Nature Notes from Big Creek, 1994

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February 1994 April 1994 May 1994 June 1994 July 1994 August 1994 October 1994 December 1994

February 1994. Our coastal streams are wonderful places to spend some time. They're all different, and they change from month to month and year to year. Of course, some things don't change much. Here in California, in the Santa Lucia Mountains, we have a summer drought and lots of unfailing springs. The result is a base flow for each stream which is clear and constant from year to year, maybe falling a little in dry years and rising some in wet years.
Here at Big Creek there are two tributaries which are almost the same size, Big Creek and Devil's Creek, and which have nearly the same base flow. But they are not the same. One of the main sources of water in Devil's Creek is South Devil's Ridge, just northwest of Cone Peak. This ridge is a spine of blinding white marble (and related rocks), and the springs in this area (such as trail spring, the "headwaters" of the south fork of Devil's Creek) carry dissolved calcium and other minerals into the stream. During the months of base flow, the amount of dissolved minerals is high and flow is gentle, so that the minerals precipitate onto the stream bed. The thin layer coats rocks, dead branches, even leaves, and is called "marl." The marl builds up over the summer and gets about 1/8" thick in late fall. It has a light gray, greenish color. If you look at the marl closely you will see that the light gray comes from the mineral itself, and that the green comes from little pockets of green algae embedded in the marl.
The north, or Big Creek fork, is entirely different. Even though there is some dissolved mineral in the water, marl does not form. Instead, a layer of slimy dark greenish-brown algae forms on the stream bed. I don't know the species name of the algae, but it is very common in streams along the coast. Where the two streams meet at the confluence, 1/2 mile from the ocean, the dark brown layer predominates. Even a small mixture of "Big Creek" water is enough to cause the brown layer to grow. If you move "marled" rocks into the Big Creek flow, the dark brown layer quickly grows (in a week or so). If you move rocks from the Big Creek flow a few feet away into pure Devil's Creek water, the brown layer slowly disappears.
Why the difference? Are the minerals in Devil's Creek poisoning the dark brown alga? Is there some nutrient in Big Creek water which the brown alga needs? Is the Devil's Creek marl formed passively, by simple precipitation of mineral onto rock, or it is a biological process carried out by algae or bacteria? What are the implications of marl formations for stream invertebrates such as caddis flies? What are the effects, if any, on fish? On the dippers, or ouzels, which feed on the stream invertebrates? On Kingfishers, which eat the fish? I don't have the answers to these questions, but would very much like to find out. A student from Berkeley was set to work on these questions a couple of years ago, but he wasn't able to do the work.
The first winter floods (assuming we get some rain) will scour the creek bed and alter the water dramatically. When this happens I'll report what happens to the creek.
Other notes: I observed several "family" groups of deer in the past month. I frequently see one or more antlered bucks, several does, and several young. I think they stay together for protection. Feynner found a young deer killed by a bobcat (the bobcat was standing next to its prey before running off). The deer weighed about 50 pounds, and seemed to have its throat crushed. The ground was all torn up as if there had been a terrific fight. Later, the bobcat returned and ate the deer. This was near to the spot where some students last spring saw a bobcat wrestling with a young deer, trying to bite its throat. Same bobcat?
The bobcat used the typical "mountain lion" technique of opening a hole on the side of the lower abdomen and extracting the guts. It also ate the hindquarters first, just like a mountain lion does, and tried to cover the carcass with leaves. However, there weren't enough leaves so it just stuffed leaves where it had been feeding. One thing was completely different from a lion, however. It did not crack and eat the bones. This (and another bobcat-deer incident last spring) got me to looking at bobcat scats around the reserve. I found many scats with deer hair! Maybe our bobcats eat young deer on a regular basis. (1/13/94)


