Month: September 2012

The Summer of the Rabid Beavers..

It started at Lake Anna in early summer where two child swimmers were attacked by a beaver and sustained lacerations. The beaver was killed and examined and tested positive for rabies, so the girls started treatment. Last month there was a similar report on the Delaware River in New York south of Philadelphia. A boyscout leader was attacked while swimming and the boyscouts saved his life by stoning the beaver to death with rocks. It also tested positive for rabies.

And yesterday an 83 year old woman swimming in Lake Barcroft was attacked. She was rescued by some local fishermen who beat the animal to death with a paddle – and because your question will be the same as mine – yes it was a beaver. Jon & I saw the orange teeth in the severed parts shown accidentally on the news last night. While it is not uncommon to hear stories about beavers being aggressive to dogs in summer when they are protecting their young, this is obviously different. It is extrememly rare for beavers to be a vector for rabies.

The attack, which occurred about 6 p.m. Tuesday, is the second in Virginia since mid-July, when two sisters swimming in Lake Anna in Spotsylvania County were bitten by a 65-pound beaver. That animal was reportedly shot with a BB gun before being transferred to a lab in Richmond, where it was found to be rabid.

How do beavers contract rabies? Beavers are extremely social, so if one member of a colony has it they probably all do. But how do they contract it in the first place? The old name for rabies is hydrophobia – or fear of water, which is one of the last stages of the disease. I guess if infected animals avoid water, they are less likely to meet beavers, and I suppose that’s why its been so unhead of before now. But obviously it does happen, and beavers do disperse over land and water and can go long distances. And this isn’t really that long, especially if the first beaver to catch the disease from a dog or raccoon in Lake Anna (in the middle) bit his two siblings, one of whom went north to the delaware river and one of whom went south to Lake Barcroft.

The typical way to test for rabies is to slice up the brain of the animal in question, so we obviously don’t do that with humans. In fact we don’t ‘test’ for rabies in humans but just start treating with a series of shots if exposure is reasonably expected. Because the shots tend to be complicated and painful, I assume they are careful about the results.

Last year we had a report in June of a Rabid Beaver attacking three in a Philadelphia Creek which I wrote about here. Obviously within the same general area. So I would imagine the cases are related. I am not at all happy at the idea that this is one more reason to kill beavers, but I suppose, the best possible outcome would be for people to regard beavers with more awareness, and think if something seems unusual to stay away from it, just like you would with a skunk in the daytime, or a skittish dog.

Despite the spate of attacks, the head of a nonprofit organization dedicated to helping people learn about beavers said beaver attacks are extremely rare. Sharon Brown, biologist and director of Beavers: Wetlands & Wildlife, has raised and aided beavers for more than 20 years. She said Wednesday that beavers are peaceful vegetarians who coexist with hordes of other animals living in their habitat and almost never attack humans.

Likewise in an effort to show how rare this occurence is, Mary O’brien of the Grand Canyon Trust forwards this

During 2010, 48 states and Puerto Rico reported 6,154 rabid animals and 2 human rabies cases to the CDC, representing an 8% decrease from the 6,690 rabid animals and 4 human cases reported in 2009. Hawaii and Mississippi did not report any laboratory-confirmed rabid animals during 2010. Approximately 92% of reported rabid animals were wildlife. Relative contributions by the major animal groups were as follows: 2,246 raccoons (36.5%), ,448 skunks (23.5%), 1,430 bats (23.2%), 429 foxes (6.9%), 303 cats (4.9%), 71 cattle (1.1%), and 69 dogs (1.1%). Compared with 2009, number of reported rabid animals decreased across all animal types with the exception of a 1% increase in the number of reported rabid cats.

Is there a moral to this story? I don’t know. I guess don’t let your dog swim with wildlife, but any dog whose behavior is going to be controlled probably doesn’t have rabies anyway. Keep a respectful distance from wildlife? I’m not happy with people using beavers for the new jaws movie, but it’s a fact that beavers are wild animals and all wild animals can be unpredictable at times, and even rabid humans aren’t good to be around, so pay attention!

