Gordillo G., Jacinto

Marquez, Cruz

Tupiza, Arnaldo

English

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NOTICIAS DE GALAPAGOS No.54
THE FIRE Oß I994AND HERPETOFAUNA
OF SOUTHERN ISABBLA
By: Cruz Márquez, Jacinto Gordillo and Arnaldo Tirpiza
(Translated by K. Thalia East)
Between February and June I994,Isabela Island
experienced its fourth wild fire this century. Approx-
imately 3,500 to 4,500 ha on the southwestern slopes
of Sierra Negra Volcano were burned. From conver-
sations with various inhabitants of Isabelaitis known
that the fire was started on 12 April by hunters who
forgot to extinguish their cooking fires. Winds then
spread the flames.
The tragic event alarmed biologists, ecologists and
natural resource managers from national and interna-
tional institutions alike. Through mass efforts by
personnel of the Galápagos National Park Service
(GNPS), the National Institute of Galápagos (INGA-
LA), the Ecuadorian Forestry Institute of Natural
Areas and Wildlife (INEFAN), the Municipality of
Isabela, the Ecuadorian Army, the Charles Darwin
Research Station (CDRS), and the Civil Defense, and
in part, due to an increase in precipitation, the fire
was finally put out on 7 June.
Fortunately the fire was only about one fifth the
strength of Isabela's last wild fire which occurred in
1985. That fire burned 20,000 ha in the same area,
in the same months, and under similar climatic con-
ditions (i|l4árquez, 1 987). While in 1 985 the fire never
endangered the tortoises of Cerro Paloma and Roca
Unión, due to the potential threat, preventative mea-
sures were taken and some individuals were evacuated
to enclosures constructed at Roca Unión and Caleta
San Pedro.
THE REPTILES
In the past, the herpetofauna of southern Isabela
and particularly that of Sierra Negra has continuous-
ly been decimated by introduced feral mammals such
as pigs, dogs and cats and even by humans them-
selves, but never by any of the known wild fires.
During the 16th to 19th centuries Galápagos was a
refuge for buccaneers and whalers (Slevin, l93l
Townsend, 1925). They decimated tortoise popula-
tions for food throughout the archipelago and in
particular on southern Isabela. However, the inter-
mediate-sized tortoise, Geochelone guntheri,
remained abundant in the grasslands of Sierra Negra
up untilthe firstdecades of this century (Slevin ,7959;
Van Denburgh,I9l4; Beck, 1903). Human popula-
tion growth in Isabela, beginning about 1891,
drastically diminished the tortoise population until
the defenseless animals became virtually extinct. A
few individuals survived in the lower, semi-arid zones
of Sierra Negra and a small colony survived in sym-
patry with a population of its relative, G. vicina, in
Cinco Cerros on CerroAzul (Fig. 1). However, even
today colonists continue to threaten the survival of
thepopulations in CerroPaloma, Cerro Cazuela, Cabo
Rosa-Roca Unión and Cincos Cerros, by killing and
eating the tortoises.
On23 April, while the fire burned, we visited the
tortoises of Roca Unión. We found that while the fire
did not threaten the tortoises in this zone, humans
continued to endanger them. 'We found eight tortoise
carapaces, whose plastron had been separated from
the carapace with a machete ; the limbs were dismem-
bered and missing. The animals had been sacrificed
for their meat.
Between 28 April and2 May we visited the tor-
toises of Cerro Paloma to look for and evacuate
tortoises to the Breeding Center in Puerto Villamil.
We did not find any evidence of recent poaching,
only the carapaces of tortoises killed in 1988 (Snell,
1988). Howeverwe did see the same type ofmachete
cuts on the cacti along the tortoise trails as those we
had observed along the trails in Roca Unión. This
suggests that the same group of men that were eating
tortoise meat on Roca Unión may also have been
searching for tortoises at Cerro Paloma.
November 1994 NOTICIAS DE GALAPAGOS
htttu
Tù\\'I
H
tJ
ffi
Lava
Area burned in 1985
Area burned in 1994
Tortoise Zones
Cerro Azul
1. Cinco Cerros
2. LasTablas
3. Los Gavilanes
4. Los Cráteres
lEõæ.iõñl
Sierra Negra
5. Cerro Caztela
6. Cabo Rosa and Roca Unión
7. Ceno Paloma
Figure 1. Map of southern Isabela Island showing locations of tortoise populations (Zones 1-7) and the areas burned in 1985 and
1994.
EVACUATION STRATEGIES
During the 1994 fire, the staff of GNPS, CDRS,
the Civil Defense and the Ecuadorian Military sur-
veyed the burned area on foot and by air. No charred
