Sunday, June 21, 2015

Southland Beaver Lives!!!

Ok now I am not really the type to apologize for not posting recently on a blog which I do for free... cuz, you know, I do it for free. And sometimes life gets in the way, I am busy with my other blog, and sometimes you just need to step away when the pace of change frustrates you.

That being said there is some good news.

Southland beaver recently passed 20,000 page views!! That might not sound like a lot but this is a fairly niche blog and it's not exactly click bait posts that I like to write so I am happy that the blog, even when I go away for it for awhile is still getting a pretty constant trickle of hits and views. 20-40 hits per day is pretty good when I am not regularly updating. And maybe some strands of the populace are waking up to the potential for beaver not only in California but other arid climes. I have made contacts with people from Arizona and Spain who have similar storylines invovlving beaver in arid lands.

I will be going on a month long beaver safari!! I just landed a month long filed position in Monterey county on the Arroyo Seco tributary of Salinas river. I am really looking forward to this one as it is an un-dammed, native trout/steelhead creek with some interesting herp fauna to boot. We will be investigating the use of non-natives in beaver ponds. I know that this a controversial topic for beaver enthusiasts because it has the potential to paint beaver in a bad light as crayfish, bullfrogs, bass, carp, and other introduced species do find potential habitat in beaver ponds BUT as I have discussed before here there is potential for beaver ponds to actually mitigate alien species by concentrating them at specific sites which allow top predator herons, mergansers, raccoons, otters, garter snakes and other predators to move in and gobble up the non-natives. Look at it this way if you are a hungry great blue heron you can gobble up one or two big bullfrogs and be full or hunt all day long to find smaller, more cryptic native California tree frogs.  A big, mucky carp is a lot easier for a raccoon to catch than a nimble, wary rainbow trout. Predators do have optimal foraging strategies and many non-natives are readily gobbled up by our native predators.

Native Black Crowned Night Heron catches non-native large mouth bass in native beaver pond Napa CA credit Hank Miller c/o Martinez Beaver
And towards a more holistic approach to non-natives: in lieu of the fact that California does not have a statewide program for completely eliminating non-natives nor do we see the political will to fund such a massive project why should we punch downwards on beaver? I mean, beaver or no beaver non-natives are going to be in our systems. If there are no beaver ponds the non-natives will finds spots in any nook or cranny that suits them. The L.A. river has no beavers and it also has no native fish species left. Also keep in mind that most of our systems have man-made lakes or reservoirs that connect with the rivers and which are stocked intentionally with non-natives by CDFW. So unless we get rid of these founding populations of invasives that connect with and reinoculate river systems every time there is a water discharge, what are we really talking about here? The beaver can not be the scapegoat for our mismanagement of native ecosystems.

Let me reframe the debate concerning non-natives. I am in touch with a lot of people in the bird world. One of the most devastating actors that thwart native passerines is the brown headed cowbird - a nest parasite. Now although it is not strictly an introduced species in California- the proliferation of pastureland has increased its presence in many parts of the state. This has created the implementation of trapping programs to diminish the brown headed cowbird. But, interestingly, there is some thought that complete eradication of the cowbird is not wanted. The reasoning is that if there is not some pressure from cowbirds the native birds will never evolve defensive strategies to thwart them.

Cowbird trap Vern-Freeman Diversion
I think a more nuanced approach to beaver and non-natives may prove useful. Yes beaver ponds provide habitat for non-native species. No we can never get rid of all non-natives. Beaver ponds also provide habitat for natives and generally increase the habitat diversity for everything in the system, especially top-tier predators that may preferentially seek out and consume the larger, more obvious non-native species thus mitigating the negative effects of non-natives on natives. And finally allowing non-natives and natives to eoexist may prove useful in allowing natives to develop evolutionary coping mechanisms to deal with these pressures. Beaver ponds may in fact prove a useful arena to allow such coping mechanisms to evolve.

I have a variety of new and interesting thought pieces on beavers biology and ecology.

I want to explore the "hidden" diversity of semi-aquatic herps in California and how the loss of beaver habitat may have negatively affected these species.

I plant on presenting a new and exciting theory for how beaver cope with and survive in drought prone habitats. Stay tuned, southland beaver world exclusive.

And I want to lay out my idea for "intentional living" with beavers. A novel and exciting idea I have been gestating upon to not only restore beaver to wild lands but deliberately use beaver in tandem with water diverting methods to maximize wetland restoration, aquaculture production, groundwater infiltration, agriculture, and generally safeguard human water resources while simultaneously increasing  available wetland habitat.

As a little hint for my next post I want you to look carefully at the next two pics... see anything in common?

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  1. Any thoughts on how beavers interact with invasive plants like arundo (giant reed)? On the one hand I've heard they might spread them or help them by eating up the cottonwoods. On the other hand a healthier watershed with beavers might be better for native plants and help them compete and it's also possible the Beavers would develop a taste for arundo. Here in Vermont they don't usually eat invasive buckthorn but I've heard of cases where they do and maybe they will do so more in the future.

