Wednesday, February 19, 2014

As the Beaver Zeitgeist Approaches....

From Wikipedia: The Zeitgeist (spirit of the age or spirit of the time) is the intellectual fashion or dominant school of thought that typifies and influences the culture of a particular period in time.

It seems as if beaver restoration/awareness is one of those activities where the saying 3 steps forward, 2 steps back is very apropo. On one side you have the robust scientific body of evidence that beaver benefit watershed, enhance fisheries, negate drought-flood-channel incision/erosion, increase biodiversity, and sequester carbon. Management practices, i.e. living with beavers by being smarter than them, with the utilization of flow control devices, beaver deceivers, and mesh-wire to protect trees has also revolutionized the game. And for the first time beaver management can be both pragmatic, co-habitable and practical. But seemingly in lockstep with the increasing realization of these benefits are outdated management practices- dynamiting dams, trapping, killing, kill quotas- and the dilemma of, what I like to call science by assertion. 

Here is an example of science by assertion, more or less paraphrased from a discussion on beaver restoration in New Mexico. Beaver dams occur on the river upstream from my property.  We are not seeing the surface flows we once did. I can't get my historical allotments, water my crops, etc etc... the beaver dams took away the water and it is all held back behind their dams. Get rid of the beavers...

At best this is a hypothesis, albeit a hypothesis not supported by the vast amount of data regarding hyporheic exchange, water tables, aquifers, and the nature of ephemeral flows in arid watersheds. Truth be told the above statement is in fact a great example of correlation does not imply causation. In reality these lessened surface flows would be there with or without the beavers and are a result of the drought stricken west, subsurface pumping, and water diversion. If anything, beaver will allow longer sustained flows in rivers/creeks of an ephemeral nature.

Never the less despite recalcitrant outdated notions that people hold onto like cherished icons of a dying faith the beaver movement is gaining grounds slowly but surely.

Senators Seek Plan to Help Bring Back the Beavers and Protect Wetlands





Wildlife biologists contend beavers could be the most low-tech, inexpensive answer that drought-plagued New Mexico has for storing up precious water and rescuing dwindling wetlands— but some of the animals are still killed every year by people who consider them nuisances.

The state Senate is considering a memorial sponsored by Sens. Tim Keller, D-Albuquerque, and Bobby Gonzales, D-Taos, asking several agencies to develop a statewide beaver-management plan to rein in conflicts between property owners and unwanted animals and to support populations where beavers are needed. Senate Memorial 4 passed the Senate Rules Committee Thursday and is scheduled to be heard next in the Conservation Committee.
“I’d like to see New Mexico craft an intentional beaver-management plan like Utah has,” said Bryan Bird, Wild Places Program director for the Santa Fe-based nonprofit WildEarth Guardians. “It would be a solution to a lot of problems. Right now, there’s no logic to how we manage beavers.”

Of course it is not too hard to make the leap from New Mexico- semiarid, drought stricken- to California (especially socal)- also semiarid and drought stricken. I think you can connect the dots. Let's hope that New Mexico proceeds and California does not lag too far behind (like Bakersfield).


In fiscal year 2011, Wildlife Services killed or euthanized more than 27,000 nuisance or injured beavers in 44 states and relocated 177. In New Mexico, Wildlife Services has killed or relocated an average of 30 beavers a year. In 2012-13, licensed trappers also harvested 121 beavers.
Beavers lived in all perennial waters in New Mexico until the late 1880s. Their numbers steadily declined due to trapping, development, livestock grazing and loss of habitat.
Without beavers, the ponds that helped store up water on many stream systems dwindled, according to another recent study on the ecological benefits of beaver dams, conducted by New Mexico State University researchers. The study found only 40 active beaver dams on streams on public lands in the state in 2013, according to Jennifer Frey, an associate professor and one of the study’s authors. She said beaver were “functionally extinct” in the state because “they are so sparsely distributed that they are not able to perform the vital ecosystem services that would improve the health of our streams.”
A 2011 report from the state Department of Game and Fish, the USDA and the U.S. Fish and Wildlife Service said there was evidence of beavers on 2,200 miles of riparian habitat in New Mexico. Population estimates for beavers in the state range from 5,254 to 11,676 animals.
You gotta say, that is some of the best news in a while- it looks like some people are listening.
And to top that one is some real science, just published in Aquatic Conservation: Marine and Freshwater Ecosystems

Now that is a title of paper I can sink my teeth into.


ABSTRACT

  1. After near-extirpation in the early 20th century, beaver populations are increasing throughout many parts of North America. Simultaneously, there is an emerging interest in employing beaver activity for stream restoration in arid and semi-arid environments (collectively, ‘drylands’), where streams and adjacent riparian ecosystems are expected to face heightened challenges from climate change and human population growth.
  2. Despite growing interest in reintroduction programmes, surprisingly little is known about the ecology of beaver in dryland streams, and science to guide management decisions is often fragmented and incomplete.
  3. This paper reviews the literature addressing the ecological effects and management of beaver activity in drylands of North America, highlighting conservation implications, distinctions between temperate and dryland streams, and knowledge gaps.
  4. Well-documented effects of beaver activity in drylands include changes to channel morphology and groundwater processes, creation of perennial wetland habitat, and substantial impacts to riparian vegetation. However, many hypothesized effects derived from temperate streams lack empirical evidence from dryland streams.
  5. Topics urgently in need of further study include the distribution and local density of beaver dams; consequences of beaver dams for hydrology and water budgets; and effects of beaver activity on the spread of aquatic and riparian non-native species.
  6. In summary, this review suggests that beaver activity can create substantial benefits and costs for conservation. Where active beaver introductions or removals are proposed, managers and conservation organizations are urged to implement monitoring programmes and consider the full range of possible ecological effects and trade-offs.
Copyright © 2014 John Wiley & Sons, Ltd.
This paper essentially synthesizes all the peer reviewed knowledge we have about beaver in xeric habitats- very pertinent to my quest here of course. The authors take a very conservative, but I would not say negative, position on when, how, and where beaver belong- and this is a very rigorous approach as there are many mitigating factors- beaver effects on non-native vegetation, animals etc etc that should be considered. And truth be told beaver advocates, including myself,  sometimes portray beaver as a bit of a panacea- but things are complicated, especially highly human modified watersheds. But the more info the better and the timing of this paper is very promising in terms of the increasing pace of beaver restoration in arid watersheds!! Exciting times!!!

Unfortunately the paper is behind a paywall, if you want a copy just shoot me an email at duanen8@gmail.com



Santa Clara River @ Santa Paula. Duane Nash
Also, since we talk a lot about salmonids (trout, steelhead, salmon) let us remind ourselves we are in a drought and we need to protect these precious, unique, and valuable anadromous fishes.

Saving California's Salmon During a Severe Drought

and don't forget the Salmonid Restoration talks in Santa Barbara this March with a special program on Beavers!!!


Carson Jeffres (c)

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