News

The IUCN Red List of Threatened Species has just published its second update of the year (10 October 2025), including reassessments for many small mammal species submitted by the Small Mammal Specialist Group. So, what’s changed and what’s new? Check out some of the first time assessments for newly described species and some Green Status of Species assessments we’ve contributed to.

Christmas Island Shrew (Crocidura trichura) – Extinct

There have been no confirmed records of the Christmas Island Shrew since 1985, despite surveys and many studies. Extinction can be difficult to prove, especially for a species as cryptic as the shrew, however, on the balance of evidence, this species has been assessed as Extinct. Extensive clearance of its rainforest habitat for mining, introduced diseases, and invasive predators are all likely to have caused the loss of this species.

Read a full article about the species by SMSG member Prof. John Woinarski here.

Harenna Mouse (Mus harennensis) – Vulnerable 

This mouse is endemic to Ethiopia, where it is known from the Bale Mountains (with most records from the Harenna forest) and the Chingawa forest. It is inferred to be experiencing a continuing decline in habitat quality as the Chingawa forest is unprotected and suffering losses of natural habitats due to agriculture, such as from increased coffee production. Urgent actions are needed to help preserve this unique forest.

Photo credit: J. Bryja

Chingawa Forest Rat (Chingawaemys rarus) – Critically Endangered  

Only known from a single specimen collected from the type locality in the Chingawa Forest of southwestern Ethiopia. It has not been recorded again despite trapping at the type locality and has not been recorded in other forest fragments in the region, therefore it is assumed that the species is rare. The Chingawa Forest is unprotected and is threatened by various human activities, including intensive coffee cultivation which has increased in recent years.
Ethiopia is a Key Region for small mammals, because of the high numbers of globally threatened species.

Palawan Moss Shrew (Palawanosorex muscorum) – Near Threatened

The Philippines is a country that has had many new species descriptions in the last few decades. Amongst these is the Palawan Moss Shrew, that has only been found on Mt. Mantalingahan, in the southwest of Palawan Island. It lives in high-elevation forest that is cool, wet, and steep, where there are thick layers of moss.

To find out more about this species, check out this blog.

Image from Danilo Balete.

Vietnamese Gymnure (Neohylomys vietnamensis) – Near Threatened

Before this species was discovered in Viet Nam, the genus was only known to have a single species, the Hainan Gymnure (Neohylomys hainanensis), which is only found on the island of Hainan, China. Almost nothing is known about the ecology of gymnures, which sit within the family Erinaceidae (hedgehogs). The species here is tentatively listed as Near Threatened, because it is currently only known to have a small range. Further surveys and research into the distribution, ecology, and threats it may face are needed.

Find the description paper here.

Photo credit: Bannikova et al. 2024 https://mapress.com/zt/article/view/zootaxa.5541.3.2

Hon Khoai Squirrel (Callosciurus honkhoaiensis) – Critically Endangered 

This species is only known from the small island of Hon Khoai in Viet Nam. Its primary forest habitat is being lost and degraded due to road construction and pollution.

Check out this article to find out more about this species and others that are threatened on this tiny island.

Santa Catarina’s Guinea Pig (Cavia intermedia) – Indeterminate GSS

Cavia intermedia evolved on, and has persisted on, a tiny island for around 8,000 years. Its Species Recovery Category is Indeterminate, which reflects the uncertainty around whether the species is declining; if not, because the species is expected to occur in similar numbers today as it has for centuries, it could be considered Functional. Research is ongoing to verify the population trend. The island is difficult to access, but some hunting may take place occasionally, so without legal protection of the island the species’ would be expected to be worse off but still Present; therefore the Conservation Legacy and Conservation Dependence are both Medium. Looking to the future, there is some probability that a stochastic event (in this case, a fire) could drive the species to extinction within 20 years; therefore, all future scenarios include the possibility of extinction. In light of this, the Conservation Gain is Indeterminate. Because the population currently fluctuates around carrying capacity, it is unlikely that the species could increase to much higher levels, but in the long term, if there was evidence that the species was not declining and that all non-stochastic threats were not operating, the species may yet be considered Fully Recovered. However, the threat of stochastic extinction makes the Recovery Potential for this species Indeterminate.

