[instrumental music]
And that's going to lead me to the second part of my talk, which is about archaeology as historical ecology.
In which I'll try to trace ecosystem change on the Northern islands through 12,000 years,
right up to the present restoration era.
And as I said before, historical ecology tries to unite paleontological, archaeological, historical and
ecological scientific data into an understanding of how ecosystems have changed through time and
how humans have affected them.
And establishing baselines from the past of what ecosystems look like turns out to be really
important, because its guiding conservation and restoration efforts on the islands and elsewhere by
defining conditions that predate this era of European colonization and widespread ecological degradation,
we can set baselines about what ecosystems looked like 400 years ago, 1,000 years ago, 10,000 years ago.
An increasing number of biologists, restoration ecologists, the National Park Service, The Nature
Conservancy are understanding and working with archaeologists actively now, to cooperate,
to try to figure out how to take these ancient data, which seemed esoteric to many people 20 or 30 years ago,
and use them in a practical sense to restore the ecosystems of the islands and
other areas around the world. [slide change] It's really, really cool.
So to start that historical ecology just remember that the Northern Channel Islands have changed dramatically.
Over 20,000 years, or less, they've lost 70% of their land mass as Santarosae broke apart.
And this, in really important ways, shaped the ecology and ecosystems of the Islands.
[slide change]
Uh, I wanna-I have a few slides here that just document how we do historical ecology.
And part of it is as I said paleontology. Here's my wife, Christina Gill, standing next to what's called a caliche
root cast on San Miguel Island. This is a tree of late Pleistocene age that the root, and root systems,
and the base of the trunk have been preserved in calcium carbonate. This one's about that big
around, maybe a little smaller, but some of them are that big around.They're Douglas firs.
So there were Douglas firs and other coniferous forests that are much more typical of Northern California or
Oregon today in the late Pleistocene. And those have largely disappeared from the islands.
This is one way we can understand plant system changes through time. Another one is to study
pollen remains, on the upper right. You can find them in sediments, sometimes lake sediments, ancient soils.
And they are very distinctive as you can see. You can identify a variety of different species of plants and
quantify them. Show the changes through time.
And then, a piece of work that my wife Christina is doing, is really important, it's using charred plant remains from
archaeological sites. Right now spanning about 10,000 years on the Northern Channel Islands.
And her work is showing that these particular charred remains, these are the corms or underground root
storage systems, like bulbs, of something called blue dicks, Dichelostemma capitatum.
And she's finding them in virtually every site that we excavate on the islands, or sample on the islands
spanning 10,000 years. And that is a really interesting story that I'll get into to.
[slide changes]
Another thing that we can do, is just, as I said, by taking a single shell from an eroding soil or an eroding sea cliff,
send it off to a radio carbon lab-it now costs $179 per sample-and they'll send you back within a few weeks a
date with a plus or minus of about 21 to 25 years. That's extraordinary advances in radio carbon dating.
And we can go to a place like this, this is San Miguel Island. This is Torrey Rick and another one of
my former students. To give you scale, this is a 100 foot dune, 120 feet maybe.
And you can see soil here, soil there, soil, soil, soil. There's soils down here.[indicates white areas on slide]
Soils down there. Soils here. Soils up there. And they all have shell middens,
the debris of Island Chumash occupations.
And you know, with just a couple thousand dollars, and a little bit of time, we can reconstruct a sequence here
that shows us 7,250 years of Chumash history and also ecosystem history.
Both the terrestrial ecosystem and the marine.
And we've done in this a number of places on San Miguel, Santa Rosa and now Santa Cruz and
they're allowing us to compile these really deep records, and really detailed records of
cultural change and ecological change through time.
The other thing that this has done, and we published a paper about ten years ago, is by doing this you can also
measure the build up of dunes on San Miguel. And that's important because these surges
in dune building have important ecological implications.
They change the coastline from rocky shore to sandy beach. They change the hydrology of where you can
get fresh water. They change the plant communities that live on them. And by charting dune building it
tells us another story about the changes in the geography of the islands through time.
[slide change]
So now I take you briefly to the historic period and the historic Chumash.
This is a, on the upper left, an old map of historic Chumash villages along the mainland, in the interior,
on the Channel Islands. This is about AD 1760, estimates of population sizes just before Spanish contact.
You can see there are about 20 historic villages known, maybe 22, 24 on the Northern Islands.
And some of them are relatively large with up to 250 individuals. There are larger, purportedly, villages
around the Goleta slough, Santa Barbara, mouth of the Ventura River. So it appears that populations were
even higher along the mainland, but we're actually not sure about that.
That's something we're taking another look at.
My main point here is that this is a large Chumash village from the historic period.
These are giant house pits. You stand in the bottom of them and the rim is up like this.
And they are composed entirely of shellfish, and animal bones, and charcoal, and burned rocks, and
artifacts left behind by Chumash people for millennia.
In this case, I think this site is up to six or seven meters deep. What's that, 20 feet? Twenty five feet?
These contain, literally, millions and millions and millions of shellfish, and fish bones, and marine mammal bones,
and bird bones that can help us reconstruct really detailed records of not only the Chumash life ways and
economy, but of the ecosystems that they were living in and harvesting from.
