Beyond their dam-constructing skills, beavers are intelligent, territorial, and tough. From their iron-layered teeth to the way they mark their territories, their influence on wildlife and even human populations is undeniable. They create habitats that support multiple species, improve water quality, and prevent floods. Discover five of their unique features below.
1. Beavers are Ecosystem Engineers
They’re cute and adorable and they’re often used as symbols for engineering. But how much do we actually know about how important beavers are for nature? While they certainly build and maintain dams and wetlands, their contributions extend far beyond this. They can even prevent floods. It’s estimated that in heavy floods in England, beavers reduced the extent of damage by up to thirty percent, demonstrating how amazing their architecture can be for sustaining life in general.
In North America, the dams they build positively influence salmon populations. The underwater channels they construct provide shelter for salmon fry, protecting them against potential predators. Their contributions are so esteemed in these ecosystems that, in California and Oregon, scientists are constructing man-made dams modeled after beavers’ designs. They do this to ensure salmon have a chance to thrive and reproduce properly.
The wetlands created by beavers also support wild bird populations. Wild ducks, swans, and some species of songbirds use beaver-made wetlands for breeding. In other words, if beavers were to disappear, their absence would significantly impact not only wildlife but also some human populations affected by flooding.
2. Beavers Have Ever-Growing Iron Teeth
Beavers belong to the rodent group, so their teeth never stop growing. This unique feature drives their constant chewing, a trait they share with other rodents such as rabbits and guinea pigs. However, what makes a beaver’s teeth truly unique is the layer of iron in their tooth enamel. This layer provides exceptional mechanical resistance against wear and tear, as well as acid resistance. It’s also what makes their teeth orange.
Even when they come in contact with contaminants, a beaver’s teeth last far longer than those of other animal species. The fact that their teeth grow continuously is what makes beavers build dams in the first place. If they were to allow their teeth to grow unchecked without daily chewing, the overgrowth would lead to potential health issues caused by their feeding ability being impeded.
3. Beavers Can Stay Underwater for Extended Periods
Believe it or not, beavers can hold their breath for up to fifteen minutes at a time. Not only is this capacity unique in itself, but they can also slow down their heart rate while staying underwater to evade predators. Their high muscle oxygen myoglobin concentration allows for additional oxygen storage, which can be relied on in times of need or stress.
Not only are they physiologically equipped to hold their breaths for longer periods of time, but they are also anatomically engineered to do so. Beavers have valvular nostrils that prevent water from entering their noses and ears when they submerge. Furthermore, their lips close perfectly behind their teeth, allowing them to gnaw underwater while keeping their breath and making it impossible for them to swallow any water at the same time.
4. Beavers Have Transparent Eyelids
It’s not uncommon for animals to have a nictitating membrane, which is the additional transparent eyelid we’re discussing in this section. Some birds – such as eagles and barn owls, fish (bony species like sharks), amphibians (like American toads), and mammals (like cats and polar bears) are all equipped with this special eyelid.
Besides protecting the eye against environmental pollutants and lubricating the cornea, this additional layer cleans the eyeball and maintains partial vision. In most animals, it’s not as effective for vision as we might think. For instance, cats can’t see well when their eyes are covered by the nictitating membrane.
But beavers have a special type of eye membrane, allowing them to use it almost like a pair of goggles in the water. The layer is entirely translucent, meaning that beavers can forage, engage in their regular construction activities, as well as navigate bodies of water almost as if they were keeping their eyes open. They have even better navigational abilities thanks to their whiskers, which allow them to assess distances, various objects, and potential dangers.
5. Beavers Communicate Using Scent Marking
Like many other species, beavers use scent to communicate with each other and establish their territories. They are particularly territorial and will defend the space they’ve marked, sometimes with lethal consequences. Scent marking is important not just to tell other male beavers that the territory is occupied and that unless they want trouble, they should stay away. Scent marking is also paramount for reproduction, attracting potential mates.
But how do beavers even use scent marking in the first place? We might think that they do it the way cats spray when they’re in heat – here, there, everywhere. But nothing could be farther from the truth. They go to extended lengths to create scent mounds, which are little hills of leaves, sticks, and other debris from the forest, on top of which they lay a generous amount of castoreum secretion.
Castoreum is a yellow-tinted secretion produced in their castor sacs (a special kind of anal glands), located near the base of the tail. Mixed with urine, it has a pungent smell that should tell other animals (other beavers included) who the laird of the land is. It has such a unique, musky smell that companies have even used it in commercial perfumes.