April 1994. The February rains have brought out the banana slugs in the canyon bottom. Like all slugs, banana slugs are a kind of shell-less snail. Not having a shell lets slugs live in habitats (such as the redwood forest understory) where a snail could not find enough calcium to grow a shell. Of course, the tradeoff is that slugs are vulnerable to drying out; they cannot just park in their shell like a snail. This is why slugs are only found in moist habitats, and why, during the dry season, they must "hibernate" inside a protective case made of hardened slime. The lack of a shell also makes them vulnerable to predators such as garter snakes (which swallow slugs whole).
During the winter months the banana slugs are most active in the warmth of the afternoon. They crawl around looking for leaves to chew. Sometimes they are lucky and find a mushroom. They are known to eat toxic species of mushrooms as well as non-toxic kinds. It may be that by eating toxic mushrooms, they gain a certain amount of toxicity themselves, which could protect them against predators. The slugs' bright yellow color is indicative of this sort of relationship, possibly warning predators that this animal may be dangerous to handle. The slime is definitely bad tasting. However, I have not been able to find any studies on this. It would be an interesting project to study the toxicity and warning coloration of these animals.
The body of a banana slug, the part that "slimes along," is actually its foot. The "upper back" looks like a thick pad wrapped around the body, and is called the mantle. This pad corresponds to the shell on a snail. The trailing end of the mantle attaches to the body, and the front end flaps over the back and head. On the right side the flap curves around an opening, the breathing hole. Slugs crawl by means of waves of muscle contraction and relaxation, passing from front to back. When viewed through a piece of glass, these look like ridges, which move toward the rear, propelling the animal forward. The head has tentacles tipped with tiny eyes. These eyes do not form much of an image but enable the animal to discern patches of light and dark in its environment.
Like many snails, banana slugs are hermaphrodites, meaning that they have male and female sex organs on the same individual. This breeding strategy is rare in the animal world but is very common in plants. In most animals, the most successful breeder is the male (or female) which overcomes its rivals for the best resources or mates. The winning strategy is usually different for each sex, with the result that a pure male, or a pure female, has the breeding advantage over a hermaphrodite who tries to do both at once. For some reason, this does not hold true for slugs, snails, plants, and assorted other creatures with hermaphrodite breeding biology. Perhaps low mobility eliminates some of the advantages of specialized breeding behavior.
Other notes: I have been watching the Red-tail Hawks spending time at the nest below Whale Point above the Big Creek canyon. Probably they will brood another pair of chicks this year....I heard a dipper (or water ouzel) singing on a rock in the middle of Big Creek. The dipper sings like a ventriloquist, with its beak nearly closed, and flashes its brilliant white "third eyelid" in a weird display.....I just met with a biologist who wants to study wild pigs in our area. Does anyone know of a steady population of pigs that could be trapped and studied for their effects on amphibians or other creature? We have too few pigs here at Big Creek for the study.
ON SATURDAY APRIL 2 WE WILL HOST OUR ANNUAL NEIGHBORS' DAY OPEN HOUSE at Big Creek. Please gather your friends and families and come see the reserve. We will have informative displays, guided hikes and driving tours. Those who know the area are welcome to hike on their own. Bring a lunch and spend all day (9am to 4pm). Big Creek is located on highway 1, 20 miles south of Big Sur, 5 miles south of Esalen and 5 miles north of Lucia. See you there! (3/20/94)


May 1994. Archaeologist Terry Jones just sent me a copy of his newest work summarizing the prehistory of our area, entitled "Big Sur: A Keystone in Central California Culture History." Investigations at 13 sites along the coast have recently been completed, including eight at Big Creek. Using this information (together with data from 4 older sites) Terry has been able to define local culture history "phases" for Big Sur. He proposes these be called: Interpretive Phase (4400-3500 B.C.), Redwood Phase (3500-600 B.C.), Willow Creek Phase (600 B.C.-A.D. 1000), Highland Phase (A.D. 1000-1250), Dolan Phase (A.D. 1250-1650), Arbuez Phase (also A.D. 1250-1650), and Santos Phase (A.D.1650-1800). The names derive from the site which best exemplifies the phase in question. Other phases may be found in future, and more information may allow finer subdivision or alteration of the proposed phases, but these seem to be the simplest categories that work.
In his article, Terry shows how the Big Sur phases are the local expression of what was happening across California. For example, the Interpretive phase corresponds well to the "Millingstone" period of Central California culture history, with similar dates and technologies. In fact, a major finding of the work is to confirm that Big Sur peoples were using very similar materials and technologies (and trading with) other peoples living along the central coast between the Santa Cruz Mountains and Santa Barbara.
The evidence also suggests that people added new tools and technologies over time, but retained the old ones as well. To me, this indicates continuity from generation to generation. The only major break seems to have been in about A.D. 1250, when the Dolan Phase culture seems to have "invaded" from elsewhere. However, the roughly simultaneous Arbuez phase sites suggest that locals "remained" in the area, perhaps maintaining the cultural continuity from the past. (I put the words in quotes because so much can happen in 350 years. The information is too crude to tell us if and how the two cultures may have interacted).
I like to imagine that there may have been an unbroken tradition of 300 or more generations in the interval between 6500 B.C. and A.D.1800, each handing to the next a detailed knowledge of the area as well as life ways which had ample time to become "in tune" with the land. It is very sad that so much was lost at the end of this time. I feel we should encourage those who are trying to revive whatever they can of this tradition, be they archaeologists, native Americans, or just "Big Sur folks."
Other notes: I spent a few hours chopping and uprooting Sticky Eupatorium, a weed that has been propagating like wildfire along the coast. This plant has pretty white flower heads (they look like flat-top clusters of fuzzy white balls), and likes to grow in moist places and road cuts. The seeds spread on the wind, and I have found isolated plants growing way up the canyons along creeks and in tree fall areas where there is running water. With sun and water it grows a heavy thatch of stems, which fall down and choke out ferns, yellow monkey flowers, and other water-loving plants. The Eupatorium grows a new thatch each year, building up an impenetrable layer.
The stems are brittle and easily uprooted, so I think the key to success in controlling the plant is to attack the plants early. Like thistles and many other weeds, its seeds seem only to germinate on bare soil, so encouraging ground cover should help prevent seedlings.
We have seen lots of Bald Eagles recently. All the ones I have seen have leg bands and seem to be among a newly establishing (we hope) resident population of birds released by the Ventana Wilderness Sanctuary over the past several years. I saw two adults performing aerial courtship tumbles, and I have seen birds perching over the seal beach. Last year I saw an eagle eating the remains of a Harbor Seal, and I suspect the same bird is here again. The seals are giving birth right now, and the tiny pups are vulnerable. I watched a female in labor, lying in shallow water on kelp and rocks. She was very hard to see. Maybe the seal's spots and diverse coat colors are nature's way of preventing eagles from finding mothers in labor and picking off the newborns as they are born.
Our April 2 Neighbor's Day open house was great fun, as always. Steve Chambers led a ridge hike, and several other groups hiked up the canyon. Many took the ridge drive up and hiked down. We had beautiful weather. I enjoyed greeting visitors and answering questions. (4/19/94)