[pause]
And the Chumash, as you know, had a very diverse and sophisticated maritime technology,
intensive regional trade with other islanders on the mainland, and it was based on a, on a monetary
economy using shell beads that were produced almost exclusively on the Northern Channel Islands.
[slide change]
So we have these very long records. We can start at 12,000 years to historic Chumash times, but
in order to compile complete sequences and connect the ecological studies of the 50's, 60's 70's, 80's and
today with the historical data on fisheries, with the archaeological data, we had a problem on the
Channel Islands. That problem was that the Chumash were removed by the Spanish fathers in the 1820's.
And we had a gap of about 100 years where we didn't know anything, basically, about what the ecosystem
looked like. There simply were no data. At least we didn't think there was any data until we started
thinking about some things that we'd largely been ignoring for years. One of them was these [middens]
There are scores of these on the Channel Islands. They are Chinese abalone processing sites.
After the extermination of sea otters on the islands, and the removal of the Chumash, the black abalone
populations in the intertidal zone were released from predation and just went crazy.
Abalones piled on top of one another. Chinese came over, mostly to work in the gold fields.
They have abalones in China, but they would have been over fished. And some of them came to the coast and
saw these incredible fisheries and they started systematically harvesting an intertidal
industry of black abalone processing; drying and then shipping to San Francisco and Chinese communities in
the West, and also all the way to China. And we kind of knew about these sites, but, you know,
we just weren't very interested in them.
Until we started thinking about historical ecology, because these date between 1850 and about 1900.
Right in that gap that we wanted to fill.
So one of my students, Todd Bradjee, who has a book, actually just about to come out, on the Chinese abalone
processing industry and its archaeology on the Channel Islands, started working on these and filling in
one of the gaps. [slide change]. The other way, that was kind of unique, that we helped fill that gap,
was a bald eagle nest on San Miguel Island.
And many of you probably know the story about the collapse of the island fox populations,
being preyed upon by golden eagles after the pigs and piglets had been removed from Santa Cruz Island.
The golden eagles started preying on foxes and nearly drove them to extinction.
One of the reasons they did that is because there were no longer any bald eagles on the islands.
They had been eradicated by the 1940's and 50's by ranchers and ultimately by DDT.
And that allowed the golden eagles to come out because bald eagles will normally keep golden
eagles out of their range.
So, this cascading series of ecological changes that started with the local extinction of bald eagles
almost led to the destruction of the island fox.
Well the park service, and The Nature Conservancy, and other agencies, once they'd figured out this story,
wanted to reintroduce bald eagles to the islands.
But before they did that, they wanted to make sure, if possible, that bald eagles wouldn't eat foxes as well,
because they didn't know for sure. They knew they'd coexisted for a long time, but,
they wanted to make, you know, let's cross all our "t's" and dot all our "i's."
They sent Paul Collins, biologists at Santa Barbara Museum of Natural History, Don Morris, retired
archaeologists with Channel Islands National Park, and myself to western San Miguel Island about ten, er
ten years, 15 years ago to excavate this amazing eagle nest. And there are photos of eagles nesting
on this in 1937. I'll show you one a little bit later. We excavated this pile of sticks like an archaeological site,
shifting all the remains, and the soil around it, and recovered 10,000 pieces of animal bone and
animal shells. And we analyzed all 10,000 of those and only three or four of them were island fox.
And those bones were from really, really old individuals that it looked like may have died and
then been scavenged. Because bald eagles are heavy scavengers as well.
So, basically the idea was, yes, it's safe to bring the bald eagles out. They won't kill the foxes.
But in the process, those 10,000 bones and marine shells told us a tremendous amount about bird and
shellfish and fish populations on San Miguel Island between 1850 and 1950.
It was a cool project that ended up having some really interesting practical implications. [slide change]
Okay, so now quickly through my historical ecology reconstruction of ecosystems through time.
Back to Daisy Cave. There's a 10,000 year sequence there of both paleontological and archaeological, of
Chumash harvesting. Around the corner is a site called Cave of the Chimneys.
And that site was occupied multiple times over the last 8,500 years ago. And when Daisy Cave was abandoned,
people seemed to have moved into Cave of the Chimneys. So we did small test pits in each of these,
collected very large samples of animal and plant remains from both sites, and then
compared them and together we have almost 10,000 years of, more or less, continuous occupation at one
spot on San Miguel Island. Incredible preservation and an incredible record that's just almost unparalleled
on the islands or on the West Coast of North America.
Interestingly enough there's a lot of evidence for fishing in kelp forest and it appears to be very stable over time.
We analyzed 50,000 fish bones and they're more or less the same species all the way through.
[slide change]
But using those records and some from nearby sites we can at least show some general trends in ancient
Chumash harvesting and economy. And this is just a simple graph that plots the meat yield of shellfish,
fish, and sea mammals-probably seals and sea lions, sea otters-through time.
Ten thousand years ago to 7,500, in 2,500 year increments to the present.
And you can see here, early on, shellfish are making up 80-85% of the protein or the meat we can measure and
it declines through time. By this time [indicates last bar: 2,500-0] there's still lots and lots of shellfish, but
they're getting smaller, as I'll show you. The other thing is that fish are going up astronomically.
