Each RVOEP newsletter features something interesting about the flora and fauna that can be found in and around the RVOEP site. Some of the features are reproduced here:

Bats || Earthworms || Fuels & Fuelbreaks || Silk Moth || Tick Watch

MOTHER NATURE INTERVIEWS A BAT Spring 2003
While hiking in Moonlight Meadow recently, Mother Nature met a friendly bat that was willing to answer some questions she had about him and his friends.

Mother Nature (MN): Before we start, I have to ask you this. You aren't a vampire bat, are you?
Bat: Oh, no! I'm a Mexican Free-tail bat, one of the most common bats in this area. I have lots of friends. We like to hang out together. Vampire bats don't live around here.
MN: Well, Ole! I can see by looking at you that you do have a tail. Do all bats have tails?
Bat: We're the only ones with a free tail. It sticks out behind the special membrane net between our back legs that we use for catching insects.
MN: Why are you called a Mexican Free-tail?
Bat: My species is common in the hot deserts of Mexico, but we're also found all over the lower half of the United States. Notice I have sombrero-like large round ears that I can pull down around my eyes to shade them from the sun when I'm flying after mosquitoes and other insects.
MN: Aren't mosquitoes hard to catch?
Bat: Maybe for you! But I have long, narrow jet wings designed for speed and I'm often flying around at 60 miles per hour!
MN: Well, Speedy, I'm sure glad you're out there. Those mosquitoes are pretty pesky. How many do you eat in a night, anyway?
Bat: I can catch up to 600 insects in an hour and over 3,000 on a good evening.
MN: Wow! How do you see them at night? How can you find them so fast?
Bat: Well, I'm the loudest bat in North America. My sounds are so high pitched that you can't hear me, but those sounds bounce off of objects in the sky like tiny mosquitoes, so I know exactly where they are.
MN: You must need a good resting spot after those busy nights. Where do you sleep?
Bat: We Mexican Free-tails evolved to live in a cave, but I will happily live in attic walls or in the eaves of a house. Farmers have started building us houses so we will stick around and help control their crop pests, which is great! We need more homes, because old barns and houses with good attics are disappearing. You know, I also appreciate that a lot of the farmers around here are going organic.
MN: How does organic help you?
Bat: When they spray insects with pesticides, the insects are full of poisons. We're so tiny that it doesn't take long for those poisons to build up in our body and kill us. I get really sad whenever I think of my cousins in the Carlsbad Caverns. About 97% of them have died from picking up DDT that is still being used in Mexico.
MN: That's terrible! And I hear that some of our current pesticides may be as bad or worse then DDT. The EPA did a study a couple of years ago that concluded that most peoples' lawns would qualify as super fund sites because of the concentrated chemicals people use.
Bat: My mother had to eat lots of mosquitoes to take care of me. Free-tail pups drink close to 30% of their body weight in milk daily and I had to get out there and start catching my own food when I was just 5 weeks old!
MN: You said, "pup". I hear some people think you are just a flying mouse! They don't realize that you're your own special kind of mammal.
Bat: Yes! Scientists have placed us in a group of our own --- Chiroptera, which means "hand wing". There are nearly a thousand species of bats, and of the twenty-three species of bats found in California, fourteen of us are found in Northern California. All of us local bats are insect eaters. None of us like to be handled, so we might bite if you try to touch us. If you find a hurt bat, do me a favor and contact the California Bat Conservation Fund. You can meet some of us up close and personal if you come to the bat workshop on Monday evening at 7:00, March 10th, at Oak Manor School.
MN: Thanks for the interview, Speedy. I hope that you will come and visit us at our next RVOEP Night Camp! You know, April 22 is Earth Day. There are a few things we can do to help the earth and bats in the process:

1. Tell somebody something good about bats!
Bats are essential to almost every ecosystem on earth. 70% of the tropical fruit we eat depends upon bats for seed dispersal, pollination and/or insect control.

2. Educate yourself about bats.
Check out www.californiabats.com to learn more about bats and get a list of good bat books.

3. Buy organic produce and garden organically.
Be careful of those pesticides that "hide" in other products (systemic rose food, for instance).

