| multiple origins of melanism in two species of north american tree squirrel (sciurus). | while our understanding of the genetic basis of convergent evolution has improved there are still many uncertainties. here we investigate the repeated evolution of dark colouration (melanism) in eastern fox squirrels (sciurus niger; hereafter "fox squirrels") and eastern gray squirrels (s. carolinensis; hereafter "gray squirrels"). | 2019 | 31296164 |
| conservation of genetic uniqueness in remaining populations of red squirrels (sciurus vulgaris l.) in the south of england. | the eurasian red squirrel (sciurus vulgaris) is an emblematic species for conservation, and its decline in the british isles exemplifies the impact that alien introductions can have on native ecosystems. indeed, red squirrels in this region have declined dramatically over the last 60 years due to the spread of squirrelpox virus following the introduction of the gray squirrel (sciurus carolinensis). currently, red squirrel populations in britain are fragmented and need to be closely monitored in ... | 2019 | 31236243 |
| a new species of eimeria schneider, 1885 (apicomplexa: eimeriidae) from the eastern gray squirrel, sciurus carolinensis (rodentia: sciuridae: sciurinae: sciurini) from oklahoma, usa. | a new species of eimeria schneider, 1885 is described from an eastern gray squirrel (sciurus carolinensis) from mccurtain county, oklahoma, usa. oöcysts of eimeria lukfataensis n. sp. are ellipsoidal with a rough pitted bi-layered wall, measure 23.8 × 14.9 µm, and have a length/width (l/w) ratio of 1.6; a micropyle is absent but an oöcyst residuum and polar granule(s) are present. sporocysts are ellipsoidal and measure 12.5 × 6.1 µm, l/w 2.0; stieda and sub-stieda bodies are present, but para-st ... | 2019 | 31077062 |
| inhibitory control and memory in the search process for a modified problem in grey squirrels, sciurus carolinensis. | inhibiting learned behaviours when they become unproductive and searching for an alternative solution to solve a familiar but different problem are two indicators of flexibility in problem solving. a wide range of animals show these tendencies spontaneously, but what kind of search process is at play behind their problem-solving success? here, we investigated how eastern grey squirrels, sciurus carolinensis, solved a modified mechanical problem that required them to abandon their preferred and l ... | 2019 | 30976933 |
| surgical sterilization of male and female grey squirrels (sciurus carolinensis) of an urban population introduced in italy. | we report a successful surgical sterilization procedure for population control of 324 male and female free-ranging grey squirrels (sciurus carolinensis) in genoa (italy). we describe the clinical procedure from the trapping of the animals to their surgical sterilization and release in another part of the city. live-trapped squirrels were transported to the veterinary clinic within 1-2 hr of capture and maintained in a hospitalization room reserved for them. the waiting period before surgery was ... | 2019 | 30828030 |
| british red squirrels remain the only known wild rodent host for leprosy bacilli. | eurasian red squirrels (sciurus vulgaris) in the british isles are the most recently discovered animal reservoir for the leprosy bacteria mycobacterium leprae and mycobacterium lepromatosis. initial data suggest that prevalence of leprosy infection is variable and often low in different squirrel populations. nothing is known about the presence of leprosy bacilli in other wild squirrel species despite two others (siberian chipmunk [tamias sibiricus], and thirteen-lined ground squirrel [ictidomys ... | 2019 | 30775369 |
| locomotor kinematics of tree squirrels (sciurus carolinensis) in free-ranging and laboratory environments: implications for primate locomotion and evolution. | the grasping capabilities and gait kinematics characteristic of primates are often argued to be adaptations for safely moving on small terminal branches. the goal of this study was to identify whether eastern gray squirrels (sciurus carolinensis)-arboreal rodents that frequently move and forage on small branches, lack primate-like grasping and gait patterns, and arguably represent extant analogs of a stem primate ancestor-adjust gait kinematics to narrow and nonhorizontal branches. we studied lo ... | 2019 | 30369092 |
| resource-area-dependence analysis: inferring animal resource needs from home-range and mapping data. | an animal's home-range can be expected to encompass the resources it requires for surviving or reproducing. thus, animals inhabiting a heterogeneous landscape, where resource patches vary in size, shape and distribution, will naturally have home-ranges of varied sizes, so that each home-range encompasses a minimum required amount of a resource. home-range size can be estimated from telemetry data, and often key resources, or proxies for them such as the areas of important habitat types, can be m ... | 2018 | 30356319 |
| widespread occurrence of squirrel adenovirus 1 in red and grey squirrels in scotland detected by a novel real-time pcr assay. | the eurasian red squirrel (sciurus vulgaris) is distributed throughout large parts of europe and asia. however, its distribution in certain regions of europe is endangered by the invasive, non-native grey squirrel (sciurus carolinensis). adenoviruses were already described in squirrels in great britain almost two decades ago. in 2013, a squirrel adenovirus (sqadv-1) was additionally found in a red squirrel from germany, which suffered from acute diffuse catarrhal enteritis, and the complete geno ... | 2018 | 30237072 |
| stress in biological invasions: introduced invasive grey squirrels increase physiological stress in native eurasian red squirrels. | invasive alien species can cause extinction of native species through processes including predation, interspecific competition for resources or disease-mediated competition. increases in stress hormones in vertebrates may be associated with these processes and contribute to the decline in survival or reproduction of the native species. eurasian red squirrels (sciurus vulgaris) have gone extinct across much of the british isles and parts of northern italy following the introduction of north ameri ... | 2018 | 29790583 |