The Dormouse Hollow

Dormouse Conservation

Dormouse Research and Conservation in Sicily / Italy:
Ecology and Distribution of Gliridae (Myoxidae) in the Mediterranean Biome.

By the Sicilian Dormouse Group

Dr. Maurizio Sarà: Department of Animal Biology, Via Archirafi 18, I-90134 Palermo, Italy


The elongated and narrow shape of the Italian peninsula spreads over some 2000 kms in length and across nearly 10 degrees of latitude; for these reasons several bioclimatic zones from the coldest Alpine range to the Southern Mediterranean ecosystems can be recognized. Physiography and climate are thus - together with anthropogenic impacts - the most important features which were responsible for the past and recent faunistic distribution over the area. A cline of decreasing diversity, according to latitude, has already been showed in several zoological taxa (mainly Coleoptera Scarabaeoidea, Coleoptera Carabidae, Formicidae, Aves and Mammalia) (cf. Massa & Schenk, 1983). This latitudinal impoverishment was named 'peninsular effect' and has its obvious complement, according to the Mac Arthur & WilsonÕs theory (1967), in the, even more, smallest number of animal species which are generally found in Sicily. This large (some 26,000 square kms) insular area is divided from the peninsula by a narrow (3 kms) arm of the Thyrrenian sea which acted as a filter for faunistic colonization.

Another characteristic aspect of biological isolates such as Sicily, is the increase of endemic taxa and, for this reason, going down along the Italian peninsula we have a gradient of fauna exhaustion, which is partially counterbalanced by the increase of endemic species or subspecies. At the latitude of Tuscany there is, more or less, the 'border' between the Northern continental areas (rich in species, poor of endemisms) and the Southern insular ones (on the contrary, poor in species, rich of endemisms).
Both Southern peninsular areas and Sicily were the natural refuges for warm taxa and for Mediterranean vegetation during the cold millennia of Pleistocenic glaciations. But the high altitudes of Southern Appennines and of the North-Eastern Sicily permitted also the relictual presence of temperate vegetation during the Interglacials, such as the sub-atlantic (colchic) belt (Fagus forest) in the Peloritani, Nebrodi, Madonie and Etna. This montane ridge with its deciduous biome, excluding the Etna, is from several point of view, just a ÔpieceÕ of Appenine, the so-called Calabro-Peloritano Arc, attached to the trunk of the island.

This general context permits to explain, coming to the Gliridae, the peculiarity of their distribution in Italy. That is the presence of relictual populations of Dryomys nitedula in the Southern Appennines and of Muscardinus avellanarius in Sicily.

The Forest dormouse, as summarized by Cagnin & Aloise (1994), has a localized distribution in the Fagus forests of Aspromonte, Pollino and Sila Grande, from 1300 to 1880 m a.s.l. (Calabria and Basilicata). Recently discovered and described as D. n. aspromontis (von Lehmann, 1964) proved to have only a low genetic distance from the North-Eastern italian population, corresponding to values recorded between local populations only recently separated (Filippucci et al., 1994). This is consistent with the hypothesis of its recent spreading from the Alps to Southern Italy (Roesler & Witte, 1968). Fossil records of Dryomys were found in a paleolithical site from middle and recent Würm.
Sicily, on the other hand, is the sole Mediterranean island (together with Corfu) which hosts the Common dormouse. Both islands are very close to their continental areas, but in the case of Sicily the Straits of Messina played an active barrier for the diffusion of this strictly arboreal dormouse. Anthropocory, a reasonable explanation for the presence of some species in some islands - for example the Fat dormouse (Myoxus glis) at Salina in the Eolian archipelago - cannot be invoked for the Common dormouse; which has not had any value (commercial, food stuff, etc.) for the human beings who travelled and settled in Sicily during historical times.

