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2006
At 33 squirrels, the Furzey squirrel population was much larger than in recent years, recovering from the very low in population of 20 in 2003. Survival in 2006 was average for fully grown squirrels (adults and yearlings) compared with median values for 1987-2006, and was unusually high for juveniles (Table ).
Journal of Zoology, 2006
The Channel Island of Jersey is 116 km 2 but has only 540 ha of woodland distributed in 237 wooded fragments with mean size of 2.5 ha. Despite this, the island supports 300 to 600 red squirrels Sciurus vulgaris, a species that is under threat in mainland Britain from habitat fragmentation, disease and the spread of the alien grey squirrel S. carolinensis. Grey squirrels are not present on Jersey. Between 1994 and 1997, using trapping and tracking techniques, we studied how red squirrels survive on Jersey by focusing on three local populations in sites B, C and S with contrasting food availability. The primary squirrel foods at site B were autumn tree seeds, at site C autumn tree seeds and summer conifer cones, and at site S autumn tree seeds and ad libitum, year-round supplementary food provided by local people. The densities of squirrels in site C (mean over 3 years 0.97 ha 71) and site S (1.21 ha 71) were more than one and a half times that of site B (0.68 ha 71), which relied on autumn seeds. Body mass and condition, and early breeding (spring litters) were not affected by food availability although conception occurred as early as November, earlier than in mainland Britain. Less than 50% of females produced summer litters, and 88% of non-breeders did not receive supplementary food. Turnover rates were lowest and most stable in site B. Annual residency was not in¯uenced by the size of the natural tree seed crop. Cat and road kills caused two out of three reported deaths. This island population seems to remain viable as a result of an extended breeding season and increased population densities in sites with summer or supplementary food. The results emphasize the bene®cial effects of extra food provided by local people. This provides a buffering effect against variations in natural food availability, and seems to be important for their long-term survival.
Italian Journal of Zoology, 1997
The methods used to assess a red squirrel Sciurus vulgaris reintroduction experiment at Parco Groane, northern Italy, are described. Population size at the removal site was estimated (c. 2400 squirrels) using drey counts, to evaluate the effect of removing animals for reintroduction. Suitability of the release site was investigated in two ways: (1) beforehand, by comparing tree seed abundance with that at the removal site, (2) retrospectively, by comparing drey-site choice between removal and release site. Increase and dispersion of the reintroduced population were monitored using drey counts and searching for species-specific feeding signs. Although only eight squirrels could be released (four males, four females), the experiment was successful and by 1996 all wooded habitats at Parco Groane were inhabited by squirrels.
biodiversity.ie
Ecography, 2003
. Patch occupancy, population density and dynamics in a fragmented red squirrel Sciurus 6ulgaris population. -Ecography 26: 118-128. We studied population dynamics of red squirrels in a group of small forest fragments, that cover only 6.5% of the total study area (4664 ha) and where distances to the nearest source population were up to 2.2 km. We tested effects of patch size, quality and isolation and supplementary feeding on patch occupation during 1995-99. Larger patches and patches with supplementary feeding had a higher probability of being occupied. No patch B3.5 ha was ever occupied. No effects of isolation were found, suggesting that the forest habitat in the study area is not sufficiently fragmented to influence red squirrel distribution across patches. For medium sized patches (3.7-21 ha), that were occupied some years, there was an increase in patch occupation over the years, even though overall population size tended to decrease. These patches had a high turnover, especially of males. Patches in which the squirrel population went extinct were recolonized within a year. For patches that were at least some years occupied, squirrel density depended on patch quality only. No effects of patch size, isolation and winter temperature on population density were found. These data suggest that in our study area habitat fragmentation has no effect on local squirrel density and that the random sample hypothesis explains the distribution pattern across patches. G. Verbeylen (goedele.6erbeylen@lin.6laanderen.be) and E. Matthysen,
Ecography, 2017
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Western North American Naturalist, 2006
Ecological Research, 2000
Interspecific competition between red squirrels and grey squirrels was investigated by comparing the population demography, spacing behavior and habitat use of red squirrels in two large conifer plantations in northern England: one site had only red squirrels (the 'red-only' site), in the other both red and grey squirrels occurred (the 'red-grey' site). Despite more abundant food at the red-grey site, red squirrel densities (0.26 ha-1 at the red-grey site, 0.29 ha-1 at the red-only site), adult survival rates and the breeding rates of females were similar at both study sites. Grey squirrels at the red-grey site occurred at higher densities (0.92-1.1 ha-1) than did the reds and tended to have higher breeding rates. In the presence of grey squirrels, the recruitment pattern of red squirrels changed and there was little recruitment of subadults. The juvenile recruitment rate in the red-grey site (13%) was much lower than in the red-only site (50%). Grey squirrels, in contrast, had higher juvenile recruitment rates at the red-grey site (41%). The core areas of the home ranges of red squirrels in the red-grey site were more strongly overlapped by grey squirrels than by conspecifics. Red squirrels did not select the habitat with the best tree seed crop (Scots pine) but preferred dense Sitka spruce plantations; they appeared to avoid the Scots pine area with its high grey squirrel density. Data on foot length and body condition indicated decreased body growth in young red squirrels when grey squirrels were present. Our data suggest that adult red squirrels suffered little from interspecific competition with grey squirrels and that the key factor is decreased juvenile recruitment in red squirrels.