And there's a total reversal. Even though there's still lots of shellfish remains being taken out of the local marine
system, there are a lot more fish. And so fish end up dominating the diet. And marine mammals
sorta gradually grow through time. The same general increase. So these are adaptive adjustments,
shifts probably to changing environments, changing technologies, and also changing population levels, and
changing impacts to local ecosystems
[slide change]
Here's one of those, I mentioned that shellfish tend to get smaller through time, and we've shown this for
California mussels, owl limpets and black turban snails, but its maybe most dramatic in
the red abalone populations. There's something we call the red abalone midden phenomenon
where there are very large and very dense middens that are mostly red abalone, and the red
abalones are always huge. The heyday of that is around 3,500 to 8,000 years ago.
And you can see that it's not a perfect picture. This is a statistical average,[pointing to angled, red line]
but overall, we have very large abalones here at 7,500 years. Still big here. Some sites with smaller ones, but
there's a general trend-and look at the last 3,500 years-there, down here, they're less than half the size
they are up in here. And we think these, this is because of human predation, the effects of human predation.
The other thing that was really interesting when we plotted this out and we started talking to biologists,
those same kelp forest biologists that I met in 2000-2001 in Santa Barbara, and I showed [slide changes]
them a picture of this. This is a San Nicholas Island red abalone midden and
it's about 55,000 years old, I think.
And there are hundreds, maybe thousands of red abalones, and, you know, there's-that's probably a black
abalone. But look how big these are. These things are like dinner plates.
And I was just breezily blowing through my overview of Channel Islands cultural ecology, like I am today, and
I went right by this, I said this is a red abalone midden. They usually date between 7,500 and
3,500 years ago. And I went on to the next slide and the kelp forest biologist were like, "STOP! STOP!
Go back. What's that?" And I said that's a red abalone midden. And they literally couldn't believe it.
And the insight that they provided that no archaeologist had ever realized-'cause we're not ecologist-was,
that they said, and it's backed up by modern fisheries data and ecological monitoring wherever sea
otters are expanding into new areas, where there are red abalones, they said it was not possible for this
kind of shell midden with these kind of red abalones to exist if sea otters were not-we're abundant or even
present in the local ecosystem. And I said, but wait, we know they were present. We find sea otter bones
all the time. But they said that, I-that's fine, but they must have been depleted, they must have been reduced, or
hunted out of certain areas. And it made me think a lot about 8,000 years ago when these first show up.
And in fact, we have one of these now at 12,000 years ago associated with all those little barb points.
[pause]
Something had happened as early as 8,000 or even 12,000 years ago where the local Chumash people, or
their ancestors, were probably hunting sea otters and depleting them down to a point where
the red abalone populations were exploding.
And the, you know it actually makes a lot of sense because sea otter fur is the most luxuriant
fur in the world. And you live on a cold, windy, foggy island and you can imagine that every single Chumash
person would probably want to have a sea otter robe, sea otter blanket, sea otter cape, something like that.
But as populations of humans grew, there weren't maybe enough sea otters and they depleted them.
Never wiped them out, but depleted them, and then because they were active foragers with traditional
ecological knowledge of the intertidal zone, they couldn't help but have understood that the red abalone
populations and black abalone populations exploded.
And it makes me think that, it'd be hard to prove, but that the Chumash after that point may in fact have
depleted otters, not just for furs, but to keep the productivity in the intertidal zone high.
An active kind of management to enhance the productivity of the local environment.
[slide change]
Well that raised another interesting question and it was related to the island foxes.
And when we started this work, um, on historical ecology, it was widely believed that the island
foxes had been there since the Pleistocene, on the Northern Channel Islands.
There were museum specimens that were supposedly found in Pleistocene sediments.
The biologist then believed that humans transported those natural foxes, island foxes, to the Southern
Channel Islands about 5,000 years ago. Well, we got interested in this issue and decided to
radio carbon date all those fossil fox bones. And what we found was a surprise.
None of them were Pleistocene in age. The oldest one was 6,500 years old. We've now dated 20 or 30
additional fox bones from archaeological sites. None of them are older than 7,000 years.
And this now makes us believe that, actually, the Chumash brought the Island Fox to the
Northern Channel Islands. It was not a Pleistocene endemic animal at all.
A really interesting idea. It remains somewhat controversial, but, um, I think the evidence is growing
rapidly and strongly towards a human introduction of the fox to the islands.
What's really intriguing to me, is if they brought them about 7,000 years ago, as it seems, it's
just about the time when the otters appeared to have been depleted. And so maybe they brought them out as
pets, but maybe they also brought them out as fur bearers because they needed another source of
nice warm blankets, pelts, capes, etc. [slide change]
So then that leads us to another question. [slide change] What about the Island Skunk?
How did it get there? Skunks aren't good swimmers. Ummm, whoops, sorry [slides changes back to skunk]
There are not any Pleistocene bones that we know of, we have not dated any of the skunk bones yet, although
I'll bet we'll get to that in the next few years.
But I suspect that the Chumash probably brought skunks to the islands as well. And that raises a really interesting
question about what kind of boat ride was that. [audience laughs]
That could have been a really interesting boat ride. A long trip.
[slide change]
Well, so, part of what I'm showing you is some impact of Native Americans on shell fisheries.
We can see it also in some fisheries, we think, measurable changes in fish bone size through time.
