Search results for "background matching"
showing 6 items of 6 documents
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 colouration 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…
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 …
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…
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…
Improved camouflage through ontogenetic colour change confers reduced detection risk in shore crabs
2019
Abstract Animals from many taxa, from snakes and crabs to caterpillars and lobsters, change appearance with age, but the reasons why this occurs are rarely tested.We show the importance that ontogenetic changes in coloration have on the camouflage of the green shore crabs (Carcinus maenas), known for their remarkable phenotypic variation and plasticity in colour and pattern.In controlled conditions, we reared juvenile crabs of two shades, pale or dark, on two background types simulating different habitats for 10 weeks.In contrast to expectations for reversible colour change, crabs did not tune their background match to specific microhabitats, but instead, and regardless of treatment, all de…
The Eurasian Treecreeper (Certhia familiaris) has an effective camouflage against mammalian but not avian vision in boreal forests
2022
A well-known example of visual camouflage in birds is the plumage coloration of the Eurasian Treecreeper Certhia familiaris, yet this species’ camouflage has never been objectively quantified. Here, we quantify treecreeper camouflage in its boreal forest habitat, test whether treecreepers better match tree backgrounds at nest site, territory or habitat spatial scales, and explore which common tree species provide the best background match. Using photographic data of the birds and forested backgrounds, we test their background match using human, ferret and avian vision modelling. We found that a treecreeper’s wing and mantle provided closest background matching, whereas the wing stripe and t…