June 1994. I just read Julia Smith's doctoral thesis based on field work at Big Creek. Julie studied the Song Sparrow, one of the most common birds on the coast, and with one of the prettiest singing voices. Their song is melodious and bubbly, with trills and many different notes. Song sparrows are brown, buff, and gray with stripes and a dark spot in the middle of the chest.
Song Sparrows are famous among bird researchers because they are so variable in their size and shape as you travel around the country. Here in California, mountain Song Sparrows are larger than coastal birds, an example of what is known as "Bergman's rule." Bergman's rule is an ecological generalization (which may or may not hold in any specific instance but nevertheless works much of the time): animals from cold climates tend to be larger than animals from warmer climes. The mountain song Sparrows also have bills of a different shape and some other shape differences when compared with coastal birds. If we could understand these differences we might get a better idea about how birds and other animals adapt to their local environment.
Some biologists have proposed that local variation is caused by natural selection favoring those individuals that have size and/or shape appropriate to their environment, causing each population of sparrows to become genetically adapted to its local environment. The problem with this idea (in the case of Song Sparrows) is that genetic studies have found that there is a lot of interbreeding, or out crossing, between populations of Song Sparrows. This suggests that, for example, mountain birds may have grandparents or cousins from the coast, so that their local population is probably not genetically distinct from the rest of the species.
Julia has proposed a different idea. Perhaps Song Sparrows in the egg or nestling stage alter their development in response to the local environment, so that birds raised in the mountains will turn out differently from those raised on the coast. She set out to study this by swapping sparrow eggs between Big Creek and Sagehen Creek, a University Reserve near Truckee in the Sierra Nevada mountains. She measured the hatching and growth of the eggs and chicks, and compared them with birds that had been similarly handled but not swapped.
Julie found that coastal birds raised in the mountains took on many characteristics of the local mountain birds, and vice-versa. She also found that the difference was caused by differences in growth of the egg rather than of the chicks after hatching. She thinks that perhaps the parents of coastal birds are away from the nest a lot more than mountain birds (probably to avoid predation on the nest). As a result, coastal eggs stay cooler and get dryer than mountain eggs, and hatch at a smaller size, with different bill dimensions. These differences are maintained through the growth process, and result in different sized and shaped adults.
Julie also found great differences in egg and nestling survival between coastal and mountain populations. Our coastal environment seems to be "loaded" with predators, such that survival is very chancy. Mountain birds had much better nest success. This is probably why those birds are willing to undertake the difficult and risky task of migrating to breed in the mountains. Once they get there, birds have a good chance of raising offspring.
Other notes: The cool weather and periodic rains have kept the flowers blooming and spring going....I have seen several turkey hens this month, followed by 4-13 chicks. After they spot me, the hens seem like negligent mothers, leading the chicks away but not really noticing if the whole brood is following. In one case a hen left 4 chicks completely behind. I suspect (and hope) she came back later and got them. In one case the chicks piled up in the middle of the road like a little pile of stones, and that is exactly what they looked like.... The Red-tail hawks are now brooding at least one chick on their nest near Whale Point, and the Black Oystercatchers are sitting on eggs in their nest in Big Creek cove. (5/19/94)


