Fritts, Thomas H.

English

Aquatic Commons

Noticias de Galápagos, No. 46, May 1988
l'
iguanas, pelicans, blue-footed boobies, frigate birds,
noddies, lava gulls, and three species of herons are
commonly seen feeding in and around the bayo
Las Grietas - These large fissures in the lava
shoreline are not far from Puerto Ayora. Where they
join with the sea, they are home to resting sea turtles
and sharks. Further inland where the water is
brackish due to mixing of seawater with freshwater
draining from the island, blind cave fish and crayfish
are found.
Cerro Crocker and Media Luna - The best views of
adjacent islands exist from this high vantage point on a
clear day. Media Luna, an old volcanic crater covered
with Míeonía plants and surrounded by moisture-Ioving
ferns, is a major nesting area for the dark-rumped
petrel.
Los Túneles - This complex of lava tubes located
on private land allows the visitor to appreciate the
magnitude of volcanic eruptions. For a small admission
charge, the visitor equipped with a flashlight can
explore one of the longest lava tubes in South
America, a natural tunnel nearly 1 km in length.
Tortoise Reserve - The tortoise reserve is located
near the boundary between the Galápagos National Park
and the Colonized Zone and can be reached on foot or
horseback by following the traíl from Santa Rosa.
Here the visitor can see giant tortoises in their native
habitats. During the wettest seasons, ponds form at
various sites and the tortoises regularly soak in the
water to remove ticks and other parasites.
Los Gemelos - The twin craters with nearly
vertical walls produced by major collapses are located
near the Cross-island Road. Surrounding Los Gemelos
is a dense forest of regenerating Sea/esía trees where
vermilion flycatchers are common.
Caleta Tortuga Negra
- A mangrove lagoon which
opens into the ocean and which is accessible to visitors
only by boat, these waters are frequently used by sea
turtles, rays, and sharks as a feeding and resting
area. Herons commonly nest in nearby trees.
Las Bachas - This small beach where sea turtles
haul out to bask and to nest is on the northwestern side
of Santa Cruz. Flamingos are occasionally seen in the
lagoon nearby. Formerly the removal of sand from the
beaches in this area for construction on Santa Cruz
threatened to produce a shoreline of barren rock. Use
of alternative construction materials has allowed
preservation of many small beaches that were
threatened.
Canal de Itabaca - This narrow body of turquoise-
blue water between Baltra and Santa Cruz is often a
visitor's first view of Galápagos when arriving at the
Baltra airport. The visitor traveling to Puerto Ayora
by the Cross-island Road must cross the canal by
ferry. Pelicans, boobies, shearwaters, and noddies
are frequently sighted over the canal. The cliffs at the
eastern end of the canal are inhabited by fur seals.
1 '
7
Amrit Work Kendrick, Charles Darwin
Research Station, Isla Santa Cruz,
Galápagos, Ecuador. Present address: Star
Route, Stonewall, Texas 78671, USA.
Bernardo Gutiérrez with the male tortoise he raised as
a pet. Bernardo Gutiérrez con el galápago macho que
crió como mascota.
HOW OLD 15 THAT TORTOI5E?
By: Thomas H. Fritts
Visitors to Galápagos frequently ask about the age,
growth, and maximal life span of the giant tortoises.
Often, the visitor has previously heard that turtles,
and especially land tortoises, are capable of living
more than a century, but the question resurfaces when
confronted with the large size and regal aspect of the
adult tortoises in Galápagos. Just how old are the
various male tortoises in the corrals at the visitor
site near the Park/Station tortoise complex on Santa
Cruz? In general, little information exists on these
tortoises because they are animals confiscated or
voluntarily returned to the Park by people who had the
tortoises in captivity at the time the Park was
declared. Because no one can be sure from which
island or population these tortoises came, they are
held at the visitor si te for educational, research, and
interpretive uses.
Recently during a casual conversation with Captain
Bernardo Gutiérrez, a native of San Cristóbal and
operator of the tourist boat San Juan, a story unfolded
that allows tentative establishment of the age for one
of the large tortoise males seen by nearly every
visitor to Galápagos. Bernardo's story follows. When
8he was about 10 years old, he lound a small tortoise
about the size 01 a dinner plate on the outskirts 01
Puerto Baquerizo Moreno on San Cristóbal. Only a
short time previously, several tortoises had escaped
Irom a makeshift corral at the Port Captain's
headquariers. The juvenile tortoises had been
conliscated by local authorities Irom a fishing boat
that had brought the tortoises Irom the northern coast
01 Volcán Woll on Isabela. It was common knowledge
among Galápagos lishermen that in contrast to most
areas 01 Galápagos, tortoises nested near the shoreline
