Hoogmoed, Marinus S.

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12 NOTICIAS DE GALAPAGOS No. 47
1975, en calidad de ayudante de carpintería para
trabajar en la construcción de los corrales de las
iguanas; posteriormente fue asignado a otras
actividades de mantenimiento y construcción de la
infraestructura física de la institución. Con el
transcurso del tiempo y por el místico esfuerzo y
ganas de aprender, fue ganándose la consideración y
respeto de sus compañeros de trabajo y jefes:
actualmente ocupa el puesto de Jefe de Mantenimiento
de la institución.
En la Estación aprendió el oficio de albañil, sus
primeras experiencias en este campo fue "asentando
bloques en la casa 'el castillo'" como él mismo
manifiesta. Por iniciativa propia fue ganando
experiencia en plomería y gasfitería. En buena
medida depende de él que la Estación y el Parque
dispongan de agua de manera permanente. Siempre
está disponible fines de semana, días feriados, para
resolver algún problema, reparar tuberías y
mangueras, etc. Cuántas veces se ha visto a Alfonso
salir de la vegetación densa, completamente mojado,
al reparar alguna pieza.
"Me gustan las Islas y mi trabajo," manifiesta;
"hubiese deseado acompañar a los científicos a las
diferentes Islas y conocer más de cerca 10que hacen."
De todas maneras, a través de la labor que ejecuta, él
sabe que también ha aportado con su grano de arena
a las diferentes actividades que la institución realiza.
Ha estado presente en épocas difíciles de duras
pruebas, también ha participado de los momentos de
éxito. En fin, en una u otra manera ha incrementado
con su presencia la historia institucional. Siempre de
buen humor y la mejor voluntad contribuye e influye
considerablemente en el buen ambiente de trabajo,
que rige en la Estación.
Don Alfonso también es chofer de la "Tortuga"
que sirve para transporte del personal de la Estación.
Fue condecorado y reconocido a principios de año,
por haber cumplido 13 años de trabajo ininterrumpido
en la institución. Alfredo Carrasco, Estación
Científica Charles Darwin, Isla Santa Cruz,
Galápagos, Ecuador.
INTRODUCED GECKOS IN PUERTO AYORA, SANTA CRUZ,
WITH REMARKS ON OTHER AREAS
By: Marinus S. Hoogmoed
During the recent International Workshop on
Herpetology in Galápagos (29 May-11 June 1988),
several participants noted the presence of a large
species of introduced gecko on buildings in Puerto
Ayora, Isla Santa Cruz. All specimens seen were
located on the walls of relatively large and new
concrete or stone buildings. It seemed worthwhile to
establish the identity and map the local distribution
of this species, which certainly was not the endemic
species, P hyllodactylus galapagensis Peters;
according to J.W. Wright (pers. comm.), the large
lizard was a recent introduction, first observed in
1979.
On the basis of information gathered in 1981 by
former Station herpetologist, Robert Reynolds, when
he first saw the species, the introduction probably
occurred a few yearS earlier. According to the
recollections of Tui De Roy and Gil De Roy, these
geckos were seen at the Ninfa Bar as early as 1975.
MaríaEulaliade Balfourwas awareofthis introduced
gecko in a house behind the Catholic Church in
Puerto Ayora in 1976.
