Establishment of introduced reptiles increases with the presence and richness of native congeners

Darwin proposed two contradictory hypotheses to explain the influence of congeners on the outcomes of invasion: the naturalization hypothesis, which predicts a negative relationship between the presence of congeners and invasion success, and the pre-adaptation hypothesis, which predicts a positive relationship between the presence of congeners and invasion success. Studies testing these hypotheses have shown mixed support. We tested these hypotheses using the establishment success of non-native reptiles and congener presence/absence and richness across the globe. Our results demonstrated support for the pre-adaptation hypothesis. We found that globally, both on islands and continents, establishment success was higher in the presence than in the absence of congeners and that establishment success increased with increasing congener richness. At the life form level, establishment success was higher for lizards, marginally higher for snakes, and not different for turtles in the presence of congeners; data were insufficient to test the hypotheses for crocodiles. There was no relationship between establishment success and congener richness for any life form. We suggest that we found support for the pre-adaptation hypothesis because, at the scale of our analysis, native congeners represent environmental conditions appropriate for the species rather than competition for niche space. Our results imply that areas to target for early detection of non-native reptiles are those that host closely related species

Den attendance patterns in swift foxes during pup rearing: varying degrees of parental investment within the breeding pair

Parental investment varies inmammalian species, with male care of young being more common in social and monogamous species. Monogamy is commonly observed in canid species, with both males and females, and often ‘‘helper’’ individuals, providing some degree of care for the young. Social units of the swift fox (Vulpes velox), a small North American canid species, usually consist of a male– female pair and occasionally helpers. The role of parental investment and behavior in swift fox society is currently poorly understood. We observed swift fox dens during the pup-rearing season in each of 2 years to evaluate attendance and frequency of visits to natal dens by adult males and females. Female foxes remained at dens longer and visited them more frequently than didmale foxes. Female attendance and visitation decreased throughout the pup-rearing season as pups became older and more independent. Environmental factors, including climate and its effect on prey, appeared to contribute to differences in fox behavior between the 2 years. We observed only one fox outside of the breeding pair attending a den in each of the 2 years, both of which were males. We concluded that each of these two foxes were living within the social unit of the male–female pair as a trio, but not serving as a helper and contributing to the care of the pups.Our results increased knowledge of the ecology and behavior of the swift fox, a species of conservation concern in the Great Plains of North America

Environmental factors influencing the occurrence of coyotes and conflicts in urban areas

The increase of global urbanization can have effects on wildlife species, including carnivores such as coyotes (Canis latrans). As coyotes continue to settle in more urban areas, reports of human-coyote conflicts, such as attacks on humans or pets, may also increase. Understanding environmental variables that might influence whether or not coyotes and human-coyote conflicts will occur in certain urban areas may assist wildlife officials in creating management plans for urban wildlife.We conducted a survey of 105 urban areas in the United States requesting information on the occurrence of coyotes and human-coyote conflicts. We analyzed the responses with data on human population size, geographic region, land cover, housing density, and precipitation. Larger urban areas were more likely to contain both coyotes and human-coyote conflicts, and were also more likely to have greater numbers of conflicts. Urban areas in the western regions with larger amounts of high-intensity development and less forested and agricultural areas were more likely to have conflicts. Most urban areas considered the management of conflicts to be of low priority and emphasized education of citizens rather than removal of individual coyotes. Our results may assist urban wildlife managers in understanding the geographic and demographic factors correlated with the occurrence of coyotes and human-coyote conflicts. Practices such as education campaigns and landscape design incorporating wildlife habitat modifications (e.g.,reducing dense cover) may reduce human-carnivore conflicts in urban ecosystems

Influence of habitat structure and food on patch choice ofcaptive coyotes

Increasing urban development can have significant effects on wildlife species, includingcarnivores. Some carnivore species have been able to adapt to and even thrive in urban envi-ronments, including coyotes (Canis latrans). The presence of carnivores in urban areas cansometimes lead to conflicts with humans and their pets. Although coyotes may frequentlyuse urban areas, they also inhabit natural areas surrounding urban development. Under-standing the various factors affecting patch choice of urban coyotes may assist wildlifeofficials in managing human-coyote conflicts. Both sex and behavioral profile can influ-ence patch choice; bold individuals are more likely to be exploratory than shy animals,which can result in increased conflicts in urban environments. Using a captive populationof coyotes, we tested whether coyotes preferred urban (anthropogenic) habitat structure,natural structure, or a mixture of structures and whether sex, behavioral profile, biologi-cal season, or food manipulation affected coyote patch choice. Coyotes generally preferredthe control, homogeneous structure representing their natal habitat (mean percentage oftime 23.3% ± 19.3 SD; P = 0.037). The next most preferred habitat for coyotes, especiallyfemales (23.7 ± 16.6% for 25% urban pen; P = 0.020) and bold coyotes (27.8 ± 23.2% for 75%urban pen; P = 0.005), was a mixture of anthropogenic and natural structures rather thanuniform structure (all natural or all anthropogenic), and this preference was more stronglyexpressed during the non-breeding season (25.6 ± 23.2% for 75% urban pen; P = 0.017). Foodhad no effect on patch choice (P = 0.983); coyotes appeared to be primarily motivated by thestructure of the habitat rather than by the amount of food within each habitat. Our resultssuggested that urban areas containing large amounts of both natural and anthropogenicstructures are more likely to be used by coyotes and, thus, could have the potential forhuman-coyote conflicts

