Animal dispersal

BACKGROUND: Differences in species richness among phylogenetic clades are attributed to clade age and/or variation in diversification rates. Access to ecological opportunity may trigger a temporary increase in diversification rates and ecomorphological variation. In addition, lower body temperatures in poikilothermic animals may result in decreasing speciation rates as proposed by the metabolic theory of ecology. For strictly freshwater organisms, environmental gradients within a river continuum, linked to elevation and temperature, might promote access to ecological opportunity and alter metabolic rates, eventually influencing speciation and extinction processes...

Dairy calf rearing unit is a management system that is only recently being implemented by some milk producer's cooperatives in southern Brazil. However, aspects related to the health profile of the heifer calves that arrive in the rearing unit as well as about biosecurity practices and microbiological challenges have not yet been evaluated in this rearing system in a tropical country. Diarrhea is the main and most frequent consequence of enteric infections in newborn calves. This study, through some etiological and epidemiological characteristics of an outbreak of neonatal diarrhea, has the aim to alert to the possibility of pathogenic microorganism spread in a dairy heifer calf rearing unit...

Many cooperatively breeding societies are characterized by high reproductive skew, such that some socially dominant individuals breed, while socially subordinate individuals provide help. Inbreeding avoidance serves as a source of reproductive skew in many high-skew societies, but few empirical studies have examined sources of skew operating alongside inbreeding avoidance, or compared individual attempts to reproduce (reproductive competition) with individual reproductive success. Here we use long-term genetic and observational data to examine factors affecting reproductive skew in the high-skew cooperatively breeding southern pied babbler (Turdoides bicolor)...

Fidelity to a past breeding site is widespread among animals and may confer both costs and benefits. Colonial species occur at specific sites that can accommodate multiple breeders, and the choice of whether to return to last year's site or disperse elsewhere can affect colony site use, the colony size distribution and individual fitness. For the colonial cliff swallow, Petrochelidon pyrrhonota , which occupies colonies of widely different sizes, we used a 30-year field study in western Nebraska to investigate how the extent of infestation by ectoparasites and colony size affected breeders' colony site fidelity between years...

Analysis of patterns in the distribution of taxa can provide important insights into ecological and evolutionary processes. Microbial biogeographic patterns almost always appear to be weaker than those reported for plant and animal taxa. It is as yet unclear why this is the case. Some argue that microbial diversity scales differently over space because microbial taxa are fundamentally different in their abundance, longevity and dispersal abilities. Others have argued that differences in scaling are an artifact of how we assess microbial biogeography, driven, for example, by differences in taxonomic resolution, spatial scale, sampling effort or community activity/dormancy...

We develop a general framework that combines long-term tag-recapture data and powerful statistical and modelling techniques to investigate how population, environmental and climate factors determine variation in vital rates and population dynamics in an animal species, using as a case study the population of brown trout living in Upper Volaja (Western Slovenia). This population has been monitored since 2004. Upper Volaja is a sink, receiving individuals from a source population living above a waterfall. We estimate the numerical contribution of the source population on the sink population and test the effects of temperature, population density and extreme events on variation in vital rates among 2647 individually tagged brown trout...

Population replenishment of marine life largely depends on successful dispersal of larvae to suitable adult habitat. Ocean acidification alters behavioural responses to physical and chemical cues in marine animals, including the maladaptive deterrence of settlement-stage larval fish to odours of preferred habitat and attraction to odours of non-preferred habitat. However, sensory compensation may allow fish to use alternative settlement cues such as sound. We show that future ocean acidification reverses the attraction of larval fish (barramundi) to their preferred settlement sounds (tropical estuarine mangroves)...

BACKGROUND: Titanium dioxide (TiO2 ) is produced at high volumes and applied in many consumer and food products. Recent toxicokinetic modelling indicated the potential of TiO2 to accumulate in human liver and spleen upon daily oral exposure, which is not routinely investigated in chronic animal studies. A health risk from nanosized TiO2 particle consumption could not be excluded then. RESULTS: Here we show the first quantification of both total titanium (Ti) and TiO2 particles in 15 post-mortem human livers and spleens...

BACKGROUND: Human-infecting microsporidia are a group of spore-forming eukaryotic microorganisms that can infect both animals and humans. Recent evidences indicate waterborne transmission of microsporidia spores to human via either drinking water or irrigation of vegetable farms with contaminated water resources. The current study aimed to evaluate the presence of human-infecting microsporidia in treated wastewater (TW) and vegetable farms irrigated with treated wastewater during a year...

Ecological networks are composed of interacting communities that influence ecosystem structure and function. Fungi are the driving force for ecosystem processes such as decomposition and carbon sequestration in terrestrial habitats, and are strongly influenced by interactions with invertebrates. Yet, interactions in detritivore communities have rarely been considered from a network perspective. In the present study, we analyse the interaction networks between three functional guilds of fungi and insects sampled from dead wood...