But there are really very few or no extinctions. The island mammoths, the pygmy mammoths, went
extinct about 13,000 years ago. About the same time that humans got there, but there's never been a kill site
of an island mammoth, either Colombian mammoth or pygmy mammoth. We may find one at some point, but
we know at that same time the islands were shrinking rapidly. Their habitat was shrinking, and
they appear to have been eating conifers in part and those were disappearing about 13,000 years ago too.
So I suspect the island mammoth was going down. And if humans did contribute to their extinction, it was
probably no more than a coup de grace, and we can't even prove that.
There is one extinction that we can prove. And with Terry Jones at Cal Poly, San Luis Obispo, and
a group of other archaeologist, myself included, we published a paper a few years ago about
Chendytes lawi, this plumb little flightless duck that used to have ground breading and nesting colonies,
large ones, on San Miguel Island that have been dated to 14,000 years ago.
They're not there any more. They are extinct all along the California coasts. They have been found
in numerous archaeological sites including that burn specimen from 11,750 years ago on Santa Rosa Island.
They went extinct about 2,400 years ago on the California coast. No longer exists.
The only well documented extinction that can be attributed to Native American hunting.
Although, I think dogs and foxes may also have contributed to their disappearance on the islands and
the mainlands. Not completely Native American hunting.
The really interesting thing about this case is that human overlapped with Chendytes for at least 10,000 years.
And yet it took 10,000 years, close to 10,000 years for them to go extinct.
That's a very long, protracted process. It's very different than flightless birds that you see in other island
groups around the world like New Zealand and Hawaii, or not Hawaii, but other Pacific islands, where
human hunting tends to tip them over to extinction, sometimes within a few hundred years,
a thousand years at most. So this is a very different kind of extinction that takes a very long time.
[slide change]
Um, one other interesting pattern that we've looked at. We've just kinda gone by animal group to animal group.
This is pinnipeds. Seals and sea lions. There are six different species on the North Channel Islands,
which is extraordinary, worldwide. The highest number of species in any one area that I think are recorded
anywhere in the world.
And they go anywhere from the huge elephant seals to the relatively diminutive harbor seal.
Archaeologically we can trace patterns of pinniped hunting back 10,000 years.
There are thousands and thousands and thousands of seal and sea lion bones in museums
from the Channel islands and up and down the Pacific coast and the modern pattern on the islands is
really dominated, even though they're six species present, they're dominated by northern elephant seals.
There are thousands of them and they take up enormous amounts of space. But when you look at
the archaeological data, there's almost never any hunting of elephant seals on the Channel Islands, and
it's rare along the mainland coast as well.
And that's really interesting because what is abundant archaeologically is the Guadalupe fur seal,
which barely even exists on the Channel Islands today.
They' re called the Guadalupe fur seal because the only place they bred was Guadalupe Island off Mexico.
And only in the last few years when there are 150 or 160,000 seals and seal lions of the other five species
have Guadalupe fur seals been shown to arrive, and pup, on San Miguel Island,
only a handful of them have been documented, but archaeologically, they are by far the most abundant.
So there is a disjunct here between the historic restoration situation and the ancient situation of
the last 10,000 years. [slide change]
So a big picture overview. We can now put together 12,000 years of sorta generalized picture of
economic change, paelocoastal-mostly marine hunting, waterfowl and birds, some shellfish, some fishing, um
but it looks like there is a lot of hunting based on the technology.
By the early Holocene, starting about 10,000 years ago to 8,000 or 7,500 years ago, the emphasis is
really heavy on shellfish collecting.
Most of the meat comes from shellfish. And its supplemented by fish, marine mammals, and birds,
and plant foods importantly, but shellfish seem to dominate.
In the middle Holocene, there's this gradually intensification of fishing and pinniped hunting, and
that really ramps up in the late Holocene, which is the last 3,500 years into the heyday of Chumash,
Island Chumash occupation, 1,500 to 500 years ago
with really intensive fishing in kelp beds and near shore, but also expanding into the big, pelagic fish like
swordfish, pelagic sharks, big tunas. And this we think is a technological, technologically facilitated expansion.
It's partly new types of fishhooks, circular shellfish hook here, starts about 3,000 to 3,500 years ago and
fish bone is ten times more abundant after that period. But these big fish out in the pelagic zone, are probably
being taken from tomols. The famous sewn plank redwood canoes of the Chumash.
And they're so stable that they allowed people to go out and do, really, open water fishing and harpooning of
these really big fish and then bring them back.
So, this is kind of, as I said, a broad overview. [slide changes]
So what we see there then is thousands of years, really, of sustainability and resilience.
The same species, almost no extinction. Yes, there are size changes in shellfish. Yes, there are changes in the
proportion of shellfish versus fish. But it's an incredible picture of 10,000 to 12,000 years of sustainable
economy and, more or less, stable ecosystems, and resilience of the ecosystems, and
all of that comes to a crashing halt in A.D. 1769 when the Spaniards arrive on the California Coast.
And the missions are built one by one in Ventura, and Santa Barbara, and up and down the coast.
