When I worked in corporate
America, I always tried to squeeze some birding in on business trips.
On one trip to New Orleans in the late 80’s I took a “swamp tour”
on the Pearl River, which is the river that divides Louisiana from
Mississippi. After the tour I tried to find a place where I could see into the
swamp – and I’d almost given up when I came upon a roadside rest stop with
a little hut nearby. The view was spectacular. An international airport of
birds. Every wader I’d ever
seen, I was seeing. And there was a huge eagle’s nest, which I later learned
had been continuously occupied for more than 75 years. Through a series of
flukes, I ended up owning that hut on the Pearl.
I started doing a lot of
business in New Orleans. Bob Russell became one of my birding buddies. I first
met him when a friend in New Orleans hired him to take us birding one day I
was in town. It wasn’t even migration and we saw 120 species, many of them
new to me, as we birded Cameron Parish in southwest Louisiana. Over the years
I joined Bob on a number of birding expeditions. Nothing prepared me, however,
for the call I got in the summer of 1999.
Bob called and told me a
story of an April Fool’s Day sighting of Ivory-billed Woodpeckers. An LSU
graduate student had been “still hunting” for turkeys, and had watched a
pair of ivorybills for a good long time. The area was along the Pearl River,
between Lake Ponchatrain and the Stennis Space Center in Mississippi. It was
just miles from my hut. The actual sighting was near a firing range in a
“Wildlife Management Area” – which is basically an area managed for
hunting. He’d told a professor
of his sighting, and had eventually been grilled by Van Remsen from LSU, the
latest in a long line of ivorybill hunters. He’d passed the third degree.
How did he pass? Without prompting, David Kullivan had correctly described one
of the fieldmarks of the female ivorybill. It is a fieldmark that had not been
discussed or illustrated in fieldguides. The female ivorybill has a
“recurved” crest ~ meaning that it curves forward from the head, rather
than back. This was enough to convince Van Remsen that the sighting was real.
The real window for
searching had closed shortly after the sighting. A few locals got out, and
some thought they heard the bird. But, others were in the area using tapes, so
it was impossible to know. When the deciduous hardwood bottomland forest leafs
out and the canopy closes in, and the mosquitoes bloom, and the temperature
rises and the water moccasins start to bask, the swamp goes from difficult
habitat to impossible habitat.
We began planning our
search for the next winter. February – when the scant information known
about ivorybills suggested that they might be vocalizing. Everything was top
secret – we even used code when we sent emails and talked on the phone.
Bob put together quite an expedition party of 10, with some famous
birders, folks who had searched in the 40’s, writers, and sloggers like
myself. Everyone brought something unique to the group.
I got a call on my
answering machine in late summer, Cheryl had “found the birds”. Needless
to say I was stunned and beyond excited. When I talked to Bob I learned that
Cheryl, a government wildlife professional, had contacted an “animal
communicator” and asked for help. The woman she contacted was the horse
whisperer for the British and US Olympic equestrian teams. She had made an
effort, and had “made contact” with a group of ivorybills. She would do so
several times over the next 6 months. And, dealing with an expedition team
that was a collection of believers and skeptics, it was interesting that most
took her advice to heart. The birds didn’t like a lot of bug spray. They
despised hunters and didn’t like camo clothing. They were in an area with
Great Blue Herons and hanging moss. This
bit of the story would continue to develop.
I just started to study.
I purchased the old $2 Dover edition of James Tanner’s classic, The
Ivory-billed Woodpecker at amazon.com for a small fortune. I spent time nestled in quad maps
of the area and maps of the Pearl River WMA. The most important thing to focus
on was the pileated/ivorybill comparison. The best fieldmark is the white
feathers on the trailing edge of the ivorybill’s wings. This can be seen on
the bird perched as a large white triangle on the lower half of the back, or
on the flying bird as a brilliant white border at the trailing edge of the
wing. The other key in the field
is the vocalization. The ivorybill call sounds like a really big nuthatch rather
than like the pileated’s laughing hyena. There
is also the famed "double rap" to listen for.
My greatest contribution
to the groups’ preparations was the promise of the expedition t-shirt. “I
Want to Believe”, which I made up for each member of the group. Yep, I’d
been an early X-Files follower, and the saying was borrowed. But it was
accurate. I did want to believe. But I didn’t believe. I just thought the
whole thing was a fabulous lark. Searching for an extinct bird in the backyard
of my Pearl River hut. I had left corporate America in June of 1999 with
enough money to go birding America for a couple of years. This was a welcome
adventure.
