In the Pursuit of the Predatory Behavior of Borophagines (Mammalia,Carnivora, Canidae): Inferences from Forelimb Morphology

Here, we perform an ecomorphological study on the major bones (humerus, radius, and ulna) of the carnivoran forelimb using three-dimensional geometric morphometrics. More specifically, we test the association between forelimb morphology and predatory behavior. Our results suggest that the main morphological adaptions of carnivorans to different predatory behaviors relate to: (i) the capacity to perform long and efficient runs as in pounce/pursuit and pursuit predators; (ii) the ability to maneuver as in occasional predators; and (iii) the capacity to exert and resist large loads as in ambushing predators. We used borophagine canids as a case study, given the controversy on the predatory behavior of this extinct subfamily. Our results indicate that borophagines displayed a limited set of adaptions towards efficient running, including reduced joint mobility in both the elbow and the wrist, aspects in which they resemble the living canids. Furthermore, they had forelimbs as powerful as those of the extant ambushing carnivorans (i.e., most felids). This combination of traits suggests that the predatory behavior of borophagines was unique among carnivorans, as it was not fully equivalent to any of the living species.     

Impact of genetic variations in ADORA2A gene on depression and symptoms: a cross-sectional population-based study

Purinergic Signalling - Genetic variants involved in adenosine metabolism and its receptors were associated with increased risk for psychiatric disorders, including anxiety, depression, and...     

Delayed herbivory by migratory geese increases summer‐long CO2 uptake in coastal western Alaska

The advancement of spring and the differential ability of organisms to respond to changes in plant phenology may lead to “phenological mismatches” as a result of climate change. One potential for considerable mismatch is between migratory birds and food availability in northern breeding ranges, and these mismatches may have consequences for ecosystem function. We conducted a three‐year experiment to examine the consequences for CO₂ exchange of advanced spring green‐up and altered timing of grazing by migratory Pacific black brant in a coastal wetland in western Alaska. Experimental treatments represent the variation in green‐up and timing of peak grazing intensity that currently exists in the system. Delayed grazing resulted in greater net ecosystem exchange (NEE) and gross primary productivity (GPP), while early grazing reduced CO₂ uptake with the potential of causing net ecosystem carbon (C) loss in late spring and early summer. Conversely, advancing the growing season only influenced ecosystem respiration (ER), resulting in a small increase in ER with no concomitant impact on GPP or NEE. The experimental treatment that represents the most likely future, with green‐up advancing more rapidly than arrival of migratory geese, results in NEE changing by 1.2 µmol m^?2 s^?1 toward a greater CO₂ sink in spring and summer. Increased sink strength, however, may be mitigated by early arrival of migratory geese, which would reduce CO₂ uptake. Importantly, while the direct effect of climate warming on phenology of green‐up has a minimal influence on NEE, the indirect effect of climate warming manifest through changes in the timing of peak grazing can have a significant impact on C balance in northern coastal wetlands. Furthermore, processes influencing the timing of goose migration in the winter range can significantly influence ecosystem function in summer habitats.     

Spatially balanced sampling and ground‐level imagery for vegetation monitoring on reclaimed well pads

Land reclamation associated with natural gas development has become increasingly important to mitigate land surface disturbance in western North America. Since well pads occur on sites with multiple land use and ownership, the progress and outcomes of these efforts are of interest to multiple stakeholders including industry, practitioners and consultants, regulatory agents, private landowners, and the scientific community. Reclamation success criteria often vary within, and among, government agencies and across land ownership type. Typically, reclamation success of a well pad is judged by comparing vegetation cover from a single transect on the pad to a single transect in an adjacent reference site and data are collected by a large number of technicians with various field monitoring skills. We utilized “SamplePoint” image analysis software and a spatially balanced sampling design, called balanced acceptance sampling, to demonstrate how spatially explicit quantitative data can be used to determine if sites are meeting various reclamation success criteria and used chi‐square tests to show how sites in vegetation percent cover differ from a statistical standpoint. This method collects field data faster than traditional methods. We demonstrate how quantitative and spatially explicit data can be utilized by multiple stakeholders, how it can improve upon current reference site selection, how it can satisfy reclamation monitoring requirements for multiple regulatory agencies, how it may help improve future seed mix selection, and discuss how it may reduce costs for operations responsible for reclamation and how it may reduce observer bias.     

Spatial pattern of invasive and native graminoids in the Brazilian cerrado

Plant Ecology - Invasive grasses are an important threat in tropical savannas and grasslands and may be affected by natural and anthropogenic features of the environment. They may affect native...     

Increased litter decomposition rates of exotic invasive species Hieracium pilosella (Asteraceae) in Southern Patagonia,Argentina

Plant Ecology - Plant invasions can affect key ecosystem processes regulating carbon and nutrient balances, i.e., litter decomposition. Exotic herb Hieracium pilosella (hawkweed, Asteraceae)...