Many microbial taxa associated with healthy animals have both within-host and free-living populations, but little is known about the magnitude, persistence and dispersal of their populations in the external environment. Advances, particularly in our understanding of the population dynamics of free-living populations and microbial cycling between the external environment and hosts, can be achieved by the creative use of current technologies. In particular, there are opportunities to adapt methods, such as capture-mark-release techniques widely used in animal ecology, to the study of symbiotic microorganisms...

Following the loss of a sensory modality, such as deafness or blindness, crossmodal plasticity is commonly identified in regions of the cerebrum that normally process the deprived modality. It has been hypothesized that significant changes in the patterns of cortical afferent and efferent projections may underlie these functional crossmodal changes. However, studies of thalamocortical and cortico-cortical connections have refuted this hypothesis, instead revealing a profound resilience of cortical afferent projections following deafness and blindness...

1.There is growing interest in understanding the functional outcomes of species interactions in ecological networks. For many mutualistic networks, including pollination and seed dispersal networks, interactions are generally sampled by recording animal foraging visits to plants. However, these visits may not reflect actual pollination or seed dispersal events, despite these typically being the ecological processes of interest. 2.Frugivorous animals can act as seed dispersers, by swallowing entire fruits and dispersing their seeds, or as pulp peckers or seed predators, by pecking fruits to consume pieces of pulp or seeds...

Changes in food availability and crowding are two critical environmental conditions that impact an animal's trajectory toward either reproduction or migration. Many insects facing this challenge have evolved wing polymorpisms that allow them to respond to changing conditions. When conditions favor reproduction, wing polymorphic species produce adults that either have no wings or short, non-functional wings; however, when conditions favor migration, adults with functional wings and robust flight muscles develop...

Phytophthora cinnamomi is one of the most important plant pathogens in the world, causing root rot in more than a thousand plant species. This observational study was carried out on a P. cinnamomi infected heathland of Erica umbellata used as goat pasture. The patterns and shapes of disease foci and their distribution were described in a spatial and temporal context using an aerial photograph record. A set of topographic traits was selected on the basis of a disease dynamic hypothesis and their effects on observed spatial disease patterns were analyzed...

The oral mucosal tissue is a compound structure composed of morphologically and physiologically different cell types. The morphological modification involves genetically determined lifespan, which may be recognized as the balance between cell survival and apoptosis. Although the biochemical processes and pathways in oral mucosa, with special regards to drug transport, delivery, and metabolism, are well known, the cellular physiological homeostasis in this tissue requires further investigation. The porcine buccal pouch mucosal cells (BPMCs) collected from 20 pubertal crossbred Landrace gilts, were used in this study...

Riot control agents (RCA) are lachrymatory, irritating compounds which temporarily incapacitate the uncontainable crowd. Ortho-Chlorobenzylidene-malononitrile (CS), 2-chloroacetophenone (CN), dibenz[b,f]1:4-oxazepine (CR), and nonivamide (PAVA) are synthetic RCAs, while oleoresin extract of chili known as oleoresin capsicum (OC) a natural irritant has been in use by various law enforcement agencies. Though efficacy of these agents is beyond doubt, they suffer from certain drawbacks including toxicity, production cost, and ecological compatibility...

Fast Green (FCF) dye is commonly used in both cytology and histology applications. Previous studies have found that it can cause mutagenic and tumorigenic effects in experimental human and animal populations. It can also be a source of skin, eye, respiratory, and digestive irritation. The purpose of this study was to examine the use of thin film membranes to degrade FCF. A thin film membrane of chitosan (CS) was fabricated and subsequently filled with zinc oxide nanoparticles (ZnO) or ZnO/CuO-heterostructured nanocomposites...

Many animal life histories entail changing feeding ecology, but the molecular bases for these transitions are poorly understood. The amphibian tadpole is typically a growth and dispersal life-history stage. Tadpoles are primarily herbivorous, and they capitalize on growth opportunities to reach a minimum body size to initiate metamorphosis. During metamorphic climax, feeding declines, at which time the gastrointestinal (GI) tract remodels to accommodate the carnivorous diet of the adult frog. Here we show that anorexigenic hypothalamic feeding controls are absent in the tadpole, but develop during metamorphosis concurrent with the production of the satiety signal leptin...

Animals must use external cues to maintain a straight course over long distances. In this study, we investigated how the fruit fly, Drosophila melanogaster , selects and maintains a flight heading relative to the axis of linearly polarized light, a visual cue produced by the atmospheric scattering of sunlight. To track flies' headings over extended periods, we used a flight simulator that coupled the angular velocity of dorsally presented polarized light to the stroke amplitude difference of the animal's wings...