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Human activities often induce maladaptive effects in urban wildlife, such as increased inbreeding and decreased gene flow, consequently leading to a loss of biodiversity. Although maladaptive effects are commonly reported in urban wildlife, some wildlife species are not affected. Understanding the conditions and factors that affect the genetic structure of wildlife is crucial for its conservation in urban environments. Eurasian red squirrels Sciurus vulgaris in Obihiro City, Hokkaido, Japan, have settled in large residential lots with a high risk of vehicle collisions for approximately 30 years, raising the possibility that the urban population would be genetically isolated from nearby rural populations and may experience a rapid decrease in genetic diversity. In this study, we analysed the population structure, genetic distance, and nucleotide diversity of squirrels in the Obihiro area using genome-wide single nucleotide polymorphisms (SNPs). Principal component analysis and ADMIXTURE showed that urban and rural squirrel populations formed distinct clusters with intermediate urban and rural boundary populations. Genetic distances between the urban populations were greater than that of other pairs. Nucleotide diversities were lower in urban populations than in other populations, suggesting limited gene flow between urban and other populations, possibly due to urbanisation. The change in the genetic characteristics of urban squirrel populations during this short period demonstrates the strong impact of urbanisation. Our findings suggest that a genome-wide approach to the genetic structure of wildlife contributes to its conservation in urban environments. [ABSTRACT FROM AUTHOR]

We investigated activity patterns of wildlife by using 28 camera traps from June 2021 to June 2022 in a forest in eastern Hokkaido, Japan. Sciurus vulgaris is generally known as a diurnal species. However, two photos recorded the night activity of this species in March 2022. One photo showed something resembling a pine cone in a squirrel’s mouth. Sciurus vulgaris might shift the timing of their activity patterns to avoid predators such as Vulpes vulpes and/or to forage food when scarce. [ABSTRACT FROM AUTHOR]

Urban environments are novel alternative habitats for wildlife. Anthropogenic food resources such as supplemental feeding (SF) are usually abundant, stable across seasons, and sometimes rich in calories. Although anthropogenic food resources could modify the seasonality and composition of the diets of urban animals, previous studies have been limited to qualitative assessments based on stomach content and food remains. Our study compared diet seasonality and niche width between rural and urban populations of Eurasian red squirrels (Sciurus vulgaris) in Hokkaido, Japan, using direct observation and stable isotope analysis. We found that dietary seasonality was lower in urban populations than in rural populations. The frequency of seed use was higher throughout the year in urban populations than in rural populations, possibly because of excessive seeds by SF in urban squirrels. Additionally, female body weights of the urban population were higher than those of the rural population. However, this was not true for males. Because high body weight can increase reproductive success in females, it is feasible that diet modification could contribute to population growth in urban squirrels. However, no differences in male body weight were observed, possibly due to energy loss caused by intense male–male competition at feeding sites. Our study highlights the importance of studying the multidimensional effects of anthropogenic foods on wildlife. [ABSTRACT FROM AUTHOR]

Scatter-hoarding animals decide their food hoarding location by assessing food quality and pilfering risk. Previous studies have proposed two non-mutually exclusive hypotheses; the optimal density model (ODM) and the habitat structure hypothesis (HSH). The ODM proposes that animals utilize low cache density to protect their valuable caches by transporting food far from food sources. The HSH proposes that animals utilize predation risk to protect their valuable caches by hoarding food in open areas. Here, we investigated the hoarding behaviours in Eurasian red squirrels Sciurus vulgaris by experimentally providing high-quality (walnuts) and low-quality (acorns) food, to examine if they follow ODM or HSH. Compared to acorns, squirrels hoarded walnuts in places further from the area where food was provisioned and in areas with low canopy cover. These results agree with both ODM and HSH, providing the first evidence that hoarding behaviour in Eurasian red squirrels is shaped by multiple factors. [ABSTRACT FROM AUTHOR]

Abstract Background The diagnosis of tularemia is not often considered in Germany as the disease is still rare in this country. Nonetheless, Francisella tularensis, the causative agent of tularemia, can infect numerous animal species and should, therefore, not be neglected as a dangerous pathogen. Tularemia can lead to massively swollen lymph nodes and might even be fatal without antibiotic treatment. To our knowledge, the case described here is the first report of the disease caused by a squirrel bite in Germany. Case presentation A 59-year-old German woman with a past medical history of hypothyroidism and cutaneous lupus erythematosus presented at the emergency room at St. Katharinen Hospital with ongoing symptoms and a swollen right elbow persisting despite antibiotic therapy with cefuroxime for 7 days after she had been bitten (right hand) by a wild squirrel (Eurasian red squirrel). After another 7 days of therapy with piperacillin/tazobactam, laboratory analysis using real-time polymerase chain reaction (PCR) confirmed the suspected diagnosis of tularemia on day 14. After starting the recommended antibiotic treatment with ciprofloxacin, the patient recovered rapidly. Conclusion This is the first report of a case of tularemia caused by a squirrel bite in Germany. A naturally infected squirrel has recently been reported in Switzerland for the first time. The number of human cases of tularemia has been increasing over the last years and, therefore, tularemia should be taken into consideration as a diagnosis, especially in a patient bitten by an animal who also presents with headache, increasing pain, lymphadenitis, and fever, as well as impaired wound healing. The pathogen can easily be identified by a specific real-time PCR assay of wound swabs and/or by antibody detection, for example by enzyme-linked immunosorbent assay (ELISA), if the incident dates back longer than 2 weeks.

