CLMs & Real Priorities

bruce85@mac.com Friends of Martinez Beavers, New Species April 13, 2008

Linda Meza

Yesterday afternoon after a two week hiatus I sped home, gobbled down dinner and rushed off to city hall. Once there I scratched my head baffled by the empty parking lot. My one consolation being I wasn’t the only one who had failed to look at the city’s website before heading over. But wait let me go back to an hour before when I scooted out of the office despite learning the surprising news that a birthday celebration for our CEO had been planned, oops! Well he has his own altruistic bend; I’ll address any quizzical glances when and if they should arise.

This is just the latest example of my determination to carve out time (precious little as it is) to seeing this exercise in stewardship through to what ever end lies before us. But it also has me questioning the why of it all. Why is it that I: can shrug off what could be perceived as a career limiting move in order to attend a cancelled meeting or suddenly care enough to pick up and throw away half full liters of coke carelessly discarded within a relative whisper of the watercourse now suddenly burgeoning with life?

I heard one observer at the foot bridge commenting on the chorus of frogs serenading the setting sun, “I don’t know why but I just feel happy.” Yeah that’s it, I just feel happy. For me it’s like someone unlocked that room in my heart entitled “child like wonder” and a flood of feelings, deeper than any perceived threat, came pouring out. Last night while straining to hear the sound of frogs under the train whistle I also heard something else; like a drip from an icicle when the water refuses to give up its crystalline advantage until its sheer weight rips it from the source, plop!

After careful study I realized the sound was originating from beneath the water’s surface. What the!?! A moment more and a fish head breached the surface. I’ll let the anglers of Martinez tell me what it was I saw; some whispered Steelhead I understand it’s entirely likely. What ever the fish it’s just one more thing to marvel over. I’m a fan of dark chocolate and had one of those Dove bites left on my desk. You know the ones with the corny little sayings on the inside of the wrapper? Mine said, “watch reruns they replay your memories”. I’ll continue to watch our beavers and all the rest, thank you very much and be richer for it.

What Is A Keystone Species?

bruce85@mac.com Educational February 28, 2009

The Beaver is often called a “Keystone Species”, but what does this mean? If we want to be good advocates of our beavers we should all understand this concept. It was introduced in 1966 by R.T. Paine who studied the impact of removing one predator from an ecosystem. (In that case a starfish) Starfish take mussels from rocks and the space they create can then be used by other species.

Paine found that the original 15 species community was quickly reduced to only 8 species when the starfish was removed, prompting his analogy to the collapse of an archway if a “keystone” is taken out. (The keystone is the center piece which holds up both sides of the arch) Beavers have a similar role because their dams create habitat which are used by other wildlife. They raise the water table, create richer sediment, alter the vegetation, and spur bushy tree growth by “coppice cutting” trees. By protecting one keystone species, you actually make conditions better for an entire eco-system of other insects, fish, birds and animals. By the same token, in removing one keystone species, you threaten the viability of an entire habitat. Just another reason why our beavers are worth fighting for.

Spring In The Air

bruce85@mac.com pictures February 12, 2008

This mockingbird was spotted near the footbridge yesterday.

Photo: Cheryl Reynolds

Another Dam?

bruce85@mac.com Beaver News, Educational, pictures February 11, 2008

Heidi Perryman

Discerning beaver watchers have noticed something new in the water over the past few days. Another little dam. Kindly and protective souls have wondered if this should be kept secret from the city, immediately removed without their involvement, or maybe covered up with water lillies so that it doesn’t provoke a general response of panic. I photographed the new structure and sent the pictures around to our beavy of beaver experts, including Skip Lisle. The general response was that this was likely a “secondary dam” not a relocation of the first one. Secondary dams are usually down stream from the “main dam”, and form what Skip calls a kind of “terrace effect” for the pond.

They are are lower in height and primarly help by backing up water against the main dam for extra support. Here’s what authors Steve Boyle and Stephanie Owens say in their paper prepared for the CO forest service: North American Beaver: A Technical Conservation Assessment.

Beavers usually build one “home” dam to create a pond for the main lodge. Secondary dams may also be built depending on food availability, soil type, and terrain (Rutherford 1964). Sometimes these dams are built at different levels, resulting in a “lock” system to control water at each level. Secondary dams allow beaver to transport food and materials to the home pond over greater distances while minimizing travel over dry land (Rutherford 1964). Beavers often construct extensive canal systems in shallow ponds or wetlands to aid in the transport of cut wood (Novak 1987).

The beavers continue to use their lodge, and work on the main dam. Indications are very strong that this will be maintained and that the beavers effort in this secondary structure will be minimal. Remember that the influence of tide gets much stronger the farther downstream they go, so the beavers success will be mitigated by very strong forces. You can tell from the patterns of the rushes that they are using this area to feed and forage.

Secondary dams are a sign of beavers doing what they are supposed to, settling in and adapting to their life.

They are not a cause for alarm, and there is little point to their removal since the beavers will likely rebuild. Since their ultimate water height is controlled by the main dam they do not present a flooding danger and will probably never need a secondary flow device.

And, as one clever beaver supporter mentioned to me, they have again chosen an area with a bridge for optimal viewing. Pretty smart beavers.