A new study put numbers to a longstanding imbalance in science: Many of the mammals discovered in poorer countries are still being physically archived in richer ones.
The official record of biodiversity helps determine who has access to knowledge, research opportunities, and influence over conservation, Phys.org reported.
Here's what to know
For mammal species identified since 1990, the researchers found a consistent split between where animals come from and where the defining specimens end up: most are from the Global South, but many of those specimens are stored in Europe and North America.
Looking at 1,116 mammal species described from 1990 through 2025, the team tracked where each holotype — the specimen that anchors a species' scientific description — is kept.
Their dataset showed that 95% of the species are native to the Global South, spanning Latin America, Africa, Asia, and the Caribbean, but 60% of those reference specimens are in wealthier Global North countries.
The study first appeared in the journal npj Biodiversity.
TCD Picks » Quince Spotlight
💡These best-sellers from Quince deliver affordable, sustainable luxury for all
Species native to the north showed a much weaker version of the same pattern. Only 22% had holotypes stored outside their country of origin, and those specimens still remained within the same broader geopolitical sphere.
Mario Moura, a professor at the Federal University of Paraíba and the study's first author, said even he did not expect the mammal figures to be this high, especially compared with other animal groups.
More background
A holotype is not just another museum specimen.
It is the benchmark scientists return to when confirming what a species is, comparing close relatives, and building the evidence base for conservation decisions.
When that benchmark is housed overseas, researchers in the country where the animal was found can encounter additional hurdles in studying it directly.
That can hinder training, limit the development of local museums, and reduce the ability of nearby institutions to lead work on their own biodiversity — even though the species originates in their ecosystems and may affect their communities.
Storage patterns also differed sharply by region.
Among mammal holotypes housed in the Global North, more than 90% were collected somewhere else. In the Global South, fewer than 8% were kept in a country other than the one where they were collected.
Compared with other vertebrate groups, mammals stood out.
The paper cited lower out-of-country holotype rates for freshwater fish and reptiles — 30% for fish species described after 2000 and 50% for reptiles described after 1990 — while mammals showed a larger imbalance.
That disparity informs concerns about scientific neocolonialism in the work of documenting biodiversity and guiding protection efforts.
What can be done?
One target for reform is where new holotypes are deposited.
Universities, museums, journals, and funding bodies can push for specimens to remain in their country of origin whenever possible, especially when qualified local institutions exist or can be supported.
That also requires investing in museum collections, storage, curation, and taxonomic training in biodiversity-rich countries.
Keeping specimens local is not just symbolic; it can strengthen scientific capacity, create educational opportunities, and allow national and regional institutions to play a larger role in decisions about wildlife protection.
International collaboration still matters, but the study highlights the need for more equitable partnerships. Shared authorship, local leadership, and sustained support for institutions in the Global South could help shift the balance from extraction toward collaboration.
Digital records can help widen access, too, but they do not replace the importance of having a physical specimen nearby for close study.
For communities living alongside threatened habitats, better local access to biodiversity evidence can support faster, more grounded conservation action.
"The mammal figures surprised us. Even though early colonists collected biological material from their former colonies, we didn't expect to see such high numbers in recent decades," Moura observed.
"The problem of scientific neocolonialism is more pronounced in mammals than in other animal groups," he added.
Where can I learn more?
These articles are not about holotypes or museum collections, but they emphasize why access to biodiversity knowledge matters when a species is documented.
They follow what happens in the field after that: mammals changing behavior under climate pressure, species rebounding with long-term protection, and conservation efforts showing measurable results.
• In Iran, scientists observed an alarming behavioral shift as large mammals adjusted their migration routes.
• In the UK, ecologists found something they didn't expect in water vole behavior.
• At Charles Darwin University, researchers identified 26 species recovered from the brink of extinction.
• Cambridge researchers observed a strong signal that conservation works against extinction.
The broader point is that the scientific record does more than name species — it helps determine who can track change, steer recovery efforts, and respond when ecosystems shift.
Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.
