One would think that in the oak woodlands, the most important predators would be mammals such as mountain lion, coyote and bobcat. But new field research is discovering that the most important predator may be rattlesnakes in terms of overall biomass. Rulon Clark, an assistant professor at California State University at San Diego, and his team of eight graduate and undergraduate students, are studying rattlesnakes and their prey at one of the newest University of California Natural Reserves, Blue Oak Ranch Reserve. The 3,300 acre reserve is situated on the west slope of Mount Hamilton, only 10 miles from San Jose.

Clark and his students have documented densities of rattlesnakes on the reserve that far exceed any they have previously encountered throughout California, including the remote Mojave Desert. Rattlesnakes have likely been left alone by humans at Blue Oak Ranch Reserve for many decades. Given the local abundance of wild prey, the snakes have reached population levels that may have been typical prior to centuries of persecution by ranchers and hunters, according to Clark.

The rattlesnake researchers, dubbed “Team Crotalus,” have just completed nearly two months of detailed studies of the interactions between the northern Pacific rattlesnake, Crotalus oreganus, and its preferred prey species the California ground squirrel, Spermophilus beecheyi. When confronted by predators, many animals engage in lengthy, conspicuous interactions involving stereotyped signals and displays. These antipredator signals have been studied mainly as warning signals directed toward conspecifics, even though they may also serve to communicate with predators. Studies of how these signals affect predators have been rare because predation is infrequent and difficult to observe in the field.

Ground squirrels are live trapped, anesthetized, an ear tag and temporary hair dyes to allow for observation after their release. Photo Credit: Matt Strimas

Team Crotalus has begun assembling a one-of-a-kind database of natural antipredator signaling interactions and predator responses. To do so, they are using a high tech assortment of tools. These range from radio telemetry transmitters surgically implanted in the rattlesnakes, to miniature, battery-powered webcams. The webcams transmit live video of snake/squirrel interactions several miles away to the reserve headquarters for recording and observation. The team also confronts snakes with a mechanical, taxidermied rodent affectionately named “Robosquirrel.” The Robosquirrel is programmed to make antipredator sounds and movements to snakes in experimental encounters. The bouts allow the scientists to test predictions of how predators and prey communicate in controlled experiments. (Watch a video of a robosquirrel being struck by a rattlesnake).

Portable wireless video cameras communicate with a long-range WIFI network. Photo Credit: Bree Putman

Graduate student Bree Putman implanting miniature radio transmitter into a rattlesnake that will be tracked using radio telemetry for the next year. Photo Credit: Matt Strimas

Team Crotalus research has focused on the behavior of rattlesnakes confronted by two prey species, ground squirrels and kangaroo rats. These two distantly related rodents have evolved sophisticated anti-snake behavior independently. Comparing the two rodents’ interactions will allow the scientists to examine the role of various ecological and organismic factors that shape predator-prey signaling interactions. Their unique approach combines these methods in studies that simultaneously consider both prey signaling behavior and predator responses in an experimental context. This system promises to provide novel insights into such areas as honesty in animal communication, antagonistic coevolution, and the role of animal sensory systems in shaping signaling behavior.

A young ground squirrel is being forcibly regurgitated by the rattlesnake that had consumed it earlier in the day. Photo Credit: Matt Strimas

“Chewbacca” the rattlesnake eating a young ground squirrel. Photo Credit: Bree Putnam

For more information:

Bree Putman’s Blog: Strike, Rattle and Roll http://strikerattleroll.blogspot.com/

Rulon Clark Lab http://www.bio.sdsu.edu/pub/clark/Site/Home.html

Blue Oak Ranch Reserve http://www.blueoakranchreserve.org

Contact information:

Rulon Clark <rclark@sciences.sdsu.edu

Hamilton Michael <mphamilton@berkeley.edu

Public land managers and livestock operators often question whether or not open space management objectives including public access for recreation are compatible with livestock grazing. Public concerns ranging from the potential environmental degradation to fear of conflict have led some public land managers to limit or curtail the use of grazing on open spaces public lands. For example in 2009, officials from the City of Walnut Creek decided to end grazing in two parks based on park users’ complaints of cattle trampling trails and “increases in attacks by cattle on dogs and people.  Cattle had grazed these parks for decades for weed abatement and the decision came after years of public outcry (TriValley 2009).

