Trichloroethylene Exposure during Cardiac Valvuloseptal Morphogenesis Alters Cushion Formation and Cardiac Hemodynamics in the Avian Embryo

It is controversial whether trichloroethylene (TCE) is a cardiac teratogen. We exposed chick embryos to 0, 0.4, 8, or 400 ppb TCE/egg during the period of cardiac valvuloseptal morphogenesis (2–3.3 days’ incubation). Embryo survival, valvuloseptal cellularity, and cardiac hemodynamics were evaluated at times thereafter. TCE at 8 and 400 ppb/egg reduced embryo survival to day 6.25 incubation by 40–50%. At day 4.25, increased proliferation and hypercellularity were observed within the atrioventricular and outflow tract primordia after 8 and 400 ppb TCE. Doppler ultrasound revealed that the dorsal aortic and atrioventricular blood flows were reduced by 23% and 30%, respectively, after exposure to 8 ppb TCE. Equimolar trichloroacetic acid (TCA) was more potent than TCE with respect to increasing mortality and causing valvuloseptal hypercellularity. These results independently confirm that TCE disrupts cardiac development of the chick embryo and identifies valvuloseptal development as a period of sensitivity. The hypercellular valvuloseptal profile is consistent with valvuloseptal heart defects associated with TCE exposure. This is the first report that TCA is a cardioteratogen for the chick and the first report that TCE exposure depresses cardiac function. Valvuloseptal hypercellularity may narrow the cardiac orifices, which reduces blood flow through the heart, thereby compromising cardiac output and contributing to increased mortality. The altered valvuloseptal formation and reduced hemodynamics seen here are consistent with such an outcome. Notably, these effects were observed at a TCE exposure (8 ppb) that is only slightly higher than the U.S. Environmental Protection Agency maximum containment level for drinking water (5 ppb)

Timing of Resource Availability Drives Divergent Social Systems and Home Range Dynamics in Ecologically Similar Tree Squirrels

Intraspecific variation in home range size has important implications for the distribution of animals across landscapes and the spatial structuring of population, community, and ecosystem processes. Among species of similar trophic guild and body mass, differences in home range size can reflect extrinsic variables that exert divergent selective forces upon spacing behavior and social organization. We tested predictions about how resource availability and timing influence social system, home range size, and territoriality in two tree squirrel species of similar size and ecological niches but that differ in foraging strategy and social organization. We estimated home range size and intraspecific home range core overlap in the Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis; Arizona USA; MGRS) and the Eurasian red squirrel (Sciurus vulgaris; Alps, Italy; ERS) as functions of species, sex, season, and individual's body mass. However, body mass did not explain differences found between the two species. We found MGRS home ranges being three times smaller with higher core area exclusivity compared to ERS in all seasons. In fact, territorial MGRS evolved in a system of brief resource pulses and are larder hoarders, whereas ERS experience prolonged resource availability and are non-territorial. Only male MGRSs increased their home range during the breeding season, reflecting interspecific differences in social organization and mating behavior. Male ERS home ranges always overlap with several females to enhance mating success although male and female MGRS maintain nearly exclusive territories throughout the year. Only during spring and summer do males temporarily leave their food-based territory to increase mating opportunities with neighboring estrus females. Home range comparisons between ecologically similar species emphasize the importance of divergent extrinsic factors in shaping variability in body size–home range size scaling relationships. Timing in resource availability influenced the social structure and space use in tree squirrels of similar body size, highlighting how the coevolution of arboreal squirrels with conifer tree species has shaped their natural history

Expert range maps of global mammal distributions harmonised to three taxonomic authorities

AimComprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW).LocationGlobal.TaxonAll extant mammal species.MethodsRange maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species).ResultsRange maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use.Main conclusionExpert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control

Competition and Combative Advertising: An Historical Analysis

Fred K. Beard (PhD, University of Oklahoma) is a professor of advertising in the Gaylord College of Journalism and Mass Communication, University of Oklahoma. His research interests include comparative advertising, advertising humor, and advertising history. His work has appeared in the Journal of Advertising, the Journal of Advertising Research, the Journal of Business Ethics, the Journal of Business Research, Journalism History, the Journal of Historical Research in Marketing, the Journal of Macromarketing, and the Journal of Marketing Communications, among others.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