on Volcán Woll, and it was possible to lind juvenile
tortoises living within a lew 100 m 01 the coast.
Since no tortoises lived on San Cristóbal near the port,
the tortoise lound was undoubtedly one 01 the
escapees.
Bernardo took the tortoise home where he and his
brothers and sisters raised it as a lamily pet. The
tortoise was lound around 1945, and based on its size
at the time, it must have been 3-5 years 01 age. The
tortoise stayed with the Gutiérrez lamily and had
grown to a large size by the late 1960s when the
tortoise was returned to Santa Cruz to comply with
Ihe law prohibiting tortoises being maintained as pels.
However, Bernardo is still able to distinguish the
tortoise Ihat he raised Irom the others in Ihe captive
herd on Santa Cruz by a particular scar on the shell
resulting Irom an injury which the tortoise received
when it unwisely tried to invade the Gutiérrez kitchen.
With some allowance lor an errar 01 1 or 2 years
in the calculation 01 the probable age 01 Bernardo's
tortoise, the tortoise is 46 to 48 years 01 age and
probably hatched Irom an egg between 1940 and 1942.
Thus, this lortoise measuring 121 cm in shell length
and having the demeanor 01 a giant patriarch is in lact
less than hallway to attaining a century 01 lile, and
younger than many 01 the admiring visitors that visit
the corral where he lives. These lacts testily to the
lact that Galápagos tortoises reach their large sizes in
only a lew decades, but this does not preclude the
possibility that they do indeed live to ages matching or
exceeding maximal longevity lor humans. Recent lield
data collected as a part 01 Park conservation programs
strongly suggest that so me tortoises reach maturity
15-20 years alter hatching and that alter maturity,
growth nearly stops in lemales and slows signilicantly
in males. Thus the tortoise probably had achieved
most 01 his growth prior to arriving on Santa Cruz and
has grown quite slowly over the last 20 years.
Should you visit the tortoise corrals at the
Park/Station Headquarters, you might recognize the
tortoise pictured in this article. Among Park and
Station personnel, he is known as "Guardian" and he
bears a codilied registration number 01 48. He may be
big and even majestic, but pie ase don't consider him
old. Tortoises have leelings too!
Noticias de Galápagos, No. 46, May 1988
TWO NEW BUTTERFL y FISH
RECORDS
FROMWENMAN ISLAND
By: Godfrey Merlen
Last summer (29 May-2 June 1987) 1 had the
opportunity to revisit the northwestern outposts 01
Galápagos--the islands 01 Culpepper and Wenman. I had
visited Wenman several times over a number 01 years
while working on the Beagle 111. Originally 1 was part
01 a crew responsible lor the placement and
maintenance 01 a series 01 tide-temperature gauges
organized by NOAA, the National Oceanographic and
Atmospheric Administration 01 the United States, and
Wenman had been one 01 the selected sites. It was
marvelous to return to this island where the cliffs are
alive with seabirds. Especially notable was the
occasional sight 01 the pelagic sooty tern Sterna
fuscata, which is an extremely abundant species in the
Central Pacilic, but within the Galápagos Archipelago
only breeds on inaccessible Culpepper.
However, this time we were on a diving
expedition, again on the laithlul Beagle 111,and we
dropped our anchor in the lamiliar anchorage lacing the
western ocean in a Ilat, calm sea. We chose as our
main diving area the two rocks, one large and the
other small, just offshore lram the southwestern point
01 Wenman (Fig. 1). We dived first on the outer
vertical wall 01 the large rock, but later lound that the
channel between the rocks and the precipitous cliff 01
the main island was much more productive with its
steep walls, boulder slopes, and stronger currents.
A questionable highlight 01 the dives was
encountering several schools 01 hammerhead sharks
with up to 20 individuals in a group. The sharks
occasionally came so close that we could count their
teeth. Numerous bottlenose dolphins in the area also
showed an active interest in uso
The most exceptional lish sightings lor me were
two fish which have not been recorded Irom the
Galápagos (Fig. 2): the raccoon butterlly lish
(Chaetodon lunula) and the threadlin or golden
butterfly lish (Chaetodon auriga) which were seen in
close proximity to one another just to the southeast 01
the small rack. They had lound something 01 a lee
lram the swirling loamy waters in a depression behind
some rocks. The bottom between the two exposed
rocks was rather Ilat and shallow (2.5-3.0 m or 8-10
It). These lish were exceptionally attractive and
recognizable with their bold stripes and markings. 1
had previously observed both species while diving off
Christmas Island in the Central Pacific and in the
Hawaiian Islands, where they are common.


How old is that tortoise?

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How old is that tortoise?

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