I stumbled across this beautiful bit of beaver writing by Kathleen Kudlinski for the New Haven Register in CT the other day and thought you would enjoy it too. I was going to just post excepts to whet your appetite, but its so delightful I decided to post the whole thing. As compensation for my thievery you must click on the charming illustration above and go to the website so their statistics record visitors to her article. I like her writing and appreciation very much, but there are 6 or 7 secret things that we know about beavers that she apparently does not. Lets see if you can guess what they are.
The beaver slid off a bank this week, surfacing nearby to stare at us. We stared back, breathless. A midafternoon sighting of this nocturnal animal1 seemed magical and fleeting. Except that this beaver did not flee. He swam around in front of his lodge, eyeing us. Were we dangerous? Apparently not2. He slapped his broad scaly tail against the water and waited to see if we would flee. We did not. He slapped again. Clearly, we’d interrupted some important beaver business.
His mate would be waiting inside the stick-and-mud lodge they’d built together years ago. Beavers mate for life at 3 and live up to 29 years3. That means this whiskery old guy may have been living in beaver bliss with his darlin’ for over 20 years. Like all beaver parents, they’ll have two or three nearly grown offspring under their roof. Ma beaver had a litter of kits in early spring, while the big, old yearlings stayed on for a while to help with the new young’uns, and then moved out this summer to start new lodges of their own.
The beaver slapped again. Sunshine glittered on his wet fur, his bristly whiskers and the fresh mud he’d slathered onto his lodge. In winter, that mud freezes and will form a great barrier to keep coyotes, foxes, dogs and bears from digging them out. These predators could never reach the beaver’s front door, a hidden underwater entrance leading to a dark, dry den a yard or so across.
The sun could shine on this pond because, over the years, this enterprising couple had gnawed through dozens and dozens of trees, punching a hole in the forest canopy, their massive, ever-growing rodent teeth working like living chainsaws. Saplings fall with a nip or two. We’ve seen these beavers drop two or three medium-size trees in a night. A maple, 16 inches across, is nearly chewed through next to their pond. We took care not to stand underneath it.
Once the beavers fell a maple, birch, willow, aspen, poplar or other fast-growing tree, they strip the bark off. They’re only after the tender, nutritious cambium layer between bark and wood. This time of year, they may eat water lily tubers, clover, apples and the leaves, but their main course is always cambium4. To keep at fighting weight, 40 pounds5, beavers have to fell many trees just to stay alive. Not one stick of wood goes to waste after it is stripped clean. It is all used in dam- building and maintenance, lodge construction and improvements, or stocking in an underwater cache for midwinter snacking.
All of this busy-beaver activity makes them a keystone species in the ecosystem. A beaver colony changes a moderately productive woodland into a sunny wetland, bursting with life. The beavers’ work supports thousands of species of mammals, fish, turtles, frogs, birds, ducks, dragonflies and a myriad of water insects and invertebrates. Almost half of endangered and threatened species in North America rely upon wetlands, and so do we.
The beavers’ multiple dams slow water flow and absorb excess floodwaters, prevent erosion and raise the local water table. Several feet of silt build up behind old beaver dams. When polluted water trickles through this fine mud, particulates are strained out. Toxins, like pesticides, are broken down by bacterial action or simply the slow trickle of time. Water is far cleaner after it goes through this natural treatment plant.
Once 60 million beavers reported to work in North America. They were hunted and trapped for their glossy brown fur, but that’s not all. We hardly notice the territory-marking scent of a beaver, but two special properties made it sought after. The smell of this “castoreum” is especially long lasting, so perfumers use it as a base ingredient in their products. Also, for some reason, beavers concentrate one chemical, salicin, from willow trees, which is transformed into salicylic acid.
Today, we know that chemical as aspirin, but Native Americans and early settlers sought it for fighting pain?, lowering fever and reducing inflammation. But it was competition that nearly did the beavers in6. We like our land dry for farming and development. Beavers like it wet. They lost. We nearly drove them to extinction by the early 1800s. Now, beavers are on the rebound. There’s nearly 14 million in the United States today. Mostly, that’s because we’ve learned to live with them.
The cranky old beaver slapped his tail one last time at us this past week. We decided to retreat to our cabin. A quick glance back through binoculars showed him already at work again, getting the place in shape for the winter ahead.
Contact Guilford naturalist Kathleen Kudlinski at kathkud@aol.com, or write her in care of the Register, 40 Sargent Drive, New Haven 06511. She is the author of 39 children’s books, including, “Boy Were We Wrong About the Solar System!”
Well that was a lovely glance at the value of a keystone species and the value of that moment in busy human life where we stop and consider the natural world. Thanks Kathleen for reminding us that beavers have a huge impact on their environment and are fun to watch! As a woman whose been seeing the Martinez Beavers four times a week for the past four years I have some additions/corrections I hope you won’d…
1 Nocturnal Animal: Early trapping records often describe beavers ‘sunning themselves on their lodges’ , which they mostly don’t do any more! It is also noted that beavers lack tapetum lucidum (light gathering crystals in the eyes) and it is generally thought that this means they weren’t ORIGINALLY nocturnal, but adapted their secretive habits when we hunted them pretty ruthlessly for 400 years.
2 Apparently We weren’t Dangerous: You were certainly dangerous enough to warn the rest of the colony about because the beaver was slapping his tail. There were others and youngsters likely near by that s/he was sending a warning message to.
3 Beavers live for 29 years: Well its better than the bizarre botanist who told our paper that beavers bred for 50 years, but just barely.Animal Ageing and Longevity Database genomics senescence info/species is just over 23 years. Beaver rehab-ers say the record in captivity is 19, and I bet 15 years is a very long life for a beaver in the wild.
4 Beavers diet depends on Cambium: Not true. Beaver in the Delta survive on tules and cattails-they have no trees at all. Young beavers eat leaves and twigs. We constantly see our beavers eat blackberry, fennel, thistle and even grass. Check out Bob Armstrong’s lovely photos of varietal feeding in his “Beavers of Mendenhall Glacier” book.
5 Adult Beaver Weigh 40 LBS: You have short-changed beavers by about 30%. This is the ‘drivers-license weight’ of adult beavers, brimming with delicate inacuracies. Our father beaver is easily 65 lbs, probably more. Mother beaver when she died had lost a great deal of weight and weighed 34 lbs. It is true that regions where it freezes wind up with skinnier beavers, simply because there is a necessary fasting that always comes at the end of a frozen winter and meager food supplies. But beavers have big jobs. And they are big. Think Labrador.
? Beavers were killed for pain killers: Well now, as a woman whose spent a year reading trapping accounts I have to say that I don’t know on that one. It is clear that they were nearly wiped out for FUR FUR FUR, and their castoreum was used to bait traps so they could get more FUR FUR FUR. I know natives made willow bark tea for pain and cramps, but whether there was some use of beaver as a ‘middle man’ in the production of salicin I do not know. I believe I found the reference cited on wikipedia to which you are referring, but I don’t see any actual data to back it up. I’ll keep asking around my fur trade buddies and get back to you on that.
6 Competition for Farm Land Did Beavers In: Sadly I know that’s wrong, because by the time farmers were staking land in the west, beavers were pretty much exterminated, at least in California. Did you know that in 1910 the were only 7 known colonies of beavers left in the entire state? I wonder what Connecticut was like then. The more likely sequence went Missionaries:Fur: Russians: Fur: Canadians:Fur: Americans:Fur: Gold:Fur:Farmland: No more Fur.By the time mines were sending silt down every river in California beavers were pretty much a thing of the past in most areas.
