Refuge Notebook
Article
April 15, 2005
Refuge ecologist visits Costa Rica
By: Ed Berg
A visit to the tropics is as close as ecologists ever get to heaven
during their mortal lifetimes. Only in the tropics can you see the full
splendor of plant and animal life – the brilliant birds, the flowers,
the little frogs and lizards, and amazing bugs of all sizes. And of
course only in the tropics can you find yourself hosting the greatest
variety of microorganisms that you would just as soon leave inside the
medical textbooks.
I recently returned from a 12-day tropical ecology fieldtrip in Costa
Rica, where I journeyed with three professors and their students from
Binghamton University in New York. We traveled in three vans and stayed
at various biological field stations and modest hotels, like pilgrims
to a biological Holy Land. We covered a wide variety of forest types,
from beaches and mangrove forests on the Pacific coast, to mountain
cloud forests at Monteverde, and the dwarf alpine (paramo) forests of
the Sierra de la Muerte at 11,000 feet elevation.
I have traveled quite a bit in Central America, but never with a group
of such expert birders. The professors have been making this trip for
13 years, and have a remarkable command of the birds, by both sight
and sound. We got up at dawn every day, when the bird singing shifts
into high gear for an hour or so. Sometimes we would hear the rumble
of howler monkeys bouncing from one heavily forested mountain slope
to another. Once the sun was up, the bird vocalizations subsided and
we retreated to breakfast in preparation for the day’s activities.
By the end of the trip we had seen and identified 282 species of birds,
out of the roughly 850 species known for Costa Rica.
One of my favorite activities in the tropics is watching the long lines
of leaf cutter ants. These ants cut half-inch pieces of leaves, which
can weigh as much as 12 times their body weight. They carry the leaf
fragments over their heads along well-trodden paths to underground borrows,
where they have a labyrinth of chambers occupying several cubic yards
of soil. They deposit the leaf fragments in these chambers and inoculate
them with a fungus, which they subsequently eat. The ants are thus actually
farming fungus gardens and are not eating the leaves.
A colony of leaf cutters is founded by a single queen, who mates with
4 to 10 males on her nuptial flight. The queen can lay millions of eggs
over a period of 10-20 years, using the original sperm stored from this
single flight. The worker ants of the colony are all sterile sisters
or half-sisters from this queen. The queen also produces a few fertile
females for future queens as well as some fertile males.
We all agreed that the outstanding bird sighting of the trip was the
mating of three-wattled bellbirds. The male bellbird had a white head
with three black wattles (strips of skin) hanging down from the base
of his beak; the wattles are about three inches long and perhaps an
eighth-inch wide. The male was perched on a high treetop, displaying
himself by opening his large mouth (which is all black inside) and swinging
his wattles. Presently a rather drab-looking female landed on a branch
near him. The male hopped on top of her, made a quick thrusting motion,
while uttering a single loud “Bonk!,” after which the female
flew away. Soon, however, she flew back, and the ceremony was repeated.
The humor of the male’s victorious “Bonk!” could not
escape us, and our howls of laughter made it hard for us focus our binoculars,
as we watched this cycle repeated fully eleven times.
The bellbird mating of course generated a discussion about the mechanics
of birds mating, of which we were all a bit unclear. Visiting the Internet
upon returning home, I learned that most birds do not have a penis and
there is no penetration involved in mating. Birds have a cloaca under
the tail feathers, which doubles as both an anus for excretion and a
reproductive port. The male’s sperm duct ejaculates into the cloaca
near the opening, so that during mating the cloaca is moist with sperm.
When the male mounts the female he must twist his tail under the female’s
tail so that his cloaca presses against her cloaca, and sperm is transferred.
The female’s vagina is connected near her cloacal opening, and
the sperm must travel into the cloaca and up the vagina to the uterus
to reach the egg for fertilization. When the egg is ready to be laid,
it must pass down the vagina and out of the cloaca.
In our travels around Costa Rica we observed that much of the land
has been deforested for cow pasture. Costa Rican cows must be pretty
athletic, to judge from the steep treeless slopes that have been cleared
for them. The hillsides were frequently contoured with more-or-less
horizontal paths created by cows trying to avoid going up or down these
declivities. Patches of wild forest still cover the steepest areas,
ridge tops, and ravines, and other areas considered uncow-worthy. These
wild patches are small refuges for biodiversity, especially for birds
that move from patch to patch.
We visited an interesting experiment in reforesting steep pastureland
near Dominical, in southwestern Costa Rica. In the early 1990s a small
group of Northamerican conservationists purchased 350 acres of mostly
steep pastureland that had been grazed for about 20 years. They wanted
to see if this barren land could be restored to forest, in an economically
practical manner, and called the project “The Tropical Forestry
Initiative.” One of the founders was Carl Leopold, son of Aldo
Leopold whose “A Sand County Almanac” is a well-known bible
of conservationist philosophy. They have planted a variety of local
trees, some with good forestry potential, and some for wildlife habitat.
