In Belgium our field study for Hazel Dormice (Muscardinus avellanarius) and Garden Dormice (Eliomys quercinus) is in partnership with Goedele Verbeylen at Natuurpunt.
Goedele Verbeylen’s research found the optimum entrance dimensions for these species and showed that rectangular entrances could give better protection from predators and competitors for nest holes than round entrances.
For Hazel Dormice we aim for a rectangular entrance of 16 mm width or a circular entrance of 22 mm diameter with internal dimensions of c. 100 to 150 mm.
Hazel Dormice are too small to protect themselves against predators and the young are particularly vulnerable while mothers are away searching for food so careful selection of nest hole height, visibility and entrance size are important to give protection.
Female Garden Dormice prefer to nest together in families to raise young so internal dimensions of nest holes have to be larger to allow space for this. For Garden Dormice we aim for a rectangular entrance of 20 mm width or a circular entrance of 30-45 mm diameter with internal dimensions of c. 150 mm.
Active adult Garden Dormice can defend themselves against some predators but mothers may have to leave their young for up to 2 to 3 hours to forage for food so protecting young from predators is important.
Our Belgian field study showed, for the first time, Garden Dormice taking an active interest in carved nest holes.
Boring techniques and chainsaw carving techniques allow entrances to be carved to a precision of +2 mm / -0 mm.
The nest hole is carved entirely through the entrance with no damage to the surrounding cambium of the tree.
For the Belgian field study, nest holes were carved in living trees and one dead or dying tree.
The Belgian field study used LSBS (Low Speed Boring System) – LSBS can be used by people without chainsaw experience but is significantly slower than HSBS (High Speed Boring System) and much slower than chainsaw carving techniques.
Passerine Birds
Nuthatch (Sitta europaea), Short-toed Treecreeper (Certhia brachydactyla), Marsh Tit (Poecile palustris), Green Woodpecker (Picus viridis), Great Spotted Woodpecker (Dendrocopos Major), Great Tit (Parus Major), Blue Tit (Cyanistes caeruleus), Robin (Erithacus rubecula) and Wren (Troglodytes troglodytes) showed an immediate strong interest in the carved nest holes.
Many of these species worked extensively throughout the winter and spring to attempt to enlarge entrances, remove debris and adapt the carved nest holes to their requirements.
Roach’s Dormouse (Myomimus roachi), Forest Dormouse (Dryomys nitedula) and the European / Siberian Flying Squirrel (Pteromys volans) are not present in Belgium.
Thanks
We’d like to thank:
Landen:
Jules Robijns (Natuurpunt Landen)
Huldenberg:
Frederik Fluyt
Astrid Cervantes
Thomas Vandenberghe and Stijn Verstraeten (Natuurpunt Druivenstreek)
Pieter Moysons (Regionaal Landschap Dijleland)
Borgloon:
Jos Reekmans
Joachim Volont and Stefan Carolus (Natuurpunt Borgloon)
Viroinval:
Ivo Vanseuningen (Natuurpunt Mammal Working Group)
Voeren:
Rian Pulles (Stichting De Slaapmuis)
Davy Noelmans (VLM)
Page prepared by Will Robertson and reviewed by Goedele Verbeylen.
References to research papers, etc. can be found here: References
“As climbing arborists, we exist at a unique confluence of art, science and athletics. Our profession has undergone a transformation from a dogmatic to a scientific era similar to that in medicine in the second half of the 20th century. As the challenges of biodiversity loss intensify, we find ourselves at a second turning point: we change from being consumers of research to leaders of the fundamental research and of the practical advances needed to ensure that trees remain homes to our most beautiful and endangered creatures.”
Blog
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From the tree crowns of an Irish forest I’d like to welcome you. At time of writing in July 2024 we’re focused on field studies, rehabilitation studies, bat counts and trying to work out what best to do after a devastating series of wildfires affecting Myomimus roachi in autumn 2023 and summer 2024 so this is just a basic site and we’ll be adding a lot more detail on species, people and techniques in English, German, French and Italian in autumn 2024. 🙂
Will 🌳🌲❤
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