Muscardinus Research Articles

Independent effects of habitat loss, habitat fragmentation and structural connectivity on the distribution of two arboreal rodents

Summary1. Habitat loss must be distinguished from habitat fragmentation so that appropriate conservation management can be applied. Few studies have evaluated the independent effects of habitat loss and habitat fragmentation on the distribution of vertebrates, and none has evaluated the independent effect of changes in structural connectivity. We carried out a landscape‐scale experiment to assess the independent contribution of these three processes and to examine what landscape scale factors affect the distribution of two forest‐dependent arboreal rodents: the hazel dormouse Muscardinus avellanarius and the red squirrel Sciurus vulgaris.2. Habitat loss, rather than habitat fragmentation per se, was the major driver of distribution patterns for both species. As predicted, structural connectivity (hedgerow networks) played an important role in determining the distribution of the hazel dormouse, but not of the red squirrel.3. Our models predict that long lengths of hedgerows (>30 km) are unlikely to increase the probability of occurrence of hazel dormouse in landscapes where there are low levels of forest cover (<5%–10%).4. Synthesis and applications. Our empirical findings indicate that structural connectivity and habitat loss may have additive effects on vertebrate distribution. For the hazel dormouse, improving structural connectivity will be ineffective if the amount of forest cover in the landscape is less than 5–10%. The key message from this study is that resources should not be invested in landscape linkages until their efficacy for the given level of suitable habitat has been assessed.

Recent range and distribution of dormice (Gliridae, Mammalia) in the Sudetes (Poland)

The paper presents updated information on the occurrence of dormice in the Polish Sudetes, based on our 1993-2008 field studies in various parts of the region, and on the results of other studies conducted and published after 1983. The studies confirmed the occurrence of 3 dormice species in the Sudetes: edible dormouse Glis glis LINNAEUS, 1766, hazel dormouse Muscardinus avellanarius LINNAEUS, 1758, and forest dormouse Dryomys nitedula PALLAS, 1778. The edible dormouse occurs in all 5 macroregions of the Polish Sudetes. It is still fairly abundant in the Central and Eastern Sudetes, while it is quite rare in the Western Sudetes. The hazel dormouse is much less common, being slightly more abundant in some ranges of Central Sudetes (Bardzkie and Sto3owe Mts, and the Landscape Park of Wa3brzych Sudetes), and Eastern Sudetes (the Z3ote Mts and the Snie?nik Massif). The occurence of the forest dormouse is limited to the Sudete Foreland (Strzelinskie Hills) and small parts of the Central (Sto3owe Mts) and Eastern Sudetes (Z3ote and Bialskie Mts, Œnie?nik Massif), where all three species co-occur. Not a single locality of the garden dormouse Eliomys quercinus LINNAEUS, 1766 was found, which points to its disappearance from the Polish Sudetes.

Fluchtverhalten der Haselmaus (Muscardinus avellanarius)

Zeitschrift für TierpsychologieVolume 8, Issue 3 p. 368-369 Fluchtverhalten der Haselmaus (Muscardinus avellanarius) Otto v. Frisch, Otto v. FrischSearch for more papers by this author Otto v. Frisch, Otto v. FrischSearch for more papers by this author First published: January‐December 1951 https://doi.org/10.1111/j.1439-0310.1951.tb00180.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume8, Issue3January‐December 1951Pages 368-369 RelatedInformation

Examination of rodents (Rodentia) for emmonsiosis in the Czech Republic, Israel and Africa.

Lung tissue of 156 rodents (genera Apodemus, Myodes, Microtus, and Muscardinus) from the Czech Republic, 29 rodents of the species Spalax ehrenbergi from Israel and 106 rodent specimens from Africa (genera Heliophobius, Mastomys, Acomys, Aethomys, Saccostomus, Tatera, Mus, Cryptomys, Dasymys, Dendromus, Grammomys, and Steatomys) were examined for presence of adiaspores of the fungal genus Emmonsia. In the Czech Republic, nine (5.8 %) animals revealed adiaspores of E. crescens. The positive samples were found in rodents sampled in three of the five Czech areas studied. Out of six species of the Czech rodents, three species were positive: Apodemus flavicollis, Myodes glareolus and Microtus agrestis. A. flavicollis was the most frequently infected species, whereas A. sylvaticus, Microtus subterraneus and Muscardinus avellanarius were negative. Adiaspores were recorded in five females and four males. A significant preference of the fungus for the host sex was not observed. Tissue samples of rodents from Africa and Israel were all negative.