Studies have shown that perceptions of livestock use of public lands are associated with type of recreational pursuit, land classification, environmental beliefs, and demographics.  Sanderson et al. 1986 found that the more experience recreationalist had on grazed lands the less likely they had negative perceptions of grazing.  Brunson and Gilbert 2003 documented that hikers were more likely to feel negatively toward livestock use in a Grand Staircase Escalante National Monument than hunters.  Research has also shown rural and urban divide in attitudes and beliefs, especially when the rural economy depends on rangelands.  Little is known about the attitudes of the urban public recreating on grazed park lands.  In particular how widespread is fear, how is fear dealt with, and how do they feel about “natural landscapes” managed with grazing cattle.

Land managers increasingly recognize the value of grazing as a land management tool (Barry et al., 2007).  But where public access is also a priority they must also be able to address public concerns. Land Managers need information about the perceptions that recreational visitors have regarding cattle.  By understanding the concerns managers are better equipped to address recreation/grazing conflicts and educate the public.

With the exponential growth in social media and the willingness of people to share ideas with internet communities there is a growing interest in what we can gleem from a photo sharing website like Flickr.com^TM. Past efforts to learn from Flickr data have focused largely on tagging and geospatial information (Kennedy et al. 2007). Recent efforts have followed earlier work on understanding the social use of personal photography (Harrison 2004, ) and now, image-sharing (Van House 2007). This project used this rich data set found on Flickr to understand perceptions of cattle grazing on park lands by addressing the following questions:

• When people visit public lands with grazing livestock present, what do they photogragh?
• How do park users respond when they encounter and choose to photograph something seemingly undesirable or potentially frightening i.e. cow pies, a rutted trail, cows on the trail?

Methods

A data set (Table 1) was developed from photos and associated comments posted on Flickr using location and subject as search terms.

Table 1.  Data sets developed from Flickr

Photo information in the date set included photo date, posting date, photographer’s name, photo name, photo comments by photographer, posted comments and commenter’s name.  Photo titles and all comments were categorized for each data set in the following categories: descriptive, photo quality statement, positive cow, positive grazing, positive landscape, negative cowt, negative landscape, fear (perceived i.e. not based on an actual event), fear (actual i.e. included a description of an event).

Results

When people visit public lands with grazing livestock present, what do they photograph?

More specifically, what do people who post photos from parks with grazing include in photo comments or photograph title?

How do park users respond when they encounter and choose to photograph and post something seemingly undesirable i.e. cow pies, a rutted trail?

Although 2% of the photos included cows pies in the photos and one picture featured a rutted trail, few comments were made about either of these elements. Comments were matter-of-fact in nature including:

No doubt about it, the cows were here;

Lots of cow poop;

A bumpy path;

How do park users respond when they encounter and choose to photograph and/ or reflect on something potentially frightening (i.e. cows on trails)?

Approximately 5 % (n= 43) of the comments from photos in grazed parks expressed fear of the cattle including comments like these:

I try to conquer my fear of cows by photographing them;

Watch out for those cows;

Got it close to this cow for this shot. You can see she’s giving me the stink eye here so I put the camera away;

The cows scared us to death;

Beware! Mad cows!

This is the cow that blocked our path! Would you want to cross him;

I told them I’m a vegetarian and they let me go;

He wasn’t too keen about being photographed. In addition to the unfriendly stare, he made menacing noises;

A cow that was not happy to see us and almost chased us;

We turned back here as the cow as on the trail path;

We turned around when we were faced with the option of having to walk right through a herd of cows;

Only seven comments ( <1%) included a description of an actual event with “aggressive” animal. These comments described being chased, for example:

Ahh,we were chased last weekend by a young male-err;

At least these cows didn’t chase us like last week’s did;

Happy cows may come from California, but bored cows come from Fremont. I actually tried to have a picnic-but then a bull comes charging us. We got up and ran for our lives. Our bread, cheese and blanket didn’t make it;

How do shared photos and comments from grazed public lands compare to photos and comments from nearby ungrazed public lands?