Although habitat fragmentation is widely reported to affect species survival and distribution, its effect in terms of host-parasite interactions in small mammal communities is poorly studied yet. Using information collected from carcasses of 34 road-kill and two preyed-upon individuals, we present the first comprehensive study dealing with the relationship between habitat fragmentation and the presence of different ectoparasite species infecting a small Sciurus vulgaris population inhabiting the Apennine ridge. We predicted that the probability to find individuals infested by parasites would be lower in highly fragmented areas because of the trade-off effects over both mammal and ectoparasite communities. Our findings showed that the most frequent ectoparasites were the squirrel fleas Ceratophyllus sciurorum and hard ticks Ixodes ricinus. Males showed higher presence of ectoparasites than females, probably because of different behaviour in space use and higher hormone levels, which may compromise host's resistance to infection. As to the relationship with habitat fragmentation, we did not find support that individuals in highly fragmented areas would be less susceptible to C. sciurorum infestation because of lower red squirrel relative density. The presence of highly suitable habitat patches in fragmented habitats may have favoured the presence of squirrels, hence promoting C. sciurorum transmission among specimens. Similarly, we did not find support that habitat fragmentation would have reduced the likelihood of generalist ectoparasites transmission among squirrels. This finding may be explained by the increasing tolerance of generalist ectoparasites towards habitat fragmentation because of the presence of species (e.g., roe deer Capreolus capreolus) able to better exploit ecotonal areas. We believe that our research provides interesting preliminary results on ectoparasites infesting red squirrels in the Apennine area, and of the potential impact which habitat fragmentation may have on them. Nevertheless, the effect of habitat fragmentation over parasite communities is still poorly considered, and further researches are needed. [ABSTRACT FROM AUTHOR]

Background: The diagnosis of tularemia is not often considered in Germany as the disease is still rare in this country. Nonetheless, Francisella tularensis, the causative agent of tularemia, can infect numerous animal species and should, therefore, not be neglected as a dangerous pathogen. Tularemia can lead to massively swollen lymph nodes and might even be fatal without antibiotic treatment. To our knowledge, the case described here is the first report of the disease caused by a squirrel bite in Germany.Case Presentation: A 59-year-old German woman with a past medical history of hypothyroidism and cutaneous lupus erythematosus presented at the emergency room at St. Katharinen Hospital with ongoing symptoms and a swollen right elbow persisting despite antibiotic therapy with cefuroxime for 7 days after she had been bitten (right hand) by a wild squirrel (Eurasian red squirrel). After another 7 days of therapy with piperacillin/tazobactam, laboratory analysis using real-time polymerase chain reaction (PCR) confirmed the suspected diagnosis of tularemia on day 14. After starting the recommended antibiotic treatment with ciprofloxacin, the patient recovered rapidly.Conclusion: This is the first report of a case of tularemia caused by a squirrel bite in Germany. A naturally infected squirrel has recently been reported in Switzerland for the first time. The number of human cases of tularemia has been increasing over the last years and, therefore, tularemia should be taken into consideration as a diagnosis, especially in a patient bitten by an animal who also presents with headache, increasing pain, lymphadenitis, and fever, as well as impaired wound healing. The pathogen can easily be identified by a specific real-time PCR assay of wound swabs and/or by antibody detection, for example by enzyme-linked immunosorbent assay (ELISA), if the incident dates back longer than 2 weeks. [ABSTRACT FROM AUTHOR]

In Ukraine during 2008–2010, the first SDM matched the red squirrel (S. vulgaris) based on GLM-by-2050, and which covered Eastern Europe, was developed and used by the Land and Resource Management Center (ULRMC, Kyiv). Our new study reveals further development of the analysis by using relevant IPCC climate change scenarios. We took into account materials on S. vulgaris (and S. anomalus) distribution, as well as selected associated species, and the WorldClim with respective maps and current bioclimatic variables, and its projections for four relevant scenarios which combined SSPs & RCPs by 2100. The simulations of scenario SSP1 & RCP2.6 associated with an average temperature increase of 1.5 °C show that climate change could cause the loss of 12 % of suitable habitats of the species in Eastern Europe and 49 % in Ukraine. The simulations for SSP2 & RCP4.5 (with average temperature increase of 1.8 °C) demonstrates, respectively, a potential loss of 14 % and 57 % of suitable habitats. Simulations of SSP3 & RCP7.0 and SSP5 & RCP8.5 scenario (with average temperature increase of >> 2 °C) shows a loss of 30 % and 41 % of suitable habitats within Eastern Europe, and more than 90 % in Ukraine. Since each percent of such changes provokes enormous losses in ecosystems and biodiversity, we emphasize the current need for countries to aim and achieve the most ambitious climate change commitments to stabilize the increase of temperature, i.e. within 1.5 °C. Our comparison platform included also SDMs of some trees (oak, beech, spruce, pine, linden, and birch — Quercus robur, Fagus sylvatica, Picea abies, Pinus silvestris, Tilia cordata, Betula spp.), as well as SDM for the marten (Martes martes), for all of which we had already developed GLM-by-2050. Consequently, the new projections demonstrated that all habitats of the red squirrel and associated species are expected to shift mostly ‘to the north’ by 2100, and their localities in the Caucasus Mountain areas might be fragmented. Most likely, in nature, this complicated displacement revealed by the mentioned modelling will happen not in the form of direct migration of individuals ‘to the north’ directly, but through active synanthropization of the red squirrel. How durable and satisfactory this mechanism is for natural selection remains a mystery. The territories from which S. v. ukrainicus (Mygulin, 1928) historically originated and was described have changed significantly: the respective landscape ecosystem losses have reached up to 50 % and more. By 2100, significant habitat changes are likely to be also demonstrated by beech and birch. This research can be used by educators in teaching the history of science, applied ecology, nature conservation, and geoinformatics in biology. This research is dedicated to the Squirrel Year 2020.

Urban wildlife faces a great variety of human-induced habitat alterations, among others changes in resource availability and composition, often resulting in serious declines in biodiversity. Nevertheless, Eurasian red squirrels (Sciurus vulgaris) occur in high densities in urban areas and seem to benefit from supplementary feeding. However, we still lack knowledge about consequences of urbanisation on mammalian foraging behaviour and nutrient intake. Thus, we investigated body mass, food choice and diet composition in squirrels from an urban core area versus a forest population in a cafeteria experiment. Urban individuals were lower in initial body mass and condition, but consumed significantly more g and kJ per day and significantly gained weight over the course of the experiment (around 2 weeks); nevertheless, the difference in body mass and condition persisted. All squirrels preferred hazelnuts, but urban squirrels had a wider dietary range and consumed more non-natural food items. Both groups prioritised fat and there was no difference in protein intake. Urban squirrels though had a significantly higher sugar intake, mainly by eating biscuits. Our results demonstrate clear effects of urbanisation on foraging behaviour and preferences, which has the potential for nutritional mismatch or negative side effects due to consumption of non-natural food items. Our findings show that highly supplemented urban core fragments might not serve as adequate refuge for wildlife. [ABSTRACT FROM AUTHOR]