I was in California at
Christmas when I got an email about necessary equipment.
We needed not just a compass, but a GPS, walkie-talkies, and some way
to deal with chiggers, snakes,
skeeters and wild boars. Further, I was the
designated videographer of the group. I was expected to film anything seen and
record anything heard.
I
love equipment. I took a picture of myself all geared up for the swamp just to
laugh about. And the picture didn’t show half of it. I had the compass, the
GPS and the walkie-talkie. I also wore Rynoskin – a chigger-proof long
underwear popular with law enforcement officers in the south. Over my jeans I
wore full length camo snake chaps. I wore high gortex socks under my boots. I
never actually wore my bug baffler – it was too cool for bugs to be an issue
the three times I’ve searched. I researched pepper spray for wild boars –
but the stuff they sell for bears has never been tested on boar. I learned
that there were more feral pigs than wild boar, and let that go. No one had
mentioned that there were actually bears in the Pearl River Wildlife
Management area, but there are. But, I only saw scat. I had a 3-chip digital
video camera which was primed for the journey, with a special directional mike
to use when I started to hear the Keent of the bird. After the first five days
of searching, I left my binoculars behind. The impulse to look at something
through binos interfered with the need to get on the bird with the camera.
Like
a good girl scout, I thought I was prepared for the journey as we got closer
to departure. We had managed to keep everything a secret. Then, just days
before we gathered in Slidell, Louisiana, the story appeared on the front page
of a Mississippi newspaper.
Wow.
The story of the sighting, with a good drawing. I expected that the article
and the spreading chain of news would bring hundreds of searchers into the
swamp the next weekend, when our search would begin. I mean, here was the holy
grail of North American birding, seemingly resurrected within an hour’s
drive of some of the finest restaurants in America! When our team convened in
Slidell the night before our first day in the swamp, we all expected to see
others in the Pearl the next day. But we didn’t. In fact, none of us have
ever seen a birder deep in the swamp.
So,
let’s answer a basic question. How could ivorybilled woodpeckers remain in
America without birders seeing them? By way of an answer, just think about
what you might see making the tough trek into the heart of a hardwood
riverbottom swamp –
The waders
White
ibis
Yellow-crowned
night heron
Green
Heron
Great
Egret
Little
Blue Heron (juvenile) (also Snowy
Egrets)
Louisiana
Heron (known in other states as the Tri-colored Heron)
Great
Blue Heron
Wood
Stork
Mississippi
Sandhill Cranes
Looking Up
Black
Vulture
Mississippi
Kite
Swallow-tailed
Kite
Down on the River
Double-crested
cormorant (winters)
Anhinga
Belted
Kingfisher
Most common big birds
Red-shouldered
Hawk
Barred
Owl
The Warblers
Northern
Parula
Kentucky
Warbler
Prothonotary
Warbler
Yellow-throated
Warbler
Worm-eating
Warbler
Hooded
Warbler
Swainson’s
Warbler
Then there are ducks
Mallards
Wood
Ducks
Ring-necked
Ducks
Lesser
Scaup
Northern
Pintail
Green-winged
teal
Common
Moorhen
Also swimming around and walking around
Alligator
(not high density – kind of puny compared to what you see in the Everlades!)
Alligator
snapping turtle (largest fresh water turtle in North America)
Diamondback
Terrapin (down by the gulf)
Walking
around
there are also a few bear, bobcat, rumoured panther, wild boar, feral pigs,
white-tailed deer, armadillos, possums, raccoon, mink, otter, rats.
What’s crawling on trunks
Brown
Creeper
Downy
and Hairy Woodpeckers
Red-bellied
Woodpecker
Yellow-bellied
Sapsucker - winters
Red-headed
Woodpeckers - winters
Red-cockaded
Woodpecker ~ in the pine forest on the north side of Lake Ponchatrain
Pileated
Woodpecker
And Finally, the Lord of the Swamp
Ivory-billed
Woodpecker
So
– remember the question? How could ivorybills still be around, and birders
never see them? Because birders
never slog into the swamps! There is nothing deep in the hardwood river bottom
swamp that can’t be seen much more easily elsewhere. Swainson’s Warbler is
probably the “best bird” of the swamp, but even it can be seen in more
accessible areas. So, you just didn’t have birders taking 7 miles hikes
through the swamp in hip waders! The
bird could easily have persisted undetected in some of these areas. When
Tanner did his famous survey searching for ivorybills, he dismissed the entire
Pearl River region in a morning’s visit in August. Tough to survey 100
thousand acres with no roads in a morning.
