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Digest 7 September 2000 - Vol. 1, No. 5

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1) Bait Tube Surveys (Mike O'Connor)

Has anyone had any success using bait tubes for dormouse surveying? I would like to trial this method in a coppiced oak woodland SSSI on behalf of the managing local authority. Is this technique a viable alternative to nestbox surveys? I would appreciate any recommendations on the optimum diameter of tubing, type of bait and positioning of tubes.


Mike O' Connor
School of Biological Sciences
Queen Mary & Westfield College
University of London

2) Reply (DM 1/4): Competition for Nestboxes (M. Sarà)

Dear Werner,
thanks for the punctual observations you've made. these are points that, I think, every dormouser has in his mind and may be some special research in this direction is welcome and should be planned.

In my experience, there is an almost perfect separation in the ecological niche (use of the nestbox = space axis of niche), mainly in the season/period of use, and in the size of the box (and of its entrance hole). Glis use only the big boxes from august to november, early december, later muscardinus came and use only the small ones till march-april; and thirdly, tits arrive in the small boxes and breed from april to july.

Overlap in the nestbox use is very limited to some few cases, mostly between muscardinus and tits, and it seems that tits, in march-april, begin to use the boxes left unused by the dormice, then, when muscardinus has gone, they spread in the grid and use also the other boxes.

These facts, as you know, can be judged according to the theory of competition either as evidence of strong past competition (gause principle, and phantom of past campetition, or as lack of it (neutral Simberloff's hypothesis). In the first view nestboxes (and therefore, for (right?) inference the natural tree-hollows) would be used in different seasons to avoid dangerous encounters and figthings for the resource 'space where to live'. The community and all the biological cycle of these species (glirids and tits) would have been regulated by the necessity to avoid competition. Whereas in the second idea, species simply act and live in different ways, just as co-owner in a building. I personally believe more to the first hypothesis, because the synchronicity of use it seems too perfect and ordered to be casual, but I do not like the following assumption that life history and community are thus ordered and ruled by competition.

Eventually, in these years we have never found tit nests destroyed or eggshells eaten, and we have had only a couple of muscardinus dead for wounds and bites (glis, adult muscardinus males, or even apodemus?). Juškaitis can give interesting data about the relationships between dormice and birds. In Lithuania, as he shown me last summer, the story seems completely different, muscardinus raid Ficedula hypoleuca nests... but I hope that Rimvydas can enter in this discussion to tell about us.

About glis living together I do not have any evidence for it, we find only young brothers living togheter.

About the third question, that is very important for all the problems related to overestimation of densities. It is possible, for example, to judge an habitat as optimal (and worth for conservation) for the high density found there in nestboxes and to disregard a second habitat not checked...

Once again, I can tell something about my experience here in Sicily. We have monitored several habitats for checking dormouse; and density changes according to the habitat features. Also in this case, It can occur, of course, a bias in each sample area, i.e. a more or less constant increase in density due to the avalaibility of 'empty flats'. But I believe that food other than space where to live, is a major constraint for the dormice presence. And perhaps, the increase in optimality of one habitat can occurr only in situations where there is good amount of food, but natural hollows lack - for example in young hazel or chestnut groves. This can be good for dormice conservation but can not produce good scientific data. Indirect evidence for the increase of density due to nestboxes are all the campaigns done, for conservation purposes, in artificial plantations of Sweden, Finland and elsewhere in Northern Europe, where hundreds of boxes are put to give place for nesting to passerines, woodpeckers and owls.

Anyway, due to the trophic niche of dormice, I do not believe, except for exceptional cases, that such densities can produce 'overgrazing' and can damage some habitats or plants.

I do not think that comparison between trapping and nestboxes densities is a good method, in that trapping almost surely produce underestimation. May be for muscardinus a better way is to check and count the natural nests and their owners in an area similar to that where are the nest boxes.

best whishes,

3) Reply (DM 1/4): Competition for Nestboxes (S. Büchner)

Dear Werner,
the only dormouse found in my study site is Muscardinus avellanarius, so I can´t tell anything about competition between dormice. About Common dormice raiding nests of birds and the probably damages to birds (especially eggs) done by dormice you find many informations in elder german literatur e.g.: Mansfeld, K. (1942): Über das Auftreten von Bilchen in Vogelnistkästen und ihre Schäden an Vogelbruten. Dtsch. Vogelwelt 67,S.13-20. and several small articles more.

Contrary to your question I found more animals raiding dourmouse nests than the other way round. But I think Rimvydas has much more data abuot this issue - so I write only some impressions on this question:

I monitored my nestboxes every 14 days and not seldom during spring I had such samples like this: first control: nest with eggs of Parus major, second: nest of Muscardinus and eaten eggs, third control: Ficedula hypoleuca and only in september again Muscardinus. So it´s vice versa birds and Common dormice.

Differently are my impressions with Apodemus flavicollis. After Apodemus was occupying the nestbox no dormouse used it for nesting even after cleaning the nestbox. I once found a young Common dormouse killed by Apodemus flavicollis in nestbox and many times Apodemus were raiding nests of Muscardinus.

At least I often found bumble bees raiding dormouse nests.

Thanks for the dormouse talk and greetings from
Sven Büchner

4) Glis data from Slovenia / usage of nest boxes and mixed litters (T. Trilar)

Dear Werner
Some data about maximum number of Glis living together and mixed litters in a large nestbox.

The data are from 1.5 ha study area with 45 nestboxes designed for different animals (bats, tits, owls) in Dinaric beech-fir forest (Abieti-Fagetum dinaricum) on Sviscaki at the mountain Snežnik in south-west Slovenia (1250 m above see level).

1999 was extremely good season with very big crop of nuts on the beech. 3.9.2000 there was present altogether 12 adults and 52 babies of Glis. After 12 year of checking the Glis nests from the nestboxes in this area we find a new (undescribed) flea species.

This year it is very bad season without beech crop. According to people living there, Glis appeared 17.6.2000 and disappeared completely a month later.

My data:

Tomi Trilar

Dr. Tomi TRILAR, Head of Entomology Department
Slovenian Museum of Natural History
Presernova 20, P.O.Box 290, SI-1001 Ljubljana, Slovenia
Home Page:

5) Mating strategy and more questions (W. Haberl)

Dear Tomi and others,
Thank you all for your replies. Wrt your (Tomi) case of 3 females with 19 young Glis together in one nestbox: It would be interesting to know if the young recognize their mothers or vice versa. Can this be seen as a form of communal investment in raising young, ie do females foster the young of others? I wonder how many young one female can suckle. Is there any evidence for infanticide? If a mother is lost, eg. due to predation, communal breeding and fostering would be beneficial for overall survival of the litters. Does this phenomenon (multiple litters) also occur in the dormice' natural nesting sites or is this related to the size of the artificial nest box? Are you aware of any research on this topic? I also think that a study of paternity / multiple paternity would be interesting and provide further insights into the mating strategy of the fat dormouse. I remember that similar questions were raised at the Edirne dormouse conference in 1999 (discussion) by Selcuk Yurtsever.



1) A Plea for Sending Contributions and Queries in English...

I am happy to read 'Dormouse Talk'. Could you, at least, provide a brief summary of the German contributions for the unlucky people not speaking German? 'Dormice in the house' are one of the more interesting (and practical) problems we are sometimes called to solve...

Maurizio Sarà

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