i.e., elk calves, mule deer [Odocoileus hemionus]). We marked cougars with Global Positioning System (GPS) radio collars and investigated 436 predation sites. We located prey remains at 345 sites from 9 male and 9 female cougars. We detected 184 mule deer, 142 elk, and 17 remains from 4 other species. We used log-linear modeling to detect differences in species and age of prey killed among cougar reproductive classes. Solitary females and females with dependent offspring killed more mule deer than elk (143 vs. 83, P < 0.01), whereas males killed more elk than mule deer (59 vs. 41, P < 0.01). Proportionately, males killed 4 times more adult elk than did females (24% vs. 6% of kills) and females killed 2 times more adult mule deer than did males (26% vs. 15% of kills). Managers should consider the effects of sex of predator in conservation and management of ungulates, particularly when managing for sensitive species. © 2011 The Wildlife Society.  相似文献   

16.
Abstract: In western Canada it is illegal to trap or snare cougars (Puma concolor), but cougars are sometimes caught accidentally in snares placed near carrion baits, a technique commonly used by trappers to harvest wolves (Canis lupus). We studied cougar foraging ecology and survival in west-central Alberta to estimate the propensity for cougars to scavenge, their susceptibility to snaring at trapper bait stations, and the implications these have for managing cougar populations. During 2005–2008, we used data from visits to 3,407 Global Positioning System (GPS) location clusters and >400 km of snow tracking of 44 cougars to locate foraging events and calculate scavenging rates. We identified 83 instances of scavenging, and 64% of monitored cougars scavenged at least once. Scavenging rates were higher in winter (0.12 events/week) than in summer (0.04 events/week), reflecting seasonal variation in carrion availability. Individual cougars scavenged at different rates, and winter feeding on carrion occupied up to 50% of total carcass handling time for some cougars. Based on these results we conclude that cougars are facultative scavengers. A propensity to scavenge made cougars susceptible to snaring causing high annual mortality in radiocollared cougars (0.11, 95% CI = 0.03–0.21). Provincial cougar mortality data demonstrate that snaring has increased dramatically as a mortality source in Alberta over the last 2 decades. Mortalities of radiocollared cougars during our study were 100% human caused and the addition of snaring mortality to already high hunting mortality resulted in low annual survival (0.67, 95% CI = 0.53–0.81). Our study is one of the first to identify population-level consequences for nontarget animals killed unintentionally by indiscriminate harvest techniques in a terrestrial ecosystem. Maintaining sustainable cougar harvest where snaring at carrion baits is permitted may require flexible hunting quotas capable of accommodating high cougar snaring mortalities in some years.  相似文献   

17.
Cytauxzoon felis is a long-recognized hemoparasite of free-ranging Florida panthers (Puma concolor coryi), but its prevalence and effect on the population has not been assessed. Red blood cell indices and white blood cell counts were compared between infected and noninfected Florida panthers and Texas cougars (Puma concolor stanleyana) from 1983-1997 in Florida (USA). The prevalence of cytauxzoonosis for both populations was 39% (11/28) for Texas cougars, 35% for Florida panthers (22/63) and 36% overall. Thirteen hematologic parameters were compared between C. felis positive and negative panthers and cougars. Florida panthers had significantly lower mean cell hemoglobin count (MCHC) and higher white blood cell (WBC), neutrophil, monocyte and eosinophil counts (P < or = 0.05) than Texas cougars. Infected Florida panthers had significantly lower mean cell hemoglobin (MCH) and monocyte counts and higher neutrophil and eosinophil counts than infected Texas cougars. Although statistically significant differences were measured for hematologic parameters in C. felis positive panthers and cougars, biologically significant differences were not likely because values were generally within expected reference ranges for healthy animals. Cytauxzoonosis does not appear to have a negative effect on the hematologic parameters of chronically infected panthers and cougars. Potential transient changes during initial infection were not evaluated.  相似文献   

