State of Mammals in the World

Mammals are a diverse and fascinating class of vertebrate animals that include humans, other primates, rodents, bats, whales, and more. There are over 6,400 known species of mammals in the world today. This article will provide an overview of the number and diversity of mammal species worldwide, the threats they face, and ways to protect them.

The largest orders of mammals are rodents and bats. Rodents make up 40% of all mammal species, with over 2,500 species including mice, rats, squirrels, porcupines, and more. Bats are the second most diverse order, with over 1,200 species.

The country with the most mammal species is Brazil, which has over 727 species. Indonesia, Mexico, and Colombia also have high mammal diversity with over 500 species each.

Over the past several centuries, dozens of mammal species have gone extinct. Currently, over 25% of the world’s mammal species are threatened with extinction according to the IUCN Red List. Habitat loss, hunting, climate change, and pollution are the biggest threats.

Number of Mammal Species

Scientists have described 6,495 species of mammals as of 2022. New mammal species continue to be discovered every year, especially small mammals like rodents and bats. However, the rate of new mammal discoveries has declined in recent decades.

The peak rate of new mammal discoveries occurred in the 19th century. Over 2,000 new species were described between 1801 and 1900. Discovery rates began dropping in the 20th century as most large mammal species had already been documented. Between 2000 and 2009, just 211 new mammals were described.

While thousands of mammals remain undiscovered, especially in remote jungles and forests, scientists believe the majority of large mammal species have now been documented. Any new species are likely to be small mammals that are difficult to find and identify.

Largest Orders of Mammals

Rodents are the most diverse and numerous order of mammals. There are 2,578 known rodent species, representing around 40% of all mammal diversity. Rodents include mice, rats, squirrels, porcupines, beavers, guinea pigs, and many more. They inhabit all continents except Antarctica.

Bats are the second largest order with 1,232 known species. There are two suborders of bats – megabats and microbats. Megabats eat fruit and live in tropical and subtropical regions. Microbats use echolocation to find prey and live everywhere except polar regions.

After rodents and bats, the next largest mammal orders are:

• Primates (lemurs, monkeys, apes) – 706 species
• Even-toed ungulates (cows, sheep, deer) – 750 species
• Carnivorans (cats, dogs, bears) – 286 species

A country with the Most Mammal Species

Brazil has the greatest diversity of mammal species, with over 727 documented. Brazil encompasses a massive area of South America, including the Amazon rainforest. This tropical ecosystem supports an incredible array of mammals.

After Brazil, the countries with the next highest mammal diversity are:

• Indonesia – 615 species
• Mexico – 564 species
• Colombia – 518 species
• Peru – 517 species

Indonesia, Mexico, and Colombia also contain tropical forests and high biodiversity. Meanwhile, arid and desert environments support fewer mammal species overall. For example, Canada is home to just 200 mammal species.

Changing Number of Mammal Species

The number of recognized mammal species has increased over time as new discoveries are made. However, in the past 500 years, dozens of mammal species have also gone extinct due to human activities.

In 1500 AD, there were an estimated 5,000-7,000 mammal species globally. Since then, at least 79 species have become extinct including iconic mammals like the thylacine, Atlas bear, and Steller’s sea cow. The extinction rate has increased dramatically in the past 200 years.

Meanwhile, thousands of new mammals have been discovered in the modern era. European colonization of Africa, Asia, and the Americas led to a flood of new mammal descriptions. The 1800s alone saw over 2,000 new species documented.

The next big jump in species counts occurred in the early 1990s, when genetic analysis led to splitting some groups like rhinoceros and bears into multiple species. Recently, most new discoveries have been of small mammals.