A relatively recent penetration during the last Glaciation (pleniglacial and tardiglacial Würm, around 75.000-15.000 years b.p.) is, for these reasons, the more plausible date for its presence in the island.
Ecological adaptation to dry and warm conditions in the Mediterranean area of these Northern (Turanic and Middle European) elements, at the limit of their distribution range is worth of study and of comparison with populations of North and Central Europe. Speciation in allopatry, i.e. genetic, morphological and eco-ethological modification of taxa, can be followed and focused by research on such local and isulated populations. Today, Dryomys and Muscardinus became also two of the best ecological indicators of the semi-natural ecosystems of Southern Italy; and, in a fast changing environment, these species and the habitats where they live are an important piece of diversity to protect.

Past status of Gliridae (Myoxidae) in Sicily

Quaternary zoological records of Sicily can be followed throughout time in a very discontinuous way. Fossil remains and assemblages are separated by black holes lasting hundreds of thousands of years; but at least one Gliridae rapresentantive was always present. These plio-pleistocenic insular dormice, belongig to the Dryomyinae Maltamys and Leithia genders, are considered to have descended from the miocenic taxon Eliomys.
Paleonthologists recognize four major faunistic stages (Kotsakis, 1996; Burgio, 1997):

  1. the Monte Pellegrino fauna an highly endemic assemblage of villafranchian age (plio-pleistocenic boundary), marked by the presence of Pellegrinia panormensis. The Gliridae present at that time was Maltamys cf gollcheri.
  2. the Spinagallo fauna, still endemic and marked by the presence of the dwarf elephant Elephas falconeri. Absolute datation for this assemblage is around 500.000 years bp (but some new data allow to hypothesize a younger datation). Two Gliridae were present at that time, Leithia cartei and L. melitensis. This last was a giant form of dormouse, around the size of a rabbit.
  3. the third assemblage was the Maccagnone non endemic fauna, whose marker was the medium-size Elephas mnaidriensis. At this age L. melitensis was still present, around 150.000 years ago, together with the Maltamys wiendincitensis.
  4. eventually, the Castello fauna was the last and more recent assemblage dating around the 12-14th millennium. This fauna marked by the presence of the horse Equus hydruntinus entered in Sicily together with Homo sapiens, a couple of millennia before the beginning of Holocene (10.000 bp). But among the mammal cohort found in the Castello sites, Gliridae have not yet found.

We must wait some millennia later to find the first fossil remains of the modern gender Myoxus. In the Middle Neolithic site of Partanna Stretto, in Western Sicily (Trapani province) some mandibles of this animal were found.
The black hole of 6-8 millennia between the presumable date of penetration in the island and first real documentation need to be filled up by new research. Anyway the presence of Fat dormouse in the area of Partanna Stretto tell us about its value as paleoenvironmental indicator. Deciduous forest of oaks were still present, and perhaps widespread, during the 6-5th millennium b.p. in an area that is today only garrigue and cereal cropland without any tree.

We have to do another jump, till last centuries to meet again records of Gliridae in the island. The only data available for the 19th century are from Minà Palumbo (1868) and Doderlein (1872). These Authors reported only vague informations, stating the presence of Gliridae in the largest wooded areas of Etna, Nebrodi and Madonie. According to them, the Common dormouse lived in the hazel and chestnut groves of these regions whereas the Fat dormouse was more common in the oak forests.
Since then, the presence of Myoxus glis was recorded in the island of Salina (Eolian archipelago) by Cristaldi and Amori (1982) and the Eliomys quercinus was reported from the largest Eolian island, Lipari (Kahmann, 1960).

Current status of Gliridae (Myoxidae) in Sicily

a) Distribution

Three species of dormice live today in Sicily: the Fat dormouse (Myoxus glis italicus Barret-Hamilton, 1898), the Common or Hazel dormouse (Muscardinus avellanarius pulcher Barret-Hamilton, 1898) and the Garden dormouse (Eliomys quercinus dichrurus Rafinesque, 1814). As we told before, a second subspecies (E. q. liparensis Kahmann, 1960) is known to occurr at Lipari.
A first sketch of their distribution on a UTM grid (100 square kms) was presented (see Sarà & Casamento, 1994) at the II Conference on Dormice held in May 1993 at Fuscaldo (Italy). Since then new informations have been added, updating their maps and relative coverages.