remains of lava lizards (Microlophus =Tropidurus
alb emarlensls), geckos (Phyllodactylus g alapag o en-
sls), snakes (Phylodryas or Alsophls sp.), land iguanas
(Conolophus subcristatus) or giant tortoises (Geoch-
elone guntheri or G. vicina) were found. Nonetheless,
the absence of copses and bones does not prove that
reptiles were not killed in the fire. Furthermore,
uncontrollable fires on Isabela had previously de-
stroyed tortoise habitat at both Cerro Paloma and Roca
Unión. Given the potential danger of the 199 4 fire to
torloise populations, the following strategies for evac-
10 NOTICIAS DE GALAPAGOS No.54
uating tortoises from the two critical areas were de-
veloped:
Tortoises at Roca Unión and San Pedro
1) The tortoises would be evacuated if the fire ad-
vanced to about 1 km either from Cerro Barahona
or the southern most extremity of the lava flow.
2) The tortoises would be transferred to the two evac-
uation enclosures constructed in 1985, one at 0.5
km from the coast at Roca Unión and the other
only 8 m from the coast at Caleta San Pedro.
3) The tortoises nearest to the enclosures would be
chosen for transfer.
4) Park wardens would be stationed at the enclosures
to feed and care for the tortoises.
5) Prior to transferring the tortoises, they would be
marked with whitepaint on the fourth dorsal plate
with the initials of the sector from which they were
taken.
Tortoises at Cerro Palomu
1) Tortoises would be evacuated if the fire advanced
towards Cerro Chato.
2) Tortoises would be moved directly to the Breeding
Center in Puerto Villamil; the smaller individuals
would be transported by burro and the larger by
helicopter.
EVACUATION OF THE TORTOISES IN 1994
Considering the real threat of poaching and the
potential threat of the forest fire on the tortoises, the
transfer of individuals to the Breeding Center was
considered the only way to recover the populations of
tortoises at Cerro Paloma and Cerro Cazuela (a tor-
toise area far from the fire but with a high level of
poaching). Due to the fire fighting activities, two
helicopters of the EcuadorianArmy were available to
evacuate the larger adult tortoises.
In the first week of May, after four days of search-
ing for tortoises around Cerro Paloma, five individuals
were captured. Of these, two (a juvenile and a male)
were transported out by burro, and the other three
(two males and ajuvenile) were evacuated by heli-
copter. In the weeks that followed, five more torloises
were evacuated (a male, a female and three juve-
niles). These tortoises will be kept in the Breeding
Center in hopes of establishing a reproductive group
andproducing young tortoises to repopulate the slopes
of Sierra Negra. These initial efforts must be contin-
ued so that the survival of the tortoise populations of
southern Isabela will be assured.
ACKNOWLEDGMENTS
We thank Santiago Matheus, President of the Per-
manent Commission of Galápagos, Mario Salzmann,
representing PNUD, the Ecuadorian Army, GNPS,
INEFAN, the Municipality of Isabela, INGALA and
CDRS for their efforts in putting out the fire and
evacuating the tortoises. We also thank TAME for
providing reduced airfare for flights between the
continent and Galápagos.
LITERATURE CITED
Beck, R.H. 1903. In the Home of the GiantTortoise.
Annual report of the New York Zoological Soci-
ety 7: 160-114.
l|ll.árqlaez C. 1981 . El incendio y la fauna herpetolog-
ica en el sur de la Isla Isabela. Rev. Geografica
24:105-710.
Slevin, J.R. 1931. Log of the SchoonerAcademy on
a voyage of scientific research to the Galápagos
Islands, 1905-1906. Occasional Papers ofthe Cal-
ifornia Academy of Sciences l7:l-162.
Slevin, J.R. 1959. The Galápagos Islands: a history
of theirexploration. Occasionalpapers of the Cal-
ifornia Academy of Sciences 25:150.
Snell, H.L. 1988. Informe de Itinerario de Viaje.
CDRS Archives.
Townsend, C.H.1925. The Galápagos tortoises and
their relation to the whaling industry: a study of
old log books. Zoologica 4:55-135.
Van Denburgh, J. 1914. The gigantic land tortoises
of the Galápagos archipelago. Proceedings of the
CaliforniaAcademy of Sciences 4th series 2:203-
314.
Cruz Márquez, Jacinto Gordillo and Arnaldo
Tupiza, Charles Darwin Research Station, Isla
Santa Craz, Galápagos, Ecuador.


The fire of 1994 and herpetofauna of southern Isabela

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The fire of 1994 and herpetofauna of southern Isabela

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