  2. Good question Charlie Hohn I have thought about arundo/beaver a lot but there is little definite evidence for beaver/arundo interaction either way. As far as I know beaver do not eat arundo nor do they use it for dam building. I talked with Heidi Perryman before about this - she runs the blog/nonprofit Martinez Beavers/Worth A Dam. The beavers that live pretty much in downtown Martinez are quite habituated to humans and she told me that although there is lots of arundo in the creek there the beaver ignore it. I could imagine arundo is quite low in nutrients, kinda like a giant blade of grass. They much prefer to eat the starchy rhizomes of cattails, various succulent water plants, and willow/cottonwood. As for spreading Arundo its sort of a double edged sword - they do create more habitat for everything including native and non-native plants. When beaver clip back willow they tend to grow back bushier and this growth habit might help crowd out arundo but arundo is pretty damn bomb proof. If beaver could develop a taste for the rhizome of arundo that would be good but have you seen their rhizomes? - very tough even for beaver incisors!!

  3. Thanks! Yeah, my worry would be that if the don't eat it they would end up eating up the natives and the arundo would get worse. though in a lot of places like the santa clara river the arundo has already displaced most of the natives in association with fire so... at worst the beavers would just starve, or leave. And like you said maybe they would help the native plants. Maybe the beaver would drown part of the arundo. Maybe they could eat the new shoots, which are very similar to bamboo. For sure the old canes don't have the same sort of cambium willows and cottonwoods have so it makes sense they probably couldn't eat it.

    if beavers promoted a more natural flood cycle that could also help the native plants but they'd need to be more widespread to do that. Fwiw i don't think the drought is going to be the new normal, but instead intense fluctuations between drought and flood would be the new normal. Anything that helps moderate stream flows will be really important either way.

    Anyway several years ago I wrote about the exact same topic... but since I've left Californai I haven't been paying as much attention to it. See . Glad someone else is taking notice of this.


  4. Oh cool I remember that blog and that is how I first got in contact with Rick Lanman etc etc. and learned about beaver in socal.

    On beaver eating natives and allowing arundo to crowd in: I think that the amount of tree felling beaver do is a little overstated. I frequently see quotes of stats like " a single colony of beaver will cut down 10,000 trees in one year" and stuff like that. I think that beaver, especially in warmer climates where there is no hard frost and therefore fresh greens year round eat a lot more emergent water plants, nice tender riparian vegetation. Cold adapted beaver have to fell a lot of trees to create a stockpile of food when photosynthesis stops during the winter. Plus coppicing willow/cottonwood might crowd out the arundo.

    Anecdotally I have seen a lot nice cattail beds and luxurious stands of willow taken hold on the lower santa clara where wastewater discharge is creating a wet oasis. Arundo, though I have seen it growing in water might actually be losing the battle in areas with high persistent water tables. Strong floods also help spread the rhizomes around and beaver - by slowing floodwaters - might help a bit there.

  5. Awesome!
    Yeah, I think beavers act differently in different places. Here in Vermont there can be issues due to the totally thrown off beaver ecology. In a natural setting the forests are adapted to them, if the beaver hit an area too hard it converts the pond edge to hemlock or fir, the beavers can't eat those, and they move on to somewhere else. The main issue with beaver eating too many trees are in little semi-developed riversides where people like particular trees and don't want them eaten. That is where the mesh comes in and it works great except during very snowy years where they walk on the top of snow and in one case got 6 feet up a tree due to a snowdrift! But overall, works fine.
    Otherwise we are having some odd issues with beavers flooding very old swamps and bogs that appear to have not flooded for hundreds of years, even before colonization in many cases. I think there are many factors. Often a road, trail, etc gives them a chokepoint they wouldn't have had otherwise. but other things include climate changes (it has become MUCH wetter here as of late, so they can spread to new areas) and lack of predators (no wolves and either no mountain lions or so few as to not make a difference... eastern coyotes don't seem to have learned to hunt them hard yet and humans trap them in the water only, and not many people do that either) so they can basically roam up the tiniest streams and set up ponds at their leisure. Overall of course the beavers are an incredibly important part of vermont's ecosystems and especially crucial right now with increasing flooding. As I type we are approaching wettest june on record status which is ridiculous considering when the record was last broken was 2013 and it was by a wide margin. As you know the beavers help regulate the flows a lot.
    In the parts of the Santa Clara I have seen, the riparian area is damn near a total loss due to arundo anyway... so the worst case scenario would be beavers just couldn't survive there and would leave or starve. I'd love to see an introduction tried, though I'm not sure when if ever that would happen. Are any of the existing beaver populations in arundo areas?
    The idea of beaver interacting with/using sewage outflow is really interesting anyway. I've seen some nice examples of constructed wetlands to help filter such water of nitrogen and such, but those always require maintenance. Why not let beavers do it? As you've noticed the willows grow like weeds in that nitrogen rich water.