The Garden dormouse (distribution map 1) has the widest distribution in a variety of habitats ranging both in the sclerophyll and in the deciduous biome, from the sea level up to 1600 m a.s.l.
At Lipari is reported to live in the dense sclerophyll maquis and in dry-stone walls of cultivated areas, but we do not have any fresh data, since the last informations came from more than 20 years ago (Godena et al. 1978).
In Sicily it was recorded, by analisys of Owl pellets or by observation, in nearly all the ecosystems. It normally occurrs in tree-less, dry and rocky areas, the Ampelodesma garrigue, such as in the Penisola di San Vito lo Capo, Monte Cane, Monte Bonifato areas. In those habitats the Garden dormouse generally lives in the small patches of maquis and ilex wood and in the caves, holes and crevices of the cliffs. Its ability to live in these secondary and degraded habitats, residues of the sclerophyll oak woods, once widespread in the whole Sicily, is important for the species' survival.
The species is still present in the arboreal countrysides such as the olive and almond groves of the mediterranean arid belt (Oleo-Ceratonion).This in spite of the always more invasive diffusion of Black rat, an EliomysÕ strong competitor, in these rural landscapes. Some records are even from artificial woods of Eucalyptus or in Pine stands (Pinus halepensis, P. maritima, P. nigra) both in the Northern (Foce dellÕImera) and Southern (Pineta di Vittoria, Foce del Platani) coastal areas, where it lives in the bark of those trees.
We also have evidence of its presence in continuous woodlands of sclerophyll (Quercus suber, Quercus ilex) and deciduous (Quercus virgiliana, Fraxinus excelsior) trees, such as in the Bosco della Ficuzza, near Palermo.
Eventually, as regard for the sub-atlantic (colchic) vegetational belt, it has been, so far, recorded only on the Madonie mountains, during trapping in the beech forests of the Anthrisco-Fagetum.

The Fat dormouse (distribution map 2) is present in the North-eastern ridge of the island, in the Peloritani, Nebrodi and Madonie mountains. more South it lives also on the Etna volcano. In these areas it is found mainly in deciduous forests between 600 and 1800 m a.s.l., namely in the beech forests of the sub-atlantic belt and in the deciduous oak woods of the samnitic belt.
In the Nebrodi range the beech formations, where the species lives, belong to the Aquifolio-Fagetum, whereas in the driest and karstic Madonie they form the Anthrisco-Fagetum association. In both areas the oak habitats are mostly composed of turkey (Quercus cerris) and pubescent oak (Quercus virgiliana), several species of maples and holly. It is also present, on these mountains, in the slopes and valleys at lower altitudes (around at 500-800 m. a.s.l.), where hazel and chestnut groves are intermingled with evergreen oaks (Q. suber, Q. ilex) and sometimes with orchards and olive groves. We have also evidence that the Fat dormouse is, also in the island, a cave dwelling such as in the Abisso del Gatto (Madonie range).
In the Etna area it has been observed both in the western and eastern sides of the volcano in mixed pine (Pinus laricio, Betula aetnensis) and oak woods from 1000 to 1600 m a.s.l.
Away from this continue range it was reported by Amori et al. (1986) in south-eastern Sicily, in the Iblei mountains at 400-500 m a.s.l., where the woodlands belong to the mediterranean vegetation belt. Does not exist any recent information on this isolated population, which in the last 20 years has suffered, together with its habitat, the heavy and yearly impact of forest fires.
In the island of Salina, where according to Cristaldi & Amori (1988), the Fat dormouse and the chestnut were presumably introduced there during Roman times as foodstuff (the species was considered as delicacy during the Roman Empire and was cooked with special recipes); it still lives on the Monte delle Felci, a mountain covered with a dense mixed mediterranean maquis and evergreen forest. The last observation of living animals, in this case, dates back to summer 1998.

