Search results for "yrs"

Camouflage in arid environments: the case of Sahara-Sahel desert rodents

2020

Deserts and semi-deserts, such as the Sahara-Sahel region in North Africa, are exposed environments with restricted vegetation coverage. Due to limited physical surface structures, these open areas provide a promising ecosystem to understand selection for crypsis. Here, we review knowledge on camouflage adaptation in the Sahara-Sahel rodent community, which represents one of the best documented cases of phenotype-environment convergence comprising a marked taxonomic diversity. Through their evolutionary history, several rodent species from the Sahara-Sahel have repeatedly evolved an accurate background matching against visually-guided predators. Top-down selection by predators is therefore …

Rodent host population dynamics drive zoonotic Lyme Borreliosis and Orthohantavirus infections in humans in Northern Europe

2021

Zoonotic diseases, caused by pathogens transmitted between other vertebrate animals and humans, pose a major risk to human health. Rodents are important reservoir hosts for many zoonotic pathogens, and rodent population dynamics affect the infection dynamics of rodent-borne diseases, such as diseases caused by hantaviruses. However, the role of rodent population dynamics in determining the infection dynamics of rodent-associated tick-borne diseases, such as Lyme borreliosis (LB), caused by Borrelia burgdorferi sensu lato bacteria, have gained limited attention in Northern Europe, despite the multiannual abundance fluctuations, the so-called vole cycles, that characterise rodent population d…

Interpretation of gut microbiota data in the ‘eye of the beholder’: A commentary and re‐evaluation of data from ‘Impacts of radiation exposure on the…

2021

1.Evidence that exposure to environmental pollutants can alter the gut microbiota composition of wildlife includes studies of rodents exposed to radionuclides. 2.Antwis et al. (2021) used amplicon sequencing to characterise the gut microbiota of four species of rodent (Myodes glareolus, Apodemus agrarius, A. flavicollis and A. sylvaticus) inhabiting the Chernobyl Exclusion Zone (CEZ) to examine possible changes in gut bacteria (microbiota) and gut fungi (mycobiota) associated with exposure to radionuclides and whether the sample type (from caecum or faeces) affected the analysis. 3.The conclusions derived from the analyses of gut mycobiota are based on data that represent a mixture of inges…

Cities and their effects on free-living and host-associated microbes

2023

Mikrobit ovat oleellisen tärkeitä elämälle maapallolla, ja niitä esiintyy vapaina ympäristössä tai isäntäorganismeissa tukien ekosysteemien ja/tai isäntien normaalia toimintaa. Ihminen vaikuttaa lähes kaikkiin planeettamme elinympäristöihin aiheuttaen niiden häviämistä ja huonontumista (mukaan lukien kaupunkien rakentaminen) sekä ympäristöjen saastumista ja ilmastonmuutosta. Mikrobiyhteisöjen (kutsutaan myös mikrobiotaksi, mukaan lukien bakteerit ja sienet) odotetaan reagoivan näihin ihmisen aiheuttamiin valintapaineisiin sopeutumalla muuttuvaan ympäristöön. Siten ihmisen aiheuttamat muutokset ympäristössä voivat muovata mikrobiyhteisöjä (sekä vapaasti eläviä että isäntiin liittyviä) muutta…

Race, Environment, and Crisis : Hurricane Camille and the Politics of Southern Segregation

2022

In August 1969 Hurricane Camille hit the Mississippi coast. We argue that the disaster caused by the Hurricane was an outcome of the entanglement between human and non-human agents. As a non-human agent, Hurricane Camille thrust the prevailing socio-economic situation in the segregationist South into the spotlight, with all its political and cultural ramifications – much to the annoyance of the local political elite that had long sought to isolate southern politics from civil rights and the desegregation agenda. Consequently, it (re)invigorated and furnished the civil rights movement and the politics defining that era with new arguments and approaches that would have been impossible to dev…

Compound climate extreme events threaten migratory birds’ conservation in western U.S.

2022

In a warming world, more intense and frequent compound climate extreme events pose serious challenges to biodiversity and conservation on Earth as one of the 2030 United Nations’ sustainable development goals (SDGs): “Life On Land” (SDG 15). In summer 2020, concurrent swelling wildfires and a sudden cold snap in the western U.S. killed a massive number of migratory birds. In August 2020, the hot and humid weather in response to the wildfire radiation and the oceanic evaporation could result in killing heat stress for migratory birds along the coastal shoreline, particularly in California. The heat and smoke of wildfires forced the migratory birds to abandon such feeding grounds towards inla…

Eco-epidemiology of tick- and rodent-borne pathogens in boreal forests

2017

Infectious diseases are amongst the ten major causes of human mortality worldwide, 60% of them being animal-borne. Variations of abiotic and biotic conditions are likely to modify the transmission of parasites and pathogens within reservoir species, and, as a consequence, alter the zoonotic risk for human. My thesis aims at elucidating the dynamics and mechanisms of the maintenance of ticks, tick-borne pathogens (TBPs) and the Puumala hantavirus (PUUV) in the reservoir host, the bank vole (Myodes glareolus, BV). In Northern Europe, tick-borne diseases are growing in importance to human because of the latitudinal expansion of the tick Ixodes ricinus. Field monitoring revealed that I. ricinus…

The effect of spatial and temporal scale on camouflage in North African rodents

2022

Abstract Background matching, a common form of camouflage, is a widespread anti-predator adaptation that hinders detection or recognition by increasing the resemblance of prey to its environment. However, the natural environment is complex and both spatially and temporally variable, which constrains effective background matching as an anti-predator strategy. Here, using remote sensing data (publicly available satellite imagery), we investigated how variation of habitat parameters predicts background matching in 16 Sahara–Sahel rodent species across spatial and temporal scales. All fur colour parameters (hue, saturation and brightness) strongly matched the respective habitats of the differen…

Les héros de la foi face aux juges ecclésiastiques et magistrats séculiers d'après l'Histoire des martyrs de Jean Crespin : des stratégies distinctes

2012

Camouflage accuracy in Sahara-Sahel desert rodents

2020

1.Camouflage helps animals to hide from predators and is therefore key to survival. Although widespread convergence of animal phenotypes to their natural environment is well established, there is a lack of knowledge about how species compromise camouflage accuracy across different background types in their habitat. 2.Here we tested how background matching has responded to top‐down selection by avian and mammalian predators using Sahara‐Sahel desert rodents in North Africa. 3.We show that the fur coloration of several species has become an accurate match to different types of desert habitats. This is supported by a correlation analysis of colour and pattern metrics, investigation of animal‐t…