David Zimmermann results 42
· Newest (Page 1/2, per page 25)
Author: David Zimmermann ×Clear All Filters
Search Results
Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group‐level processes such as subgroup formation and fission–fusion dynamics. Although critical to animal sociality, a comprehensive understanding of the factors influencing coh...
References for Small Fluorescence Quantum YieldsNARA Subscribed
Three compounds with fluorescence quantum yields in the range of 10 − 5 to 10 − 4 and emission spectra covering the UV/Vis spectral range are suggested as new references for the determination of small fluorescence quantum yields. The compounds are thymidine (dT) in water, dibenzoylmethane (DBM) in ethanol, and malachite green chloride (MG) in water, representing the blue, green, and red regions of the spectrum, respectively. A...
The EnMAP imaging spectroscopy mission towards operationsNARA Subscribed
Perishing rich, expanding poor: Demography and population genetic patterns in two congeneric butterfliesNARA Subscribed
In human‐altered landscapes, specialist butterflies typically form spatially restricted populations, genetically differentiated due to dispersal restrictions. Generalists, in contrast, display minimum differentiation but high genetic diversity. While local‐level actions suffice to conserve specialists and landscape‐level actions are necessary for generalists, minimum information exists regarding conservation of species with in...
Global maps of soil temperatureNARA Subscribed
Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1‐km 2 r...
Plant community impact on productivity: Trait diversity or key(stone) species effects?NARA Subscribed
Outside controlled experimental plots, the impact of community attributes on primary productivity has rarely been compared to that of individual species. Here, we identified plant species of high importance for productivity (key species) in >29,000 diverse grassland communities in the European Alps, and compared their effects with those of community‐level measures of functional composition (weighted means, variances, skewness...
Functional traits driving species role in the structure of terrestrial vertebrate scavenger networksNARA Subscribed
Species assemblages often have a non‐random nested organization, which in vertebrate scavenger (carrion‐consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177...
Summary of Findings and Research Recommendations from the Gulf of Mexico Research InitiativeOA Marine
Following the Deepwater Horizon explosion and oil spill in 2010, the Gulf of Mexico Research Initiative (GoMRI) was established to improve society’s ability to understand, respond to, and mitigate the impacts of petroleum pollution and related stressors of the marine and coastal ecosystems. This article provides a high-level overview of the major outcomes of the scientific work undertaken by GoMRI. This initiative contributed...
NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the NeotropicsNARA Subscribed
Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal specie...
Ex situ management as insurance against extinction of mammalian megafauna in an uncertain worldNARA Subscribed
The persistence of endangered species may depend on the fate of a very small number of individual animals. In situ conservation alone may sometimes be insufficient. In these instances, the International Union for Conservation of Nature provides guidelines for ex situ conservation and the Convention on Biological Diversity (CBD) indicates how ex situ management can support the CBD's objectives by providing insurance policies fo...
Scavenging in the Anthropocene: Human impact drives vertebrate scavenger species richness at a global scaleNARA Subscribed
Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim...
As large carnivores recover throughout Europe, their distribution needs to be studied to determine their conservation status and assess the potential for human‐carnivore conflicts. However, efficient monitoring of many large carnivore species is challenging due to their rarity, elusive behavior, and large home ranges. Their monitoring can include opportunistic sightings from citizens in addition to designed surveys. Two types...
Effects of urbanization on the population structure of freshwater turtles across the United StatesNARA Subscribed
Landscape‐scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will n...