Overall, most comments could be categorized as descriptive (637 from 934 comments). Examples of descriptive comments include:

• Lots of wildflowers and cows.  Hello tiny cows on the hillside.
• Taken at Lake Del Valle.
• Cow pool party.
• I don’t know why but I thought cows in CA where kept indoors.   (Points to a need for education!)
• A cow grazing….
• They are pastured to keep the fire danger low
• Cow munchin on some grass near the lake

However there were far more  positive cow and grazing comments than  negative cow comments ( 126 versus 8).

Positive subject cow and grazing comments included:

• Wonderful to see cows being just cows and happy ones. Beautiful scene.;
• Superb…love the cow;
• Beautiful spring at Morgan Territory. Green grass, clouds and the cows.;
• As much as I struggled over the steep hills on this hike, all the grazing cattle and howling coyotes made it worth the sweat.
• Oh I just love fuzzy winter cows
• Happy cows eating grass not corn
• I went on a really long hike and saw some cool thing from meadows to steephills to trees, cows and interesting rock forms
• Cows happily range over the lands of Sunol Regional Wilderness, keeping down the fuel load
• The sign said that cows have been known to nudge hikers when startled. Its hard to picture a cow nudging a hiker. I doubt that would be the adjective I would use to describe it if I saw it happen. Generally they are scared of hikers and actually help to spread sees, control non-native plants and overall keep a healthy preserve. I kind of like sharing the green hills with them.

Examples of  negativecow comments  include: it’s a little anti-climatic when you hike uphill for 2 hours and see a herd of cows upon arrival.

• However this kind of landscape also attracts a lot of cows which seem to have more priviledges than me in roaming around
• The only downside was/is that there are cows grazing there a lot and hence: cow patties! Many of the dogs had a taste and all rolled in cow poop quite thoroughly.

Questions to be further analyzed include:

How do shared photos and comments from grazed public lands compare to photos and comments of other subjects that people may find environmentally negative or fearful such as smog or snakes?

How do the type of comments compare to shared photos and comments about other parks with and without grazing?

Discussion and Implications

Is there overwhelmingly negative public opinion towards grazing on public lands as suggested by the article in the TriValley newspaper (Walnut Creek, CA) in 2009?  Park users visiting grazed park parks in the Bay Area and sharing their photos didn’t seem to express this opinion. They largely shared descriptions and positive comments about the cattle they saw and the grazed landscape. In addition recent events in Walnut Creek indicate that there is some strong public opinion in support of grazing.. The Contra Costa Times reported in June 2011 that 150 park neighbors in Walnut Creek Open Space park signed a petition that requesting that the cows return to graze the park lands. They neighbors fear potential wildfire from the resulting unmanaged growth of vegetation.  The grazing supporters also spoke at a Park Commission meeting where they outnumbered those opposed to the cattle returning 23 to 6.

While park managers have implemented some strategies to reduce public/cattle conflict including signage and timing of grazing, there are undoubtedly opportunities for improved public outreach. Park visitors would benefit from not only understanding the biological value of managed grazing programs but also from better information on livestock behavior and how to interact with livestock they may encounter. Continued education of our urban audience will be essential if livestock grazing is going to continue to be a viable took for managing open space lands.

Literature Cited

Barry, S. T.Schohr, and K. Sweet. 2007. The California Rangeland Conservation Coalition. Rangelands. 29(3):31-34.

Brunson,M. W. and L. Gilbert. 2003. Recreationist responses to livestock grazing in a new national monument. J. Range Manage. 56 (6): 570-576.

Harrison, B. 2004. Snap Happy: Toward a Sociology of “Everyday” Photography. In: C. Pole (Eds), Seeing is Believing? Approaches to Visual Research. Studies of Qualitative Methodolgy, Volume 7: 23-39.

Kennedy, L., M. Naaman, S. Ahern, R.Nair, T. Rattenbury. 2007. How Flickr Helps us Make Sense of the World: Context and Content in Community-Contributed Media Collections. MM’07, September 23-28,2007, Augsburg, Bavaria, Germany.