Small Terrestrial Mammals (Soricomorpha, Chiroptera, Rodentia) from the Early Holocene lLyers of Mala Triglavca (SW Slovenia)

At least 132 specimens belonging to no less than 21 species of small terrestrial mammals from the Boreal were identified within the finds from the Early Holocene sediments from Mala Triglavca (the Kras Plateau, SW Slovenia), namely Crocidura suaveolens, Sorex alpinus / araneus, S. minutus, Talpa cf. europaea, Barbastella barbastellus, Sciurus vulgaris, Cricetulus migratorius, Arvicola terrestris, Microtus agrestis / arvalis, M. subterraneus / liectensteini, Chionomys nivalis, Myodes glareolus, Dinaromys bogdanovi, Glis glis, Muscardinus avellanarius and Apodemus flavicollis / sylvaticus / agrarius / uralensis . This small mammal assemblage indicates that their habitat was presumably a mosaic of a mixed, predominantly deciduous forest, dotted with small meadows and some rocky substrate. A comparison of allochronous microfaunas from the Kras Plateau indicated a rapid faunistic change in the last 5,000 years.

Isolation and characterization of 10 microsatellite loci in the common dormouse Muscardinus avellanarius

To assess the level and spatial pattern of genetic diversity of the common dormouse, Muscardinus avellanarius, we developed polymorphic microsatellite loci from partial genomic libraries enriched for microsatellite motifs. Ten dinucleotide polymorphic microsatellites were isolated and levels of genetic diversity were assessed in 139 individuals from Bontuchel, (Denbighshire, Wales). We observed high levels of heterozygosity (mean H(O) =0.792±0.077; mean H(E) =0.730±0.084) and a large number of alleles (N(a) =6-17). There was no evidence of deviations from Hardy-Weinberg conditions, or genotypic disequilibrium between any pairs of loci. This is the first description of microsatellite primers from a common dormouse and these loci are currently being used to quantify dormouse spatial genetic structure.

SMALL TERRESTRIAL MAMMALS OF ALBANIA: ANNOTATED LIST AND DISTRIBUTION

We report a synopsis of the small mammals of Albania (Erinaceomorpha, Sori- comorpha, Rodentia), outlining both new records and previously published data. Twenty-four species (one hedgehog, six soricomorhps and 17 rodents) have been collected in 161 localities surveyed throughout the country. Nine species (Neomys anomalus, Crocidura leucodon, Talpa stankovici, Dryomys nitedula, Muscardinus avellanarius, Micromys minutus, Mus macedoni- cus, Myodes glareolus and Microtus thomasi) are recorded for Albania for the first time. The present list is far from being complete and the probable presence of a further 11 species has to be confirmed.

Hazel dormouse Muscardinus avellanarius (L.) nest site selection in hedgerows

The natural nest sites in hedgerows of the hazel dormouse Muscardinus avellanarius were investigated in Devon, in south-west England. A total of 73 nests were found in the autumn by careful searching of hedgerows, all of which were species-rich. In hedgerows that had not been cut for 6 years or more, most nests were in bramble Rubus fruticosus agg. and field rose Rosa arvensis margins, with a few in holly Ilex aquifolium bushes. In contrast, in hedgerows that had been cut within 6 years, the majority of nests were in shrubs, the dense protective growth at the cut line being strongly favoured. Blackthorn Prunus spinosa was preferentially selected, hazel Corylus avellana was avoided. It is suggested that the availability of safe nest sites may limit population density and that where nesting conditions are good the hazel dormouse may prefer to build nests in unenclosed situations rather than in hollows, whether natural hollows, such as tree holes, or artificial ones, such as nest boxes. To encourage hazel dormice in hedgerows, bramble and rose margins should be allowed to develop, and some lengths of hedgerow should be cut occasionally, particularly where blackthorn is present.