Italian Journal of Zoology, 1997
The behaviour of eight radiotagged red squirrels (Sciurus vulgaris Linnaeus, 1758) reintroduced at Parco Groane, northern Italy, was monitored for two months following their release. Both male and female squirrels moved over considerable distances the first two weeks after introduction, exploring the new habitat. Two types of exploring behaviour were observed: (i) gradually expanding the home range, moving only short distances each day; and (ii) making regular excursions of more than 1 km followed by short periods of activity in a small area. The latter behaviour resulted in very large home ranges during the exploring phase. After the initial exploring, home range size decreased and one male and two female squirrels changed their space use by increasing the number of activity centres (core-areas) within their home range. Post-settlement home ranges were spaced out over the available habitat and all squirrels used almost completely exclusive core-areas. Only four red squirrels (two males and two females) survived long enough to be the potential founders of the new population that established itself at Parco Groane. We discuss methods to decrease post-release mortality in red squirrels and consider genetic and demographic consequences of squirrel reintroductions.
Animal Conservation, 1999
We investigated the distribution of red squirrel (Sciurus vulgaris) populations on the Isle of Wight using Generalized Linear Models (GLMs) and a spatially explicit population dynamics model (SEPM) with the aim of identifying management options for red squirrel conservation. The presence/absence of red squirrels in habitat blocks in the landscape was used as the dependent variable and the size and separation of habitat blocks as independent variables in the GLM analysis. Red squirrel presence within a woodland was significantly related to woodland size and the distance to the nearest wood known to contain squirrels. The SEPM-generated predictions on population viability were closest to the field data when a low dispersal distance of 1 km was used. This suggests that squirrel dispersal on the Isle of Wight is restricted. Our results suggest that some large interconnected woodlands should be maintained if red squirrels are to be conserved for the future.
Mammal Review, 1993
American Midland Naturalist, 1989
Topographic distribution and daily activity of the European ground squirrel population in Bugacpuszta, Hungary, 2002
Urban Forestry & Urban Greening
Because the amount of urban areas has increased, it is important to investigate the abundance of wildlife species in relation to urban environments. Analyzing the impact of urbanization on the presence of forest-dwelling mammals is of interest due to the possible effects of urbanization on human-wildlife relationships and urban biodiversity. The Eurasian red squirrel (Sciurus vulgaris) is a declining forest species, and its occurrence in urban environments has been inadequately studied. The loss and fragmentation of forests due to urbanization may be detrimental for squirrels, whereas the abundant and predictable food resources and the low number of natural predators in urban areas may encourage squirrels to invade towns. We used large-scale data collected by volunteer bird watchers along a 950 km south-north gradient to study whether the winter abundance of squirrels in Finland is dependent on urbanization, while controlling for effects of habitat type, food abundance (spruce cone crop; number of winter feeding sites), predator abundance (northern goshawk, Accipiter gentilis; feral cat Felis catus), season and latitude. We found that squirrel abundance increased with human population density, number of feeding sites and spruce cone crop and decreased with latitude and season. Feral cats showed weak negative connection with squirrel numbers, but there were no effect of goshawks. Relative squirrel abundance was approximately twice as high in urban habitats than in forests. Artificial feeding rather than a low number of predators may attract squirrels in urban environments. Planting spruce trees in urban environments will also benefit squirrels. Our results indicate that urban areas are an important habitat for the red squirrel even along the northern edge of their distribution range, where natural forest areas are still widespread. We conclude also that a citizen science-based bird survey protocol associated with mammal surveys seems to be a good largescale monitoring method to study the urbanization of squirrels.
