Creatures great, small… and unexpected

From Bourkes to bettongs, Block 25 (as it is known locally) is Sand Hutton’s very own Noah’s Ark … if Noah also had to think about biosecurity protocols and specialist diets. Tucked away in the Yorkshire countryside, this unassuming building houses an astonishing array of species, each here for a different reason, and each demanding its own brand of expert care. Originally built as a wildlife research facility, Block 25 is now managed by Fera Science Ltd in close partnership with the APHA wildlife team, working together to deliver high quality care and cutting-edge science.

Block 25 is also an ASPA (Animals Scientific Procedures Act)* licensed establishment, housing the infamous squirrel immune-contraceptive captive breeding colony, which is a title that sounds like the start of a wildlife thriller, but is in fact a cornerstone of serious scientific work.

This specialised colony supports research into humane population management solutions for invasive grey squirrels. While the squirrels themselves remain blissfully unaware of their scientific fame, the team caring for them navigates a world of precise protocols, careful monitoring, and the occasional acrobatic escape attempt. It is specialist, meticulous, and sometimes unexpectedly chaotic, but it is also a vital part of developing innovative, welfare focused approaches to protecting native species.

Dora the binturong

In addition, Sand Hutton often finds itself acting as a temporary home for some rather unexpected guests. Working closely with Border Force and the APHA imports team to house both Convention on International Trade in Endangered Species (CITES) and non-CITES species for quarantine purposes. The unit serves as a designated quarantine facility for Avian Influenza and Newcastle Disease, alongside its rabies licensed facilities for domestic cats and zoo/wild animals. Block 25 operates with the same calm efficiency you would expect from an international airport terminal, only with more feathers and the occasional set of sharp teeth!

Animals brought to this facility are quarantined before rehoming, a process that can take considerable time, particularly for parrots, given the potential associated risk of Psittacine Beak and Feather Disease (PBFD) spreading to other shipments and collections. Ensuring these charismatic characters remain healthy requires meticulous monitoring, robust hygiene measures, and, at times, an appreciation for the dramatic flair parrots tend to bring to any situation!

The team also provides essential support following seizures associated with the National Wildlife Crime Unit, both the Scottish and Royal Society for the Prevention of Cruelty to Animals, and the Invasive Non-Native Species inspectorate (INNS).

Galah cockatiels​

Housing varies widely inside the unit - from large aviaries that allow short-distance flight, to smaller finch-style cages, to robust floor pens and specialist enclosures for rabies quarantine mammals. This diversity is not just for show; it reflects the astonishing range of species that pass through Block 25 and the care required to meet their individual needs. One area might hold delicate finches perfecting their fluttering skills, while another contains reinforced quarters built with considerably more teeth in mind!

Outdoors, the Sand Hutton site offers extensive enclosed pens, paddocks, and a secure arena building with internal divisions, providing flexible environments for both birds and mammals.

These spaces allow the team to accommodate everything from nervous newcomers to boisterous animals in need of room to stretch their legs (or wings). Combined, the indoor and outdoor facilities form a well-planned patchwork of habitats, each intentionally shaped to safeguard the welfare, safety, and comfort of the animals in our care.

Challenges we face

We are not great at saying no, so capacity is always our biggest hurdle. Catering for such a diverse range of species means quarantine, housing, and husbandry often feel like strategic exercises fit for wartime planning! Add biosecurity demands and the ever-unpredictable British weather, and it is easy to wonder whether we have bitten off more than we can chew.

Peregrine falcon at our Sand Hutton facilities

PBFD remains one of our most significant concerns: highly contagious, incredibly persistent, and notoriously difficult to eradicate. Yet by working collaboratively with avian and veterinary specialists, we are exploring promising solutions, including testing after natural feather moult cycles.

Unpredictability is the name of the game in this field of work, but it certainly keeps us on our toes to ensure we are prepared for every eventuality. Whether it is toucans, gyrfalcons, binturongs or raccoons, each species comes with a completely different set of dietary requirements, enrichment needs, and welfare considerations.

One thing is certain, no two days are ever the same, and there is always something new to learn.

Quarantine for a Maine Coon cat seized at the border It is all about teamwork!

But that is enough about the facilities, it is the animal staff that are the heart and soul of the facility, ensuring every day runs like clockwork. Our animal staff have kindly shared their thoughts on what it is like to work in such a diverse facility and share their insight on their day-to-day life:

Ailsa

What I enjoy most is working with quarantine species. There is something uniquely rewarding about the combination of biosecurity, welfare, and hands on care. Among them, parrots have quickly become my favourites. Their intelligence, personality, and sheer presence make every day interesting. Two decades in, my work continues to evolve, and I am enjoying the journey more than ever.

John

After more than two decades, what keeps me motivated is simple: the people, the purpose, and the pride in knowing that the work I do helps enable world‑class science every single day. It has been quite a journey, and I am still enjoying the ride.

Matt

Working in this environment has given me the opportunity to gain extensive hands-on experience with an incredibly diverse range of species. From fish, cattle, goats, rabbits, and poultry to small mammals such as mice, rats, guinea pigs, hamsters, and gerbils, each species has taught me something new. My work has also included wild animals, including badgers, foxes, squirrels, stoats, deer, and various birds - such diversity!  After so many years, my motivation remains the same: to champion excellent welfare‑on experience with an incredibly diverse range of species.

Nikki

I bring more than two decades of dedication, experience, and professionalism to the role with a deep commitment to animal welfare, scientific integrity, and culture of care. My extensive hands-on knowledge and experience with wild animals is particularly broad, encompassing mice, rats, badgers, grey and red squirrels, stoats, deer, goats, and birds. This diversity of experience has equipped me with a comprehensive understanding of species-specific needs and welfare considerations.

Mandy 

I have a particular passion for grey squirrels and the specialist work associated with them.  

Jacob 

Every day brings something different, and that variety is exactly what keeps me motivated.  

Dwight 

Working in this field has given me the privilege of caring for an incredible range of species — from mammals with fascinating behaviours to majestic birds of prey whose intelligence never ceases to amaze me. For me, being an animal technician is more than a job; it is a vocation built on curiosity. 

Finally

Finally

I would like to take this opportunity to extend my sincere thanks to the staff for their never-ending hard work and dedication. To every member of this exceptional unit - thank you. Your dedication, resilience, humour, and commitment to excellence make the impossible possible. If there is one thing, we have all learned over the years, it is this: expect the unexpected… and embrace it!

*The Animals (Scientific Procedures) Act 1986 (ASPA) serves as the primary legislation governing the protection of animals used in scientific research.

https://aphascience.blog.gov.uk/2026/04/29/creatures-great-small-and-unexpected/

seen at 10:07, 29 April in APHA Science Blog.