Painted Tree-rat (Callistomys pictus) – Largely Depleted GSS

This Endangered species is endemic to the Atlantic Forest in Bahia State, Brazil. It has a Green Status of Species Recovery Score of 25% (Largely Depleted), reflecting its high extinction risk and low ecological functionality in the sole unit of its indigenous range. Most of the 11 known records are near protected areas, suggesting some benefit from habitat protection. While limited data prevent firm conclusions, conservation may have prevented extinction. The species’ presence in cacao plantations indicates some tolerance to agroforestry, so Conservation Legacy is assessed as Low.

If current protections continue, the species is likely to persist in its present state. Its occurrence in cacao plantations may make it vulnerable to fluctuations in land use driven by market forces. However, a worsening of status is unlikely without major loss of range, which is already likely underestimated. Nine municipalities have been identified for future surveys (Sanchez et al. 2025). Based on these considerations, Conservation Gain is also assessed as Low.

Without protected areas, habitat loss – especially from oil palm expansion – would likely increase. While the species might persist in oil palm to some extent (Sanchez et al. 2025), range contraction would likely occur, but not enough to cause a status decline within 10 years. Conservation Dependence is thus assessed as Zero.

Due to sparse data, true distribution and population size remain unclear. While recovery may not be feasible under worst-case assumptions, improving habitat connectivity, incentivising sustainable cacao, and enhanced monitoring could support range expansion and halt declines, potentially improving the status to Least Concern. Therefore, Recovery Potential is Medium.

A huge thanks to SMSG Intern Salomé for her work to get this species drafted and published.

The SMSG team welcomed Ivy Johnson for a summer internship focussing on Red Listing of some newly described species, reassessments, and creating maps for the extinct species on the list! Hear from Ivy below:

SMSG Intern Ivy Johnson

“I’ve been doing a six week summer internship with the IUCN SSC Small Mammal Specialist Group, working on preparing drafts of Red List assessments with Ros Kennerley. It’s been really interesting to see how even with one or two sources an accurate assessment can be drawn up, allowing a species to be represented on the Red List.
My favourite species that I’ve worked on have been these woolly flying squirrels from the Himalayas and the Tibetan Plateau – they’re really big gliding squirrels and they’re genuinely the cutest thing (as well as some of them being under threat, and generally not well understood with more research being needed). I also did the draft assessment for the brown rat (Rattus norvegicus) though, and found it really rewarding to be able to update the maps for it.
I’ve just finished my first year studying Biology at university, and whilst I’m open to changing my mind, I’m hoping to end up in conservation. I think it’s a really interesting subject whilst also being worthwhile – not just considering the foundational science but the practical implications of biology in the modern world in order to benefit the global ecosystem.

It’s been a really interesting internship – and a massive thanks goes to Ros for organising everything, and correcting all my mistakes!“

Some of the species that Ivy has been working on are:

The newly described Fansipan Shrew Mole 

The newly described Woolly Flying Squirrels

Various Extinct small mammals in the Caribbean

The SMSG team welcomes Ashlynn Stout for a summer internship focussing on the Green Status of Species! Ashlynn is based at the Global Center for Species Survival at Indianapolis Zoo. Hear from Ashlynn below:

GSS intern Ashlynn Stout

“I am taking part in a three-month summer internship with the Global Center for Species Survival at the Indianapolis Zoo. This opportunity was made available to me through Butler University, where I will be going into my third year, and its Office of Sustainability. Butler has a fantastic interdisciplinary program for liberal arts, and I major in environmental studies with a minor in ethics. Alongside school, I also volunteer with the Indiana White River Alliance’s River Assessment Field Team, where we test local river streams for water quality. I am passionate about the environment, sustainability, and now conservation because of this internship!

I am working as an intern under Justin Birkhoff, one of the conservation experts at the Global Center for Species Survival. My project is to conduct Green Status of Species assessments for two small mammals, the Salt-marsh Harvest Mouse and the Western European Hedgehog. At the start of my internship, I took the Red List and Green Status trainings through the IUCN to establish my understanding of the Green status process. I have been conducting literature reviews and research to fill out the online workbooks that take me through the Green Status assessments step by step.