18.
Understanding the social dynamics of large carnivores is critical to effective conservation and management planning. We made the first attempt to delineate both paternity and relatedness for a population of cougar (Puma concolor) using microsatellite data. We analyzed a long-term genetic dataset collected from a hunted population in the Garnet Mountains of western Montana. We assigned paternity for 62.5% of litters sampled using both exclusion and likelihood analyses. Attempts at reconstructing unsampled paternal genotypes resulted in delineating possible sires for 8 more litters. Sires were on average younger than reported for males involved in pairings assessed via field data in other cougar populations. Although most mating pairs were unrelated, 5 of 17 pairings involved cougars with levels of relatedness corresponding to half-sibling and full-sibling or parent offspring relationship (r = 0.215–0.575). Relatedness among adult and subadult males was higher than relatedness levels among adult and subadult females. Relatedness among males in the Garnet population differed from patterns hypothesized to occur under male-biased dispersal theories for cougars. The long-term impact of the turnover of resident cougars in hunted populations is still unclear and warrants additional research. Our results highlight the utility of monitoring cougar demographic parameters using a combination of genetic and field data that in turn may assist managers with determining cougar harvest quotas or strategies, harvest seasons, sustainable harvest, and the appropriate management level of cougar populations. © 2011 The Wildlife Society.  相似文献   

19.
This study extends our comparative knowledge of Pseudacteon interactions with Solenopsis fire ant workers. Reported in this work are development times for seven Argentinean parasitoid species reared on two hosts, Solenopsis richteri Forel and Solenopsis invicta Buren, under laboratory temperature regimes comparable with those of the climatic zones occupied by these host species. Developmental times spanned 31-66 d across phorid species, and in general did not differ between genders or host species, but were longer at lower temperatures. The size distribution of flies reared was bimodal, with a group of large (Pseudacteon borgmeieri, Pseudacteon nocens, Pseudacteon obtusus and Pseudacteon tricuspis) and small (Pseudacteon cultellatus, Pseudacteon curvatus, and Pseudacteon nudicornis) species. P. borgmeieri was exceptional with respect to length of developmental time. Also reported are results of initial oviposition and developmental studies of some of these phorid species on other Argentinean Solenopsis ant species; P. curvatus was the only species able to complete its development on nonhost fire ants. These results support the concept of incorporating several complementary species of Pseudacteon in the biological control of pest fire ants.  相似文献   

20.
Several conceptual models describing patterns of prey selection by predators have been proposed, but such models rarely have been tested empirically, particularly with terrestrial carnivores. We examined patterns of prey selection by sympatric wolves ( Canis lupus ) and cougars ( Puma concolor ) to determine i) if both predators selected disadvantaged prey disproportionately from the prey population, and ii) if the specific nature and intensity of prey selection differed according to disparity in hunting behavior between predator species. We documented prey characteristics and kill site attributes of predator kills during winters 1999–2001 in Idaho, and located 120 wolf-killed and 98 cougar-killed ungulates on our study site. Elk ( Cervus elephus ) were the primary prey for both predators, followed by mule deer ( Odocoileus hemionus ). Both predators preyed disproportionately on elk calves and old individuals; among mule deer, wolves appeared to select for fawns, whereas cougars killed primarily adults. Nutritional status of prey, as determined by percent femur marrow fat, was consistently poorer in wolf-killed prey. We found that wolf kills occurred in habitat that was more reflective of the entire study area than cougar kills, suggesting that the coursing hunting behavior of wolves likely operated on a larger spatial scale than did the ambush hunting strategy of cougars. We concluded that the disparity in prey selection and hunting habitat between predators probably was a function of predator-specific hunting behavior and capture success, where the longer prey chases and lower capture success of wolf packs mandated a stronger selection for disadvantaged prey. For cougars, prey selection seemed to be limited primarily by prey size, which could be a function of the solitary hunting behavior of this species and the risks associated with capturing prime-aged prey.  相似文献   

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