So, is the bird extinct, or
just lurking deep in untraveled swamps?
Let’s
shift focus now, and talk about extinction – the causes of extinction.
Rarity
Rarity
leads to extinction. Why are some species rare? Why do others become rare?
What troubles afflict rarities?
Rare birds have a more
tenuous hold on life. Smaller population is a problem because it creates a
lower threshold for a collective catastrophe. Factors include human activities
--hunting, trapping, destroying habitat, introduction of exotic animals,
pesticides, stealing eggs, blocking migratory routes. Also more random factors
come into play like weather (drought, lightning fires, hard winter,
hurricane), increase in predator population, parasites, or aberrations in
gender ratio of newborns.
How about Ivorybills?
Historical comments all said that the bird was rare/uncommon except one
comment by Audubon about the area along Mississippi River, where they could be
seen flying back and forth. Best
estimates are that a pair of Ivory-billed Woodpeckers needs about 6 square
miles of habitat, compared to an estimated 6 pairs of Pileated Woodpeckers on
1 square mile of territory. Historically, the IBWP covered a relatively large
area – “southern swamps” from North Carolina down through all of
Florida, across gulf states to Texas, and up the Mississippi River to southern
Illinois.
One interesting way to
approach this question is to look at relative numbers if woodpeckers in good
habitat. Both Pileated Woodpeckers and Red-bellied Woodpeckers have
significantly broader ranges than the historical range of the Ivory-billed
Woodpecker, and both inhabit their ranges extensively, not just along “the
bottomlands” of Mississippi and the swampy forests of the coastal plain. To
put it in further perspective, habitat suitable for ivorybills is great
habitat for other woodpeckers, including pileateds, red-bellieds, red-headed,
hairy, downy, and sapsuckers. James
Tanner estimated that for each single Ivorybill there would be 36 Pileated
Woodpeckers and 126 Red-bellied Woodpeckers in an area.
I’m sure most of you
have hiked long days in suitable pecker habitats.
Even when they’re abundant – you know that it would be quite a hike
to come across 36 Pileated Woodpeckers. In that amount of area, in suitable
habitat, when things were good, there’d be one ivorybill around.
That’s a rare bird.
So
first, rarity.
Specialization
Habitat specialists are
more vulnerable than habitat generalists
What are all these
woodpeckers doing in this “good habitat”?
More to the point, what is the most similar species, the Pileated
Woodpecker, doing in this habitat, and how does that compare to the
ivorybill’s use of resources?
What differentiates the
species is food.
The favorite food of the
Pileated Woodpecker is ants. Carpenter ants, big black timber ants, are said
to be the gourmet goody, along with palmetto ants, white ants, you name it.
(From the turn of the century –“there were as many as 2600 ants in
a single stomach!”) The ant infested trunks of large trees are their
preferred diner. All dead wood
harbors food for Pileated Woodpeckers, until the trunk and stump decay into
the soil. They also eat beetles,
eggs and larvae, and wild fruits and berries. Like flickers, they will feed on
the ground, ripping open ant mounds.
Ivory-billed Woodpeckers
favor wood boring insect larvae. They relish beetle larvae and grubs. Their
Latin name means “Principal lover of grubs”.
They selectively eat the borers that live between the bark and sapwood
of a newly dead tree, which they get at by “scaling” the bark from the
tree. Rather than bore holes
straight into the wood, the ivorybill uses that huge powerful bill to whack
sideways at sections of bark – first one way, then the other – knocking it
off. When the bark flies off, the bird eats the abundant larvae underneath.
There’s a description of how an ivorybill smushed her belly up against the
tree to keep any of the larvae from falling to the ground.
So, what’s the bottom
line? When a limb or tree dies, the insects that live beneath the bark attack
first. They begin to reach
abundance about a year after the death. They reach peak abundance about two
years after the limb or tree dies, and then they’re gone.