The analysis of eco-physiological parameters in wildlife may represent a priority for their conservation and management, not only to establish causal relationships, obtaining a set of raw data, but also to monitor the effectiveness of management strategies. We studied Hair Cortisol concentration (HCC) in Eurasian red squirrels Sciurus vulgaris in four selected study areas in Italy. Areas differed from one another for vegetation type, degree of urbanization and anthropic disturbance, density of red squirrel populations and presence or absence of alien squirrel species. HCC measurements showed the highest values in a high-density population, subjected to a high predation pressure (i.e. in areas characterized by deciduous vegetation). Conversely, the lowest HCC levels have been observed in areas with the lowest squirrel density, i.e. in urbanized environments, where the species is established for a rather long time, and in areas with mixed vegetation and presence of conifers. Measuring HCC provides reliable information on the long-term activity of hypothalamic–pituitary–adrenal (HPA) axis and associated allostatic load. Furthermore, it constitutes a non-invasive method of investigation. The use of hair tubes further supports our non-invasive approach. Because of its simplicity and low costs, hair collection might be applied to monitor the long-term physiological response of wild species even in larger areas, besides focusing in the promotion of citizen-science data collection. [ABSTRACT FROM AUTHOR]

Abstract Landscape structure can affect dispersal and gene flow in a species. In urban areas, buildings, roads, and small habitat patches make the landscape highly fragmented and can inhibit movement and affect dispersal behavior. Similarly, in rural forested areas, large open areas, such as fields, may act as barriers to movement. We studied how landscape structure affects natal dispersal distances of Eurasian red squirrels (Sciurus vulgaris) in an urban area and a rural area in Finland, by monitoring juvenile red squirrels with radio telemetry. We observed extremely long dispersal distances—up to 16 km—in the rural study area, but shorter distances—on average only half a kilometer—in the urban study area. The landscape structure affected the eventual dispersal paths; in the rural landscape, dispersers favored spruce dominated areas and avoided fields along their dispersal route, although they occasionally even crossed wide fields. In the urban landscape, squirrels preferred areas with deciduous or coniferous trees. The movement steps made by dispersers were longer in the more hostile landscape compared to forested areas. Despite these effects on movement path, the landscape structure only had a minor effect on straight line dispersal distances moved from the natal nest. In other words, individuals moved longer distances and were likely to circumvent barriers in their path, but this did not affect how far they settled from their natal home. This result indicates that, although landscape structure has obvious effects on movement, it still may have only a small effect on other aspects of the population, for example, gene flow.

Timber harvesting practises can lead to loss of suitable nesting opportunities and thus have a negative impact on reproductive success and abundance of arboreal species. For many species, the impact of forest operations and the effectiveness of mitigation, such as pre-operational surveys, retention of trees with nests or the use of nest boxes, are unknown. This study aimed to assess the impact of forest operations and the utility of nest boxes as a conservation tool, using the Eurasian red squirrel (Sciurus vulgaris) as study species. We carried out the first quantitative assessment of drey survey effectiveness and tested the predictions that (1) red squirrel drey use increases postthinning (2) nest box use increases post-thinning when their availability may be critical; (3) nest box use increases over time due to habitation and (4) nest box characteristics and placement affect nest box use. Our results show that thinning has led to squirrels changing their nesting behaviour with increased drey use post forest operations. We conclude that drey surveys are inefficient due the dynamic nature of drey use by red squirrels and that although foresters can detect a small proportion of active dreys, it is impossible to assess whether dreys are in use. Furthermore, nest box use increased after forest operations and nest boxes placed at a lower position in the tree were preferred. Our results suggested that red squirrels habituate to nest boxes over time as nest box use was higher during the second year after deployment. Overall, we propose that nest boxes can be a useful conservation tool to mitigate the impacts of forest operations and conclude that early deployment of nest boxes can contribute to red squirrel conservation by providing shelter for red squirrels after forest operations - and potentially for juveniles during natal dispersal. [ABSTRACT FROM AUTHOR]

Intraspecific variation in home range size has important implications for the distribution of animals across landscapes and the spatial structuring of population, community, and ecosystem processes. Among species of similar trophic guild and body mass, differences in home range size can reflect extrinsic variables that exert divergent selective forces upon spacing behavior and social organization. We tested predictions about how resource availability and timing influence social system, home range size, and territoriality in two tree squirrel species of similar size and ecological niches but that differ in foraging strategy and social organization. We estimated home range size and intraspecific home range core overlap in the Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis; Arizona USA; MGRS) and the Eurasian red squirrel (Sciurus vulgaris; Alps, Italy; ERS) as functions of species, sex, season, and individual’s body mass. However, body mass did not explain differences found between the two species. We found MGRS home ranges being three times smaller with higher core area exclusivity compared to ERS in all seasons. In fact, territorial MGRS evolved in a system of brief resource pulses and are larder hoarders, whereas ERS experience prolonged resource availability and are non-territorial. Only male MGRSs increased their home range during the breeding season, reflecting interspecific differences in social organization and mating behavior. Male ERS home ranges always overlap with several females to enhance mating success although male and female MGRS maintain nearly exclusive territories throughout the year. Only during spring and summer do males temporarily leave their food-based territory to increase mating opportunities with neighboring estrus females. Home range comparisons between ecologically similar species emphasize the importance of divergent extrinsic factors in shaping variability in body size–home range size scaling relationships. Timing in resource availability influenced the social structure and space use in tree squirrels of similar body size, highlighting how the coevolution of arboreal squirrels with conifer tree species has shaped their natural history.

Cryptosporidium spp. and Enterocytozoon bieneusi are two well-known protist pathogens which can result in diarrhea in humans and animals. To examine the occurrence and genetic characteristics of Cryptosporidium spp. and E. bieneusi in pet red squirrels (Sciurus vulgaris), 314 fecal specimens were collected from red squirrels from four pet shops and owners in Sichuan province, China. Cryptosporidium spp. and E. bieneusi were examined by nested PCR targeting the partial small subunit rRNA (SSU rRNA) gene and the ribosomal internal transcribed spacer (ITS) gene respectively. The infection rates were 8.6% (27/314) for Cryptosporidium spp. and 19.4% (61/314) for E. bieneusi. Five Cryptosporidium species/genotypes were identified by DNA sequence analysis: Cryptosporidium rat genotype II (n = 8), Cryptosporidium ferret genotype (n = 8), Cryptosporidium chipmunk genotype III (n = 5), Cryptosporidium rat genotype I (n = 4), and Cryptosporidium parvum (n = 2). Additionally, a total of five E. bieneusi genotypes were revealed, including three known genotypes (D, SCC-2, and SCC-3) and two novel genotypes (RS01 and RS02). Phylogenetic analysis revealed that genotype D fell into group 1, whereas the remaining genotypes clustered into group 10. To our knowledge, this is the first study to report Cryptosporidium spp. and E. bieneusi in pet red squirrels in China. Moreover, C. parvum and genotype D of E. bieneusi, previously identified in humans, were also found in red squirrels, suggesting that red squirrels may give rise to cryptosporidiosis and microsporidiosis in humans through zoonotic transmissions. These results provide preliminary reference data for monitoring Cryptosporidium spp. and E. bieneusi infections in pet red squirrels and humans. [ABSTRACT FROM AUTHOR]