Wright (1983a) identified the introduced large
gecko in Puerto Ayora as Phyllodactylus reissi, but
later he (Wright 1983b) changed his opinion and
tentatively considered it P. pumilis, not giving the
reasons forthis change. However, studying specimens
soon convinced me that they actually belong to
Phyllodactylus reissi Peters rather than P. pumilis
because of the lizard' s size, the fact that the scales on
the dorsal surface of the thighs and on the proximal
one-fourth of the tail are homogeneous, and the fact
that the scales in the supraocular region are the
largest ofthe interorbital series. Additionally, when
the distribution of both species on the mainland was
taken into consideration, it appeared much more
likely that P. reissi would be introduced accidentally
from the mainland to Galápagos than P. pumilis,
which is only known to occur in a rather small, and
relatively inaccessible, area with no major shipping
March 1989 NOTICIAS DE GALAPAGOS 13
ports. P. reissi, however, inhabits coastal Ecuador
from Manabi (Manta) southward to northern Perú,
where it even enters the upper Amazon Basin (Dixon
and Huey 1970). It also occurs in Guayaquil, a major
shipping port with traffic to Galápagos. Dixon and
Huey (1970:54) considered this species "the most
abundant scansorial gecko of northern Pero" and
stated that their nocturnal activities are "essentially
on vertical surfaces, i.e., trunks of trees, walls of
building s, boulders, cacti, and fence posts . . . ."
Among the daytime retreats of this species they
mentioned cracks in adobe walls and "beneath palm
leaves, constroction materials and fruit crates."
Especially the last-mentioned daytime retreats could
facilitate the transport of P. reissi from the mainland
to the Galápagos Islands, when in close proximity to
human settlements. The regular boat service from
Guayaquil provides the Islands with numerous
necessities like construction materials, vegetables,
and other products.
Phyllodactylus reissi reaches a snout-vent length
of 75 mm in males (mean 59.4 mm) and 73 mm in
females (mean 57.5) (Dixon and Huey 1970). The
largest specimen (male) from Puerto Ayora measured
75 mm. All specimens observed in Puerto Ayora
were pale grayish, with indistinct, diffuse, darker
spots that did not form distinct bands. The belly of
most specimens was yellow or white with a yellow
area. These two characters (size and color) are
sufficient to distinguish P. reissi from the much
smaller P. galapagensis (maximum snout -vent length
45 mm [Van Denburgh 1912; Lanza 1973]), whichis
distinctly patterned with bold, dark spots and bands
on a brownish gray background (Wright 1984:26,
lower lefthand picture). Upon closer examination,
more differences between the two species become
apparent: P. reissi has a distinct frontal depression;
an oblique row of enlarged, projecting postanals; a
midventral row of transversely enlarged subcaudals;
truncate scansorial discs; and it lacks any pigment
spots on the ventral s (which are white in preservative);
P. galapagensis lacks the frontal depression, has no
enlarged postanals and subcaudals, has rounded
scansorial discs, and has a small black spot on each
ventral (light brown in life [Van Denburgh 1912]).
During two surveys, parts of Puerto Ayora were
checked for the presence of these large geckos.
During the first survey on 31 May 1988 (2000-2130),
the dock area around the Catholic Church and the
Hotel Las Ninfas was intensively searched by J.W.
Wright, L.A. Fitzgerald, and myself. A total of 28
specimens was captured and another 10 were seen
but escaped. 1did the second survey by myself on 9
June 1988 (2000-2100), and at that time saw a total
of eight specimens on the walls of the hospital, the
Hotel Las Palmeras, the Hotel Lobo del Mar, the
Municipal building, the Sala de Uso Multiple, and
opposite the INGALA building (see Fig. 1, triangles).
During the two surveys and on some additional,
casual evening observations, only four P.
galapagensis were observed, all on the walls of
buildings belonging to the Hotel Sol y Mar (Fig. 1,
stars), where they seemed to occupy the same niche
as P. reissi did in the more central part of Puerto
Ayora. The only difference observed was that the
buildings on which P. reissi occurred were in less
rural areas than those on which P. galapagensis
occurred (surrounded by open areas). Nowhere were
the two species observed together. Though the data
collected so far only can be considered anecdotical,
they nevertheless seem to indicate the following:
1) P. reissi is well established in the central part
ofPuerto Ayora, being much more numerous in the
dock area than elsewhere in town, where 1 only
observed single individual s and no concentrations as
on the Catholic Church and in the Hotel Las Ninfas.
It appears that it has not spread beyond Puerto Ayora,
though no search was made for this species outside
the village.