Species’ surrogacy for conservation planning: caveats from comparing the response of three arboreal rodents to habitat loss and fragmentation

The use of surrogate species in conservation planning has been applied with disappointing results on relatively large sets of species. It could still prove useful for optimizing conservation efforts when considering a small set of species with similar ecological requirements, however few field tests of this nature have been carried out. The aim of this research is to compare the response of three arboreal rodent species—the fat dormouse (Glis glis), the hazel dormouse (Muscardinus avellanarius) and the red squirrel (Sciurus vulgaris)—to habitat loss and fragmentation, with the aim of identifying priorities for conservation and evaluating possible optimization of conservation efforts under different scenarios: habitat restoration and selection of focal patches. We studied the distribution of the three species in a sample of patches in a highly fragmented landscape in central Italy, using a patch-landscape scale approach. The distribution was studied by using hair tubes, nestboxes and nocturnal surveys. The three species showed analogous responses to increasing isolation and decreasing size of habitat patches; what differed however, was the magnitude of responses. Our results show possible application of surrogacy within this restricted group of species, however several caveats arise depending on the conservation strategy and available funding. If habitat restoration is the objective, then the fat dormouse should be the target species for guiding size and isolation of patches. On the other hand, the magnitude of the differences and patch requirements for this species, question the feasibility of these conservation actions. If selection of focal patches for conservation is the objective then selecting the fat dormouse as a focal/umbrella species would overlook areas suitable for the other two species. Feasible optimisation of conservation efforts may be possible only between the red squirrel and the hazel dormouse.

Long-term common dormouse monitoring: effects of forest management on abundance

The common dormouse (Muscardinus avellanarius) is a species included in Annex IV of the Habitat Directive and red-listed in many European countries. Monitoring of M. avellanarius is implemented in several countries using different methods. In Lith- uania, regular control of standard bird nestboxes and marking of all dormice caught were used during 1984-1990 and 1999-2007. Nestboxes were spaced in a grid system at 50 m intervals in an area of 60 ha. Monitoring of the M. avellanarius population was carried out in a managed forest with varying levels of human activity occurring in most parts of the forest (felling of all understorey, selective felling of trees, clear felling, etc.). During the entire study period, the average density of the population was comparatively low (about 1 ind./ha in spring and 3 ind./ha in autumn), but stable and without substantial fluctuations in spite of considerable human activity. The forestry management operations that were used in different parts of the forest over different years had only temporary and localised negative effects on the abundance of M. avellanarius, and did not influence the whole population substantially. The spacing of nestboxes in a grid system in a large forest area increased the level of accuracy with which the monitoring scheme reflected the population status. This enabled both the state of the entire population of M. avellanarius and tem- porary changes in abundance in selected smaller plots to be tracked.

Hibernation as a far‐reaching program for the modulation of RNA transcription

In eukaryotic cells, pre-mRNAs undergo several transformation steps to generate mature mRNAs ready to be exported to the cytoplasm. The molecular and structural apparatus for mRNA production is generally able to promptly respond to variations of metabolic demands. Hibernating mammals, which periodically enter a hypometabolic state, represent an interesting physiological model to investigate the adaptive morpho-functional modifications of the pre-mRNA transcriptional and processing machinery under extreme metabolic conditions. In this study, the subnuclear distribution of some transcriptional, splicing, and cleavage factors was investigated by ultrastructural immunocytochemistry in cell nuclei of the liver (a highly metabolizing organ involved in multiple regulatory functions) and the brown adipose tissue (responsible for nonshivering thermogenesis) from euthermic, hibernating, and arousing hazel dormice (Muscardinus avellanarius). Our observations demonstrate that, during hibernation, transcriptional activity significantly decreases and pre-mRNA processing factors undergo an intranuclear redistribution moving to domains usually devoid of such molecules; moreover, in hepatocytes, there is a preferential accumulation of pre-mRNAs at the splicing stage, whereas, in brown adipocytes, pre-mRNAs are mainly stored at the cleavage stage. Upon arousal, the pre-mRNAs at the cleavage stage are immediately utilized, while the maturation of pre-mRNAs at the splicing stage seems to be restored before transcription had taken place. Our data suggest a programmed intranuclear reorganization of the RNA maturation machinery aimed at efficiently and rapidly restoring the pre-mRNA processing, and, consequently, the specific cellular activities upon arousal. Once again natural hibernation appears as a highly programmed hypometabolic state rather than a simple fall of metabolic and physiological functions.

Common Dormouse as a Prey Item of Breeding Tawny Owls in Five Districts of Lithuania

The diet of the Tawny Owl (Strix aluco) from five administrative districts in Lithuania was studied in the breeding seasons of 1999–2005. A total of 67 samples with 3,211 prey items were analysed. The common dormouse (Muscardinus avellanarius) comprised 2.0% by numbers and 1.4% by biomass consumed. The difference between districts was 2.3-fold and 2.6-fold, accordingly. It is obvious that this species is not a primary prey, but 15 species of mammals and 30 bird species were represented by numbers not exceeding that of M. avellanarius. Thus, we do not consider M. avellanarius among the rarest prey items. Moreover, in Lithuania, especially in the central part (Kėdainiai district), the share of M. avellanarius in the diet of S. aluco is one of the highest in Europe.