Over the last few decades, urban environments have been regarded as alternative habitats for wildlife. Given the continuous anthropogenic disturbance, however, it remains largely unknown whether urban environments are truly beneficial to some animals or whether the animals are merely just surviving. Glucocorticoids, which play an important role in coping with environmental challenges, are often measured as primary biomarkers of physiological stress. Chronic secretions of these hormones can have deleterious effects on animal health. Some urban stressors are constantly present and may increase the risk of chronic stress. In this study, we compared fecal cortisol metabolite (FCM) levels to evaluate stress levels between an urban and rural population of Eurasian red squirrels Sciurus vulgaris. We hypothesized that if squirrels suffer from greater stress in urban environments, their FCM levels would be significantly higher than that of rural squirrels. Our results showed that FCM levels were not significantly different between the urban and rural squirrel populations, and urban squirrels did not weigh less than rural squirrels. We conclude that the urban squirrels were not subjected to greater stress than their rural counterparts. Urban environments may be preferable for red squirrels, possibly because of release from predators and increased food availability through artificial feeding. [ABSTRACT FROM AUTHOR]

Landscape structure can affect dispersal and gene flow in a species. In urban areas, buildings, roads, and small habitat patches make the landscape highly fragmented and can inhibit movement and affect dispersal behavior. Similarly, in rural forested areas, large open areas, such as fields, may act as barriers to movement. We studied how landscape structure affects natal dispersal distances of Eurasian red squirrels (Sciurus vulgaris) in an urban area and a rural area in Finland, by monitoring juvenile red squirrels with radio telemetry. We observed extremely long dispersal distances—up to 16 km—in the rural study area, but shorter distances—on average only half a kilometer—in the urban study area. The landscape structure affected the eventual dispersal paths; in the rural landscape, dispersers favored spruce dominated areas and avoided fields along their dispersal route, although they occasionally even crossed wide fields. In the urban landscape, squirrels preferred areas with deciduous or coniferous trees. The movement steps made by dispersers were longer in the more hostile landscape compared to forested areas. Despite these effects on movement path, the landscape structure only had a minor effect on straight line dispersal distances moved from the natal nest. In other words, individuals moved longer distances and were likely to circumvent barriers in their path, but this did not affect how far they settled from their natal home. This result indicates that, although landscape structure has obvious effects on movement, it still may have only a small effect on other aspects of the population, for example, gene flow. The landscape structure can affect movements and behavior of animals. Juvenile squirrels move far from their mothers, regardless of the obstacles on their path. Landscape affects movement paths of young squirrels when they are moving away from home, but the total distance travelled from their mother's home range is not substantially affected by the landscape structure. [ABSTRACT FROM AUTHOR]

Native red squirrels Sciurus vulgaris in Great Britain and Ireland are threatened by alien grey squirrels S. carolinensis through exploitation competition and spillover of squirrelpox virus (SQPV). By accelerating the replacement of red squirrels by the invader, SQPV represents a fundamental factor to consider when planning management and conservation strategies. In mainland Europe, grey squirrels introduced to Italy threaten the survival of the whole continental red squirrel population, but no extensive surveys for SQPV presence have been carried out in the region. We therefore investigated SQPV infection in north Italian grey squirrel populations through a combination of serological and molecular methods. Firstly, we analysed sera from 285 individuals through an enzyme‐linked immunosorbent assay (ELISA) to detect antibodies against SQPV. Secondly, a PCR designed to amplify a segment of the G8R SQPV gene was carried out on DNA extracted from swabs and skin tissue samples from a second set of 66 grey squirrels. ELISA tests identified four reactors (1.4%), but the subsequent PCR survey did not detect any SQPV DNA. Based on the low prevalence observed and on PCR results, we believe that the four suspected positives were the result of an ELISA cross‐reaction following exposure to another pox virus. Considering sample size and performances of the two methods, confidence of freedom from SQPV resulted above 99.9%. However, because of the severe impact of SQPV on red squirrels, we recommend the implementation of a passive surveillance plan for the early detection of an SQPV emergence in continental Europe. Squirrelpox virus transmitted by alien grey squirrels played a crucial role in the decline of native red squirrels in Great Britain and Ireland. It is still unknown whether the virus is circulating in Italy too, where it could potentially threaten the whole European red squirrel population. We extensively surveyed grey squirrels introduced to Italy for squirrelpox virus infection through a combination of serological and molecular methods, but did not find any evidence of the disease in the area. We discuss the implications of this absence and recommend the activation of passive surveillance plans to avoid any disease emergence that could threaten native squirrels survival. Photo credit: Sandro Bertolino. [ABSTRACT FROM AUTHOR]

The Open Field Test (OFT) and Mirror Image Stimulation (MIS) are used to measure behaviours related to an individual's personality. These tests, carried out in a same novel arena, have been used for different taxa, but only a few papers underline the importance of method validation. Here we investigate how Eurasian red squirrels (Sciurus vulgaris) and Eastern grey squirrels (Sciurus carolinensis) behave during OFT and MIS. Next, we compare the performance between three analytical methods: the Principal Component Analysis (PCA), the Factor Analysis (FA) and an expert-based (EB) method. The EB approach classifies behaviours in groups relating on researchers' knowledge and returns personality-trait values for each individual facilitating comparisons over studies and/or with new datasets. The comparison between the three methods gave similar results and high repeatabilities in some expert-based personality traits as well as PCA components and FA factors, showing that all three methods were valid to measure activity using OFT (both species) and sociability using MIS (grey squirrel). Repeatabilities of the other traits were less strong. Proportion of time spent in different behaviours did not differ with test duration, since shorter tests yielded valid measures of individual differences in personality. Shorter tests reduce operator time in the field, and are likely to reduce stress and arena-habituation of the animals. Test sequence affected the outcome of OFT: squirrels tested for the first time were more active than squirrels tested a second time. For the two squirrel species investigated, we recommend an OFT of 4 min and a MIS test of three and suggest to test an individual no more than 2 times per season with at least 2 months between repetitions. [ABSTRACT FROM AUTHOR]