2) In the human environment, P. galapagensis
seems to occupy the same niche as P. reissi. In the
natural environment, it lives among and under
boulders, as 1 observed in 1981 in the CDRS.
3) The species do not occur together on the same
buildings. This might mean they are mutually
exclusive. Whether this exclusion is an active one,
with P. reissi eating or harassing the much smaller P.
galapagensis, or whether other factors are involved,
is unknown.
4) The present distribution of both species in
Puerto Ayora seems to suggest a spreading of P.
reissi into the village, with the dock area as the center
of dispersal. Whether itjust occupied an empty niche
in this artificial habitat, or whether it supplanted P.
14 NOTICIAS DE GALAPAGOS No. 47
1 Ninfa Restaurant
2 Pro-Insular Market
3 Post Office
4 Catholic Church
5 Hospital
6 Hotel Las Ninfas
7 Pharmacy
8 Banco de Fomento
9 Trail to Tortuga Bay
10 Los Gemelos Restaurant
11 DITURIS Office
12 Hotel Las Palmeras
13 Gallardo
-
Mechanico
14 New movie theater
15 Municipal building/Library
16 Dr. Darquea
17 Hotel Lobo del Mar
18 Police
19 La Garrapata Restaurant
20 Hotel Sol y Mar
21 4 Lanterns Restaurant
22 Pelican Bay store
23 Hotel Galápagos
24 National Park Information
25 National Par k dock
Map adapled from a map prepared by Holel Galápagos (nol lO scale)
Figure 1. Map of central part ofPuerto Ayora showing localities for Phyllodactylus galapagensis (stars) and
P. reissi (triangles). The route ofthe two surveys is indicated with a broken line. Mapa de la zona central de
Puerto Ayora enseñando localidades de Phyllodactylus galapagensis (asteriscos) and P. reissi (triángulos).
La ruta investigada durante ambos censos está indicada por la linea rayada.
galapagensis, is not known.
5) The rate of dispersal from the point of
introduction is not known, but by regular monitoring
it could be established in the future.
The population of P. reissi, though largely in
central Puerto Ayora, still might be controlled by a
regular hunting and extermination programo Because
no special skills are needed for this, and because
logistics are not a problem, it should be possible to
enlist the help of a variety of Park and Station
personnel, visiting scientists, and students for"gecko-
shoots," to eradicate this introduced species before it
spreads into the natural environment, where it would
realIy be impossible to control. The spread into the
natural environment does not seem impossible,
because its mainland habitats (Dixon and Huey 1970)
are similar to habitats found in Galápagos. A regular
program to monitor the population of P. reissi in
Santa Cruz would be advisable in order to ascertain
whether the "gecko-shoots" do have an effect. 1
estimate that the species could be removed from the
presently inhabited area within 2 years' time. At the
same time, care should be taken that no new
introductions stem from ship cargo arriving to Santa
Cruz and air cargo arriving on Baltra. Rigorous
inspection of cargo by the Port Captain before it is
brought ashore would be important to preventing
future introductions.
According to Wright (1983a, 1983b) another
species of gecko, Lepidodactylus lugubris (Duméril
March 1989 NOTICIAS DE GALAP AGOS 15
and Bibron), also has been introduced to Puerto
Ayora, although 1did not observe it during my visito
This is a small gecko, comparable in size to P.
galapagensis; the species is distributed from Ceylon
eastward throughout the Pacific to New Zealand and
to western Central (Panamá) and South America
(Ecuador, Colombia). Undoubtedly this species is of
Southeast Asian origino Due to its close association
with man and human transport, this species has
achieved its present distribution. It probabl y reached
Galápagos from the east via the Ecuadorian mainland,
where it is well established. Periodic surveys of this
species will be necessary to keep track of its spread.