4. Build a bat house.
Benefit from the bat's unique mosquito catching skills by building an eye-catching bat house and then watching them move in and get to work.

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EARTHWORM ECOLOGY IN CALIFORNIA Winter 2002
We'd like to add on more creature for which California's oak woodlands are critical habitat--the earthworm. Yes, California has its own, native earthworm fauna, with species found nowhere else in the world. At the Hopland Research and Extension Center, these organisms in the grasslands and oak woodlands are being studied.

Most earthworm species native to California began their evolution over 100 million years ago and are among California's oldest residents. As climate and habitats have changed, earthworms have adapted, proving themselves to be hardy, resilient survivors. Today they are most abundant in oak savannas but can be found in almost all habitats, from semi-desert chaparral to coastal forest. The only habitats in which native earthworms fail to thrive are those heavily affected by human activity, including irrigated croplands, orchards, and suburban areas. There, they have largely been displaced by earthworm species introduced from Europe, Asia, and Latin America.

Native species can get by with much lower-quality food sources and tolerate drier soils. So although the exotic species are more prolific and will "take over" suitable areas, native species hold their own in less-disturbed habitats. Earthworms, whether native or exotic, influence soil fertility in three important ways: interaction with soil microorganisms (bacteria and fungi); physical and chemical changes in the soil through burrowing and casting activity; and serving as a food source to other animals. By breaking up plant residues on the soil surface and mixing them with topsoil, earthworms bring these materials into contact with soil microorganisms that aid in decomposition and formation of soil organic matter. The microorganisms themselves are a nutrient-rich food source for earthworms and are ingested along with soil and plant residues. The worms return these nutrients to the soil, primarily in their feces (casts), which are readily available for uptake by plants. Earthworms also facilitate the transport of microorganisms throughout the soil and have been shown to promote the colonization of plants by symbiotic fungi (mycorrhizae).

Burrowing and casting activity increases the size and number of soil macropores, which improves water infiltration and aeration. Earthworm burrows also provide channels for root growth and enhance gas exchange for both roots and associated microorganisms, especially in compacted soils. Earthworm casts generally are higher in pH and have higher concentrations of carbon, nitrogen, phosphorus, and other nutrients than bulk soil. Depending on soil type, casts can persist as macroaggregates in the soil for long periods of time, serving as a form of slow-release fertilizer.

Earthworms form an important component of both below- and above-ground food webs. As mentioned, earthworms graze on soil microorganisms. After death, their bodies serve as food for scavengers, predatory insects, birds, and mammals. Earthworms also form a major link in the chain of bio-accumulation of pesticide and heavy metal residues. They store relatively high concentrations of pesticides and heavy metals in their bodies (up to 10 times the concentration found in soil) which are passed right along to their predators. Birds are especially vulnerable to poisoning in this way. This raises serious questions about the wisdom of using municipal sludge contaminated with low concentrations of heavy metals or organic compounds as a soil amendment.

Because earthworms play such an important role in soil processes, any practice that favors earthworms will pay off in the long run in enhanced soil fertility. In agroecosystems, practices that promote earthworm populations include using organic amendments (composts and cover crops) and reduced tillage. In pastures, fertilization and planting high-quality forage will increase earthworm densities, but possibly at the expense of native earthworms.

Preliminary studies suggest that differences exist in how native and non-native earthworms process soil nutrients that may have long-term consequences for soil fertility in pastures. Native earthworms tend to be active at the soil surface for a longer period of time throughout the year, so their net effect on soil fertility may be greater overall.

Much remains to be learned about the species diversity, life habits, and functional roles of California's native earthworms. But this much is certain: earthworms are a significant component of both natural and managed ecosystems and, as such, are worthy of our best efforts at conservation. We may find that one of our most valuable and cost-effective tools in maintaining long-term soil productivity lies, literally, at our feet.

This article is excerpted from Winsome, Thais, and Paul Hendrix. 2000. Earthworm Ecology in California. Pages 4-5 in J. Vreeland and B. Tietje, Eds. Oaks 'n' Folks Newsletter, Univ. of California Berkeley, Integrated Hardwood Range Management Program. Volume 15, Issue 1, March 2000.