This is often kind of a romanticized, you know, the mission period, the mission fathers, the Spanish
uh, we've got Fiesta Days in Santa Barbara, Spanish architecture everywhere, but
it's worth remembering that this was a period of tremendous suffering and really terrible
time for the Chumash. Um, old world diseases that they'd never had any experience with,
had no resistance to, decimated them. Probably 90% of the population died within 50 years to
60-70 years in the mission period. From disease alone.
And then, uh, you know, everything else that colonialism brought in, and the ranching and a total conversion of
globalized economies, and trade, and over hunting and over fishing and over grazing that comes after that.
[slide change] And that's-this globalization of world economies led to things like the Sea of Slaughter.
There's a great book called Sea of Slaughter that talks about the 18th and 19th century whaling and sealing,
um, mostly to produce oil that was burned in lamps in Europe and America and only really stopped once
petroleum production started, people figured out how to make fuels from petroleum,
but uh, worldwide decimation of marine populations. [slide change]
The fur trade, this is in Alaska, but the piles of furs here; furs seals, sea otters and many other fur bearers
were just hunted nearly to extinction or to extinction. Around the world.
The ranching period is also romanticized here in California and on the islands.
But the early ranching, with heavy livestock levels especially of sheep, and pigs, and cattle, and horses,
the introduction on Santa Rosa of deer and elk,
fundamentally altered the ecosystems of the Channel Islands. And it's only with their removal,
relatively recently, that things are starting to restore and we're getting a better picture of what
the real Channel Islands looked like.
[slide change]
At the same time in that historical ranching era, there were a lot of new species, exotic species, of plant.
Olives, grape vines, eucalyptus, fennel-for cooking-Italian cooks on the Channel Islands brought fennel out, and
it spread like wildfire and changed fundamentally some of the plant communities out there.
This is one of the next big challenges for the park service and The Nature Conservancy is to
figure out how to get rid of some of the invasive plants now that they've successfully
removed the livestock and other exotic mammals.
[Slide change]
Yet, the devastation that was reeked in this colonial era and continues worldwide in many ways,
on a planet that is so altered by humans that scientists are on the verge of recognizing a
brand new geological epoch.
There's the Pleistocene and then the Holocene and I would guess within a year or two
they're going to officially designate the Anthropocene as a new geological epoch,
marked by human domination of global ecosystems and systems in period.
Watersheds, water, fisheries, um, atmosphere, the presence of radio-radioactive isotopes and
ice, ice in Greenland. It's an amazing story of the accumulation of human impact on
earth ecosystems through time.
And I believe it-we will be living in-well, I think we are living in the Anthropocene now.
The big debate we're having is whether the Anthropocene starts in A.D. 1950, as
it looks like it's going to, or whether it should really start 10,000 years ago or 5,000 years ago
when agriculture was developed and other changes around the world started to accumulate. But in this
geological epoch, the Anthropocene of human domination and alteration and
intervention of natural ecosystems.
One of the reasons I keep going back to the Channel Islands is that they, for me and many others, are
literally landscapes of hope and inspiration. They are what California used to look like.
And every year, they're starting to look more and more like what California used to look like.
And The Nature Conservancy and the national park services removal of livestock and other exotic mammals
is literally restoring the islands terrestrial ecology, changing our notions of biodiversity,
the nature of edible plant foods on the islands, animal populations, and the very hydrology of the islands,
the fresh water resources. When everything was mowed down by sheep, goats, cattle, [pause]
the plants were so low to the ground that they didn't extract almost any water out of the fog
Now the plants are growing up again and they're literally combing water out of the fog,
what they call fog drip, and it doubles in many places the annual precipitation on the islands.
It's changing the very nature of watersheds out there and the availability of fresh water, which
we used to think was really restricted. Now we better understand why there were huge Chumash villages
out in the middle of a spot where there's no fresh water.
It's because the fresh water resources have been so altered in the last 150-200 years of ranching, and
erosion and plant change.
This, I told you about blue dicks, the Dichelostemma.
This is on Santa Cruz Island last year, after three years of severe drought.
And everyone of those purple flowers is a blue dick with a bulb full of carbohydrates, like a potato, about that big.
And Christina, as I said, has been finding these in archaeological sites everywhere.
This is an absolutely incredible resource, edible food resource, that the Chumash had for 10,000 years that
we literally didn't know they had until recently, or we didn't know how abundant it is.
It's virtually inexhaustible, I think.
And so archaeologists used to think the Chumash had to import most of their plant foods from the mainland.
I don't think they had to import anything.
If they brought anything in the way of plant foods from the mainland, it was like a spice, or something different.
You might get sick of blue dicks everyday after 361 days of eating them, although they're pretty tasty.
But it's a phenomenal resource and its also one of those success stories where we can now see that
native plant communities are coming back from 150 years of devastation.
[slide change]
There are other success stories just like it. The island fox is a great one.
The park service with The Nature Conservancy and other partners has done a great job of managing and
restoring and reviving a very threatened species of island fox. And I don't care whether the Chumash
brought the fox there or not, it's been there for 7,000 years and its an important part of those
island ecosystems today.
When those foxes were put in cages for captive breading, I gotta tell you, doing archaeology
on the Northern Channel Islands got pretty rough.
Seagulls were everywhere and they harassed us relentlessly and it was just terrible.
[audience chuckles]
Anacapa Island and Santa Barbara Island are like that today. They are dominated by seabirds and
we want to keep them that way.