One of the coolest parts of this experience is having meetings with conservation experts from all over the world, like the United Kingdom. Additionally, communicating with the species experts directly and asking them questions about their research has been a highlight. My career goals are broad, as I am hoping to do anything in the environmental field that relates to sustainability, conservation, and nature. I am making invaluable connections during this experience, and I am incredibly grateful for the opportunity!”

Western European Hedgehog

We are sad to announce that Abi has left the role of Programme Officer for the IUCN SSC Small Mammal Specialist Group. 

Abi has been in post since May 2022 and was based at Durrell Wildlife Conservation Trust.

Abi is moving on to a full-time position as an Ecologist for a local authority in the UK, but we are delighted to say that she will be staying on as a member of the group and will continue to contribute to a couple of different projects.

On April 27, 2025 a contingent of three Ukrainian scientists from the Kyiv Zoo arrived in San Diego for a study tour with the San Diego Zoo Wildlife Alliance. The Ukrainians have been involved in the conservation breeding and reintroduction of the now Critically Endangered European Hamster (Cricetus cricetus) into the steppe region of Ukraine. The project is led by Dr. Mikhail Rusin of the Kyiv Zoo, also a SMSG member. As a supporter of this program, Zoo New England (ZNE) requested and received a grant from the foundation Trust for Mutual Understanding to provide the scientists from this war-torn country a chance to learn from one of the world’s best captive breeding and reintroduction team.

Kyiv Zoo team and Zoo New England facilitator at San Diego Zoo

The Ukrainian team was supported by Peter Zahler of ZNE, also a SMSG member, and hosted by Dr. Debra Shier, who is the Alliance’s Brown Endowed Associate Director of Recovery Ecology. Dr. Shier and her group work on a number of small mammal translocations, including a very successful Stephen’s Kangaroo Rat (Dipodomys stephensi) program and the program the Ukrainians observed during their visit, on the Pacific Pocket Mouse (Perognathus longimembris pacificus). These tiny mice, the smallest in North America, were thought extinct until a small population was discovered in the 1990s. They currently can be found in only three sites, and probably still number only about 200 animals along the coast of southern California.

Over the next nine days, the Ukrainians were provided with both presentations and hands-on opportunities to learn cutting-edge methods in husbandry, breeding decisions, hormone trials, genetic studies, health assessments, and data management protocols. They also learned about the complex decision-making that goes into identifying potential release sites. Finally, they learned about behavioural competency conditioning for the mice to prepare them for life in the wild, including predator avoidance, shelter use, and foraging.

The team also went into the field to help with a “soft release” of 50 Pacific pocket mice into small cages out in the coastal scrub, helped with vegetation surveys, and finally went out to remove the “soft release” cages and free what might well be 20% of the wild population of this highly threatened small mammal. They have since returned to Ukraine where they will attempt to put what they’ve learned into practice for the European hamster initiative.

The reintroduction site, the Ukrainian team conducting fieldwork in the coastal sage scrub (middle) and a “soft-release” trap where the mice spend a week getting used to being outdoors (right).

This month, after 13 years in the role, Tom is stepping down as the Co-Chair of the IUCN SSC Small Mammal Specialist Group (SMSG). Here we look at some of the huge contributions and achievements Tom has made to the group over this period.

Tom replaced Don Wilson as the co-chair of the newly formed SMSG back in 2012, with his focus on developing small mammal work across the Americas. He served as co-chair first with Rich Young and more recently with Ros Kennerley. During his time as Co-Chair, Tom was a professor at Texas A&M University (TAMU), until his retirement a few years ago. Through academic connections and teams of students at TAMU, he oversaw the previous Global Mammal Assessment for the Americas.

Since his retirement from TAMU, Tom has been able to assist in the renewal of the Red List Partnership between TAMU and the SSC and promoted strong continued interest in the SMSG as well as assessment activities more widely, among faculty, staff, and administrators. The university has also renewed an agreement that Tom had previously negotiated with Re:wild to enhance capacity for both Red List and Green Status assessments.