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By Clare Nunamaker, private consulting forester (RPF #2606) Fall 2002

We all know that fuels feed fires. But did you know that there are different types of fuels that feed fires in different ways? And that we can manage those fuels to help people fight fires?

There are three kinds of fuels - ground, ladder, and crown. Ground fuels are those on the ground, like herbaceous vegetation, downed logs, and leaf litter. Crown fuels include the tops of trees, or the canopy. And ladder fuels include anything that helps a fire climb from the ground to the crown fuels. Common ladder fuels include tall grasses, shrubs, and tree branches, both live and dead.

Reducing ground fuels breaks up the horizontal continuity, reducing how quickly the fire can spread and limiting the amount of material available to burn. Similarly, reducing ladder fuels breaks up the vertical continuity, limiting how quickly a fire can climb upwards. In both cases, the end result is a fire that is less intense and less likely to climb into the tree canopy.

While researchers tell us that it is most important to reduce surface and ladder fuels, it's also helpful to reduce crown fuels. Spacing trees out so that there is room between the individual tree crowns does two things. First, it makes it more difficult for the fire to spread from treetop to treetop. Second, creating spaces allows for the heat from a ground fire to escape upwards, rather than being trapped by tree branches.

One way to reduce fuels is to build what's called a "fuelbreak" which, as its name implies, breaks up the continuity of fuels. It might be a strip of land in which vegetation is entirely or partially removed. The idea is to significantly reduce the available fuels so that when a wildfire comes through, the amount of available fuel for the fire is significantly reduced, which reduces the intensity of the fire.

Fuelbreaks are strategically placed where firefighters will have good access and where natural and human-made features will help them fight the fire. Fuelbreaks are often put on top of ridges. And because roads themselves serve as fuelbreaks, often vegetation is reduced in strips 30 feet or more wide alongside the roads in order to increase the size and effectiveness of the fuelbreak.

Many people think of these fuelbreaks as strips of land cut down to the ground, with nothing growing in them. But these days many communities are establishing "shaded fuelbreaks" where brush (like manzanita and ceanothus) is controlled and trees are thinned. A rule of thumb for thinning trees in fuelbreaks is dbh+4+1/3 ("dbh" is (diameter at breast height, or 4.5'). Take the diameter of the tree in inches, add 4, then multiply by 1.33 to get the spacing of leave trees in feet. So between 11-inch diameter trees, you would want a spacing of 20 feet. This breaks up the crown fuels. Sometimes the lower limbs on remaining trees are removed to reduce ladder fuels. What is left is a widely spaced stand of overstory trees over an understory that has been largely cleared of brush.

Vegetation management, by reducing and breaking up horizontal and vertical continuity of fuels, can result in fires spreading at a slower rate and having a more difficult time reaching the canopy. In some cases, fires in the tree canopy have even dropped to the ground in areas that have been properly treated for fuels reduction. The key is to be proactive and to do the vegetation management before the fire comes.

Think Like A Flame
As you look at these photos, think like a flame. How will you travel from tree to tree? How will you climb from the forest floor upwards? How big will you be? How easy will it be for you to grow? If people want to stop you, would they be able to do so?

In this area, no thinning was done, and there is an abundance of fuels.

• Ladder fuels: You can see many branches, both live and dead, that provide an easy way for fire to climb up the bushes and trees into the crown layer.
• Crown and ground fuels: The forest stand was so dense that the photo had to be taken from the road, and it wasn't possible to get a picture where you could see the crown or ground fuels clearly. Look closely to see the close spacing of the trees (look for the straight tree trunks). Trunks that are closely spaced mean that the crowns are closely spaced, too.

In this adjacent area, fuels treatment was done. All brush was removed, and trees under 11" dbh were thinned. The photo was taken from within the stand.

• Ladder fuels: Notice how there are relatively few areas where a fire could climb up branches of brush to get into the crowns of trees.
• Crown fuels: Look for the sunlight on the forest floor. That tells you the crowns of the trees are well spaced.
• Ground fuels: There is a layer of duff, but there aren't large amounts of fuel on the forest floor.