Sanderson, R.H., R.A. Meganck, and K.C. Gibbs. 1986. Range management and scenic beauty as perceived by dispersed recreationist. J. Range Manage. 39:464-469.

Van House, N. A. 2007. Flickr and Public Image-Sharing: Distant Closeness and Photo Exhibition. CHI 2007, April 28-May 3, 2007, San Jose, CA, USA.

Understanding the Role of History on California’s Oak Forests

In his book The Destruction of California, Ray Dassmann (1965) chronicled the dramatic impact land-use practices have had on wildlife populations throughout California during the past 150 years. He articulates the impacts from the loss of wetlands, forest conversion and urban expansion on a number of economically important wildlife species.  In his book, he quotes an early California pioneer, A. B. Clark (1852) who recorded the abundance of vertebrate diversity that was so apparent in the early days of exploration.  Mr. Clark wrote, “ I have no where seen game as plenty as in the (central) valley.  We killed an antelope in the morning.  We could frequently see herds of deer and elk in different directions around us, as well as wild horses”.   Today, concentrations of deer, elk and waterfowl populations can be found in remnant habitats distributed in small, isolated patches throughout the valley.

More recently, Walter (1998) provides a complete overview of how past land-use practices have changed the landscape of California so dramatically that in some cases counties “have lost their natural heritage” and are mere remnants of their past biological richness.  Brown et. al. (1994) and Marchetti and Moyle (1995) have outlined the once abundant numbers of salmon and how historical land-use practices directly impacted anadromous fisheries and how the legacy of these practices continues to impact these species.   They specifically identify water diversions and related watershed degradation caused by past and on-going human activities as the direct cause of these declines.  Moyle et. al. (1994) has identified as many as 10 anadromous species (including salmon, steelhead trout, lamprey, sturgeon, smelt) that meet the scientific criteria necessary for special protective status.

The common thread binding the terrestrial and aquatic inhabitants of pre-settlement California is the fact that many of these species were found in areas that we commonly referred to as oak (Quercus) woodlands. In many cases, the abundance that has been chronicled illustrates the importance of oak habitats to many of the species which spent a significant portion of their life history living in, or migrating through, oak woodlands. Because of their ubiquitous distribution oaks have been impacted throughout California during the past century. An early account written by Willis Linn Jepson (1909) states; “In some regions where the horticultural development has been rapid or the needs of an increasing population urgent, extensive areas have been cleared to make room for orchards or gardens, and scarcely a [valley oak] tree remains to tell the story of the old time monarchs of the soil,  in other regions the destruction has not been so complete” (Pavlik et. al. 1991). Modern day land-use impacts on oak woodlands continue through urbanization and the conversion of oak woodlands to intensive agriculture.

California’s History of Forest Policy toward Oaks

In 1885, the Governor of California approved an act that authorized the appointment of a three-man State Board of Forestry, the first such body in the nation.  Because of a lack of clear statutory authority and minimal budgeting, the original Board was only able to act in an educational and advisory capacity.  By 1905, the Board of Forestry was supplemented by creation of the post of State Forester and in 1927 the Division of Forestry was organized.

In 1947, the original Forest Practice Act was passed by the State Legislature.  Although the responsibilities and powers of the Board under the old act were less than they are today, the 1947 Act laid important foundations of experience and procedure which led to further development for the Board.

Throughout the period of the 1950s and 1960s, the Board of Forestry functioned under the mandate of the 1947 Act by formulating forest policy for the state. When the Division of Forestry was elevated to departmental status in 1977, the organizational relationship between the Department and the Board was retained.  This reorganization of the Department had no effect upon the Board's mandated duties and responsibilities.   With the passage of the Z'berg-Nejedly Forestry Practice Act of 1973, the Legislature reorganized the Board and concomitantly expanded its powers and responsibilities.    To achieve a balanced approach to forest land policy, the Public Resources Code delineates the character of the Board by designating that five members will be from the general public, three are chosen from the forest products industry, and one member is from the range-livestock industry.

