Macroparasite Fauna of Alien Grey Squirrels (Sciurus carolinensis): Composition, Variability and Implications for Native Species
نویسندگان
چکیده
Introduced hosts populations may benefit of an "enemy release" through impoverishment of parasite communities made of both few imported species and few acquired local ones. Moreover, closely related competing native hosts can be affected by acquiring introduced taxa (spillover) and by increased transmission risk of native parasites (spillback). We determined the macroparasite fauna of invasive grey squirrels (Sciurus carolinensis) in Italy to detect any diversity loss, introduction of novel parasites or acquisition of local ones, and analysed variation in parasite burdens to identify factors that may increase transmission risk for native red squirrels (S. vulgaris). Based on 277 grey squirrels sampled from 7 populations characterised by different time scales in introduction events, we identified 7 gastro-intestinal helminths and 4 parasite arthropods. Parasite richness is lower than in grey squirrel's native range and independent from introduction time lags. The most common parasites are Nearctic nematodes Strongyloides robustus (prevalence: 56.6%) and Trichostrongylus calcaratus (6.5%), red squirrel flea Ceratophyllus sciurorum (26.0%) and Holarctic sucking louse Neohaematopinus sciuri (17.7%). All other parasites are European or cosmopolitan species with prevalence below 5%. S. robustus abundance is positively affected by host density and body mass, C. sciurorum abundance increases with host density and varies with seasons. Overall, we show that grey squirrels in Italy may benefit of an enemy release, and both spillback and spillover processes towards native red squirrels may occur.
منابع مشابه
Diversity and host specificity of coccidia (Apicomplexa: Eimeriidae) in native and introduced squirrel species.
Introduction of alien species into new areas can have detrimental effects on native ecosystems and impact the native species. The present study aims to identify coccidia infecting native and introduced squirrels in Italy, to gain insight into possible transmission patterns and role of monoxenous coccidia in mediating the competition between alien and native hosts. We collected 540 faecal sample...
متن کاملThe use of DiazaCon™ to limit fertility by reducing serum cholesterol in female grey squirrels, Sciurus carolinensis.
BACKGROUND The grey squirrel, Sciurus carolinensis Gmelin, is an invasive alien species introduced into Great Britain in the late nineteenth century and into Northern Italy during the early twentieth century. Grey squirrels have displaced the native European red squirrel, Sciurus vulgaris L., throughout much of Great Britain and have a significant impact on trees and woodlands through bark-stri...
متن کاملCoccidian parasites of red squirrels (Sciurus vulgaris) and grey squirrels (Sciurus carolinensis) in England
Coccidian parasites of red squirrels (Sciurus vulgaris) and grey squirrels (Sciurus carolinensis) in England S.J. Ball, P. Daszak, A.W. Sainsbury & K.R. Snow To cite this article: S.J. Ball, P. Daszak, A.W. Sainsbury & K.R. Snow (2014) Coccidian parasites of red squirrels (Sciurus vulgaris) and grey squirrels (Sciurus carolinensis) in England, Journal of Natural History, 48:19-20, 1225-1230, DO...
متن کاملEffects of Parasitism and Morphology on Squirrelpox Virus Seroprevalence in Grey Squirrels (Sciurus carolinensis)
Invasive species have been cited as major causes of population extinctions in several animal and plant classes worldwide. The North American grey squirrel (Sciurus carolinensis) has a major detrimental effect on native red squirrel (Sciurus vulgaris) populations across Britain and Ireland, in part because it can be a reservoir host for the deadly squirrelpox virus (SQPV). Whilst various researc...
متن کاملA Test of Interspecific Effects of Introduced Eastern Grey Squirrels, Sciurus carolinensis, on Douglas’s Squirrels, Tamiasciurus douglasii, in Vancouver, British Columbia
In western Canada, Eastern Grey Squirrels (Sciurus carolinensis) were introduced to Stanley Park in the city of Vancouver, British Columbia, shortly before 1914. The three to four pairs of introduced Eastern Grey Squirrels came from eastern Canada (Robinson and Cowan 1954). In the early 1980s, Eastern Grey Squirrels colonized the rest of the city of Vancouver, including many of its urban parks....
متن کامل