The third introduced species of gecko in Galápagos
(only on San Cristóbal) is Gonatodes caudiscutatus
(Günther). Originally it was described as G. collaris
Garman and considered to be endemic to San
Cristóbal. As such, it was reported again by Mertens
(1963). Vanzolini (1965), however, showed the type
specimen of G. collaris to be identical with G.
caudiscutatus from western Ecuador. This opinion
was supported by Rivero-Blanco (1979) and Wright
(1983c). Apparent1y this species has been reported
only from Wreck Bay (Puerto Baquerizo Moreno)
and from El Progresso. Wright (1983c) assumed that
it was introduced on San Cristóbal with agricultural
products from the Guayaquil area. In contrast to the
other two introduced geckos, G. caudiscutatus is an
inhabitant of relatively wet areas, and in San Cristóbal
it is found in the wet highlands and in artificially wet
gardens in the coastal area. It is unknown whether
this species is spreading or noto A regular monitoring
program would be desirable.
Not all introductions involve long-distance
movements. Wood (1939) reported the presence of
Phyllodactylus leei Cope, a species supposedly
endemic to San Cristóbal, in Puerto Villamil on
Isabela. Lanza (1973) thought that it was accidentally
introduced into Puerto Villamil from San Cristóbal
by human traffic between Islands. Wright (1983a,
1983b) mentioned its introduction to Isabela, but was
doubtful whether the species still existed on Isabela.
Clearly, mammals, birds, insects, and plants are
not the only introduced organisms in Galápagos.
Geckos are notorious migrants that can cover large
distances as stowaways in human cargo, either as
eggs, as juveniles, or as adults. Of the three species
introduced from mainland Ecuador, the largest one,
P. reissi, may pose the greatest threat to the smaller
native species of Phyllodactylus. The effects of L.
lugubris and G. caudiscutatus on the native geckos
are not known but might be lessened because these
species seem to prefer wetter habitats than
Phyllodactylus from Galápagos. However, these are
only speculations based on few observations, and
careful research is needed in order to correct1y estimate
their impact (if any) on the native geckos and the
ecosystem.
The fact that interisland transportation already
seems to be responsible for the translocation of one
endemic species of Phyllodactylus shows how careful
one should be in transporting material s from one
island to another. Possibly more interisland
translocations have occurred but have gone unnoticed.
One species (P. galapagensis) occurs on all the
central Islands (Santa Cruz, Isabela, Fernandina,
Santiago, Pinzón, Baltra, Daphne [Lanza 1973;
Wright 1983a, 1983b]). Our present knowledge of
this group does not enable us to distinguish between
populations. Future research, especially in the field
of genetics, might provide more data on recent
movements of native species. For the time being, it
seems advisable to start monitoring introduced gecko
populations and, as soon as possible, tomakedecisions
on whether their removal would be a high priority or
noto My participation was made possible by a grant
of the Van Tienhoven Foundation, Amsterdam, The
Netherlands, and by the Tinker Foundation which
sponsored the workshop in Galápagos.
LITERA TURE CITED
Dixon, J.R., and R.B. Huey. 1970. Systematics of
the lizards oí the gekkonid genus Phyllodactylus
of mainland South America. Los Angeles County
Museum, Contributions in Science 192: 1-78.
Lanza, B. 1973. On some Phyllodactylus from the
Galápagos Islands (Reptilia, Gekkonidae). Pp. 1-
34 In Galápagos, studi e ricerche. Spedizione L.
Mares-G.R.S.T.S. Museo Zoologico dell'
Universita di Firenze.
Mertens, R. 1963. Die Wiederentdeckung der
Geckonengattung Gonatodes auf den Galapagos.
Senckenbergiana Biologica 44(1):21-23.
16 NOTICIAS DE GALAP AGOS No. 47
Rivera-Blanco, C. 1979. The neotropical lizard
genus Gonatodes Fitzinger (Sauria:
Sphaerodactylinae). Unpublished dissertation,
Texas A&M University, College Station.
VanDenburgh,J. 1912. Expedition ofthe California
Academy of Sciences to the Galapagos Islands,
1905-1906. VI. The geckos of the Galapagos
Archipelago. Proceedings of the California
Academy of Sciences, Fourth Series, 1:405-430.