The Board is recognized as having the legislative authority to regulate both privately owned conifer and oak woodland forest types.  Historically, the Board has focused its regulatory authority on those lands capable of producing commercial lumber products choosing to support an educationally based program for oak woodlands.  The educational path was established with the creation of the University of California’s Integrated Hardwood Management Program (IHRMP) in the mid-1980s.  In 1993 the Board delegated to the IHRMP the responsibility of assisting counties in the development of locally based conservation strategies for oak woodlands.  In response to this directive, counties have developed a wide array of resolutions, ordinances and monitoring efforts through a variety of committees, Board of Supervisor actions and local initiatives.

Current Forest Policy and Oaks

Under the direction of the Z'berg-Nejedly Forestry Practice Act of 1973 the Legislature identified the timberlands of the State to be “among the most valuable of natural resources….are of great concern ….relating to their utilization, restoration and protection”. The legislature further recognized the need to “encourage prudent and responsible forest resource management while giving consideration to the public’s need for watershed protection, fisheries and wildlife, and recreational opportunities…”. The Act further defined timberlands as, “[non-federal] lands available for, and capable of, growing a crop of trees of any commercial species…..”.  The Board further defined “commercial species” to include most economically important conifers and some hardwood species, when growing on timberland.

The impact of the Z'berg-Nejedly Act has continually evolved, since its inception. The Act, through a separate set of Forest Practice Rules, recognizes the need for the protection of watershed elements by establishing minimum standards for streams zone protective widths (by stream class), archaeological sites, soil stability and cumulative effects.  These requirements are mandatory for any landowner who wishes to engage in timber harvesting.  The Act in combination with the Rules is designed to identify and mitigate any potential negative impacts from the harvesting of timber as a requirement of the California Environmental Quality Act (CEQA).   As a result of the Act, a landowner is required to secure the services of a Registered Professional Forester (RPF) to submit a Timber Harvest Plan (THP) for review and approval by the California Department of Forestry and Fire Protection (CDF) prior to the harvesting of commercial tree species.  The THP, only one of several vehicles used by CDF and RPFs, is viewed by the State as serving as the functional equivalent of an Environmental Impact Report (EIR) under CEQA..

By definition, most species of Quercus are currently not recognized as commercial species. Only under specific circumstances are pre-determined oak species (Q. Kelloggi and Q. Garryana) recognized by the Forest Practice Rules. In all other situations, if any oak species, including the two identified, occur on lands not designated as timberlands they are not afforded protection under the Forest Practice Act, thereby, not given statewide considerations under CEQA.  However, many of these oak woodland species occur as a continuum of forest canopy in many watersheds of California.  In many situations throughout the State a common vegetative pattern exists with conifer dominated coastal and mountainous forests transforming into oak dominated types in drier or lower elevation sites.

Inconsistency is in the Policy not the Forests

An obvious inherent conflict with current land-use forest policy is the recognition of tree species (and thereby habitats) afforded protections under CEQA relative to their economic values and not their ecological values thereby creating an artificial delineation of forest types.  A glaring example of the inherent inconsistency with this current policy situation is best exemplified by the State’s role in providing protection to salmonid species in northwestern California under CEQA.  Under the current Forest Practice Rules, salmon and steelhead, are afforded some level of protection (though a recent independent scientific panel determined the level of protection was inadequate to protect salmonid resources: Ligon et. al. 1999) when they enter freshwater habitat located in a conifer forest setting.  However, in many cases, those same fish will continue their upstream migration passing through the conifer belt and ultimately complete their journey in a predominately, oak woodland habitat type. This scenario is true for fish in the Russian, Navarro, Eel, Klamath, Smith and Sacramento and San Joaquin River systems. Under these scenarios, the stream and the forest cover represent an ecological continuum for the fish as it moves through the system from the marine environment to its natal spawning grounds in order to complete its life history.  Furthermore, once spawned and hatched, many of the juvenile fish will spend a significant portion of their early life stages in the oak dominated portions of the watershed. However, as the fish move from one forest type to another, the level of protection is not contiguous thereby providing only a minimal level of protection for a small portion of the overall habitat.

