Bats at the National Slate Museum: Protecting Our Smallest Residents During Redevelopment

As the National Slate Museum continues its major redevelopment programme, an important community of residents remains very much at the heart of our plans - our bats! 

Working closely with ecologist Carola Hoskins of SK Environmental Solutions ltd, we’ve been carefully monitoring and protecting ten known bat roosts across the site. 

These roosts are home mainly to common and soprano pipistrelle bats, two of the smallest bat species in the UK. 

Seven of the roosts are used by individual males or non-breeding females, but one is particularly special - a soprano pipistrelle maternity roost that supports around 65 bats at its Summer peak.

A Safe Place for New Life

Although the colony is currently winter hibernating elsewhere, by late April the bats will begin to return. 

At this time around 35 females will settle into the maternity roost and by late May or early June, each Mother gives birth to a single pup doubling the colony size almost overnight. While 65 bats might sound like a lot, it’s a relatively small maternity colony for soprano pipistrelles, making every individual important.

One of Nature’s Cleverest Adaptations

“Bats have many remarkable traits, but one of the most fascinating is delayed fertilisation." said Carola. "Female bats mate in autumn, but they delay pregnancy until spring, storing sperm through the winter months. This ensures that pups are born at exactly the right time when warmth, food, and safe roosting conditions give them the best chance of survival. It’s one of the many reasons these tiny mammals are so well adapted to life in the UK."

Conservation at the Heart of Our Redevelopment

Because bats and their roosts are legally protected, all redevelopment work involving the roofs at the Naional Slate Museum or potential bat habitat is carried out under licence, and only during winter while the bats are away. 

Carola is working alongside our Museum and Construction teams to guide every step of this process, by ensuring that roost entrances remain open, structures remain suitable, and the bats can return safely each spring.  This careful approach allows us to progress with essential redevelopment while safeguarding a species that has lived alongside the museum buildings for generations.

The National Slate Museum redevelopment project is funded by The National Lottery Heritage Fund, UK Government via Cyngor Gwynedd as part of the Llewyrch o'r Llechi project, Welsh Government including the Community Facilities Programme, the Wolfson Foundation, Garfield Weston Foundation and other funders. We are extremely grateful to all our funders for their support.