Localities of three rare mammal species in central and northeastern Poland

Analyses of 69 collections of the tawny owls' pellets (28 containing over 100 prey items) revealed the pres- ence of three rare mammal species on several localities in central and northeastern Poland: Muscardinus avellanarius (11 localities), Sicista betulina (3), and Crocidura leucodon (2). The obtained results supplemented data on their distri- bution close to the borders of continuous ranges. The Kampinos Forest was confirmed as important refuge of M. avel- lanarius, and the lower basin of the Biebrza Valley for both M. avellanarius and S. betulina.

Holocene sequences and archaeology from the Crabble Paper Mill site, Dover, UK and their regional significance

The results of multidisciplinary investigations of the Quaternary sediments of the Dour valley, extending inland from Dover, Kent, are reported. The oldest sediments are unfossiliferous coarse gravels and silts of probable Late Devensian age. These are overlain by a complex series of peats and tufaceous sediments of early to mid-Holocene age. Pollen, mollusc, ostracod and vertebrate fossils (including the earliest British Holocene record of hazel dormouse) enable detailed reconstructions of the local environments and the vegetational and faunal history. A chronology is provided by a number of radiocarbon dates. The sequence is mantled by colluvial hillwash. The younger sediments have produced evidence for the presence of early humans (marine shells and flint artefacts) during the Bronze Age.

Nest site preference of common dormouse (Muscardinus avellanarius) in two different habitat types of Central Italy

Nest site preference of common dormouse was studied in two different habitat types of central Italy: a mesophilous deciduous forest dominated by Fagus sylvatica, and a thermophilous deciduous oak wood with Quercus cerris and Q. pubescens. In each site, 50 nest boxes were fixed to trees and monitored monthly for two years (May 1998–April 2000). Moreover, in both study sites, 19 habitat variables were measured within a 3‐m radius circular plots centred on each nest box. We hypothesised that specific habitat features may induce common dormice to choose a particular site for nesting. Therefore, we compared habitat variables, recorded at the neighbourhood of either occupied or unoccupied nest boxes, in order to identify the importance of factors in nest site preference. In both beech and oak woodlands, the choice of nest site was affected by understorey vegetation structure rather than species diversity. In particular, the common dormouse prefers sites with high understorey density probably for the presence of route‐ways through branches and visual protection from predators.

Trophic habits of Muscardinus avellanarius (Mammalia Gliridae) as revealed by multiple stable isotope analysis

Multiple stable isotope analysis was used to investigate the diet of the common dormouse Muscardinus avellanarius in a mixed Mediterranean forest. δ13C and δ15N values of dormouse tissues compared to those of the vegetal and animal sources available in the area showed that the isotopic composition of both adult and juvenile M. avellanarius could be explained by a mixture of vegetal and animal organic matter. The isotopic composition of the assimilated nitrogen was mostly explained by the organic matter from flora. Among the vegetal components, flowers of Fagus silvatica, Quercus robur, and the rarer Crataegus oxyacantha, berries of Ilex aquifolium and acorns of Q. robur were found in the adult diet, while juveniles relied mainly on flowers of F. silvatica and acorns of Q. robur. Organic matter from eggs of passerines (Parus caeruleus and P. major) sharing nest-boxes affected the carbon isotopic signals in the assimilated fraction. The common dormouse in the mixed holly forests of the northern Sicily feeds primarily on the vegetal species which are abundant in its habitat. However, the diet of this small arboreal mammal cannot be fully characterised without considering the contribution of animal organic matter represented by bird eggs.