July 1994. This month Steve Harper, David Nelson, several others, and myself hosted the first "Santa Lucia Natural History Symposium", perhaps the first such meeting of its kind in our area. We invited experts in the various fields of natural history who have actively worked in the local area, to get together for a full day of presentations and discussion. Twenty five people attended, including botanists, ornithologists, marine biologists, , restoration ecologists, an archaeologist and several others. Esalen Institute provided meals and let us use a meeting room all day.
Each participant was invited to summarize what is or isn't known about their field of interest in Big Sur, and to discuss what they feel to be issues of interest and importance to the group. We learned that Corky Matthews' book, Flora of Monterey County was near the final stages of preparation, and should hopefully be available in a year or so. This will be an enormous aid to botanists working in the area, partly because it narrows the field of choices when identifying species, and partly because it will provide detailed information on plants in our county. We also learned about the recently compiled Breeding Bird Atlas for the county, and about the Ventana Wilderness Sanctuary bird studies taking place at Molera State Park. A revision of Don Roberson's Monterey Birds book is also planned. It was clear at the meeting that our birds and plants are at least inventoried, and relative to other subjects, fairly well-known.
The marine biologists painted a different picture. They discussed how the marine plants and animals seem to be changing rapidly, with species from the south often replacing those from the north, and how badly we needed basic information on species distributions and abundances. Nicole Crane also discussed research on rockfish biology, and how important it was for us to try to protect the kelp forest habitat. She is now planning a new project in the Big Creek Marine reserve to monitor changes in the biota.
We received several bibliographies of references from the attendees, as well as books and materials for incorporation into the Big Creek library. We also discussed means for improving the bibliographic and library collections. Our goal is to develop a system for exchanging books, articles, and information among the group, as well as to make information available to the community at large. I plan to put together a bibliography and "proceedings" of the meeting in the next few weeks. This will be available for anyone who wants a copy.
Other notes: The oystercatchers in Big Creek cove just hatched two tiny little black chicks. The parents are carefully guarding and feeding the little ones all day long. They seem to be doing well in spite of the noise of the sandblasting taking place overhead under the highway bridge. The crew plans to take two months to complete the job, so Kim and I plan on a noisy summer. We call it "Yosemite Falls" when the blaster is operating!...We hosted the annual butterfly count: the counters saw 36 species this year, which is typical. If we had a few more counters we could probably get 40 species, since the coverage during mid-day was incomplete. (6/17/94)


August 1994. Researchers from the Department of Fish and Game have been recording ocean temperatures in the Big Creek Marine Reserve. They use an automated recording device called a "Hobo." Since they began recording in May, we have experienced very cold water, with surface temperatures of around 51 degrees and bottom temperatures (at 50 feet of depth) of about 49 degrees. This cold water probably results from several months of strong upwelling in the ocean.
In early July the winds slowed and we had a few days of calm, glassy water. The water was full of plankton and fish schools, and viewing conditions were excellent. I observed thousands of sea birds feeding offshore, as well as whales, dolphins, and other marine mammals. I also saw a group of basking sharks, feeding on the plankton. Sometimes a school of basking sharks congregates on the surface (for some unknown reason), at which time they look like a pod of orcas with huge. floppy triangular fins sticking out of the water. However, this time the sharks were spread for miles along the coast, feeding on plankton. During feeding the sharks are nearly always submerged and the big dorsal fin seldom sticks up in the air. Occasionally the small rear dorsal fin and tail appear, giving away their presence. I called Cheryl Bouduini of the Moss Landing Marine Lab, who is studying these elusive creatures. She came down with a crew to sample the waters where the sharks were feeding. Unfortunately she arrived too late in the day and the sharks had disappeared underwater.
About the same time as the calm air arrived, so did the summer fog. It has been exceptionally cold and wet the last week or so, with daytime temperatures between 50 and 60 degrees here at my house. The creek is also very cold (about 54 degrees). The moisture and cool air has been good for the flowers and the coastal slopes here are yellow from Lizard Tail and orange from Monkey flowers. Several deer are munching the lizard tail flowers with relish. The deer seem fat and healthy this year, and the fawns are chunky as if they were very well fed. Of the approximately six does with fawns I have been observing lately, two have twin fawns, another indicator of good conditions.
Steve Chambers passed along to me a packet of information about range land reform on BLM and USFS lands. These agencies are in the process of reforming their policies on grazing allotments, such that grazing will be permitted only after the kind of review other special use applications must undergo. Grazing fees are also going to be raised. As I read the material I thought about the problems of deciding best use for public lands. Although I strongly favor allowing degraded lands to recover their former productivity, soil characteristics, and biological diversity, I also see a great need for working with, rather than against, your neighbors. My experience working here at Big Creek is that neighbors are potentially the best agents for detecting and solving problems, and that their cooperation should be integral to planning and decision-making. I believe that long-term cooperation is the key. (7/15/94)