But on the Northern Channel Islands, when they let the foxes out of those cages,
those birds are still there, but there not as abundant and it's a lot more pleasant working out there.
[audience laughs]
[side changes]
Another great success story, I told you about that eagle nest that we dug.
It was, I don't know, that's a pretty big bird and that's a huge nest. It's built entirely out of lemonade berry roots.
And all those lemonade berries that used to live on western San Miguel Island, which is
like a caliche, eroded landscape now, it
apparently was full of lemonade berries earlier in the historic period.
The cattle and sheep ate them, they died, the roots became available, eroded on the surface,
the eagles picked them up, made the nest. I can't tell you-someone who's worked a lot in Alaska,
seen a lot of eagles-how wonderful it is to go back to the Channel Islands and see eagles
flying over the landscape naturally and nesting on the islands. Great success story.
[slide change]
The pinniped rookery on San Miguel Island, this massive Point Bennett pinniped rookery with sea lions here,
sea lions there, all over here, all over there. Elephant seals, fur seals, you know, at any given day there
might be 50 or 80,000 of these things barking 24 hours a day. It's an amazing place to camp and do work.
Um, there are archaeological sites on these points.
I've had a pinniped biologist take me down there, shoo them away gently, briefly,
and they're destroying those sites, and so we're doing everything we can to at least date them, and
sometimes take a small sample before the pinnipeds destroy them completely.
It's, but this too, in 30-40 years is a tremendous success story. The weird thing about it, as I said is that this is
a population of pinnipeds, six different species, that's reviving, restoring, coming back, but
it's coming back in a structure that we don't recognize in historical or archaeological data.
They're reassembling themselves in what might be natural conditions, but they might not be.
And maybe they will eventually reach a natural condition that we can see in the archaeological record, but
maybe we won't. I think what we need to celebrate for now is that there is
a 100,000 seals and sea lions at Point Bennett.
There is, by the way, a house pit, a big Chumash house pit village down in this area, in the middle of that rookery
that was occupied 500 years ago. And I guarantee you, when those people lived there was no rookery or
pinnipeds around that village. [audience laughs] So that again suggests that
it may something of a historical anomaly, but something like it has existed for 10,000 years,
probably just more likely that it was out on rocky islets offshore than on the mainland here.
[slide change]
And so, in concluding part two, archaeology and historical ecology tell us that the Channel Islands
and the mainland, Ventura County, have changed dramatically over the last 15,000 years
since humans have been here.
The Island Chumash actively shaped island ecosystems for millennia. They had measurable impacts to
some resources that we can see. And they also, I think, actively managed the habitat and enhanced the
habitat via things like periodic burning that kept grasslands larger
and kept blue dick fields, corm geophyte fields more extensive.
The Chumash clearly thrived on the islands for many, many thousands of years, and
they created an amazing, complex, sustainable culture and economy, and
it was devastated by European colonization. The Island Chumash were removed, um
many of them died to diseases, the traditional economy, the monetary economy, the trade networks
all broke down and over 200 years of overhunting, overfishing, overgrazing
fundamentally changed the nature of Channel Islands ecosystems. And actually, to such an extent that
at one point we thought they were relatively marginal habitat for humans.
And now, I believe they aren't; I think they were paradise for 12,000 years or more, and
paleocoastal peoples went there immediately and stayed there forever because the resources were
amazingly rich in ways that we can only now understand, because the restoration of the islands
is providing these lessons of hope, inspiration, resilience
as well as a new understanding of their original richness of these island ecosystems.
[long pause]
I might have one more. [slide change] Thank you!
Along with thanking all of you, I want to point out that what I've talked about tonight is not just my research.
This is 50 people or more working for 30 or more years. Lots of students that aren't listed here.
There are Chumash people, and archaeologists, and biologists and geologists, park service people,
Nature Conservancy people listed here. I'm quite sure I forgot many that I should have put on here, but
there's only limited space. It's also been funded by a wide array of different agencies, and
universities, and institutions, museums, and supported in a major way by the National Park Service
and now The Nature Conservancy and I hope all of you will continue to support the park service,
Channel Islands National Park, the marine sanctuary, The Nature Conservancy, and all these other
good organizations and individuals that help us not just understand the past, but use it
to more effectively create a sustainable and amazing ecosystem off our coast.
[slide change]
I leave here with that last frontier I mentioned before and a picture of me in a submarine last fall.
This is not what I normally do, but The Nature Conservancy got a submarine for four days.
Uh, somebody donated the use of the submarine and they insisted that if they were gonna pay a little
bit of money for a support boat, that I had to be in the submarine. And it was to explore the sea bottom
between Santa Rosa and Santa Cruz islands, that area that I mentioned called Crescent Bay.
It was, initially I wasn't going to do it, and then I thought "Oh, when are you ever going to get a chance to do this."
I had no idea that the submarine was only four and half feet long in the interior.[audience laughs]
And I'm six feet tall. So my face was literally, I'm lying on my stomach like this with my face in a face plate,
my legs buckled up behind me for two hours of every dive. It was unbelievably uncomfortable,
we filmed the sea bottom the entire time and I've never done anything more exciting in my life.