European Hedgehogs as Hosts forBorreliaspp., Germany

To the Editor: The European hedgehog, Erinaceus europaeus, is known to host a variety of tickborne pathogens, including the virus that causes tickborne encephalitis (1) and at least 3 species of the Borrelia burgdorferi sensu lato group: B. burgdorferi sensu stricto, B. afzelii, and B. garinii (2). Members of the B. burgdorferi s. l. group are the most common vectorborne pathogens of humans in central Europe (3). The role of hedgehogs as hosts for these pathogens is, therefore, of considerable epidemiologic interest. Hedgehogs are a common synanthropic species that live in urban, suburban, and rural environments (4) and are known to carry not only the hedgehog tick, Ixodes hexagonus, but also the most common European tick, I. ricinus (2,5). Both of these ticks are known vectors of B. burgdorferi s. l. and tickborne encephalitis virus; I. ricinus is the most important vector of both throughout Europe (1,5). To date, however, only limited information has been available on the role of the hedgehog as a host or reservoir for B. burgdorferi s. l. in Germany. We report the presence of 3 species of the B. burgdorferi s. l. group in European hedgehogs from Germany. To our knowledge, this is the first report of these species in hedgehogs in this country and the first report of B. spielmanii (A14S) (6) from this host. The investigated hedgehogs came from 2 sources: 9 from the ≈40 in an experimental plot in the city of Karlsruhe, state of Baden-Wuerttemberg, and the remainder from wild hedgehogs that had been brought to hedgehog care centers from various areas of Germany. All hedgehogs had died naturally, and tissue samples were taken from 43 animals (kidneys from 43, heart from 22, bladder from 33). The bodies had been frozen at –17°C before the samples were taken. DNA isolation was done by using the Maxwell 16 Instrument and System (Promega, Madison, WI, USA). Tissue samples were 3×3×3 mm. To detect B. burgdorferi s. l., we used 2 PCR protocols. The first was a nested PCR done according to the method of Rijpkema et al. (7). The target for the PCR was the spacer region between 5S and 23S rRNA genes of B. burgdorferi s. l. The nested primers generated a product of 226 bp. The amplified products were analyzed by agarose gel electrophoresis. The second protocol, a LightCycler-PCR hybridization assay (Roche Diagnostics, Mannheim, Germany) (8), simultaneously detects and genotypes the 3 genomic groups of B. burgdorferi s. l. This assay was specific for B. burgdorferi senso stricto, B. garinii, and B. afzelii (8) but also amplified B. spielmanii and B. valaisiana. The target for the PCR was the OspA gene. The PCR products of both systems were sequenced. For DNA sequencing reaction, the fluorescence-labeled didesoxynucleotide technology (Applied Biosystems, Darmstadt, Germany) was used. The sequenced fragments were separated, and the data were collected with an ABI PRISM 310 Genetic Analyzer (Applied Biosystems). The obtained sequences were then analyzed and compared by using BLAST (www.ncbi.nlm.nih.gov/BLAST). For 6 hedgehogs, Borrelia spp. could be clearly defined by using both gene sequences. Two additional animals had positive results, but sequencing was not possible because of either too little DNA or a mixed infection. B. spielmanii DNA was detected in the kidneys of 2 hedgehogs: 1 from Karlsruhe and 1 from 30 km west of this city in the German federal state of Rhineland-Palatinate. When sequences were compared by using BLAST, 4 BLAST sequences ({type:entrez-nucleotide,attrs:{text:AM055823,term_id:78482935,term_text:AM055823}}AM055823, {type:entrez-nucleotide,attrs:{text:AM055822,term_id:78482933,term_text:AM055822}}AM055822, {type:entrez-nucleotide,attrs:{text:DQ133518,term_id:74476812,term_text:DQ133518}}DQ133518, AY 995900) showed 100% similarity with B. spielmanii. B. garinii was detected in the heart of 2 animals (from Berlin and Karlsruhe); B. afzelii in 3 animals (in the kidney of 2 from Hamburg and Karlsruhe and in the bladder of 1 from Rhineland-Palatinate). A single animal (from Karlsruhe) had B. afzelii in the kidney and bladder and B. garinii in the heart. Preliminary results have also shown that ticks collected from hedgehogs from the Karlsruhe site were infected with B. afzelii (an I. hexagonus nymph and an I. ricinus female) and with B. spielmanii (an I. ricinus female, a nymph, and a larva) (Skuballa et al., unpub. data). These results show, that hedgehogs harbor at least 3 of the 5 recognized Borrelia genospecies found in Germany, all of which are known (B. afzelii, B. garinii) or are strongly suspected (B. spielmanii) of being pathogens for humans (9,10). To our knowledge, ours is the first report of B. spielmanii from hedgehogs, a Borrelia sp. that is usually associated with rodents, especially with garden and hazel dormice (10). That Borrelia spp. infections commonly occur in European hedgehogs is likely. However, questions remain about the role of these pathogens in regulating the populations of European hedgehogs and about the status of these common synanthropic mammals as a reservoir host of B. burgdorferi s. l. in periurban and rural environments.