Ominous Politician (Hinkity Pinkity)

heidi08 Beavers elsewhere, City Reports September 5, 2012

“Sinister Minister”

Ottawa has moved into the lurking stage of beaver management, and defenders of the Paul Lindsay Park Beavers are on the lookout for dastardly deeds. You will remember two adult beavers thoughtlessly moved into a storm water pond and decided to start a family. A panicked city ripped out the lodge that protected the family and the mother and kits have been exposed for several months. The father disappeared, possibly slain or looking for potential habitat in drought-stricken Ottawa and then hit by a car. A potential safe place at a nature reserve was proposed for relocation but this was denied by the local authorities as being ‘out of their jurisdiction’. Apparently there has been a official-looking white- haired stranger at the pond, and Anita has been told they are planning a imminent and clandestine relocation.

Stittsville beaver defenders brace for new fight

OTTAWA — The city is trying for a second year in a row to evict beavers from a Stittsville stormwater pond in a move that would send them to almost certain death, the rodents’ defenders say.

Life has not been good for the furry refugees in the Paul Lindsay Park pond. The city only backed off a plan to trap them last fall after their human defenders warned that “conibear” traps meant to kill the beavers relatively humanely might end up drowning them instead, or could inadvertently catch family pets. Officials were supposed to come up with a broader wildlife strategy before moving in on the beavers again, but that’s still in development.

Now beaver defenders are on the watch and trying to keep an eye on the pond in case there’s a sneak attack. They are hoping to make tshirts to identify themselves and approached us for images. We of course directed them to some fine options and will give them anything they need!

The concern for the beavers’ future is sparked by residents who’ve seen a stranger poking around the pond and asking about the beavers, according to a news release from several wildlife organizations like DuBreuil’s. Anita Utas, a vocal advocate for the beavers, said she’s heard from Christine Hartig of the city’s bylaw department (best known for her years caring for the city’s flock of Royal Swans) that the plan is to move the beavers to somewhere else “local.” There’s a sanctuary west of Algonquin Park that could probably take them safely, DuBreuil said, but that’s likely not what the city has in mind.

I remember what it was like to watch the dams anxiously for city interference and I have nothing but respect for the Ottawa defenders. Lets hope all this sunlight makes the city uncomfortable enough to do the right thing, and bring in someone who knows what they’re doing and knows what it means to move beavers without a lodge a month before winter into a strange location. In the mean time, good luck with your vigil! And keep us posted on the tshirt efforts!

Sharon Brown of Beavers: Wetlands & Wildlife send this photo of husband Owen at Lily’s pond from their recent visit to Ottawa.

Busy Beavers Bulletin

heidi08 Beavers elsewhere, Creative Solutions September 4, 2012

From the “dead spot” to grand central station, it feels like I can’t keep up with the beaver news these past few days.Let’s start with this fantastic headline I saw Sunday:

The nuisance conflict: Can animals and humans peacefully coexist?

No trapping was necessary for the beavers in Adamant, either, after Cory Cheever, the Fish and Wildlife technician, got to work on their dam. Cheever, the beaver specialist, is in his fourth year of an assignment that runs from April to November and takes him all over the state. He installs up to 35 treatments a year, of two kinds: for road culverts and for beaver dams. “They like culverts,” he said, “because the road is their dam.” All they have to do is plug up the aperture, and the pond that’s a key part of their habitat will start to grow. The culvert treatment, on the upstream side, is to install a fence that prevents the beavers from getting in to fill the hole. Simple enough.

How exciting to see this work done at the state level! Mind you this is in Vermont (the home of Skip Lisle who invented the beaver deceiver), so they have a better shot than most at knowing better. I wrote both Skip and Mike excitedly to see if they knew Corey, but neither of them did. That and the fact that they refer to the install as a ‘baffle’ makes me a little cautious. If Cheever wants to install flow devices that work he should talk to the experts and keep talking. But still, I’m just squinting and trying to imagine fish and game paying for flow devices! Nope, can’t do it.

“The reason we do this,” Cheever said of the treatments, “is we want to maintain these habitats where possible.” That’s partly because beaver ponds help sustain dozens of other species.