Thanks to new data, the Common dormouse (distribution map 3) distribution has doubled in the last years, but the species is still the rarest and more localized terrestrial mammal among those living in the island. Its distribution from Peloritani to Madonie has some gaps; but, for the presence of potential habitats, we argue that these are probably due to the lack of specific exploration; as for the Etna where it has not recorded yet.
The species is generally sympatric and syntopic with the Fat dormouse in the deciduous forests from 800 to 1600 m a.s.l. All the beech, oak, hazel and chestnut woods, pure or mixed are suitable for the species. And, in these ecosystems, it is also present at lower altitudes (500-800 m) on the northern slopes of the river valleys (the so-called fiumare) of Nebrodi and Peloritani.
Its habitat can even spread at much lower altitudes, all along its known distribution area; since we have recently discovered in the lower Madonie some populantions living in the sclerophyll vegetation. For example, in areas such as Carbone and Guarneri, at around 200-400 m a.s.l., Muscardinus avellanarius lives in dense maquis of heather and arbutus mixed with stands of Aleppo's pine, ilex and cork oaks.

b) Ongoing research

Research on Myoxidae ecology in Sicily has been focused on the Common dormouse and started in late 1995 on the Madonie Regional Park (Sarà et al., 2000). Nearly 200 artificial wooden nest-boxes have been placed in grids or transects and moved among different sample areas to detect the presence and relative density of the species. So far, 200 monthly visits have been performed, resulting in nearly 5000 checks of the nest boxes and some 700 animals handled (Table 1). (link to pictures 1-5)

Sample area Study period Habitat

Altitude slm

N boxes


Surface (ha)

SILLITTA Ago99-Dic99 termophilous mixed oak maquis





MUNCIARRATI Apr96-Apr97 termophilous mixed oak wood





POLIZZI Set95-Ago98 hazel grove and termophilous wood





GIMMETI Set95-Dic99 mesophilous oak and holly wood





GIMMETI Apr95-Ago98 chestnut grove





CANNE Set95-Apr96 mesophilous oak wood





SERRE CORCO' Set97-Set98 pure ilex wood





MONTE DAINO Mag97-Set98 pure beech wood





PIANO CERVI Nov98-Ott99 pure beech wood





Total for the Madonie


Sample area

N visits

N checks

N captures

























































Total for the Madonie






Density of Common dormouse in the woodland ecosystems of the Madonie Regional Park (Sicily). DAT% is the relative frequence (n captures/n checks). Density/ha is the mean n of adults.