In addition to his work for the SMSG, Tom has had many other engagements with the wider SSC activities. He first became engaged with the SSC when he was Executive Director of the Center for Applied Biodiversity Science at Conservation International in the early 2000s. He helped organise the funding of both the SSC Chair position (at the time Holly Dublin) as well as the first GMA (then under Simon Stuart) – so it has been nearly a quarter century of engagement! Tom also served on the Red List Committee from 2010 to 2023.

Innsbruck / Garmisch-Partenkirchen, March 2025 — A new cross-border initiative has been launched to protect one of Europe’s rarest mammals, the Bavarian Pine Vole (Microtus bavaricus). The Alpenzoo Innsbruck-Tirol (Austria) and the Bavarian Environment Agency (Germany) have officially joined forces in a landmark conservation project to secure the future of this species. During a ceremonial event, the two partner institutions signed an agreement for a transboundary initiative dedicated to protecting this vole.

The Bavarian Pine Vole was first discovered in 1962 near Garmisch-Partenkirchen (Bavaria, Germany). Considered extinct after decades of absence, it was rediscovered in Mittenwald in 2023 by the Bird Protection Agency Garmisch-Partenkirchen at the Bavarian Environment Agency. Until then, the only known population occurred in North Tyrol (Austria), near the Alpenzoo. With an extremely limited range and very small population, the species is classified as Critically Endangered (CR) on the Austrian Red List and as Extinct / Lost on the German Red List.

At the heart of the conservation effort is the EUREGIO Zugspitze-Wetterstein-Karwendel region, which includes vital habitats for the vole. Funded 75% by the EU’s Interreg Bavaria-Austria 2021–2027 program, with additional support from the Alpenzoo, the project’s measures to protect the Bavarian Pine Vole include:

• monitoring of populations in Bavaria and Tyrol,
• conservation of the species and preservation and management of its habitats, and
• public awareness campaigns and environmental education about this unique alpine species.

The project also contributes to establishing an IUCN Centre for Species Survival at the Alpenzoo to ensure long-term preservation of endangered small mammals and alpine species. This aspect is implemented in collaboration with the IUCN Small Mammal Specialist Group.

The Alpenzoo and the Bavarian Environment Agency are jointly committed to preserving this rare species. Dr. André Stadler, Director of the Alpenzoo, emphasized the importance of cross-border cooperation:

“This project is a prime example of species and habitat conservation across borders. Together, we can save an endangered species that hardly anyone knows about—but is a vital part of our alpine biodiversity.”

Sabrina Blandau, Managing Director of EUREGIO Zugspitze-Wetterstein-Karwendel, added:

“We are proud to support this unique project through the Interreg program. It’s a meaningful way to contribute to species and nature conservation in the European Alps.”

This agreement signals a hopeful future for the Bavarian Pine Vole—and a stronger commitment to biodiversity conservation in Europe’s alpine region.

Persons present at the event:

Günther Platter, President of the Alpenzoo Innsbruck-Tirol Association

Dr. André Stadler, Direktor of the Alpenzoo Innsbruck-Tirol

Dr. Nora Weyer, Conservation Officer at the Alpenzoo’s Centre for Species Survival

Dr. Simon Ripperger, Scientific Expert, Bavarian Environment Agency

Sabrina Blandau, CEO of EUREGIO Zugspitze – Wetterstein – Karwendel (EZWK)

Simon Damerow, Regional Management of EZWK Innsbruck-Land

Today, 4th April, is World Rat Day, so what better day to celebrate some of the world’s most diverse and fascinating mammals? 

The first thing that springs to mind with the word “rat” might be the widespread and recognisable Brown Rat (Rattus norvegicus). In actual fact, “rat” is a broad term that has been used to describe hundreds of species of muroid rodents. The name “rat” typically covers the true rats of the Rattini tribe (including, for example, species of the Rattus genus), but has also been used in common names for groups such as the kangaroo, mosaic-tailed, spiny, mole and rabbit rats.  

Native rats play key roles in ecosystems everywhere. They are scatter-hoarders, scavengers, burrowers, predators, and prey. However, lacking the obvious characteristics of larger flagship mammals, most rats are completely overlooked and underrepresented in the media, as well as in funding, conservation and research.  

Below, we are spotlighting some of these remarkable yet at-risk rats.