These photos were taken in 2001 in Yuba County. About 30 landowners participated in a project to reduce fuels along Moonshine Road. Photos by Clare Nunamaker.

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By Joe Barnwell (Summer 2002)

The RVOEP is home to the Ceanothus silk moth, Hyalophora euryalus, one of nature's more impressive insects. The moth itself is not too often seen, as it has a short life span and chilly pre-dawn spring habits. It is the cocoon that usually draws human attention.

These cocoons can be quite noticeable attached lengthwise to bare winter shrubbery. They are the size and shape of a small chicken egg, and shine a light gray in the sun. Their silken armor is very tough, and they have been used for millennia by Pomoan and other California Indian groups as ceremonial rattles. The cocoons would be gathered, their occupants evicted, and gravel inserted for sound. They they would be sewn onto ceremonial dress or glued onto a handle to make a rattle. The Eastern Pomo name for both cocoon and rattle is "maa-yoy!".

The Saturniidae (silk moth) family is a hymn to the glory and mystery of life. There are 65 species of these moths in North America, 15 in California. They are all large, strikingly patterned creatures, and include the Luna and Cecropia moths of the East Coast.

The Ceanothus silk moth is the western version of the Cecropia. It has 4 1/2 inch wingspan, and its reddish-brown uppersides are marked with white, crescent-shaped slashes and a small eyespot in the corner of the upper wing. Its naked green caterpillar eats and molts its way through the summer to an eventual length of four inches and develops yellow protuberances on its segments in its last stages.

The adults emerge in spring from the cocoons through a visible "neck" at one end, and live but a week or two. Their mouth parts are atrophied and they do not feed. They are out looking for love, and a "calling" female can summon a male from a distance of three miles with her pheromone scent. Many members of the silk moth family are easily raised, and they have been the subject of most pheromone studies.

Once the date has been made, male and female will remain coupled in a day long mating process. The female then visits chaparral and woodland, scattering a few eggs per shrub, up to a final total of about 400.

The cocoons have numerous predators. Woodpeckers and jays can punch through the tough silk, and deer mice, other rodents, ichneumon flies with long ovipositors, ants, and humans also take a toll.

About half the Maa-yoy! I find are viable. I spent a month or so recently peering up the skirts of thousands of shrubs in the Mendocino National Forest. I've found most of mine on manzanita, but other ceanothus, poison oak, dogwood, coffeeberry, and live oak have also served. I have found them most everywhere, but they are nowhere common. They are to be expected from the coast to 3,000 meters in altitude.

I have kept a couple of predated cocoons but leave them alone otherwise. They are a source of life and spiritual traditions that I would rather revere than take.

The Web is a rich source of information on the family Saturniidae. A search using "silk moth" can keep you occupied and entranced for hours.

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by Cathy Monroe

Ticks are small, mite-like animals commonly found in our fields and forests. They are parasites, feeding upon the blood of other animals. Among the species that include humans as their host is the Western Black-Legged Tick. This tick is small with black legs, the female having reddish-brown bodies and the male is blackish brown. Because this tick carries Lyme disease, many people have become concerned about going outdoors and getting a tick bite. Fortunately, only a small percentage of ticks carry the disease and most experts agree that a tick needs to stay lodged for over 24 hours in order to transmit the disease. With care you can watch out and find the ticks before they get under your skin.

Take care when going through tick habitat.
Adult ticks climb up onto the tips of grasses in search of their host (a rabbit, deer, dog, or you!). They have no eyes to see, but sense movement with photosensitive skin and recognize certain distinct chemical smells of mammals. They can patiently perch on a blade of grass for months until the right host brushes against them. This behavior is called questing. Adult ticks are most active in Fall, Winter, and Spring. The younger, tiny nymph tick is most active in late Spring and is found in the leaf litter under trees where it seeks rodents, lizards, birds, and larger mammals. (you!) **Any time you go off of the trails, especially through grassy fields or lie down on the ground, you are more likely to come into contact with ticks.

Wear protective clothing.
Wear long pants during tick season (Fall through Spring) with your socks pulled over the ends of your pants so ticks can't crawl up inside.

Keep checking.
As you hike check for ticks every 10 to 20 minutes and very thoroughly at the end of the outing.