Data ultimo aggiornamento 29/02/00
Aggiornato da MAUSAR

Habitat structure and diversity seem to be the major factors limiting the abundance of the species. Presence of a dense understorey and of high and diverse shrubs and trees species seem, among the main habitat features necessary for supporting a rich dormouse population.
It is possible today to have information about its density per hectare in different woodlands and about its population dynamics
In its Northern range common dormouse has a shorter activity season and occupies the nest-boxes from April to the beginning of November, going to hibernate on or under the soil, during the rest of the year. The Sicilian population of common dormouse on the Madonie mountains, has a continuous reproduction with the two yearly peaks (Fig. 1), resulting in a bimodal population cycle (Fig. 2). The summer breeding of Northern dormice has shifted here to late autumn and early winter; and this appear to be a feature of the adaptative process to the Mediterranean climate and ecosystem. In these woodlands high palatable and energetic food (i.e. seeds such as holly berries, hazel nuts, sweet chestnuts, fruits as brambles, wild pear, etc.) together with oak and beech acorns is available exclusively during autumn and winter. In late spring, the presence of soft berries or flowers and blossoms (e.g. Rosa canina, Crataegus monogyna, Lonicera etrusca and L. implexa, Acer spp.) permits the lower second peak of reproduction. The dry and hot summer appears to be the season more difficult to deal with; and at that period, dormice leave the nest-boxes and estivate elsewhere. It is not possible to state now, if they live outside among the vegetation, or go underground in search of humidity and lower temperatures.
Mild weather conditions in autumn and winter favour the biological activities of dormice and the full growth of litters born in those months. Mediterranean winter permits, as consequence, to avoid the constraint of hibernation and to re-allocate energy and time, necessary for fattening, to reproduction. The average body weight of this population is stable and fluctuates very little, not showing the phase of winter increase recorded in Continental dormice for facing hibernation (Fig. 3). In this wiev, torpor seems to be more an individual strategy, rather than a populational trait; put in practice to save energy when singles are in bad physiological conditions; since the animals found in dormancy are very few and have low body weights. The bad weather and snow, affect them, but not the greater part of the population, which is in full activity and reproduction; e.g. lactating their pups.
This adaptation is successful, even if there is an increasing evidence of some juveniles mortality during unpredictable heavy climatic perturbations, since the species is still able to survive in its Sicilian range, producing litter size and having density per hectare similar or even higher to those found in the England or in Lithuania.

c) Future research

Even if we have now a sketch of the general ecology of the Common dormouse, a good body of raw data are still to be carefully analysed to draw the complete picture of its ecology at this latitude. Two sample areas are today still working on, the one of Sillitta, in a typical Mediterranean fire-selected ecosystem, where dormice live in a termophilous high maquis of heather, arbutus and oaks, at low altitude, i.e. in an unusual habitat for the species. Response and resilience to fire is also under study, since some of the nest boxes have been set in a burned parcel of the grid.
At Gimmeti, the fifth consecutive years of study is allowing to gather data on the medium-term trend of population and the capture-marking-recapture program run from the 1998 will give information on territoriality and mortality.

In summer and autumn 1999 this area was colonised also by the Fat dormouse. We have thus, for the first time in Sicily (and in southern Italy), the opportunity to collect basic data on the species' biology and ecology (link to picture 6-7). Analisys of space competition, if any, among the two dormice and the Blue tit (Parus caeruleus) is also on going.

d) Conservation

The Common and the Garden dormice are protected by law in Italy and Sicily according to the EEC Directory 92/43 and they were listed as vulnerable in the national Red List (Bulgarini et al., 1998).

Woodland habitats conservation is the final goal of our researches. Sicilian woodlands have suffered in the past centuries an heavy deforestation and fragmentation verging to extinction (e.g. the lesser spotted woodpecker, Picoides minor) or to extreme rarity several species of vertebrates (e.g. the long eared owl, Asio otus) The presence and good population density of dormice is an useful biological indicator for the welfare of the woods in which they live. Indicriminate forest cut and clearing, together with summer fires are the major threats for these forest dwellers.
Unfortunately, they are common and widespread also in protected areas such as the Madonie Regional Park. Year after year fires and a wrong forest management are eroding thousand of hectares of maquis and woodlands.
Knowledge on dormice ecology became thus another important tool to urge the Regional Administration of Parks and Forests to a better and more incisive habitat conservation policy.

References cited in the text:

The Sicilian Dormouse Group is formed by Dr. M. Sarà at the Department of Animal Biology and by students in Natural Sciences Degree of the Science Faculty (Palermo University): A. Aiello, G. Ardizzone, F. Cascino, A. Emma, W. Falletta (dormouse thesis), R. Imburgia (dormouse thesis), A. Milazzo (dormouse thesis), A. Spinnato (dormouse thesis).

Contribution to The Dormouse Hollow by Dr. Maurizio Sarà © 2000

Department of Animal Biology, Via Archirafi 18, I-90134 Palermo, Italy.

Photos © by M. Sarà

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