FEEDING BY THE COMMON DORMOUSE (MUSCARDINUS AVELLANARIUS): A REVIEW

The common dormouse (Muscardinus avellanarius) feeds on both vegetable food and food of animal origin. The dormouse has a varied diet, which depends upon latitude and nutritional plant species available and follows a strongly seasonal pattern. The main vegetable food sources are flowers in spring, berries in summer, nuts and soft fruits in autumn, but dormice also use many other food sources. Among vegetable foods, generative parts of plants (flower-buds, catkins, flowers, berries, and seeds) are preferred, whereas vegetative parts (leaf-buds, leaves, and shoots) are only subsidiary foods for these rodents. In spite of tannins that oak acorns contain, they may play an important part in the diet of dormice. During periods of scarcity of suitable vegetable food (e.g. in late spring and early summer), dormice use food of animal origin, primarily insects and bird eggs. Feeding on food of animal origin is expected to be more important in suboptimal habitats with a low diversity of nutritious plants. Some feedi...

Tail autotomy in the common dormouse ( Muscardinus avellanarius): Some ecological aspects

Key words: Muscardinus avellanarius, tail loss, demographic parametersCaudal autotomy – the ability to shed the tail– is a common and well-recognised antipre-dator defence mechanism in reptiles andamphibians. A review of the occurrence ofthis phenomenon in rodents is presented byShargal et al. (1999). These authors state thattail autotomy occurs in at least 35 species andhas evolved separately in eight rodentfamilies, with no clear pattern in systematics,geography, or habitat use. Two major typesof tail loss are recognised in rodents: simul-taneous loss of an entire part of the tail, whenthe tail breaks across vertebrae, and sheddingof a portion of the tail skin alone withsubsequent loss of the denuded part of thetail (Mohr 1941). These two types are calledtrue autotomy and false autotomy, respec-tively (Dubost and Gasc 1987; McKee andAdler 2002).In general, earlier studies of tail loss were notaccompanied by field research, and onlyanatomical/histological aspects of this phe-nomenon were studied (e.g., Go¨gl 1930;Mohr 1941). Several later studies dealt alsowith some ecological aspects of tail loss inrodents: Florida mouse (Peromyscus florida-nus)(Layne 1972), black rat (Rattus rattus)(Michener 1976), common spiny mouse(Acomys cahirinus) and golden spiny mouse(A. russatus)(Shargal et al. 1999) as well asCentral and South American spiny rats(Proechimys)(Dubost and Gasc 1987;McKee and Adler 2002).False tail autotomy in dormice (Gliridae) is awell-known phenomenon, which is men-tioned in some generalised publications onthese rodents (e.g., Vietinghoff-Riesch 1960;Storch 1978; Airapetyants 1983; Morris 1997;Rossolimo et al. 2001). However, onlyanatomical/histological aspects of tail autot-omy have been studied in dormice (Go¨gl1930; Mohr 1941), any ecological aspects ofthis phenomenon were not reflected. The aimof the present study was to analyse thefrequency of occurrence of tail autotomy inseparate demographic groups, annual survi-val rates of tail-less individuals and someother ecological aspects of tail autotomy inthe common dormouse (Muscardinus avella-narius) populations.Studies of two isolated common dormousepopulations were carried out in Lithuania intwo locations: at study site A (south-westernLithuania, Sˇakiai district; 55103

Predicting species occurrence using information-theoretic approaches and significance testing: An example of dormouse distribution in Cumbria, UK

Predicting the occurrence of species is an essential part of conservation biology. The range of techniques used to do this has increased in recent years. This has included wider use of information-theoretic approaches; particularly Akaike’s information criteria (AIC). AIC is often used with regression modelling when predicting species distribution. The traditional method of model selection in regression modelling, stepwise significance testing, is also still widely used. This paper compares the two approaches, using the occurrence of the dormouse ( Muscardinus avellanarius) in Cumbria, UK as an example. The dormouse is a protected species whose abundance and range have declined nationally. Knowledge of its occurrence in Cumbria is required in order to increase measures for its conservation in the area. The paper uses the habitat features woodland size, altitude, soil type, tree species present, temperature and rainfall as potential predictors. As only presence data was available for dormice in Cumbria, pseudo-absences were generated to allow logistic regression modelling. The use of pseudo-absences was justified using a false record permutation test. Cross-validation allowed the ability of models to predict the data to be assessed. This was judged using ROC plots. The size of the wood, temperature and whether the soil was wet or dry were the best predictors of dormouse incidence in Cumbria. The two approaches produced different models; those from the information-theoretic approach had a better ability to fit the data. The information-theoretic approach also had the advantage of enabling model averaging and provided greater understanding of the system.