If a tick does bore in, it's important to remove it promptly and properly.
Use a pair of fine-point tweezers. Grasp the tick as close as possible to the point of attachment and slowly and gently pull until your skin starts to lift. Keep up the gentle pressure until the tick comes loose. Don't twist or jerk. If you don't have tweezers and use your fingers, wear thin gloves or hold plastic wrap or paper between your fingers and the tick. After you remove the tick, use antiseptic on the wound and wash your hands and tools. If you leave part of the tick imbedded in your skin, it should be removed by a physician to avoid infection. It is natural for a tick bite to get inflamed and hurt for several days, but if an expanding red rash with a clear center develops (a "bull's-eye" rash), this could be a symptom of lyme disease and you should see a physician. Be alert for flue-like symptoms which often occur during the first stage of the disease. Early treatment with antibiotics usually eliminates lyme disease entirely.

If you do find a tick, take time to watch it and check it out under a handlense. You will be fasinated by what you see!

The Western Black-legged Tick and Lyme Disease
By Rebecca Eisen and Lars Eisen

Most people probably associate Lyme disease with the northeastern United States. From 1992 to 1998, more than 44,000 cases were reported from New York and Connecticut alone. During the same period, California reported only 867 Lyme disease cases. However, unfortunate for us, most Californian cases occur in Mendocino, Humboldt, and Trinity counties (see Fritz and Vugia, 2001; The infectious Disease Review 3, 111-122)

Lyme disease is caused by a spiral-shaped bacterium called Borrelia burgdorferi. In California, it is transmitted to humans and domestic animals by the Western Black-legged Tick, Ixodes pacificus. We do have other human-biting ticks in California (such as the dog tick, Dermacentor variabilis, and the Pacific Coast Tick, Dermacentor occidentalis) but they cannot transmit the Lyme disease bacterium.

The Western Black-legged tick has 3 active life stages; larva, nymph and adult. All stages need a single blood meal to be able to develop to the next stage (larvae and nymphs) or lay eggs (females). Larvae and nymphs usually feed on small vertebrates such as lizards, rodents, or birds, but the female ticks need so much blood that they must feed on larger animals, like jackrabbits or deer. Female ticks feed once, lay up to 1,000 eggs and then die. Because the tick stays inactive during the warm, dry summer and fall months, it usually takes 3 years for a tick to complete its life cycle. One study in the Potter Valley area (see Cover and Lane 1995; American Journal of Tropical Medicine and Hygiene 53, 237-240) indicated that most Lyme disease cases were associated with bites of the nymphal tick stage but that female ticks also contributed to the transmission of Lyme disease bacteria. Ticks generally need to be attached for 24-48 before transmitting Lyme disease bacteria. The smaller nymphs tend to cause less of an immune response than the female ticks and probably are able to feed for a longer time before being detected. In fact, people with Lyme disease are often unaware of being bitten by a tick.

Nymphs can be active from late February to early October in Mendocino County, but peak activity usually occurs from mid-April to mid-May. People are at risk for nymphal bites in leaf or fir needle litter areas. Nymphs are also present in grassland but since they do not climb vegetation there is little risk of human exposure. Nymphs are generally more abundant in oak or madrone woodland than in redwood areas. The Lyme disease bacterium appears to be present wherever the Western Black-legged Tick is found, usually with 2-15% of nymphs infected.

Adult ticks are active from late Fall to early Spring, but are most abundant in the winter. Host-seeking adults are found in grasslands and chaparral areas, but rarely in leaf litter. On average, only 1 to 2% of adults are infected with the Lyme disease bacterium. The decreased rate of infection from nymphs to adults is probably because nymphs feed abundantly on Western Fence Lizards, which can eliminate Lyme disease bacteria from feeding ticks.

Rebecca and Lars Eisen are post-doctoral fellows with Prof. Robert S Lane, Dept. of Environmental Science, Policy and Management, University of California at Berkeley. For additional information, see "Lyme Disease in California" by Robert S. Lane, http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7485.html.

Bats || Earthworms || Fuels & Fuelbreaks || Silk Moth || Tick Watch

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