Abstract A number of conservation approaches are used to manage threatened species. However, some of these approaches require intensive planning and can often be restricted by funding. Supplementary feeding is a non-invasive and cost-effective approach to manage vulnerable populations, but we lack data on its usefulness. Here we investigated the effects of supplementary feeding on a population of red squirrels (Sciurus vulgaris), a UK priority species which faces competition from the non-native grey squirrel (Sciurus carolinensis). The study took place October-December 2015, lasting 8 weeks. Twenty feeders were installed 1 week prior to the beginning of the study in a protected woodland free from grey squirrels, either containing food (full feeders) or no food (empty feeders), and squirrel abundance before and after feeding was recorded at each feeder (for a total of 27 feeding and recording events). Six times more squirrels were seen at full feeders, and numbers increased by 7 fold after feeding. We also observed that the activity of red squirrels in the vicinity of full feeders increased during the course of the study. Eighty-five hair samples were collected during the study, all of which were found at full feeders. Results demonstrate red squirrels can differentiate between full and empty feeders, suggesting their awareness increases when supplementary food is present. Increased abundance of squirrels at full feeders after feeding times not only implies that squirrels are attracted to and can benefit by supplementation, it also shows that food supplementation can be used to regulate the movement of individuals across habitats. Understanding how red squirrel populations are affected by supplementary feeding will contribute towards existing conservation efforts to improve this species future survival. [ABSTRACT FROM AUTHOR]

Lyme borreliosis (LB), caused by spirochetes of the Borrelia burgdorferi sensu lato (s.l.) complex, is one of the most common vector-borne zoonotic diseases in Europe. Knowledge about the enzootic circulation of Borrelia pathogens between ticks and their vertebrate hosts is epidemiologically important and enables assessment of the health risk for the human population. In our project, we focused on the following vertebrate species: European hedgehog (Erinaceus europaeus), Northern white-breasted hedgehog (E. roumanicus), Eurasian red squirrel (Sciurus vulgaris), and Common blackbird (Turdus merula). The cadavers of accidentally killed animals used in this study constitute an available source of biological material, and we have confirmed its potential for wide monitoring of B. burgdorferi s.l. presence and genospecies diversity in the urban environment. High infection rates (90% for E. erinaceus, 73% for E. roumanicus, 91% for S. vulgaris, and 68% for T. merula) were observed in all four target host species; mixed infections by several genospecies were detected on the level of individuals, as well as in particular tissue samples. These findings show the usefulness of multiple tissue sampling as tool for revealing the occurrence of several genospecies within one animal and the risk of missing particular B. burgdorferi s.l. genospecies when looking in one organ alone.

Territoriality arises when the benefits of resources exceed the costs of defending them. The dear enemy phenomenon, where familiar territorial neighbours refrain from intruding on one another and mutually reduce their defensive efforts, allows for reduction of these costs but requires discrimination between conspecifics. We hypothesized that territorial vocalizations in red squirrels (Tamiasciurus hudsonicus) are used for this discrimination. We performed a speaker replacement experiment where red squirrels (N = 41) were temporarily removed from their territories and replaced with a speaker broadcasting their own call, an unfamiliar call, or silence. Contrary to our prediction, there were no differences in overall intrusion risk among our three playbacks, but the identity of intruders did vary. Existing variation in familiarity within territorial neighbourhoods should be considered, rather than the binary classification of familiar or stranger, when studying dear enemy effects. We also discuss the variable importance of silence in acoustic territorial populations. [ABSTRACT FROM AUTHOR]

Alien squirrels may seriously threaten native species by means of interspecific competition. In our work, we analysed whether the distribution of alien Siberian chipmunks within the Sigurtà Garden urban park (north-eastern Italy) changed after the natural spread of native Eurasian red squirrels in a 20-year period. Distribution of both squirrels was estimated through a citizen-science approach, in the first 10-year after red squirrel arrival 1 (i.e. Decade 1: 1997-2006) and in the second 10-year interval (i.e. Decade 2: 2007-2017). We compared habitat use of both species and we assessed whether a vertical segregation occurred through a dissimilarity index. Woodlands were selected by both species in both decades. Red squirrels also selected tree lines in Decade 1. A vertical segregation was apparent in Decade 1, whereas in Decade 2 both squirrel species were observed on the lowest branches or on the ground, where they are fed by humans. This was also confirmed by the habitat niche-overlap index, which increased in Decade 2. The extent of occurrence of Sciurus vulgaris increased throughout the park, whereas those of Eutamias sibiricus decreased. Differently from what is usually observed with alien squirrels, the spread of the native species appears to be halting and reversing the expansion of the non-native one. [ABSTRACT FROM AUTHOR]

Abstract: 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 American invasive grey squirrels (Sciurus carolinensis). We extracted glucocorticoid metabolites from faecal samples to measure whether the presence of the invasive species causes an increase in physiological stress in individuals of the native species. We show that native red squirrels in seven sites where they co‐occurred with invasive grey squirrels had glucocorticoid concentrations that were three times higher than those in five sites without the invasive species. Moreover, in a longitudinal study, stress hormones in native red squirrels increased after colonisation by grey squirrels. When we experimentally reduced the abundance of the invasive grey squirrels, the concentration of faecal glucocorticoid metabolites in co‐occurring red squirrels decreased significantly between pre‐ and postremoval periods. Hence, we found that the invasive species acts as a stressor which significantly increases the concentrations of glucocorticoids in the native species. Given that sustained elevations in glucocorticoids could reduce body growth and reproductive rate, our results are consistent with previous studies where the co‐occurrence of the invasive grey squirrel was associated with smaller size and lower reproductive output in red squirrels. [ABSTRACT FROM AUTHOR]