Vanzolini, P.E. 1965. On the Gonatodes of the
Galapagos Islands (Sauria, Gekkonidae). Papéis
Avulsos de Zoologia 17(2):17-19.
Wood, G.c. 1939. Results of the Pinchot South Sea
Expedition, III.-Galapagos reptiles. Notulae
Naturae 15:1-4.
Wright,J.W. 1983a(revisedMay 1984). Reptilesof
the Galapagos Archipelago. Unpublished reporto
1 pp.
Wright, J.W. 1983b (revised 1984, 1988). Reptiles
of the Galapagos Archipelago. Unpublished
reporto 2 pp.
Wright, J.W. 1983c. The distribution and status of
Gonatodes collaris in the Galapagos Archipelago.
Herpetological Review 14:32.
Wright, J.W. 1984. The origin and evolution of the
lizards of the Galapagos Islands. Terra, March/
AprilI984:21-27.
Marinus S. Hoogmoed, Rijksmuseum van
Natuurlijke Historie, Postbus 9517, 2300 RA
Leiden, The Netherlands.
EFECTOS DEL INCENDIO DE 1985 EN LOS INVERTEBRADOS DE
SIERRA NEGRA, ISLA ISABELA
Por: Sandra Abedrabbo
El incendio del sur de Isabela, ocurrido en marzo
y abril de 1985, permitió evaluar su impacto en las
comunidades de invertebrados y examinar los
procesos de recolonización. En junio y noviembre
del mismo año se hizo un chequeo preliminar de los
invertebrados del área quemada y desde febrero de
1986 se empezó con muestreas sistemáticas en el
sector de la pampa de Sierra Negra (1,loom); puesto
que fue una de las áreas más afectadas por el fuego,
y homogénea en cuanto a vegetación y tipo de suelo.
Con el fuego los invertebrados soportaron una
gran mortalidad, pero estos empezaron a recolonizar
fácilmente el área quemada pocos meses después del
incendio. Invertebrados pioneros como Orthoptera
(grillos y saltamontes) y camivoros oportunistas
como Araneae (arañas) y Carabidae (escarabajos)
fueron los que iniciaron el proceso. Posteriormente
con la regeneración de la vegetación empezó la
recuperación de los invertebrados herbívoros que
dependen estrictamente de ella, como Homoptera
(pulgones) y larvas de Lepidoptera (mariposas).
La recuperación de los invertebrados en el área
quemada esta intimamente relacionada con la
restitución de la capa orgánica del suelo y la
vegetación. En refugios esta fauna no fue casi
alterada y se consideran "Islas" que ayudan a
reestab1ecer el equilibrio. La recuperación del área
quemada de Sierra Negra ha sido bastante rápida,
tanto en la recolonización de la vegetación como de
los invertebrados. Se estima que en uno o dos años
se puede tener una "estabilidad" de estas comunidades.
EFFECTS OF THE ISABELA FIRE OF 1985
ON THE INVERTEBRATES
OF SIERRA NEGRA
The Eireon southern Isabela in March and April of
1985 created the opportunity to study the impact of
fire on the invertebrate community and the processes
involved in recolonization. In June and November of
1985, a preliminary survey of the invertebrates in the
burnt area was completed. Subsequently, in February
1986, systematic sampling was begun in the Sierra
Negra pampa (1,100 m) because this was one of the
areas most affected by the fire, and previously was
one of the most homogeneous in terms of vegetation
and soil characteristics.
The invertebrates suffered a high mortality as a
result of the fire, but they readily began to recolonize
the burnt area only a few months after the Eire.
Pioneer colonists such as orthopterans (crickets and
grasshoppers), opportunistic carnivores such as


Introduced geckos in Puerto Ayora, Santa Cruz, with remarks on other areas

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Introduced geckos in Puerto Ayora, Santa Cruz, with remarks on other areas

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