2008
s 11 List of Participants 45 II. EGSM 2008 Czech Republic Introduction 3 2 European Ground Squirrel Meeting 1-5 October 2008, Svatý Jan pod Skalou Dear Ladies and Gentlemen, The organizing committee welcomes you at the II. European Ground Squirrel meeting in Sv. Jan pod Skalou, Czech Republic. We are glad that we can take a share in a tradition of the regular EGS meetings, following the successful I. EGSM in Felsıtárkány, Hungary in 2006 and the conference “Ecology and Conservation of the European souslik (Spermophilus citellus)” in Madjarovo, Bulgaria in 2002. The meeting offers a unique opportunity to present scientific results and conservation experiences concerning the European ground squirrel to a wide group of ground squirrel experts. We hope you will enjoy not only the new information about different aspects of the ground squirrel biology and conservation, but also the surroundings of Sv. Jan pod
Folia Oecologica, 2021
In the past, the European ground squirrel represented a common part of Slovakian fauna. During the 20th century, there was a substantial decrease in its number, mainly due to the intensification of agriculture. Currently, several programs focused on the recovery and preservation of ground squirrel colonies have been implemented. The aim in supporting the population of the European ground squirrel is to increase the number of birds of prey and to ensure a food base for them. In this paper, we focus on evaluating the success rate of European ground squirrel (Spermophilus citellus) management measures. The research was realized at two localities in the Protected Bird Area Slovenský kras (Hrhov and Gemerská Hôrka) in the years 2015–2018. Activities were focused on the management of grassland and supplemental feeding during the breeding period. As a result of the management measures and the supplemental feeding, we managed to maintain a positive trend in the populations’ development, as ...
Ecological Research, 2000
Interspecific competition between red squirrels and grey squirrels was investigated by comparing the population demography, spacing behavior and habitat use of red squirrels in two large conifer plantations in northern England: one site had only red squirrels (the ‘red-only’ site), in the other both red and grey squirrels occurred (the ‘red–grey’ site). Despite more abundant food at the red–grey site, red squirrel densities (0.26 ha−1 at the red–grey site, 0.29 ha−1 at the red-only site), adult survival rates and the breeding rates of females were similar at both study sites. Grey squirrels at the red–grey site occurred at higher densities (0.92–1.1 ha−1) than did the reds and tended to have higher breeding rates. In the presence of grey squirrels, the recruitment pattern of red squirrels changed and there was little recruitment of subadults. The juvenile recruitment rate in the red–grey site (13%) was much lower than in the red-only site (50%). Grey squirrels, in contrast, had higher juvenile recruitment rates at the red–grey site (41%). The core areas of the home ranges of red squirrels in the red–grey site were more strongly overlapped by grey squirrels than by conspecifics. Red squirrels did not select the habitat with the best tree seed crop (Scots pine) but preferred dense Sitka spruce plantations; they appeared to avoid the Scots pine area with its high grey squirrel density. Data on foot length and body condition indicated decreased body growth in young red squirrels when grey squirrels were present. Our data suggest that adult red squirrels suffered little from interspecific competition with grey squirrels and that the key factor is decreased juvenile recruitment in red squirrels.
Italian Journal of Zoology, 2010
The European ground squirrel (Spermophilus citellus) is an endangered species and typically inhabits steppes and open woodland of Central Europe and the Balkans. Knowledge about its distribu- tion and status in the southern part of its range is scanty. Distribution of the species in Bulgaria over two periods (1950-1989 and 1990-2008) and recent status of 90 colonies in three model regions (mountain region, Sofia field and Thracian valley) are evaluated in the paper. Data on 254 UTM squares inhabited by S. citellus during the first period and 212 UTM squares inhabited during the second period were available, but these data could not be compared because of the different survey methods used. S. citellus colonies in southwestern Bulgaria may be already extinct and population decline is supposed to take place at the southwestern periphery of the species' distribution range. About 30% out of 90 investigated colonies have disappeared, 28% are vulnerable and only 42% are stable. The big...
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