Minimally invasive precision techniques to carve roost and nest holes for tree dwelling endangered species.
We’re a largely unfunded international collaboration of leading climbing arborists, ecologists, conservationists and zoologists working together to design and develop new minimally invasive tools and techniques to carve nesting and roosting opportunities for our most endangered tree dwelling bat, dormouse and squirrel species.
We develop our techniques through in-depth statistical analysis, studies with animals in rehabilitation at 2 of Europe’s leading wildlife rehabilitation centres and field studies.
We bring together deep experience in chainsaw technique; tree biology; the ecology and zoology of families Vespertilionidae, Gliridae, Sciuridae and Arionidae; wildlife rehabilitation; field study structure and organisation; statistics; GIS and precision machining with extensive experience in tree care, climbing, commercial forestry and substantial muscle power.
Species
Here’s a quick introduction to some tree dwelling species we work to protect. All these creatures have exceptional climbing abilities and are strongly adapted to life in the trees however many have come under serious pressure and suffered precipitous declines in their population in Europe due to habitat loss and past forestry, agricultural and arboricultural practice.
We’re hoping to have a separate page for each species with much more detailed information online this autumn.
Roach’s Mouse-Tailed Dormouse (Myomimus roachi)
Roach’s Mouse-Tailed dormouse is Europe’s smallest, rarest and most endangered dormouse species. They’re thought to nest exclusively in tree holes and Europe’s only population is found in a small area in the South East of Bulgaria. They were badly affected by wild fires in autumn 2023 and summer 2024. Myomimus roachi is Vulnerable globally on the IUCN red list.
Hazel Dormouse (Muscardinus avellanarius)
The Hazel Dormouse is native to England and much of Europe but numbers in England have declined dramatically in recent years. They eat berries, nuts and insects and nest in tree holes or in nests built in thorn bushes. Because of their small size they’re unable to defend nest holes against competitors including many bird species so entrance size and shape must be chosen with care. They’re slightly larger than Myomimus roachi and like Myomimus, they have very few of the guard hairs that protect most mammals from rain and so are susceptible to hypothermia in wet conditions. Originally regarded as one species, genetic studies have revealed several distinct species.
Brown Long-Eared Bat (Plecotus auritus)
With it’s large and uniquely shaped ears, Plecotus auritus is able to hunt insects by listening for sounds they make as well as by ultrasound echo location. It roosts in large attic spaces in houses and in tree roosts. The Brown Long-Eared Bat is medium sized compared to other European species – this photo is of one in a chainsaw carved roost at Bat Rehabilitation Ireland.
Garden Dormouse (Eliomys quercinus)
Typically live and nest in close-knit family groups. They’re more dependent on tree holes for nesting than Hazel Dormice. They are slightly larger and more able to defend nest holes against some competitors than Hazel Dormice but are still vulnerable to many competitors and predators. Their diet is typically richer in insects, other invertebrates and small vertebrates than other dormouse species. Although Garden Dormice can coexist with humans, they are close to extinction in several European countries and are Vulnerable globally on the IUCN Red List.
Forest Dormouse (Dryomys nitedula)
Around the same size as Eliomys quercinus and with a similar appearance, Dryomys nitedula are one of Europe’s least understood dormouse species – they inhabit Alpine forests but their full distribution isn’t well known. Current genetic studies are revealing several distinct species. Dryomys nitedula is IUCN: Vulnerable in Switzerland.
European Flying Squirrel (Pteromys volans)
Pteromys volans is smaller than our other native squirrel the Red Squirrel (Sciurus vulgaris). They were found across Northern Europe but are now found only in Northern Finland and Asia. Unlike our bat and dormouse species, squirrel species cannot go into torpidity (cold sleep) or hibernation to conserve energy and remain warm all winter so they build larger, better insulated nests than dormice. They rely on nesting in holes in trees, ideally with entrances too narrow for the larger Red Squirrels. Pteromys volans is IUCN: Vulnerable in Finland
Red Squirrel (Sciurus vulgaris)
The Red Squirrel is widespread across Europe however has become endangered in several areas including England due to habitat loss and squirrel pox – caused by squirrel fibroma virus spread by larger non-native grey squirrels (Sciurus carolinensis). The first deaths from squirrel fibroma virus in Scotland and Ireland were confirmed in spring 2024.
This Red Squirrel in rehabilitation at Stiftung Wildstation Landshut shows the darker colouration in the foothills of the Alps while in Ireland they have a white-ish section towards the end of their tails.
Leisler’s Bat (Nyctalus leisleri)
Leisler’s Bat is a conservation priority in the UK and South of Germany but more common in Ireland, it’s one of the largest bat species in Europe. Although native to the forest, Leisler’s can roost in both houses and tree hollows and can hunt insects in both forest and urban environments.
Bats often roost together with other bats of the same species – these two are in a chainsaw carved roost at Bat Rehabilitation Ireland.
Garden Dormouse (Eliomys quercinus) in a nest hole in our Belgian field study ©Goedele Verbeylen
“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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