Recent global warming and other anthropogenic changes have caused well‐documented range shifts and population declines in many species over a large spatial extent. Most large‐scale studies focus on birds, large mammals, and threatened species, whereas large‐scale population trends of small to medium‐sized mammals and species that are currently of least concern remain poorly studied. Large‐scale studies are needed because on a smaller scale, important patterns may be masked by local variation and stochastic processes. Here, we utilized snow track census data from Finland and NW Russia to estimate population growth rates of the Eurasian red squirrel Sciurus vulgaris for a period of 17 yr in an area of over 1 000 000 km2. We also studied the effects of changes in summer and winter temperatures, winter precipitation, predator abundance, and canopy cover on estimated red squirrel population growth rates. Our results suggest that red squirrel populations have declined in most parts of the study area, the only remarkable exception being SW Russia. These results are in concordance with previous studies suggesting that species that are still common and of least concern may be declining. However, our findings are in contrast to the common pattern of northern populations of boreal species increasing due to global warming. The estimated population growth rates are in synchrony over vast areas, suggesting that the underlying reasons also operate on a large scale. We indeed find that the population growth rate was lower in regions where winters warmed faster during the study period, suggesting that changes in the environment (or biotic changes associated with it) are linked with the decline of red squirrels. [ABSTRACT FROM AUTHOR]

Conservation trans -locations using captive bred red squirrels ( Sciurus vulgaris ) is increasing in the United Kingdom (UK). However, project managers are often unaware of the risk of pathological adenovirus (ADV) infection. In this study we illuminate the viral threat using transmission electron microscopy (TEM) and polymerase chain reaction (PCR) assays. Both techniques were used to screen samples collected from 26 English and Welsh captive red squirrel collections. Of 181 carcasses received between 2002 and 2016, 129 (71%) were suitable for routine surveillance post mortem examination (PME). A range of tissues were examined with ADV identified from a variety of samples by PCR and TEM in 92 (72%) cases encompassing 23 of the 26 study collections (89%). ADV enteritis was histologically confirmed in two deaths (2%) with another 39 (30%) through both laboratory and clinical findings, considered as likely clinically-significant ADV cases, but advanced autolysis precluded accurate assessment and confirmatory histological diagnosis. Other positive cases were more indicative of sub-clinical infection. Clusters of ADV red squirrel deaths were recorded with circumstantial evidence suggesting inter-collection movement of presumed ADV infected donated animals had triggered mortality in recipient collections. During the study, several collections intermittently experienced ADV-associated deaths. Definitive cause of death was not determined in most cases, but a diverse range of diagnoses were recorded in 25 (19%) animals. Implications of these findings for captive United Kingdom (UK) red squirrel husbandry are discussed. It is recommended that protocols be drawn up to minimise potential intra-species ADV infection and highlight the danger of contact with ADV infected wood mice ( Apodemus sylvaticus ). [ABSTRACT FROM AUTHOR]

Scatter-hoarding by animals is an effective mechanism for seed dispersal and plant regeneration in natural ecosystems, however, studies on the interaction between hoarding animals and urban forest are insufficient. By methods of acorn placement experiment, cache and seedling survey, the relationship between acorn dispersal and seedlings distribution of Mongolian oak ( Quercus mongolica) and scatter hoarding rodents was investigated at the Northeast Forestry University Woodland of Harbin, China. Results indicated that main scatter hoarding rodents of acorns were squirrels ( Sciurus vulgaris) and chipmunks ( Eutamias sibiricus). Mongolian oak seedlings were distributed primarily in Mongolian Scotch pine, birch and larch parcels ( df = 3, χ = 1502.77, P < 0.01). Most seedlings were 4 ~ 6 years ( df = 3, χ = 408.23, P < 0.01) and mainly dispersed within range of 100 m from the parent trees. The activity frequency and cache habitats of squirrels coincided with the distribution pattern of Mongolian oak seedlings, which meant scatter hoarding rodents had important effects on acorn dispersal and seedling establishment of urban Mongolian oaks. [ABSTRACT FROM AUTHOR]

In 2013, an adult red squirrel ( Sciurus vulgaris) was found dead showing, during necropsy, acute diffuse catarrhal enteritis. Using a virus screening pipeline based on a pan-viral DNA microarray with downstream next-generation sequencing a novel squirrel-associated virus was identified with mastadenovirus-typical sequence elements. Phylogenetic analysis of hexon protein amino acid sequences demonstrated the highest similarity to Equine adenovirus (AdV) 2, but a strong divergence to a squirrel AdV from Korea and other rodent AdVs. Shorter hexon gene segment investigations confirmed a close relationship with other squirrel-derived AdVs from Europe. The novel virus species was tentatively designated as Squirrel Adenovirus-1. [ABSTRACT FROM AUTHOR]

Near Berlin, Germany, several juvenile red squirrels (Sciurus vulgaris) were found with moist, crusty skin lesions. Histology, electron microscopy, and cell culture isolation revealed an orthopoxvirus-like infection. Subsequent PCR and genome analysis identified a new poxvirus (Berlin squirrelpox virus) that could not be assigned to any known poxvirus genera. [ABSTRACT FROM AUTHOR]

Myoglobins (Mbs) are heme-proteins involved in dioxygen storage necessary for metabolic respiration. Mbs are intensely investigated as archetype to investigate structure/function relationship in globular proteins. In this work, the myoglobin from Sciurus vulgaris meridionalis has been for the first time isolated and purified with a high yield and homogeneity. The primary structure characterization has been performed by applying a strategy based on high resolution tandem mass spectrometry. Proximal (position 93, α-helix F8) and distal (position 64, α-helix E7) histidinyl residues as well as most of the amino acid residues (i.e., Leu29, Lys45, Thr67, Val68) involved in the autoxidation mechanism are conserved in the squirrel Mb. The structural and dynamical properties of the squirrel Mb have been also deeply investigated by CD, NMR. Furthermore, molecular dynamics studies of Mbs from different species have been performed. In addition, the functional properties of squirrel Mb have been characterized by determining its autoxidation kinetic and thermal stability in comparison with crested porcupine and reindeer Mbs. Interestingly, a higher autoxidation rate was revealed for squirrel Mb with respect to reindeer and crested porcupine Mbs. Even considering the very similar structural fold, molecular dynamics data show a higher conformational mobility of squirrel Mb with respect to reindeer and crested porcupine. [ABSTRACT FROM AUTHOR]