October 1994 The Department of Fish and Game just finished their fall research cruise at Big Creek. This summer has been unusual in that the ocean has been turbid and full of plankton since may, conditions that coincide with strong northwest winds. The kelp has been very well-nourished and has grown to be very thick, which makes it very dark underneath. These factors, poor visibility and darkness, severely hampered the divers, and the crew had to struggle to accomplish even part of their research agenda. I just learned that the water is also full of tiny "bat ray" type creatures, which seem to "fly" through the water on 1/2" long wings. These are a kind of swimming snail called a sea butterfly. They use their sticky "wings" (which are actually a modified foot like other snails have) to swim and to gather their food. They eat tiny plankton, which stick to the wings and are transported to the mouth.
Kim spotted a large brown doe with a large white rump patch, quite different from our typical black-tailed deer, which are gray and with the tail covering a small rump patch. We think it was a mule deer from further inland. Does anyone have more information on this?
We have been seeing a golden eagle in the canyon fairly frequently. The typical pattern I have seen in past years is for the golden eagle to be here in summer and fall, with fewer sightings in winter and spring. Winter and spring is when the bald eagles are here. I wonder if they interact somehow?

The coastal scrub vegetation is extremely dry this year. The sticky monkey flower bushes are nearly dead, and some coyote brush plants have died. The creek is as low as it ever was during the 1987-91 drought. There seems to be a pretty good acorn crop this fall, in fact most of the berry-producing trees and shrubs have a good crop. I have been seeing small- to medium-sized flocks of band tail pigeons in the area, a sign of good berry and nut crops.

I just got back from a trip to Glacier Park in Montana. While I was there our group spotted a grizzly bear and we were treated to lots of stories about these animals. The field researchers who work there all carry cans of pepper gas, but have doubts about whether there would be time to use them if they were attacked. I kept thinking how different it must have been for people who were living here 100 years ago, and who encountered grizzly bears on a regular basis. Bears like the same rich food sources that humans do. This means that in those days, if you found a great berry patch or good fish run, a very dangerous animal was probably guarding it.... That brings to mind the thought that it must have been really different 10,000 years ago, when there were as many as 65 species of large mammal living in North America! (9/22/94)


December 1994 On October 9 there was a small wildfire in the highlands area above Devils Creek, at about 2500' elevation. Feynner and I were up talking with the fire crew and noticed hundreds of black beetles crawling on ashes and burned stumps. When I asked the fire crew about them they told me they called them firebugs, and that they appeared at nearly every wildfire. They thought that perhaps they emerge from the ground or tree roots during fires. I saw the beetles mating and Feynner discovered that they were voraciously hungry and thirsty by putting an apple slice down and watching them gather on it. I noticed that they sometimes sit on your neck and make little bites that don't hurt but are annoying.
Later I did some research and called Jerry Powell, an entomologist from Berkeley who works at Big Creek. He told me they were called Melanophila or "smoke' beetles, and that they are attracted to fires, heat and smoke. Sometimes they appear at cement plants or power plants, sometimes a great distance from forests that are their true home. They are attracted to heat and they seem to prefer surfaces at about 150 degrees. Jerry also said the heat of their bodies touching your skin causes the "biting" feeling. Other people say they definitely bite, however. They have small but very powerful jaws that look capable of chewing through wood.
Jerry sent me some articles about smoke beetles' natural history. Other species in same genus Melanophila are not attracted to fires, and they seem to lack special "smoke-" or "heat-detector" sense organs on the underside of their legs. Really very little is known about their life history. What do they do when there are no fires in an area? What attracts them to some fires and not others? It would make an interesting study.
I have noticed unusually large flocks of migratory or winter visitor birds recently. On one walk I felt surrounded by hundreds of birds all afternoon. Ruby crowned Kinglets are very common, but there are lots of other species. I have also seen lots of Hermit Thrushes, more than in the past two years but fewer than the numbers seen 3-4 years ago. Another unusual sighting (for me at Big Creek) are large flocks of goldfinches wheeling and turning in tight formation. They visit the spring up at Whale Point. Once I saw two sharp-shinned hawks swooping through the flocks but I didn't see them catch anything. (11/7/94)

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