The soils in this area are relatively young volcanic soils and are
fairly rich, by tropical standards, despite the typical red clay appearance
with little organic content. In less than ten years many of the new
trees have grown to more than 50 feet in height and diameters of 6 to
8 inches; the canopy is closing and a new, secondary forest is well
underway. Further up the steep ridge there is uncut primary forest with
huge buttressed trees with thick vines, and a many-layered canopy structure.
The difference between the original primary forest and the new secondary
forest was of course striking, but even more striking was the rate at
which the new forest was catching up with the old forest.
This experiment at least shows that steep deforested slopes can be
reforested fairly quickly with fast growing tree species, and much of
the forest value for wildlife can be restored, perhaps within a few
decades. For forestry purposes, however, the trees would probably have
to be skidded out with horses to avoid destroying the new growth and
gullying the slopes. Industrial foresters would probably never be convinced
by this example, but it does represent a promising possibility for sustainable
small-scale local forestry.
Sustainability is a big issue in the tropics. We saw extensive plantations
of teak and oil palms, planted in neat rows with very little growing
between them. The teak is cut on a short rotation of 20-30 years, and
the oil palms must be killed off with herbicides and replanted every
few decades to keep up productivity of the oil-rich fruits. After a
few cycles the soil will be depleted, and it will be necessary to add
expensive petroleum-based fertilizers, which is only practical in a
world with cheap oil.
Our last night was spent at Hacienda Baru National Wildlife Refuge,
which is another remarkable conservation experiment. In 1972 this area
along the Pacific coast was a cattle ranch with 150 cows on 800 acres,
managed by a young American named Jack Ewing for some Tennessee investors.
The ranch hired three people full-time, and maybe another dozen during
the rice harvest.
Jack told us how one of his cowboys had killed a beautiful ocelot,
and Jack – an experienced hunter – for some reason felt
bad about this killing. He started putting up “No Hunting”
signs and hired guards to keep out poachers, which did not contribute
to his popularity with the locals. The wildlife populations increased
substantially, however, which did not go unnoticed.
In 1986 the road was paved and truckers with guns began shooting animals
along the road. A local group was formed to stop this practice, and
a particularly flagrant poacher was jailed. Other towns joined the anti-hunting
group, and worked to set up a string of mostly private wildlife refuges
called “The Path of the Tapir,” which now protects a corridor
of 15,000 acres. In the 1980s Hacienda Baru abandoned cattle ranching
and the land was allowed to return to forest, and was subsequently reorganized
as a wildlife refuge. Today Hacienda Baru is funded solely by ecotourism
(15,400 visitors last year) and employs 33 people housing, feeding,
and guiding visitors through the lush forests. The beautiful beach with
vigorous surf is a further drawing card, as are the canopy tours with
ropes and aerial platforms.
The Costa Rican government has taken some very good steps to prevent
further deforestation and has recognized ecotourism as a major economic
force. Over 20% of the country is in some kind of protected status,
and this is drawing ever more tourist dollars into the national economy.
Legislation has been passed recently to pay forest landowners for the
ecosystem services of their forests, such as watershed protection. Water
users downstream from uncut forests, such as hydroelectric utilities,
are being asked to pay a water tax that will go to the forest landowners.
When the forests are removed, the quality of watershed ecosystem service
is severely degraded: rainfall tends to decrease (when the water transpired
from the trees is lost), and the streams discharge quickly in floods
of muddy water.
The Costa Rican government also recognizes that forests remove carbon
from the atmosphere, so there is a gas tax which is used to finance
the planting of new trees to offset the CO2 emissions from burning gasoline.
These are impressive, ecologically aware steps for a small under-developed
country, and it would be nice to see such ideas implemented in the US.
Costa Rica is a friendly country for travelers, and I can see why it
has become a popular retirement destination for Americans. It has no
army, and you don’t see a lot of bored, heavily armed soldiers
standing around, such as in other Central American countries. As in
Alaska, ecotourism is a fairly benign growth industry, compared to cattle
ranching or resource extraction industries. I find it heartening that
the government of Costa Rica views ecotourism as a sustainable industry
for the future, and is taking concrete steps to protect the natural
resources that tourists come to see. It is a lesson that should not
be lost on Alaskans.
Ed Berg has been the ecologist at the Kenai National Wildlife
Refuge
since 1993. Previous Refuge Notebook articles can be viewed on our website
http://kenai.fws.gov/. He would encourage readers interested in visiting
Costa Rica to enjoy Jack Ewing’s new book, “Monkeys are
Made of Chocolate,” available at http://www.haciendabaru.com/.
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