Animals are adapted to a range of activity patterns, from diurnal to nocturnal. Under normal conditions, the 24-hour rhythm is entrained by changes in light intensity during twilight, i.e. the light and dark cycle. Many rodent species exhibit predator avoidance by adjusting their activity in relation to space or time, which isweighed against the need for food. Hence, an individual's foraging activity consists of a compromise between foraging and predation risk, in addition to competition. Our study species, the Eurasian red squirrel, is diurnal and utilises dense forest habitats. In the present study, we used non-invasive camera traps to model diel activity during the winter months in 2014-2015 (December to February 24-hour day). We found that the Eurasian red squirrels exhibited a strictly diurnal feeding activity pattern and the shape of the modelled activity curve was unimodal and concentrated in the daylight hours, starting at sunrise and peaking in the morning. [ABSTRACT FROM AUTHOR]

Urban expansion and associated habitat fragmentation are expected to be detrimental to global biodiversity. Natural habitat that is extensively modified often poses challenges to native fauna that must adapt to new conditions to survive. While some species decline in numbers or become locally extinct, the Eurasian red squirrel (Sciurus vulgaris) successfully inhabits cities. Because squirrels are sensitive to habitat fragmentation and their spaceuse patterns are influenced by the distribution and abundance of major food resources, their movement patterns are likely to be modified in response to changes in environmental conditions brought about by urbanization. Therefore, to investigate whether supplementary food resources are key to its success, the home ranges of squirrels inhabiting a large city park were related to both natural food sources (NFS) and anthropogenically-provided food sources (PFS) in 3 seasons. The combination of home ranges that were relatively small, year-round food availability and the lack of a seasonal body mass change indicates that the semi-urban environment can be highquality habitat. The squirrels' home ranges encompassed areas with a year-round NFS supply, but they shifted their home range core areas closer to PFS in seasons where they were more reliable, even though NFS were also abundant at the time. Additionally, heavier individuals' core areas were located closer to PFS. Consequently, our results show that human activity (i.e., via PFS) had a direct, measureable effect on squirrels' feeding habits and movement patterns even though NFS were available. However, the consequences of urbanization are not always detrimental for native animal species and an improved knowledge of energy resources and their effect on habitat use is important for understanding and minimizing the long-term impacts of humans on urban wildlife. [ABSTRACT FROM AUTHOR]

The causes and consequences of physiological stress in wildlife are of great interest in a wide range of biological disciplines including understanding how environmental changes affect species fate and persistence. In some areas, the Eurasian red squirrel (Sciurus vulgaris) faces local extinction because of the invasive Eastern gray squirrel (Sciurus carolinensis). Whether or not physiological stress is induced by the presence of invasive species or contributes to local declines in Eurasian red squirrels is unknown. Here, we develop an assay that can be used to quantify physiological stress in fecal samples from Eurasian red squirrels to eventually address these questions. We captured free-living squirrels (6 females, 11 males) and placed them into captivity for 48 h. Fecal glucocorticoid metabolite (FGM) concentrations in female and male squirrels were significantly higher 24 and 32 h after initial captivity with a lag time to peak excretion ranging from 24 to 36 h. We measured FGM concentrations in free-living squirrels (37 females, 45 males) over a 3-year period. Lactating free-living squirrels had higher FGM concentrations compared to nonbreeding or pregnant squirrels but there were no differences in FGM concentrations in males with scrotal and abdominal testes. Free-living squirrels had the highest FGM concentrations in the winter and lowest in the summer (winter > autumn > summer). Squirrels kept in captivity for 4-48 h had significantly higher FGM concentrations than free-living squirrels (111 fecal samples from 82 squirrels). FGM concentrations in captive but not wild squirrels were significantly repeatable. We found no sex differences and no association with body mass in FGM concentrations in captive or free-living squirrels. Our results indicate that this assay can accurately quantify physiological stress in Eurasian red squirrels, which may be useful for future studies to document how the invasive Eastern gray squirrel contributes to local extinction. [ABSTRACT FROM AUTHOR]

The red squirrel (Sciurus vulgaris) is an arboreal species, relatively common in mixed, deciduous and coniferous forests and in urban parks. From autumn to early spring the main diet of red squirrels is seeds in closed conifer cones. In this study, we investigated characteristics of a habitat in western Poland where red squirrels were feeding on Scots pine (Pinus sylvestris). Understory cover, number of tree species, distance to an open area, distance to the nearest great spotted woodpecker (Dendrocopos major) anvil, and size of ten randomly selected Scots pine trees were measured on 70 transects. We used binary logistic regression to test which forest habitat parameters affected the presence of feeding signs of red squirrels. Feeding signs of red squirrels were found from sites close to forest edges with less understory cover, higher tree-species richness and larger size of trees. Red squirrels did not avoid sites close to great spotted woodpecker anvils. We conclude that forest stand structure is important for red squirrel feeding site occurrence, but red squirrels do not avoid close contact to open areas. [ABSTRACT FROM AUTHOR]

We studied the responses of red squirrels, Sciurus vulgaris, to food supplementation and avian predation risk during two winters in Finland, when the level of natural food production, spruce seeds, varied markedly. We performed an open experiment with 6 replicates in the landscape where squirrel signs were counted near a feeding station and/or active predator nest and control site. Within each site, we counted squirrel snow-tracks and feeding-signs and checked the usage of two nest-boxes. We observed that during the winter when natural food was less plentiful, red squirrel snow-tracks decreased at sites with predator. The same was observed, only less clearly, during the winter with more natural food. Food supplementation had no obvious effect. We conclude that predators have a clear effect on red squirrels in winter. Furthermore, in situations where a species is specialized in using fluctuating amounts of natural food resources, the role of artificial food supplementation may remain unclear. [ABSTRACT FROM AUTHOR]

Parasites are recorded from the red squirrel, Sciurus vulgaris, from Cheongju, the Republic of Korea. A total of 5 road-killed squirrels were thoroughly examined for internal and external parasites from November 2011 to May 2014. Total 4 parasite species, including 1 tapeworm and 3 ectoparasite species were recovered. They were morphologically identified as Catenotaenia dendritica (Cestoda: Catenotaeniidae), Hirstionyssus sciurinus, Leptotrombidium pallidum, and Ceratophyllus (Monopsyllus) indages. Among them, C. dendritica and H. sciurinus are recorded for the first time in the Korean parasite fauna. In addition, the possibility that the red squirrel could act as a reservoir host for a zoonotic disease like tsutsugamushi disease with L. pallidum as its vector has been raised. [ABSTRACT FROM AUTHOR]