This inconsistent application of standardized protective measures is most apparent in those counties with the absence of local requirements to mitigate land-use impacts on streams i.e. grading ordinance, stream zone buffers, etc. Under the existing statewide forest management policies the current statewide mechanism to protect forest streams (Forest Practice Rules) do not provide a continuous level of protection throughout a watershed based on the definition of commercial vs. non-commercial tree species.

The lack of a standardize statewide approach to oak conservation has promoted a variety of measures to be developed, modified and implemented throughout the oak region of California in an attempt to address both riparian and upland issues.  A collection of resolutions (Tehema, Shasta, Madera Counties), ordinances (Sonoma, Napa, Santa Barbara), evaluation committees (Lake, Madera), monitoring efforts (El Dorado) and ballot measures (Santa Barbara) targeting an equally wide array of issues.   In many instances, the adopted mechanisms have focused on a single resource issue such as water quality (Napa and Sonoma Counties) or heritage tree preservation (various county tree ordinances) and have not produced comprehensive measures with adequate monitoring mechanisms capable of evaluating their effectiveness or large landscapes or watersheds.

The current inconsistencies in oak management policies and strategies will certainly continue to fuel the intense debates currently underway throughout the oak region of California as land-use practices increase in scope and magnitude. A need exists to evaluate current local policies and develop comprehensive strategies that promote, protect and enhance oak woodlands and all of their inherent resources.

Literature Cited

Brown, L. R., P. B. Moyle and R. M. Yoshiyama. 1994.  Historical Decline and Current Status of Coho Salmon in California. No. Am. J. of Fisheries Mngt. 14: 237-261.

Dassman, R. F. 1965. The Destruction of California. MacMillan Co. New York. 247pp.

Marchetti, M. P. and P. B. Moyle.  The decline of sea-run fishes in California: An ongoing tragedy. Cal Ag. 49 (6): 74.

Moyle. P. B. 1994. The Decline of Anadromous Fishes in California. Consv. Biol. 8 (3) 869-867.

Walter, H.S. 1998.  Land Use Conflicts in California. Eco. Studies 136:108-125.

As part of a long-term blue oak thinning study in the Southern Sierra (see “Thinning Enhance Blue Oak and Interior Live Oak Acorn Production”), 49 trees were felled. Each tree was aged, and fire scars were dated. Fire scars were identified on 8 of the sample trees (16 percent of the population), allowing us to determine fire history in the stand from 1850 to the present.

Results and Conclusions:
Figure 1 below shows the dates of the 10 fire events that occurred between 1851 and 1996 on the study site in Tulare County near California Hot Springs. The mean fire return interval was 12.8 years (+/- 2.3 years), with a range from 6 to 25 years. There were no fires on the site since 1966.

Based on the age structure of the sample trees on this study site, less than 25 percent of the trees became established from 0 to 3 years after the fire, and another 55 percent were established 4 to 11 years after fire (Figure 2). These results show that the date of fire was much less important than the McClaran and Bartolome (1989) and Mensing (1992) studies, where most of the trees were established immediately following fire events.

Fire suppression has changed the the pattern of fire in blue oak stands. Fire, from both prescribed burns and from natural sources, is much less common in blue oak stands today. This results in large fuel build-ups, higher stand density and crown cover, and different stand structures. Instead of relatively frequent, low intensity fires, we now anticipate infrequent, high intensity fires. Strategies to re-introduce fire, or to achieve restoration of fire-resilient stand structures, is appropriate as part of a long-term sustainability strategy for blue oak woodlands.

Literature:
McClaren, M.P. and J.W. Bartolome. 1989. Fire-related recruitment in stagnant Quercus douglasii populations. Can. Journal of Forest Research 19:580-585.

McCreary, D.D. 2004. Fire in California’s oak woodlands. UC ANR on-line publication. 8 pp. http://ucanr.org/sites/oak_range/files/59574.pdf

Mensing, S. A. 1992. The impact of European settlement on blue oak (Quercus douglasii) regeneration and recruitment in the Tehachapi Mountains, California. Madrono 39(1):36-46.