[more laughing] So anyway, that's all I have to say. There is a last frontier out there,
uh, these submerged landscapes. We've just started this four year project to try and map them and
understand them and see if we can actually find evidence for human occupation off the current shore
which will add another exciting chapter, I think. So stayed tuned.
[audience claps loudly and camera pans out to show Dr. Erlandson at podium]
[clapping ends]
(female moderator) So we'd love to open it up for questions now if anyone has questions for him
and if you'd like to wait for the microphone [other inaudible directions]
[long pause]
(female audience member) I'm really interested in the crescents and how they used the crescents, um,
did they have any kind of bows or did they just throw them at the birds or [er, um] did they have to get
close enough to hammer at them? How did that work?
(Erlandson) And I'm supposed to repeat the questions for the camera. And so, ah, the questions was
you're very interested in the crescents and how were they use? And our best guess at this point is
that they were tied to the end of darts that were then thrown with atlatls, the throwing stick
that's sorta like, you know, leverages-it's like a tennis racket-it allows you to throw a dart a long ways.
And, um, so that's what we think they did.
We don't think they had the bow and arrow this early, although in Japan, they think
the bow and arrow did exist this early, so we're not absolutely sure, but most likely they were put on darts
and then launched at either individual birds or birds in flight.
[pause]
(male audience member) I have a question. In the expansion that happened [interruption]
[now louder with microphone] In the expansion that happened in the 40 to 50,000 years ago from the
Pacific, in your slide it showed them going back up to the north. No chance like for higher ground (?) or getting across to
South America, back then? Or...
(Erlandson) Yeah, was there any chance that rather than come around the North Pacific Rim that they
went across the Pacific, 40 or 50,000 years ago?
It is not impossible. It is possible and it will only take one significant discovery to show that it happened.
All you have to do is find a 40,000 year old site on Easter Island or somewhere.
(audience member) Wouldn't that be underwater though, back at that time?
It would be, which is difficult, but, you know, the sites in Melanesia that I mentioned, um
there are places there where the shoreline is extremely steep, it basically drops straight into
a deep oceanic trench. And there are cave sites there,
they didn't think anyone was on those islands before 35,000 years ago, but those shorelines have basically
not moved in 40,000 years. If they moved, they moved a few hundred yards, which means that people in
those caves were always close to the ocean because it drops straight into the sea.
And they were surprised, these were Australian archaeologists that dig test pits in
caves on those islands expecting to find 35,000 year old material, and they found 37,000 year old material, and
40,000 year old material and that only happened about 20 years ago.
And additional sites like that are still being found almost every year.
So, it's not impossible that somewhere else out in the deep remote Pacific,
a discovery like that could be found.
The genetic evidence is increasingly compelling however and the people who moved into New Guinea and
Australia have distinctive mitochondrial haplogroup types and those are not found in the new world.
And so, it seems unlikely, but you know, even that genetic work is in its early stages so
I don't doubt we're going to learn a lot of things in the next 20, 30, 40, 50 years that will
upset some of what I've been saying today.
I did an interview recently for a magazine article in which I said something like,
"everything I learned in graduate school was wrong."
It's great. And it wasn't completely true, because I learned a lot of stuff in graduate school that was
really helpful, but some of these basic theories, you know, have just done down the tank and
reserved 180 degrees, and as more and more evidence accumulates, I know some of these things will change.
Yeah? (audience member) I have a question. Do you know much about that, I think a few-a year ago I heard
about a 14,000 year old skeleton found off the Yucatan, but I haven't heard anything about that lately.
Is that, am I remembering that correctly or what do you know about that?
(Erlandson) Yeah. The question is about an ancient skeleton found in a submerged cave off
the Yucatan coast, and it's in a karst limestone landscape where there are these deep, you know,
rivers, where rivers have run underground basically and created long, linear caverns, and there have been divers
exploring those and they found a skeleton roughly eight or ten years ago, I think. As I recall.
And brought it up and carbon dated it, and because it was underwater for so long
and then also exposed to sea water, as sea level rose over that cave,
um, there's some question about the dating.
A good friend of mine was involved in it, he's really good at radiocarbon dating.
It was in National Geographic a few months ago. There was a cover story on the first Americans that
talked about some of our work on the islands, but the cover, and much of the discussion was about
that woman skeleton from that cave. So if you could go back and look at that or the
National Geographic website I think you'll find out more.
Um, my recollection is that they concluded it was between 12 and 13,000 years old.
But they couldn't be more certain than that and it's, it's, what the media usually does is take the oldest date
that you hear and then that just gets repeated over and over again, so it could be 13,000, but
I don't think its 14,000. But its still really old. And really well preserved. It's quite a find.
(audience member) So my question is related to your paleo ecology reference to, uh, the resources of the
Chumash, we're getting, uh, in terms of water temperature, we know now how El Nino does
effect kelp forest ecology
In the past, in terms of the resources then they, is there a measure of the temperature, for example
that may have made this, the resources available to the Chumash. For example, were the red abalone
ever [inaudible word] at different times and are accessible where pelagic fish, pelagic fish showing up
later because water got warmer. Uh, is that temperature warming?
(Erlandson) Yeah. That's a very good question about sea surface temperature changes and how they've changed
through time and how those might have affected the availability of resources for the Chumash.