Anticoagulant Rodenticide Exposure and Toxicosis in Coyotes (\u3ci\u3eCanis latrans\u3c/i\u3e) in the Denver Metropolitan Area

Anticoagulant rodenticides are widely used in urban areas to control rodent pests and are responsible for secondary poisoning in many nontarget wildlife species. We tested the livers of five coyotes (Canis latrans) in the Denver Metropolitan Area, Colorado, US, for anticoagulant rodenticides. All five livers were positive for brodifacoum, with values ranging from 95 ppb to 320 ppb, and one liver was positive for bromadiolone, with a value of 885 ppb. Both of these rodenticides are second-generation anticoagulants, which are more potent and more likely to cause secondary poisoning than first-generation anticoagulants due to their accumulation and persistence in the liver. We concluded that exposure to these rodenticides may have caused the death of at least two of the five coyotes, and urban coyotes in our study area are commonly exposed to rodenticides

Rapid assessment of olfactory sensitivity using the “Sniffin’ Sticks”

Introduction: Assessment of olfactory performance is of high clinical interest in the contexts of smell loss as well as neurological diseases, and recently gained attention in obesity research. Available olfactory tests, especially for assessing olfactory sensitivity, are time-consuming and require high cognitive capacity. Therefore, we aimed to establish a short procedure for reliably testing olfactory sensitivity using a subtest of the “Sniffin’ Sticks” battery. Evaluation criteria are test duration, validity, and test-retest reliability. Methods: In a preliminary study using a within-subject repeated-measures design, we measured olfactory sensitivity for n-butanol in 20 young and healthy participants. We compared sensitivity obtained with three different measures during two sessions in a pseudo-randomized order: a standard single-staircase three-alternative forced-choice procedure with seven reversals (SSP_7); an abbreviated version with five reversals (SSP_5); and an ascending presentation of 16 dilution steps from lowest to highest odor concentration (brief ascending procedure, BAP). Results: Compared to the SSP_7, the BAP was 51%, and the SSP_5 26% shorter in duration. Both the BAP and SSP_5 scores were highly correlated with the SSP_7. The test-retest reliability in all three tests was similar to that typically reported in olfactory research. Conclusion: The abbreviated tests are valid measures of olfactory sensitivity. Especially, the BAP is as reliable as the standard method, but remarkably faster and easier to perform. Implications: Thus, the short procedures bear potential for both research and clinical practice, especially for complex study designs with time constraints on olfactory testing and for patient populations with attention deficits

Hidden symmetries in five-dimensional supergravity

This thesis is concerned with the study of hidden symmetries in supergravity, which play an important role in the present picture of supergravity and string theory. Concretely, the appearance of a hidden G_2_(_+_2_)/SO(4) symmetry is studied in the dimensional reduction of d=5, N=2 supergravity to three dimensions - a parallel model to the more famous E_8_(_+_8_)/SO(16) case in eleven-dimensional supergravity. Extending previous partial results for the bosonic part, I give a derivation that includes fermionic terms. This sheds new light on the appearance of the local hidden symmetry SO(4) in the reduction, and shows up an unusual feature which follows from an analysis of the R-symmetry associated with N=4 supergravity and of the supersymmetry variations, and which has no parallel in the eleven-dimensional case: The emergence of an additional SO(3) as part of the enhanced local symmetry, invisible in the dimensional reduction of the gravitino, and corresponding to the fact that, of the SO(4) used in the coset model, only the diagonal SO(3) is visible immediately upon dimensional reduction. The uncovering of the hidden symmetries proceeds via the construction of the proper coset gravity in three dimensions, and matching it with the Lagrangian obtained from the reduction. (orig.)SIGLEAvailable from TIB Hannover: RA 8919(2003-015) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman