Nature Notes from Big Creek, 1992

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January 1992 February 1992 March 1992 April 1992 May 1992 June 1992 July 1992 August 1992 October 1992 November 1992

January 1992. This month we received a copy of the geology report Geology of the Point Sur-Lopez Point region, Coast Ranges, California: A part of the Southern California allochthon. This special paper of the Geological Society of America was written by Clarence Hall, a geologist at UCLA. Clarence spent several months at Big Creek in 1988, mapping the geological faults along the coast between Limekiln Creek and the Little Sur River. According to Clarence, the mapping was challenging not only because of the rugged, brushy landscape but because the land itself is so folded and unstable. Clarence's first task was to map recent landslides, since these cover much of the land surface along the coast and hide faults underneath. Then, working between the landslide areas, he had to locate the exposed faults. Making use of his many years' experience as a "field grunt" geologist, he then determined the angle and extent of each fault.
The resulting maps were very revealing. Before, most local faults had been described as a very complicated series of strike-slip faults (like the San Andreas fault). These faults were thought to have occurred as the continent was assembled like a jigsaw puzzle from pieces sliding into place. Clarence found the picture to be much simpler, with the faults being part of a single "thrust" fault created as the ocean-bottom slid underneath the North American continent 50-60 million years ago. The fault was later folded and eroded into complex shapes and angles, which fooled previous attempts at mapping. The "Southern California allochthon" mentioned in the title is the name proposed for the rock above the thrust fault.
Clarence also verified that a very active fault, the "San Gregorio-Hosgri fault", runs along a line connecting the mouth of the Little Sur River to a point offshore of Lopez Point on the south coast. (The small earthquake we felt last winter was along this fault, deep underground near Lopez Point.) The fault runs right through the Big Sur valley, crosses under Ventana, and runs out to sea at Rancho Grande. A drawing in the report illustrates how stream channels in the Ventana area have been displaced by fault movement, including the "beheading" of Sycamore canyon which may have once carried the Big Sur River. This fault may absorb some of the movement that would otherwise occur along the San Andreas fault.
Other notes: We noticed the autumn arrival of Common Poorwills to the reserve. These birds usually appear in the fall and are seen fluttering along the roads at night, looking for insects.... The Coffee berry bushes are in fruit, providing lots of food for foxes and other animals. Only a small crop of bay trees came into fruit this fall. We have seen very few, very small flocks of Band-tailed Pigeons this year. Perhaps they have gone elsewhere this year because of the scarcity of Coast Live Oak acorns (which are small enough to swallow?) and bay tree fruits. These strong flying birds can go hundreds or thousands of miles in search of good sources of fruit, acorns, and seeds (even as far as Central America).....The redwoods have a big cone crop growing on the trees. I suppose the seeds will drop next fall. Maybe then the creek will turn burgundy red. This actually happened in 1986 after an autumn wind brought the seeds down in huge numbers, releasing their red dye in the water. (12/6/91)

February 1992 Derek Sikes, a student from UC Santa Cruz, has just completed a study of burying beetles at Big Creek. These are wide, black beetles about one inch long with short "clubbed" antennae. They are usually found feeding on carcasses of dead animals. When they find a small carcass such as that of a mouse they will try to drag it away and bury it. Once buried, they will chew off the fur and "mince" the carcass into a food ball, and then lay their eggs. The mothers (and sometimes the fathers) tend the eggs and larvae after they hatch, leaving the food ball only after the young are off to a good start. These creatures are one of nature's ways of "recycling" small carrion.
Another interesting thing about these beetles is that they carry tiny mites on their body. The mites feed on carrion along with the beetle and require beetle transportation in order to locate food. In return for this service, the mites feed on blowfly eggs and larvae. If unchecked, such fly larvae will out-compete beetle larvae, growing faster and "stealing" the food. By killing the fly larvae, mites indirectly ensure their own transport to new food sources by helping the beetle larvae survive.
Beetles of this genus (Nicrophorus) are found nationwide, but little was known of the Pacific Coast species (negrita). Derek's project was to study this species for comparison with other species, and to discover if there were any new, unusual traits or behaviors. This is not a trivial project because California coastal species are usually quite different, owing to the mild, wet winters and dry summers along the coast. For example, Derek found the beetles to be continuously active from March through November, and to be much more abundant than expected. He found a reliable way to distinguish male from female beetles, and that the beetles possess a hidden capacity for red coloration. Derek also found that the mother accurately regulates the number of young beetles living on a food ball so that each beetle has optimum nutrition. Although these findings may seem trivial, they illustrate the complexity of life experienced by each species, even "humble" carrion feeders.
Other notes: UC Santa Cruz graduate student Svarup Wood told me of a fresh Mountain Lion kill at the mouth of Brunette Creek where it joins Big Creek. Although he never saw the animal, he probably disturbed the lion while it was feeding on a deer. When my daughter Annie and I walked to the spot two days later we discovered five small "caches" of deer body parts buried under redwood litter. The remains we found included front legs, broken off at the long bone, and shoulder blades in one cache, broken off hind legs and pelvis at another, the stomach in a third, and miscellaneous body parts in the remaining two. Each cache was covered in piles of redwood litter about 8 inches deep, made by scraping the ground in a circle around the cache. The deer had been very neatly divided and almost totally consumed. I could not find tracks but speculated, based on the apparent skill with which the deer was handled, that this was a kill by a mature animal. Perhaps it was the large lion whose tracks we spotted last month.
I saw a flock of Golden-crowned Sparrows feeding inside a dense thicket of "Lizard Tail" bushes. The entire flock of 30-40 birds emerged one by one from the dense cover and flew away....Above the highway bridge I saw a mature Bald Eagle fly up and sit on a rock. It sat for about a minute then flew off to the southeast. Maybe it was looking for dead fish along the coast? (1/19/92)

March 1992. During the past two months we have found three Ringtails killed along the highway, yet previously I had never seen any of these animals in Big Sur. Ringtails are petite relatives of the Raccoon, about the size of a half-grown cat. They have a long, fluffy tail ringed in black and white. They eat rodents as well as fruits and berries, and sometimes live in cabin attics. They can be very beneficial, acting as effective mousers and seldom making a mess (we had Ringtails in Tucson where I grew up). Their huge eyes enable them to be almost completely nocturnal. I suspect that they avoid lighted areas (or do they shun house cats?), since they are seldom seen by people nor do they live in towns or suburbs. Little is known about Ringtails in California. Does anyone in our area have Ringtails in their cabin or yard, or have other stories? I would be interested to hear.
In January two students were hiking in Devil's Canyon and heard a Mountain Lion growling. This is the same area in which a lion was encountered last summer, and in which lion "screams" have been reported in previous years. It seems that we may have an unusually vocal lion living there, or perhaps the place causes lions to make noise for some reason.
UC Berkeley student Jane Marks is studying stream algae in Big Creek and in the Eel River in Northern California. She is interested in the filamentous type (Cladophora), which is the bright green "hair" that sometimes grows in the creek. She wants to know when it will "bloom," that is, grow vigorously into large masses. We suspect the blooms depend on nutrients washing into the creek from the land. This idea is supported by the fact that the most recent blooms have taken place after the first rains of the season; this year in January and last year in April. In some areas this alga "blooms" in response to human pollution. Big Creek is a good place to study its "natural" blooming.
Barbara Woyt and the Coastwatch citizens group in Big Sur approached me about a study of bacterial contamination in the local streams. Their idea was to compare counts of intestinal bacteria in the Big Sur River, which has experienced problems with contamination, to Big Creek, which has no significant sources of human contamination (not even hikers). The Big Creek count should thus indicate the baseline amount of intestinal bacteria produced by animal scats and other natural sources. I am enthusiastic about the project since it will give us baseline data as well as assist the community in determining sources of contamination. I helped take the first set of samples on December 18, and more samples will be taken as the season progresses. Repeated samples are necessary to accurately interpret the results. (2/18/92)

April 1992. Willows are leafing out along the creek bottom this month. Two species are common in our area, the hairless Arroyo Willow and the fuzzy-leafed Coulter's Willow. The arroyo willow usually grows in clumps, and may or may not have a large trunk. A single clump of arroyo willow usually spreads from parent trees which fall over and root. Such clumps are called "clones" because all parts are genetically the same. This time of year it is easy to distinguish the clones, since each one begins producing leaves at a different date in the spring and/or has catkins of different sexes (unlike most plants, willow trees are either male or female, but not both). Mature catkins are about 1-2" long, and the males have long, slender stamens tipped with yellow anthers, which distribute pollen to bees or into the air. The female catkins have little capsules, about 1/2" long, each tipped by a greenish stigma. The capsules are slender at first, but ripen after they are pollinated. Here at Big Creek I have noticed that, unlike the arroyo willow, the Coulter's willows produce leaves in "synchrony", and do not grow in clumps.
I study caterpillars and other insects that feed on willows. In the early spring at Big Creek, the most important insect herbivore is a "web-worm" (actually three species of web-worm in the moth family Tortricidae). The webworms are highly successful and often strip the trees of new growth during March and April. I found that their success is dependent on the presence of willow twigs of intermediate age. If twigs are too mature when the moths begin laying eggs, the tiny caterpillars will not be successful, and the same thing happens if the leaves are too small. As a consequence, I have found that some clumps of arroyo willow do not suffer much damage by the webworms, while others are defoliated. In contrast, the Coulter's willows are uniformly attacked, which is to be expected since their leaf flush is synchronous. During the last two years all Coulter's willows have been nearly defoliated each spring by the webworms.
I also have discovered that the arroyo willow leaves contain bitter chemicals related to aspirin (one compound, salicin, is occasionally sold as an aspirin substitute). The Coulter's willow leaves are free of these compounds, and have no taste. I don't know how the webworms deal with the chemicals, but I discovered some beetles (in the family Chrysomelidae) which not only tolerate the chemicals but actually benefit from them. The larvae look like little spiny caterpillars (like ladybug larvae if you know what those look like from your garden), but have two rows of glands running down the back. Enzymes in the glands break down the bitter chemicals taken in with the food, to produce sugar and an oily, irritating chemical called salicylaldehyde. This chemical is stored in reversible pockets, which are everted when the beetle is attacked by a bird or ant. The back of the beetle then "bristles" with noxious droplets which may then be withdrawn when the attack is over. The beetles need this protection from their enemies, and, not surprisingly, are found only on certain species of willows that contain the bitter chemicals in their leaves.
Other notes: We saw a pair of Bald Eagles in Big Creek canyon during February, and a few days later saw a pair of Golden Eagles. It also looks as if the Red-tail Hawks are going to move into the same nest tree that they occupied last year. It might be a very good year for hawks and other predators this year. The green foliage caused by our rains is just what voles (meadow mice) need for active reproduction. If these short-legged, prolific little mice get "going", the grasslands could be packed by summer time. Voles make runways through the grass, and, when crowded, make little nests in the grass as well. All kinds of predators are attracted by the abundant prey, from garter snakes to Black-shouldered Kites.
The community is invited to our annual "Neighbor's Day" open house scheduled for Saturday April 4, 9AM to 4PM, at Big Creek. Kim Smiley is planning the program. She says the activities that the Pacific Valley students are planning should be fun for the whole family, so bring yours and spend a few hours learning about California's unique Oak Woodland community. We will also lead hikes to different parts of the reserve including the 6500 year old midden site and the spectacular ridgelines (there should be flowers this year!). We will also give driving tours if requested. (3/17/92)

May 1992. I received a 550-page report produced by Terry Jones, director of the 1990 summer archaeology project at Big Creek. In the report Terry summarized the data from six sites. I was very impressed with the diversity among the sites: no two were the same. The oldest site (the oldest found in Big Sur to date) was the Interpretive Trail midden. This site has been occupied more or less continuously for 6500 years. The earliest occupants used a set of tools known by archaeologists as the "Millingstone Complex"; these people were thought to have settled most of California during 4500 BC.
The redwood terrace site was occupied for only 500 years or less starting in about 3500 BC. This site has mortar and pestle as well as few other technological improvements, but retains the tools of the earlier phase. Terry named this phase of tool and resource use the "redwood" phase, which extends from 3500 BC to 600 BC. This phase corresponds to the "early" period of California prehistory. (A site at Willow Creek defines the following "middle" period, 600 BC to 1000 AD, for the Big Sur coast; no site at Big Creek had an unmixed assemblage of middle period artifacts.)
The "late" period is more diverse, with more than one "phase" at the same time. Terry speculates that new peoples moved into the area after 1250 AD, perhaps mixing with the indigenous peoples. For example, the "Harlan Springs" site was apparently a fishing village, but curiously lacking in arrowheads. In contrast, the Dolan site nearby was occupied at approximately the same time but had abundant arrowheads and less emphasis on fishing. Different yet was the Highlands site, which had fishing gear and spear points but not late period arrowheads. Clearly, sites were occupied by different peoples, doing very different things. Maybe Big Sur was a refuge for peoples fleeing the troubles that seem to have been taking place during that time. Sounds like the Big Sur of today!
Another finding reminiscent of today was that change seemed to take place by "addition" of new tools and technologies, with people still retaining the old ways. Perhaps life in the Big Creek area is so rugged that simple, old techniques work best, with only selected "modern" improvements being adopted. (This rings true to me as I sharpen a machete to go clear a trail.)
Our open house was wonderful! Lots of folks attended, most of who were treated to a marvelous educational experience by the students from Pacific Valley. Kim Smiley and the entire Pacific Unified School (students and staff) deserve thanks from all of us. Their sincere, professional attitude made a tremendously difficult project come off without a hitch. Several volunteers also contributed essential help. Thank you all. (4/17/92)

June 1992. Along the Big Sur coast, ocean upwelling is caused by prevailing winds, which blow along the shoreline from the northwest. These winds push surface water down the coast and, because of the rotation of the earth, they also push the surface water offshore. This is replaced by water from the deeps, laden with nutrients and very cold. This March, winds were mainly from the southwest, and the upwelling slowed considerably, reducing the amount of nutrients available for the marine food chain and changing the current patterns.
David VenTresca of the Department of Fish and Game directs a research project on fish reproduction in the kelp forest. The researchers scuba dive in the spring and summer months at selected sites along the central coast (including Monterey Bay, Big Creek, and Piedras Blancas) and study the tiny "young of the year" rockfish produced each year. Rockfish, or "rockcod," are the most abundant and diverse group of fish living in the kelp forest. David's studies have revealed how the complex life cycles of the rockfish depend on the upwelling currents. For example, Blue Rockfish release eggs along the coast in late winter. The tiny hatchlings are carried offshore by the surface currents, where they feed on plankton in the upwelling zones. In April and May the fingerlings make their way back to shore and take up residence along the shoreline.
As David described to me in early April, the late winter/early spring upwelling was weak this year. As a consequence, the young rockfish probably had little to eat and he predicted this year to be poor for survival. Sure enough, the underwater surveys this month have reported this to be true. As of late May, the numbers were about ten times lower than normal.
The Lucia fishermen have collaborated with this study by providing catch data. Studies of the otoliths ("ear bones") in adult fish reveals the year in which the fish was spawned. By tabulating the year of birth for large numbers of fish, it has become clear that there are "good" and "poor" years for fish reproduction for the Blue Rockfish, with the good years corresponding to the years of strong March upwelling.
Other notes: This is a wonderful spring for butterflies. Yesterday, Jerry Powell saw 30 species in a late afternoon walk. I have seen lots of Buckeyes with huge eyespots sitting at the edge of the road, and little swarms of Common Blues next to the creek drinking. I have also seen many hawk moths feeding at flowers in the late afternoon, looking like small, slow hummingbirds. There also seems to be a vast number of caterpillars feeding on foliage this year. We are having our fourth annual "fourth of July" butterfly count on June 6, so we'll see how this year compares to others. (5/23/92)

July 1992. It was a beautiful winter and spring, and now summer is here. The creek level is dropping to summer flow rates, about the same flow as last June. The winter rains gave us tall stands of bunch grasses and the shrub growth is luxuriant, making up for the previous dry years. I saw a fat, healthy doe with twin fawns the other day, an indication of good deer forage.
This is the "best" butterfly year I have seen, with many species in great abundance. Unfortunately our spring butterfly count was scheduled on June 6, a day with cold, cloudy weather. We saw only 250 butterflies, invalidating the count. We can't re-schedule because the counters' schedules are filled with other count days elsewhere. Still, there were some interesting surprises. One butterfly seen during count week was a brilliant yellow Mexican sulfur butterfly called Phoebis sennae. Apparently the rains in the southwestern deserts have grown nectar flowers and senna plants all across Sonora, Arizona, and California, and the Mexican butterflies have followed. These were once common along the southern California coast and may become re-established now.
Even though this was a good spring for deer and butterflies, it has been very difficult for the rockfish in the kelp beds. The Fish and Game researchers have found that the species of kelp fish, which live in the water column and depend on plankton for food (such as the blue rockfish), seem to be starving. The warm southern water and unusual wind patterns have been preventing upwelling currents from reaching the surface, and the plankton have not "bloomed." The rockfish are thin and often have their stomachs filled with algae rather than plankton. The divers also reported fewer and smaller adult fish in the kelp forest. Where have they gone? One possibility is that they moved to unfamiliar habitats to find food and became prey to predatory fish such as lingcods. The lingcods this year seem to be unusually fat and well fed.
Two Black Oystercatchers nest in Big Creek cove every year. These large black birds have bright orange bills and feet, and live by eating shellfish along the coastline. This year they began brooding eggs in early May, and by June 10 at least one fuzzy black chick hatched. Now the parents are busy feeding bits of shellfish to the chick. I have not been able to see if there is more than one chick in the nest. (6/17/92)

August 1992. A group of divers from UC Santa Cruz spent a week at the reserve during July. Working on a project sponsored by the US Fish and Wildlife Service, they were measuring and counting algae and certain kinds of animals in the kelp forest. Big Creek is one of many study sites for this project, which covers the whole range of Pacific coast kelp habitats, from Alaska down to the Channel Islands in Southern California. Although the project is not finished, the researchers have already found that kelps are much more abundant in some areas than others. They have found that, in areas with lots of kelp such as Big Sur, very little gets eaten in a 24 hour period. In contrast, kelp fronds in other areas (such as Bodega Bay in northern California) get 100% consumed. They attribute the difference to feeding by herbivore animals such as sea urchins and snails, which are so abundant in Bodega Bay that they have consumed the entire kelp forest, leaving only scattered kelp plants. The researchers think that our herbivores are eaten by sea otters before they become too abundant. If true, the sea otter may be an example of a "keystone species," one whose activities can alter the ecological balance of an entire habitat. In this case, their activities may allow the kelp forest to exist as we know it.
The divers studying rockfish reported cold water and some good upwelling near shore, which will help feed the hungry fish out there. They also saw huge fins offshore, which at first they thought belonged to orcas but turned out to be basking sharks. Kim and I paddled out to see these huge fish. Although similar in some ways to the great white shark, the basking shark has very different feeding habits. They swim very slowly and calmly through the water with their mouth wide open, straining plankton (tiny shrimps and jellyfish, etc.) through their gills. From our kayaks we could see their enormous white toothless mouths (about 3-4 feet in diameter) swim right under the boat, followed by huge bodies about 6 feet in diameter and 25 feet long. The dorsal fin (which only sometimes breaks the surface) was a three-foot tall triangle, and the long slender tail trailed behind. They paid no attention to us, and would swim directly at us, only veering slightly at the last second to avoid contact. Occasionally they stuck their pointed snout and tiny eyes up into the air, maybe to look at us. One time they gently brushed Kim's kayak. From our experience I would say these are truly gentle creatures in spite of their enormous size.
Basking sharks are found in cool waters around the world. In warm waters they seem to be replaced by the much larger Whale Shark. Donna Schroeder, one of the marine biologist divers, told me that some basking sharks may be able to lie dormant on the ocean bottom for several months when food is scarce. She thought that California basking sharks may not need to do this, however, since food is probably available year round. One field guidebook says that basking sharks were once hunted for their huge livers, to extract lamp oil. The book also said that they are often found in huge groups of 2-300 individuals, and that less than 10% of each group ever come to the surface. We saw about 15 on the surface at once, so the size of our group may have been quite large.
Other notes: The summer came on quickly and many of the late summer flowers bloomed early or not at all. It was a good year for baby animals; we have had twin baby raccoons, twin young foxes, and lots of does with twin fawns. We also watched a western gull family raise a chick. Earlier in the month there were two chicks but one disappeared. By early August the surviving chick was swimming around the cove, unable to fly but a good swimmer. A few days later we saw it flying. (7/x/92)