And there are really good records of ancient sea surface temperatures. They come from the Santa Barbara basin,
cores drilled into the bottom of the Santa Barbara basin where there are what we called varved sediments.
It basically layers there, one per year. They change color every year depending on the season.
And because it's, uh, a basin that has no oxygen in the bottom of it, it has tremendous preservation.
So they can bring those cores up and analyze oxygen isotopes and diatoms and radial area,
these micro organisms that are found in each layer and document the sea surface temperature and
how it has changed through time. And they have shown, pretty emphatically, pretty clearly,
that there have been significant changes through time.
Like the El Ninos that we have now there have been El Nino shifts in the past , but there have also been
broader, like millennial scale, thousand year periods when sea surface tempers were
either warmer or sometimes colder.
One of them was the Younger Dryas periods its called and it started about 12,900 years ago to
about 11,800 years ago. And some of those shell middens at, on San Miguel Island
that are 12,000 years old come from that time period,
and the shellfish in them are cold water fauna. It's red abalones, which are still there, but there's also some
chitons and things that are really from the north.
And then there are other periods, 8,000 to 10,000 years ago when it appears sea surface tempers were
a little warmer when the red abalones basically disappear along with those other cold water faunas.
So there are definitely changes through time. They may, potentially, affect the distribution of kelp,
but we don't think. We modeled the extent of kelp forest through time around the islands, we think they were
actually much more abundant, uh, 14,000 to 10,000 years ago in that they've shrunk through time.
Um, but it's a very good question; there are changes. The plot that I showed of red abalones
shrinking through time, at the very bottom of that, if I was to bring it back up,
you would have seen these bars that said "W," "C" and "neutral," and those are cold water periods,
warm water periods and neutral periods, and when we look at changes in shellfish size through time
one of the first things we look at is what was the water temperature and could that explain the
change in size rather than human predation.
So far, that doesn't, it appears to be to be human predation that is the main predictor.
The other thing that we can do is we can take a mussel shell or an abalone shell that's 8,000 years old or
1,000 years old and we can analyze, we take little drilled samples, and you can analyze
the oxygen 18 isotope ratios. It's oxygen 18 to oxygen 16 and that tells you what the water temperature was,
to within half a degree, plus or minus. And you can actually see the change through the year and we
can determine what part of the year the shellfish were collected based on water temperature change.
But it also shows you much broader changes across the archipelago at the same time,
cold water on San Miguel Island, warmer water on Santa Cruz and then changes through time.
So the, I mean the technologies that archaeologists can harness now are just phenomenal.
The ancient DNA, the oxygen isotope, the carbon dating and other dating methods,
you know we can ask questions now that archaeologists wouldn't have even dreamed of 50 years ago, and
certainly couldn't have answered because the science is always changing.
That's one of the reasons museums like this and my museum at the University of Oregon are so important.
We archive those samples, basically forever, and as new scientific techniques are developed
you can start to do analyses that you never even could of dreamed of before.
So we're constantly going back to old museum samples and reanalyzing them to
get more and newer information out of them. Great question.
(audience member) I have a question about ber-ringe-ga, is that how you pronounce it, ber-ring-ia
(Erlandson) Beringia (audience member) Beringia
It covers a wider swath than I was aware of for a long time. It seems like its around the oceans and
also north of the oceans, in like central Alaska going over into Siberian.
Um, and I was looking at your charts of sea, of sea level depth and whether or not
eight or ten waves of people that came across [background noise drowns out speaker] time between so
there could have been waves coming down to the central United States and along the West Coast
where there were gaps of thousands of years when nobody came down at all or nobody could get
across land without a land bridge.
Yeah. So the question is about Beringia and its extent and also is it possible that there was more than one
wave of human migration into the Americas from Northeast Asia.
And Beringia as its been reconstructed from sea level changes was as much as 1,000 to 1,500 km wide at
its maximum. And then it shrunk over a period of about 10 to 12,000 years ago and then was fully submerged.
But even today, in the middle of winter, Inupiat people can walk from Asia to Alaska,
or dog sled or take a, you know, power sled at this point
because it freezes over and so even after sea level rise submerged the central part of Beringia it was
still possible to go back and forth without a boat in the winter.
The archaeological and other evidence has long suggested that there were at least three migrations.
One was this, maybe, initial coastal migration or maybe it was walking across Beringia, but it was early,
14-15,000 years ago. There was probably another one. They call it the Nadiad people,
Apalastic speaking peoples who most people think came maybe 9,000 years ago.
And then there was another one 3,500 years ago when the ancestors of Eskimo people, Inuit, Inupiat peoples
clearly came out of Northeast Asia and kind of swept across the Arctic.
And its quite possible that there was interchange back and forth and there may actually have been more waves
than those three. We just don't know for sure.
The genetic data are providing a whole new way of analyzing these questions, and
unfortunately you get these studies that are published where somebody emphatically says there
was only one wave. And then somebody else will come along six months later and
say emphatically there were five waves.
And I just don't think we have enough data yet to really say, emphatically, anything of that kind.
We need more information.
But it clearly was a route that people have gone back and forth, I think, for many thousands of years.
(moderator) And unfortunately that's all the time we have for questions tonight.
I would like to just give another thank you to our speaker tonight Dr. Jon Erlandson [loud audience clapping]
(Erlandson) Thank you!