DAMAGE DUE TO SCENT MARKING BY EASTERN GRAY AND FOX SQUIRRELS

The stripping of bark by eastern gray squirrels (Sciurus carolinensis) is a serious problem in England with 50 to 100% of the trees damaged in some locations (Shorten 1957). The economic consequences of such damage have resulted in much research (Kenward 1982, 1983; Kenward and Parish 1986); squirrel-induced damage to trees also occurs in North America (Allen 1943, Brenneman 1954) but is rarely of the magnitude observed in England. At least 10 hypotheses (reviewed by Kenward 1983) have been suggested to account for bark-stripping damage including: 1) reduction of tooth wear; 2) uncontrolled gnawing reflex; 3) source of nesting material; 4) water, 5) genetic mutation; 6) scent-marking; 7) displacement activity related to agonistic behaviors; 8) trace nutrient deficiency; 9) sap as an emergency food; and 10) sap as a preferred food. However, only hypotheses 6 through 10 appear to have merit (Kenward 1983). Gray squirrels in England regularly visited marking points to chip bark and sometimes urinate which suggests that some bark removal is related to scent marking (Taylor 1968, 1977). Many ground squirrels (Halpin 1985) and tree squirrels (Benson 1980, Ferron 1983) scent mark using oral glands. Fox squirrels (S. niger) frequently bite the substrate prior to scent marking (Benson 1980). Although squirrels do ingest bark and cambium (Packard 1956), some bark removal is related to scent-marking activities (Taylor 1969, 1977). Scent marking, including the rubbing of oral glands on a substrate and occasional urination at traditional marking points, is an almost exclusively adult male activity that occurs throughout the year (J. L. Koprowski, unpubl. data). Damage in urban areas may be highly visible, unappealing, and intolerable to residents. Herein, I report the characteristics of scent-marking points and discuss the extent of bark removal by fox and eastern gray squirrels at marking points with reference to preferred timber size classes in an urban parkland

Using a substitute species to inform translocation of an endangered territorial mammal.

Substitute species can inform management strategies without exposing endangered species to unacceptable risk. Furthermore, experimental approaches may help to identify the causes of translocation failures, improving the chances of success. We used a surrogate subspecies, Tamiasciurus fremonti fremonti to test different translocation techniques to inform on potential management actions with regards to the endangered Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis). Individuals of both subspecies defend year-round territories in similar mixed conifer forests at elevations between 2650-2750 m, where they store cones to survive over winter. We fitted VHF radio collars to 54 animals, and we monitored their survival and movements until individuals settled on a new territory. We considered the effect of season, translocation technique (soft or hard release), and body mass on survival, distance moved after release, and time to settlement of translocated animals. Survival probability averaged 0.48 after 60 days from the translocation event and was not affected by season or translocation technique. 54% of the mortality was caused by predation. Distance moved and number of days to settlement varied with season, where winter was characterized by shorter distances (average of 364 m in winter versus 1752 m in fall) and a smaller number of days (6 in winter versus 23 in fall). The data emphasized on the potential of substitute species to provide valuable information for possible outcomes of management strategies to closely related endangered species

Merrick_Koprowski2016_Dispersal_correlates

Data set used to model dispersal distance and probability of non-philopatric distance dispersal in juvenile Mt. Graham red squirrels from 2010 - 2013 as a function of intrinsic and extrinsic factors

Can we use body size and road characteristics to anticipate barrier effects of roads in mammals? A meta-analysis

Habitat fragmentation and loss caused by road development are recognized as major threats to biodiversity and challenges to reconcile the pursuit of economic growth with the protection of wildlife habitats. Assessment of potential environmental impacts is essential in planning and design of road projects. Behavioral responses such as road avoidance that causes barrier effects are critical in assessment of effects of roads on species persistence. In this study, we synthesized literature of barrier effects on mammals to identify road characteristics and species traits that might serve as management indicators to anticipate barrier effects. We conducted a meta-analysis with 118 statistics of road crossings by 45 species from 36 studies. We used logit-transformed proportion of individuals not crossing roads as the effect size of barrier effect. Overall, all types of roads, from major highways to narrow forest roads, can impede movements for certain species of mammals. For data collected by observational methods, body mass, road width, road surface and data collection methods explained 53% of variation among data. Barrier effect decreased as body mass increased, and was increased by greater road width. Paved roads posed stronger barriers compared to gravel dirt roads. Capture-recapture methods tended to detect a weaker barrier effect compared to methods that tracked individual movements. For data collected by experimental translocation, the probability of crossing following translocation was not affected by road width and body mass. We showed that interspecific variation of mammals in barrier effects can be explained by road characteristics and body size under natural condition, and can be useful to anticipate the species-specific magnitude of barrier effects of roads and aid in planning and design of road projects, as well as reassessment of existing roads