By Chelsea Jandreau, Nature Educator
The mammalian group gives us some of the most well-known, large, charismatic animals out there. They are fuzzy and cute, and on average have a larger body size than many other animals. If I asked you, without any context, to make a list of animals that live in the habitats closest to you, what would you come up with first? There are a few who will start off with birds or bugs, but for many people that list begins with deer, foxes, bears and other large mammals.
However, by the numbers, over half of those are actually rodents or bats, and neither of those are words that tend to inspire the cute, cuddly feelings we have with other mammals. If we are looking at it from a species level, around 40% of mammalian species are considered rodents and another 20% of species make up Chiroptera, the bat group.
Because the word rodent is often associated with pests, mice and rats are a pretty common image that comes to mind, but there are over 2,000 species of rodents in the world. Start looking up animals classified as rodents, and you will soon find that the vast number of species allow for some unexpected and interesting adaptations and species that may be overlooked.
We are just past Groundhog Day, where it seems that the Groundhog Punxsutawney Phil did not see his shadow this year, predicting an early spring. The sunny weather as I write this certainly seems to agree, but we will see what the next couple of months bring. That popular Groundhog is technically a rodent. Yesterday, I sat and watched a chipmunk emerging from its underground burrow to look for food. Chipmunks and squirrels? They’re also rodents. Other rodents, such as guinea pigs, chinchillas and hamsters, are popular as pets.
Rodents come in all shapes and sizes, and they are found in biomes across the globe, all the way from South America’s three-and-a-half-foot long Capybara to the smallest African Pygmy Mouse. So with such impressive diversity, how did these animals end up lumped together?
Scientists group organisms based on a shared group of physical, behavioral and genetic characteristics. All animals, not just mammals, are classified into a hierarchy of groups with increasing specificity. One of these groups in the middle is called an order. Within these orders are a variety of families which are further divided into genus and finally species. The order Rodentia is a group of mammals including mice, beavers, squirrels, porcupines, guinea pigs and others.
The common denominator in this group lies with their teeth. Rodents have four large front teeth, two on bottom and two on top, called incisors. These are used for gnawing and chewing. After all, mice and squirrels are considered pests when they take up residence in houses for a reason. They usually have some sort of protective enamel covering the front of the teeth to strengthen them. This is even more important when you learn that rodents need to gnaw on things in order to wear down these incisors, which will continue to grow throughout their entire life. Many rodents have magnesium in the enamel. Beavers have iron instead to help with their heavy duty gnawing, which is why their front teeth are orange on the outside.
Although there are some other general similarities, there are also countless ways these rodents are different. Flying squirrels can glide between branches with an extra flap on skin between their front and back legs. Porcupines have quills all over their body for protection. Jerboas and jumping mice have the body of your average mouse, but the way they move is more similar to a kangaroo. They use their long, powerful back legs to jump great distances and hop along.
Most of these small mammals fill important niches in their habitats as a mechanism for seed dispersal as they collect, transport and store food for winter, in addition to being a food source for many larger predators. Beavers transform landscapes, creating wetland habitats for themselves and other organisms. Many rodents burrow, making tunnels that will be used by other wildlife.
Some rodents, such as your general house mouse and the Norway Rat, have adapted well to changing landscapes and urbanization. There are places, usually islands, where rats have been introduced as a non-native species and are in turn, wreaking havoc on those ecosystems. However, this is not the case for most rodents, especially ones that struggle to survive in spaces dominated by humans. Many species are threatened or endangered for the same reasons as their more charismatic animal counterparts. Habitat loss, pollution and non-native predators such as cats all impact their populations. For others, there simply isn’t enough information or research to determine a status at all.
Rodents are not particularly glamorous and don’t often inspire the same interest or level of care as many other animals. They are never going to be the face of any conservation organization or fund, and I absolutely understand your desire to keep them out of your home. Despite all of this, rodents are still important parts of most terrestrial ecosystems and food chains around the world, so just maybe this underappreciated group deserves a second look and another chance.
Audubon Community Nature Center builds and nurtures connections between people and nature. ACNC is located just east of Route 62 between Warren and Jamestown. The trails are open from dawn to dusk. The Nature Center is open from 10 a.m. until 4:30 p.m. daily except Sunday when it opens at 1 p.m. More information can be found online at auduboncnc.org or by calling (716) 569-2345.
To learn more about rodents and other mammals in New York, go to chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://extapps.dec.ny.gov/docs/administration_pdf/mammals2.pdf
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