The borers favored by Pileated Woodpeckers start to increase as the
wood becomes more rotten, and may thrive for ten or more years in the dead
wood. This means that the food of
Ivory-billed Woodpeckers is less abundant, and more unevenly distributed than
the food of Pileated Woodpeckers. Tanner
estimated that there is forty (40) times as much food for Pileated Woodpeckers
as Ivory-billed Woodpeckers in a mature/virgin forest.
“The
Ivory-bill appears to be a woodpecker dependent upon an abundant food
supply, in quantity greater than is usually present in the average forest.
Wood boring insects are plentiful only when there is a large number of dying
or dead trees, such as is caused by fire or storms, or perhaps when a large
number of trees weaken and die at the same time from old age. Such deaths of
timber causing outbreaks of borers occur irregularly and are likely to be
widely scattered, since they are in the nature of accidents. The ivorybill
must be a far-ranging species as it depends for existence on such unusual
numbers of borers.“ James
Tanner
The ivorybill is what we
now call an opportunistic feeder.
The ivorybill’s
northerly counterparts are the Black-backed and Three- toed Woodpeckers, who
cover the Canadian forests, who also scale bark for larvae, and who are also
known to be opportunistic feeders, ranging wide areas for burned over, fire
killed, storm damaged, and beetle infested woods.
Although uncommon, these birds are not critically endangered, due to
the fact that unlike the great Southern forests, their world hasn’t been
clearcut. But, they’re still tough to see. A study in Ontario counted 153
blackbacks. Then, they did transects, and estimated that there were probably
more than 15,000 of the birds in the area where they’d seen 153. So, it’s
tough to see birds that are wide-ranging over large areas.
The
Pileated Woodpecker is a generalist, and the Ivory-billed Woodpecker a
specialist. This is another factor that predisposes the Ivorybill to
extinction. Then add . . .
Loss
of Habitat
Now things get really
ugly. Another major factor in extinction is loss of habitat. Ivorybills lived
in the great bottomland forests of the south, and up the Mississippi River.
Logging of the upper reaches of its range along the Mississippi was in
full-force by the 1870’s. And,
successively, the great southern forests were clearcut.
The mood of the country
was that logging forests was progress. Even when it was well-known that the
famous Singer Tract in Madison County, Louisiana was the last verified habitat
for ivorybills, sustaining perhaps six birds, the area was clearcut. German
prisoners of war cut this last virgin forest. The wood was used to create
chests to ship tea to British soldiers. The land was then planted with
soybeans.
Pretty
tragic. Let’s move on to the next predisposing factor for extinction:
Ecological Isolation
Conservation biologists
first studied ecological isolation as it pertained to islands. Between the
1600’s and mid-1990’s 171 species and subspecies of birds went extinct. Of
these, 155, or 90% lived on islands, while only 20% of all bird species are
endemic to islands. Hawaii has
lost more bird species than all the continents on earth. An island bird is 50
times more likely to face extinction. And a bird endemic to a small island is
much more at risk than a bird from a large island.
When a population is
restricted to an island, it never gets reinforced by wanderers from other
populations. There’s no new input to the gene pool. There’s no help when
random bad fortune such as severe weather or predation of nests, or unequal
gender in offspring weaken the already small population.
Tanner’s survey of
likely habitat areas for ivorybills in 1937-1939 led him to estimate that the
remaining population at that time was 22 birds. He believed there were six
birds in the Big Cypress region of Florida, two at Highlands Hammock in
west-central Florida, four in the Gulf Hammock/Suwanee region, along
Florida’s gulf coast, also four birds further north and east, in the
Apalachicola. The final six birds
were in the Singer Tract in Louisiana, which was soon to be clearcut.
I think he was very wrong – and that there were perhaps three or four
times that many birds still with us. But, the picture he paints is a picture
of extremely small populations of birds confined to islands. Because,
practically speaking, the insular nature of a swamp surrounded by soybeans is
the functional equivalent of a island.
We
now have a “naturally” rare bird, a habitat and feeding specialist, who
has suffered severe habitat loss, leading to extreme ecological isolation.
Let’s consider the last major factor pressuring ivorybills.
Hunting
and Collecting
Ivorybills historically
were lightly hunted by native peoples. There is a peace pipe in one museum
that is decorated with 6 bills and crests of ivorybills. Bills were also
traded among Indian peoples – with some traveling into collections in the
far west.
With the coming of
Europeans, hunting likely increased. Audubon reports that along the
Mississippi steamboat passengers could buy 2-3 ivorybill heads for 25 cents.