Very well said! Of course you realize that having a name like Cheever and installing pipes for beaver is just asking for a limerick to be written for you? I’ll try to resist just to praise the excellent decision by Vermont Fish and Wildlife Department to spend a little money solving beaver problems without trapping by protecting habitat for the other fish and wildlife who depend on their dams. Go read the entire article which is all about humane exclusion. Now all I have to do is introduce Corey to a few friends…

Vermont Fish and Wildlife’s, Cheever

Installs flow devices for beaver

Their ponds grant the wishes

Of game, fowl and fishes

And now Adamant’s a believer!

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This was a fun article that rang a nice civic memory bell in my head

South Portal display features beaver

Vince Belleci has answered thousands of questions about beavers and other critters over his 60-plus years as a trapper and wildlife expert. But the question he was asked by a youngster on Wednesday left him temporarily flabbergasted.

“Can they swim without a life preserver?” asked one of the 30 children from the Klamath County’s YMCA preschool program during a presentation at the South Portal Building, where Belleci introduced a display on beavers.

“That was a good question,” he said afterward.

Information about beavers is featured in a display at the South Portal Building at 205 Riverside Drive. Along with rotating displays that the building houses of the Klamath Watershed Partnership, Discover Klamath and the Klamath County Chamber of Commerce.

If the name Belleci sounds familiar to Martinez residents, it should. The Belleci name is one of the old Italian families forever in Martinez. I was very surprised to meet Vince at the beaver conference in Oregon 2011. He introduced himself as a former local with family in town after I presented on the Martinez Beavers. He was there to learn about installing flow devices and live trapping to broaden his skill set. He had heard all about the famous beavers from his family in town and knew all about the story. He was excited by my presentation and to see them first hand. Small, small, small beaver world.

Ginny Monroe, the partnership’s outreach coordinator, said it is hoped school groups of all ages will visit the beaver display, which will remain at the building until November. She and Belleci are part of a Beaver Management Team that was formed three years ago to oversee a 10-year program to manage Klamath Basin beavers. Although Belleci has no firm numbers on the region’s beaver population, he estimates there are about 1,000. One of the team’s goals is to humanely trap and tag problem beavers — those damaging agricultural lands — and relocate them to areas where their dam-building doesn’t cause problems.

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More local news:

Martinez beaver supporter, faithful reader of this website and for years a maintainer of his own, fierce libertarian and resident spelling-nit-picker who oddly once nominated me for Contra Costa woman of the year, has died. I first met George when I accidentally putting a link to ‘my videos’ wrongly on the website. The link was actually for ‘your own videos’ so when he clicked on it he found pictures of his granddaughter on a ‘beaver website’ and was incensed. We eventually solved the mystery and soothed all the feathers, and went on to greener pastures and civic adventures of sorts. It is very sad to report that I received this from his actual granddaughter this morning.

“George passed away on July 7 peacefully in his home in Martinez, CA. He was quite ill before he died but was not in pain. There was no memorial service, per his request.”

There will never be another George Thomas Kysor and memorial service or no – he will not be forgotten. Thanks for the everything.

Heliocentrism and Beavers…

heidi08 Beavers September 3, 2012

When I opened this article it was like turning on the evening news and seeing your best friend in 1st grade had just founded a hospice or had a school named after them. This is a remarkable read in more ways than one. Check this out:

Beavers play important role in region’s watershed

By Sherry and Ted Guzzi and Mary Long

We offer you an army of volunteers, born and raised in Lake Tahoe, who if given the chance, will filter and purify our lake’s water as it flows in from its tributaries. Without the use of fossil fuel, they work for free, expecting nothing in return for their tireless efforts and structurally sound engineering. They are the North American beavers.

Whoohooohooo! The Sierra Wildlife Coalition to the rescue! Mary and Sherry and Ted have been stalwart champions of beavers since they came on the stage in 2009 when they pushed the issue of trapping beavers at Kings Beach right into the front pages. They gathered a meeting of interested folks and asked Worth A Dam to be there and showed Mike’s DVD. Our own Lory and Ron drove to Tahoe to attend the meeting and offer their support and solutions. We even offered them a scholarship to aid with the installation of the flow device.

Well it turned out those first beavers had been shot by USDA workers wearing night goggles the night before the children were protesting on camera, but that only sealed their resolve to make a difference. They sand painted trees. They went to meetings. They worked at events and spread the word. They drove to Oregon to attend the conference, sonoma to join the beaver meeting, and Martinez to be part of the beaver festival. Twice. Soon they were installing flow devices and being agents of change in their own front yard. Always they were challenged with the old wives tale that ‘beavers weren’t native to the sierras’.Well that’s going to change.