In urban environments, roads are one of the major threats for moving animals. Roads can act as barriers to movement either through mortality during crossing attempts or through behavioral avoidance. This can have severe population-level consequences such as population fragmentation and demographic or genetic isolation. A major limitation for determining the effects of roads, however, is the lack of studies on responses of animals to roads during dispersal. In a radiotelemetry study, we investigated the responses of dispersing juvenile red squirrels (Sciurus vulgaris) to roads in an urban environment in Finland. We observed that, during routine movements within their home range, squirrels were located further from roads and crossed them less frequently than simulated random walk paths, while they did not avoid roads when performing explorative and dispersal movements. Moreover, during routine movements squirrels rarely crossed roads with high traffic volume, whereas during dispersal, they crossed both big and small roads. Traffic did not seem to be a major cause of mortality for juvenile squirrels, based on our observations. Our study provides striking evidence that movement behavior during dispersal differs from that of nondispersers. For road ecology, this implies that the evaluation of the role of roads as barriers for, for example, gene flow cannot be based on the interpretation of movements of nondispersers. [ABSTRACT FROM AUTHOR]

To test postglacial population expansion in small arboreal mammals dependent on boreal and subboreal forests, we used complete mitochondrial cytochromebgene sequences (1140 bases) to investigate the phylogeography of the Eurasian red squirrel (Sciurus vulgaris orientis) on the Hokkaido Island of Japan. This subspecies is common in the boreal and subboreal forests of Hokkaido. We examined 61 specimens from 27 localities in Hokkaido. Phylogenetic relationships among 29 haplotypes found in the Hokkaido populations were not associated with geographic distribution of sampling localities. There were four mitochondrial DNA phylogroups. Phylogeographic analyses support sudden expansion ofS. vulgaris orientisfrom restricted refugium in the southern part of Hokkaido during the last glacial period. The phylogeographic structure of this subspecies directly reflects the boreal and subboreal forest dynamics occurring in Hokkaido. [ABSTRACT FROM AUTHOR]

Summary Toxoplasmosis is a parasitic disease that affects man and animals worldwide. The primary hosts and major reservoir for Toxoplasma gondii are felids and the intermediate hosts are most warm-blooded animals including man. This report describes fatal toxoplasmosis in three different rodent species in Germany: a female red squirrel ( Sciurus vulgaris ) and a male Swinhoe's striped squirrel ( Tamiops swinhoei ), both kept as pets, and a female New World porcupine ( Erethizontidae sp.) from a zoo. All three animals had multifocal necrotizing hepatitis. Additional findings included lymphohistiocytic and necrotizing myocarditis in the New World porcupine and the Swinhoe's striped squirrel, lymphohistiocytic encephalomyelitis in the New World porcupine and suppurative lymphadenitis in the red squirrel. Numerous tachyzoites were identified associated with the lesions. The diagnosis was confirmed by Toxoplasma. gondii immunohistochemistry and electron microscopy. This is the first report of toxoplasmosis in a New World porcupine and a Swinhoe's striped squirrel. [ABSTRACT FROM AUTHOR]

To improve our understanding of squirrelpox virus (SQPV) infection in the susceptible host, three red squirrels were challenged with wild-type SQPV via scarification of the hind-limb skin. All squirrels seroconverted to the infection by the end of the experiment (17 days post-challenge). Challenged animals suffered disease characterised by the development of multiple skin and oral lesions with rapid progression of skin lesions at the infection site by day 10 post-challenge. No internal pathological changes were found at post-mortem examination. A novel SQPV Taqman ® Real-time PCR detected viral DNA from multiple organs, with the largest amounts consistently associated with the primary and secondary skin and oral lesions where viral replication was most likely occurring. Immunohistochemistry clearly detected viral antigen in the stratified squamous epithelium of the epidermis, tongue and the oropharyngeal mucosa-associated lymphoid tissue and was consistently associated with histological changes resulting from viral replication. The lack of internal pathological changes and the detection of relatively low levels of viral DNA when compared with primary and secondary skin lesions argue against systemic disease, although systemic spread of the virus cannot be ruled out. This study allowed a comprehensive investigation of the clinical manifestation and progression of SQPV infection with a quantitative and qualitative analysis of virus dissemination and shedding. These findings suggest two separate routes of SQPV transmission under natural conditions, with both skin and saliva playing key roles in infected red squirrels. [ABSTRACT FROM AUTHOR]

The Eurasian red squirrel (Sciurus vulgaris) is under threat in the UK from the introduced North American grey squirrel. National measures to save the species include large conifer forest reserves where management encompasses measures to bolster the native species. However, forests are multipurpose environments and foresters have to balance different timber production, amenity and conservation objectives. We present a mathematical modelling framework that examines the impacts of potential felling and restocking plans for two reserves, Kidland and Uswayford forests, in northern England. In collaboration with forest managers, we employed an iterative process that used the model to assess four forest design plans (felling and restocking scenarios) with the aim of improving red squirrel population viability. Overall, the model predicted that extinction in both forests at the same time was rare, but high in Uswayford (84%) alone. Survival could be drastically increased (from 16% to 70%) by felling and restocking adjustments, and improving dispersal between the two adjacent forests. This study provides an exemplar of how modelling can have a direct input to land management to help managers objectively balance the differing pressures of multipurpose forestry. [ABSTRACT FROM AUTHOR]

Red squirrel (Sciurus vulgaris) mortality was monitored opportunistically during the period 2004 to 2013 on the island of Anglesey in North Wales. Road traffic proved a most significant cause of death (48%) mirroring the findings of earlier United Kingdom (UK) studies. Red squirrels were alsofound to have died from a range of pathological infections and disease previously unrecorded in Wales. These data have increased our knowledge on the national distribution of such causal factors. The study found male red squirrels were less likely to have an adenovirus infection than females and that animals dying from disease had a lower body mass than those associated with a traumatic death. No red squirrels were found with squirrelpox infection or antibodies to this virus which reinforces earlier findings from Anglesey that intensive grey squirrel (Sciurus carolinensis) culling reduced the prevalence of this infection within sympatric populations. Finally we highlight the potential intra and inter-specific infection risk presented by supplemental feeding. [ABSTRACT FROM AUTHOR]