There was also some hunting for eating.
A.T. Wayne was quoted in 1895 as saying that ivorybills were “better
than ducks”.
The
biggest problem for ivorybills, however, was “collecting”. One of the
additional problems of rarity in our world is that museums and individual
collectors wanted a “skin” of a rare bird, and perhaps an egg or two. This
is one of those terrible inverse relationships – the rarer the bird, the
greater the pressure for collection. The
food critic A.T. Wayne made a career of “collecting” ivorybills. In a
three year period between 1892 and 1894 he killed at least 44 ivorybills. The
first two years he collected 17 individuals in the Suwanee region, and in
1894, over a three month period, he killed 19 of the birds – causing local
extinction of the population of the California Swamp north of the Suwanee.
Another grim reaper of
ivorybills was a man with the initials W.A.D.
He killed approximately 25 ivorybills near Sanford, Florida over a 10
year period causing another local extinction.
There are more than 250
ivorybill “skins” in American museums. I’ve never seen a count of
specimens in Europe, or in the hands of private collectors. Nor have I ever
seen an estimate of how many birds were killed, with their skins being damaged
beyond commercial use.
Surely
“collection” was a factor driving the ivorybill to the brink of
extinction, and is a stain on the community of curators and academics who
responded to the bird’s crisis with greed rather than protection.
Hunting
and Hunters Today
Obviously there will be no
permits for collecting ivorybills again. But, hunting remains a stress factor
for remaining birds as most large areas of bottomland swamp are currently
managed for hunting.
Hunters are a resource for
birders seeking ivorybills. They were a resource for Audubon and for Tanner,
and for every other searcher. They are the only people who have been spending
time in these habitats. Tanner developed a technique for talking with hunters.
Ask about wildlife generally, birds, then woodpeckers. Do you have any big
woodpeckers? Do you have more
than one kind? Jefferson and Benton Basham used that technique in the Pearl
River area, and got fascinating results. I, too, have talked with hunters who
can describe the Ivorybill without prompting.
The
Profile for Extinction: Rarity,
Specialization, Loss of Habitat, Ecological Isolation, and Hunting
So,
talking about extinction – the Ivorybill fits the profile. I didn’t know
this much about the birds when I headed to the Pearl River for my first
search. Nor did I realize that one of the classic problems in the modern era
has been declaring extinction too early.
“The Tasmanian Tiger”, which was actually a carnivorous marsupial
– kind of like a wolf, with a rear pocket, was declared extinct in the
30’s. This spared the government the embarrassment and expense of trying to
preserve a species that it had purposefully and systematically eradicated over
the previous years with a bounty program for carcasses. (Pressured by forests being cut for pasture, the Tasmanian
tiger may have begun to prey on sheep.) There
is clear evidence that this bizarre creature persisted for long after its
declared demise, and some weak evidence that it may still live.
The fact is, you can’t
prove a negative. Who, for example, deputized The Nature Conservancy to
declare the Ivory-billed Woodpecker extinct in 1996? This, although they had
done nothing to conduct any kind of comprehensive search of remaining
habitats? What possessed them? Can
you imagine a committee room, an agenda – hey, OK, Item Number Three --
let’s declare the Ivory-billed Woodpecker extinct! All in favor?
And, I can only guess that
there was some fear that The Nature Conservancy had “one-upped” the rest
of the conservation organizations with this brilliant vote. Searching the
Internet I discovered that in 1997 the National Wilderness Institute had taken
it upon themselves to petition Bruce Babbit, then Secretary of the Interior,
to delist the Ivorybill as an endangered species – on the basis of
extinction. The petition noted that the USFWS had squandered some $2,400 on
the species.” Oh My.
The story
continues . . .
At this point in my talk I
recounted stories of my searches. I gave
this talk in the winter of 2002. That year, I searched for another bird
thought to be extinct, the Eskimo Curlew.
Talk about a tough ID challenge in the field ~ you had to get a look at
the wingpit of the bird ~ looking for cinnamon wing linings! No luck.
I have already shared my
thoughts and feelings on seeing the Ivory-billed Woodpecker in Arkansas in
2003. It is my hope that the bird has made it through the bottleneck of
habitat destruction, and is poised to continue with us into this new century.
But, as the focus of this talk makes clear, the challenges to the bird’s
survival are huge.
Mary
Scott