Before we go any further, let’s get the “they are native” “they aren’t native” argument settled. This debate that has plagued the very existence of these animals in our area will be resolved in an upcoming edition of California Fish and Game Scientific Journal. Two articles present both physical and historical evidence showing that beavers were native to the Sierra Nevada.

Samples taken from a buried beaver dam at 4,000 feet above sea level on an upper Feather River tributary were carbon dated at 544 AD. The Washoe Tribe and other mountain tribes had a word for beavers, but none for any other non-native species. The earliest Europeans to arrive in North America reported beaver living in every suitable waterway from the Arctic tundra to northern Mexico. After all, what insurmountable obstacle would have prevented beavers from living in the high Sierra? And, they have been here for a very good reason.

Now that was a surprise! How much of a surprise? Well, remember how Galileo caused that big uproar by suggesting that everything didn’t actually revolve around the earth? And the earth moved (and was moving) all the time? Everyone (but some unnoticed pagans) had believed the earth was the center for ages and it fit nicely with the theology of the time. So arguing that the sun actually stayed still and the planets moved around (and earth was just one of those planets and not the center of the universe) was UNTHINKABLE. Galileo was tried for heresy, placed on house arrest, and ordered to recant. The Catholic church didn’t actually change their mind and apologize to him for 400 years.

Well call me crazy, but this might just be close.

The bomb-dropping article isn’t even published yet and Rick has warned me not to blow the advancing horn too soon, but I suppose that cat’s out of the bag now (and spawning beaver kittens all over the place)! Galileo was right. The church was wrong. We are right. And science has been wrong a long, long time. What better place for the sierra-beavers debut than in the actual sierras? Who better to slice the first cut off the cake than our own Sierra Beaver champions from the front lines. I’m very proud of them all and the article is sure to raise all kinds of ire and consternation and debate. Good. It takes time to change minds. Let’s start now.

Oh and happy labor day. I interview Bob Arnebeck of New York today for Agents of Change. Wish me luck!

Advice From the Experts

heidi08 Beavers September 3, 2012

Mary and Sherry of the Sierra Wildlife Coalition posted some great questions about estimating pipe size for their next installation on the beaver management facebook forum and I thought the discussion this morning would be appreciated.

Sharon Brown of Beavers: Wetlands & Wildlife. You could also use a USGS topo map of the area to estimate the size of the drainage basin (find the largest continuous line surrounding the site and then use the map’s scale to estimate the size). An 8″ diameter flex pipe normally drains about one sq. mile, but sites with severe slopes or much development may require more pipes.

Mike Callahan of Beaver Solutions: When installing pond leveler pipes this question of sizing is often asked. Sharon Brown was correct in her recent BMF post about the value of using the USGS topographical maps to calculate the size of the watershed upstream of the beaver dam. I use these maps on nearly every pipe installation that I do.

As a general rule of thumb for single wall pipe I will use a 10 inch diameter pipe for watersheds up to one half square-mile, a 12 inch diameter pipe for watersheds up to one square-mile, and a 15 inch diameter pipe for watersheds of up to two square miles. If only double wall pipe were used then I would increase the watershed area by 50%. However, since I do not use double wall pipe very often, maybe someone else with more experience with double wall pipe such as Skip Lisle could comment on this.

Keep in mind that the hydrology of every watershed is different, so two watersheds with the same area can have different stream flows. Some variables that can affect stream flows are the amount of man-made or natural impervious surfaces, as well as natural springs in the watershed. With experience, field observations of the stream flow at the time of the site assessment combined with local knowledge of recent weather events are also helpful in determining what size pipe to use. For example, in the summer if there hasn’t been much rain I will observe how much water is flowing and anticipate that during wetter periods of the year the normal stream flow will be significantly greater than what I am observing at that time and larger pipes will be needed. By the same token if I’m doing a site assessment during a prolonged rainy period or large storm event the reverse is true.

A great way to learn how much water a certain diameter pipe can move is to observe the amount of water flowing downstream of an installed pond leveler pipe. When the pond leveler pipe is flowing at near capacity I have found that observing the amount of water moving in the stream channel downstream of the pipe is a great learning experience.