Threatened Mammal Species

According to the IUCN Red List, over 1,600 mammal species are threatened with extinction. This represents 25% of all known mammal diversity. The major threats endangering mammals are:

• Habitat loss: Logging, agriculture, development, and urbanization destroy forest and grassland habitats vital for most mammals.
• Hunting: Mammals are hunted for meat, traditional medicine, and the pet trade. Larger species with tusks, horns, or fur are especially targeted.
• Climate change: Global warming causes habitat shifts, droughts, storms, and fires that can wipe out small mammal populations.
• Pollution: Toxins, plastics, and waste harm mammals through ingestion, entanglement, and contamination of food and water sources.
• Disease: New pathogens spread by invasive species can devastate native mammal populations with no immunity.

Vulnerable and endangered mammal species span all continents. Some examples include orangutans, snow leopards, giant pandas, black rhinos, vaquitas, mountain gorillas, monarch butterflies, and right whales. Immediate conservation is needed to prevent further mammal extinctions.

How to Protect Mammals

There are a variety of conservation strategies that can be implemented to protect threatened mammals and their habitats:

• Establish protected areas like national parks to safeguard habitats from destruction and overhunting. Patrol these areas to enforce protections.
• Implement sustainable forestry practices like reduced logging rotations and thinning to minimize habitat disturbance.
• Control invasive species that compete with native mammals for resources and bring new diseases.
• Enforce hunting regulations and poaching bans, especially for endangered species killed for the wildlife trade.
• Require environmental impact assessments for developments to mitigate habitat damage.
• Make buildings “mammal friendly” by turning off lights during migrations and using high frequency sounds to deter roosting.
• Fund conservation breeding programs for critically endangered species to boost populations.
• Support environmental education to teach the public about mammal conservation and research.

With prompt action, we can preserve mammal biodiversity for generations to come through both habitat protection and species-specific management plans. The fate of the world’s incredible mammals is in our hands.

Conclusion

Mammals are a beloved and integral part of global biodiversity. There are over 6,400 mammal species playing vital ecological roles worldwide. However, habitat loss, hunting, climate change, pollution, and disease threaten over a quarter of all mammal species. Improving habitat connectivity, enhancing legal protections, and funding conservation efforts can help safeguard mammal diversity into the future.

With commitment from governments, scientists, and the public, we can ensure the survival of both iconic mammals and obscure small mammals for years to come. Learn here more about mammals and their lifestyle.

FAQs:

How many species of mammals are there?

There are around 6,500 known species of mammals worldwide. Scientists are continually discovering new species every year, especially small mammals like rodents and bats.

What are the major groups of mammals?

The largest groups of mammals are rodents (around 40% of all species), bats, primates, ungulates (hoofed mammals), and carnivorans (cats, dogs, bears, etc). Marine mammals like whales and seals make up around 130 species.

Which country has the most mammal species?

Brazil has the greatest diversity of mammals with over 727 documented species to date. Other countries with very high mammal diversity include Indonesia, Mexico, Colombia, and Peru.

Are mammals still being discovered?

Yes, new mammal species are still being discovered each year, but at a much slower rate than in centuries past. Most discoveries now are of small mammals like shrews, rats, and bats. Larger undiscovered mammals likely only remain in very remote habitats.

How many mammal species are threatened or endangered?

According to the IUCN Red List, over 1,600 mammal species are currently threatened with extinction. This represents 25% of all known mammal diversity.

What are the major threats facing mammals today?

The biggest threats to mammals are habitat loss, hunting, climate change, pollution, and disease. Deforestation and development destroy habitats while hunting and poaching target mammals for meat, medicine, and other uses.

How can we protect mammal species?

Strategies for protecting mammals include habitat conservation, enforcement of hunting regulations, controlled invasive species, environmental impact mitigation, mammal-friendly building design, breeding programs, and environmental education.

Which mammal species are most at risk?

Critically endangered mammal species include mountain gorillas, vaquitas, Sumatran rhinos, and tiger subspecies. Vulnerable species include pandas, polar bears, orangutans, elephants, and lemurs.

Are extinct mammal species ever coming back?

Extinct species are gone forever, but a few such as mammoths or thylacines could potentially be “de-extincted” using biotechnology in the future. However, the habitat still needs protection for any revived species.