October 1992. There has been a lot of animal activity this past month. The deer in the canyon seem very thin. They have eaten all the foliage in our garden and are defoliating everything else around. I don't know if this is just localized to my house area but it is very noticeable. There is hardly anything green left in the canyon! My impression is that this has been a very dry summer for the vegetation and wildlife.
Feynner, our reserve steward, reported an injured bobcat a couple of weeks ago. He saw it staggering down the road on the ridge above his cabin. The side of its head and its shoulder were torn up badly, and the wounds were so severe that they were probably inflicted by a mountain lion. The next day, Feynner and Cheryl Briggs, a researcher, saw a fox in the same area, with similar (though less severe) wounds. Based on this observation, Feynner and I guessed that perhaps a young lion was learning to hunt, and was "practicing." This possibility was confirmed a week later, when Feynner saw the tracks of a medium-sized lion along the road nearby. These tracks were the same size as those of the juvenile lion we found dead on the reserve in 1990.
The kelp has stopped growing and is rotting in place in the giant beds along the reserve. The Harbor Seals have left the kelp bed and the haul out beach, as they do every August and September. I wonder if they are repelled by the kelp decomposition? I seem to remember the kelp breakdown other years, but I am not sure.
Other notes: We had an Osprey (a huge fish-eating hawk), in our canyon a few weeks ago. It spent several days near the beach, probably fishing in the kelp beds. Ospreys are dark brown above and light colored below, and fly with a "crook" in their long wings....Feynner reports there is a young Great Horned Owl at his cabin, begging from the parents....We haven't seen wild boar tracks on the reserve in a long time. Last spring, they seemed to disappear from the reserve. (9/15/92)

November 1992. This month Terry Jones brought a group of six archaeologists to Big Creek to study mussels. Their goal was to measure the sizes of mussels growing in "safe" areas where people haven't harvested them (in recent times). They went out in kayaks and sampled mussels from the shore. They tried different harvesting techniques, measuring how long it took to gather and prepare the food. They also weighed the meat and measured the shells for comparison with midden shells. They found that it is much more efficient to individually pick the largest mussels rather than to try and gather sheets, and that the sizes of the mussels gathered correspond well to the sizes in the oldest layer of the 6500 year old interpretive trail midden. They also found huge quantities of commensal barnacles and other shelled organisms riding on the mussel shells, which might account for the presence of these rather inedible creatures in the middens.
Mussels were an important food for the people who lived here in prehistoric times. Analysis of mussel shells from the middens at Big Creek has revealed an amazing fact: the prehistoric peoples harvested them continuously for over 6000 years without depleting the resource. This is evident by averaging the sizes of mussels gathered from the different layers of the middens; the sizes are roughly constant between 6000 years ago to the present. The only exceptions were at the very bottom of the midden (6500 years ago) where somewhat larger mussels were found, and in the time of great ecological upheaval around 1200 AD, when mussel use seemed to stop temporarily. This is wonderful scientific evidence for the possibility of "sustainable" resource harvesting over long periods of time. "Sustainable use" is obviously the only way our culture is going to make it into the 22 century, so let's learn from some situations where it actually happened!
Other notes: The deer continue to inhabit the gatehouse yard. On Monday morning, after returning from a four-day trip to San Jose, Kim discovered a dead fawn in our laundry room under the house! It had been partially eaten 2-3 days ago by a Mountain Lion, with a big hole in the side where the lion had pulled out the lungs, liver and guts. The hindquarters were eaten too. The deer was about four feet long and had lost its spots about 3 weeks ago. I carried the carcass up the road and left it to see what would happen to it (some coyotes finished it off).
We guess that the lion was same young one, which attacked the bobcat, and fox last month, and which has been living in our area recently. At least now it seems to have learned to hunt deer! It also did not return to the kill after Friday evening when a group came in, possibly indicating some caution around humans (of course, it could have made another kill and felt no need to return to the first).
I saw a wild goat running up the cliffs by the beach. It looked like some Asian species, all brown (no black, gray or white) and agile as a Rocky Mountain goat. Does anyone have any information about such animals in the area? I would like to find out more about them. (10/19/92)

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