One does not have to be a well-trained hydrologist, or need expensive hydrologic studies in order to determine the best pipe size for a given dam. However, pipe sizing is definitely a skill that is developed over time. When I first started doing this work it was one of the most difficult aspects of flow device installation, and was the cause of some early failures as I underestimated how much water could be moved through certain diameter pipes. In general, if the water course is called a river chances are it cannot be cost-effectively piped. Fortunately though, almost all beaver dams are located on smaller order streams which are amenable to being piped.
One final comment, when sizing pipes it is also important to consider what human development surrounds the beaver pond to determine how much water level fluctuation can be tolerated. When human development is very close to the beaver pond then not much fluctuation can be tolerated in the water level. When that is the case I’ll err on the side of installing slightly larger pipes that I think are needed. The extra pipe capacity will move water past the beaver dam quicker during periods of high water flow giving the beavers less chance to hold back the extra water to cause pond level fluctuations.

From Skip Lisle of Beaver Deceivers International:

You have to look at the characteristics of the dam, too.I shoot for optimum efficiency, so I use smooth-walled pipes, often including pvc. I also put them in quite straight with little “humping” at the dam or “snaking” elsewhere. This, as well, increases capacity and is more resistant to the “valley-sedimentation” process (inside pipes) that gravity is known to produce. All of this translates to more gallons per minute in a given pipe size.

“Sizing for dams” is a complex subject that is necessarily “fuzzy” and, if you will forgive me, requires some long-windedness. There are numerous variables and factors to consider in addition to watershed size and pipe efficiency. For instance, the nature and the length of the dam, the behavioral tendencies of beavers, and the elevation that the pipe will be set relative to the dam.

I don’t need to see numbers on flow rate or watershed size to make decisions, but I am unusually experienced. I can usually tell the rough pipe requirements with a quick, in-person visual analysis of the site and the stream. I also know that beaver dams are restricted to a certain flow regime. With a “regular” beaver dam (not one “braced” by a manmade structure like a culvert), the watershed can only be so big. Beyond that, dams do not endure floods, and thus don’t need to be controlled with flow devices. Furthermore, I recognize that there are only a couple available, practical pipe sizes to choose from. For example, in a big watershed it is 12″ or 15″. I think 18″ is a little too unwieldy to be generally practical. If it is a really big watershed, and assuming there is space, I may start with two systems. Then I observe the site over the months and years to see how things develop, or, if far away, respond to feedback from my client if its provided. I am quite open to adding additional systems if there is an apparent need, and the money is available. But sites that big are rare.

Also, the goal of a pipe system should be to control the vertical growth of the dam by holding the water down, and eliminating “spill-over” stimuli, for some significant portion of the relatively low-flow damming season. To do this, a system does not need to carry all the flow all the time. This, of course, also affects the pipe-size decision. When big flows come, water is expected to flow over the top of the dam, but over a dam that is at a lower level, possibly a far lower level, than otherwise would have been the case.

Another thing to consider is that the beaver dam is part of the system. There has to be a predictable damming plane for one to pierce with a pipe. Furthermore, the size of that dam is a function of the length of time beaver’s had been damming there before the flow device was installed—a factor completely unrelated to the flow device builder, or the installation process.

And if the beavers are killed, or discouraged from working the site? Then no dam maintenance will occur and, ultimately, the dam, in whole or part, will wash away. You will be left with an expensive pipe system that’s doing nothing. The danger of over-piping a beaver dam, particularly if one’s goal is partly to maintain the wetland, is that it increases the likelihood that beavers will abandon the effort at that point (they do not continue long with obviously futile activities), start a new dam just upstream or downstream (neutralizing the flow device), or leave the area altogether. Dam control represents a delicate, complex, and nebulous equation, which a client often doesn’t fully understand. It is why I enjoy the more straightforward nature of culvert sites. The beauty of beaver dams and wetlands is their dynamism, but the human brain seems to seek simplicity, certainty, and specificity. Part of the remedy is getting people to think different, as the folks at Apple would say, and which you have been trying to do for a long time.

Well this should get you all started. Now we need installers in California. Anyone like to play in the mud as a child? We’ll set you on a career path and get you the best possible training! Send your application now!