Cayot, Linda J.

Marquez, Cruz

Morillo, German

English

Aquatic Commons

1991 NOTICIAS DE GALAPAGOS 17
Historical Research Center, Reference Division,
Maxwell Air Force Base, Microfilm ree1 32958.
PanamaCanalDepartment. 1947. Galapagos. USAF
Historical Research Center, Reference Division,
Maxwel! Air Force Base, Microfilm reel 32958.
Roosevelt, P.D. 1942. Letter of 4 March from Dr.
Waldo LaSalle Schmitt. Franklin D. Roosevelt
Library, Box OF 4017: Galápagos Islands.
Roosevelt, P.D. 1944. Memorandum of 1 April to
the Secretary of State. Frank1in D. Roosevelt Li-
brary, Box OF 4017: Galápagos Islands.
Schmitt, W.L. 1942. Diary. SmithsonianInstitution
Archives, Record Unit 7231: Waldo LaSal!e
Schmitt Papers, Box 100, Folder 8.
Wetmore, A. 1942a. Letter of 5 June to Dr. Waldo
LaSal!e Schmitt. Smithsonian Institution Ar-
chives, Record Unit 7006: Alexander Wetmore
Papers (unprocessed) Box 90.
Wetmore,A. 1942b. Letterof7 JulyfromDr. W.L.
Schmitt. Smithsonian Institution Archives, Record
Unit 7006: Alexander Wetmore Papers (unproc-
essed) Box 90.
Wetmore,A. 1942c. Memorandumof20November
to Mr. M.L. Leap, Department of State. Smithso-
nian Institution Archives, Record Unit 7006:
Alexander Wetmore Papers (unprocessed) Box 90.
Wetmore, A. 1942d. Letter of 25 August from Dr.
W.L. Schmitt. Smithsonian Institution Archives,
Record Unit 7006: Alexander Wetmore Papers
(unprocessed) Box 90.
Wetmore, A. 1942e. Letter of 10 December to Mr.
M.L. Leap. Smithsonian Institution Archives,
Record Unit7006: Alexander WetmorePapers (un-
processed) Box 90.
Wetmore,A. 1942f. Letterofl7DecemberfromMr.
M.L. Leap. Smithsonian Institution Archives,
Record Unit 7006: Alexander Wetmore Papers
(unprocessed) Box 90.
John M. Woram, 45 Lakeside Drive, RockvilIe
Centre, New York 11570, USA.
A 25-YEAR MANAGEMENT PROGRAM PAYS OFF: REPATRIATED
TORTOISES ON ESPANOLA REPRODUCE
By: Cruz Márquez, German Morillo, and Linda J. Cayot
The first indisputable evidence of successful re-
production by repatriated Galápagos tortoises
(Geochelone spp.) was recorded on Isla Española on
30 November 1990. Two hatchlings were found
approximately 90 m north ofEI Caco (one of the two
release sites). Both were approximately 1month old
and had been eaten by hawks. Female No. 57 was
observed completing a nest (0930), and female No.
61 showed evidence ofrecent nesting activity (dried
mud covering her posterior region). The females
were also located within 80-100 m of El Caco.
A total of four nests were found and were estima-
ted at 1, 2, 5, and 8-10 days old. Al! were located
within 100 m to the northwest ofEI Caco. Attempts
at nesting (scrapes or holes in the soil) were found
in the area surrounding El Caco, encompassing ap-
proximately 800 m to the north, 500 m to both the
east and west, and 200 m to the south. Nest attempts
were also seen in the region above Las Tunas (alter-
nate release site). C. Márquez and T. Fritts had not-
ed similar scrapes resembling nesting attempts on Es-
pañola in December 1985 but now the evidence that
the repatriated tortoises were reproducing is irrefu-
table.
Española tortoises (G. hoodensis) are the only race
bred in captivity at the Charles Darwin Research Sta-
tion (CDRS) as part of the breeding and rearing
program runjoint1y by the CDRS and the Galápagos
National Park Service (GNPS; MacFarland et al.
1974a, Márquez et al. 1990). Tortoises from other
Islands are reared in the program, but using young
extracted from natural nests. By the mid-1960s, the
native population was too low for successful repro-
duction (MacFarland et al. 1974b). Beginning in
August 1963, al! tortoises found on Española were
transferred to the breeding center at the CDRS. A
third male, retumed to the CDRS from the San Diego
Zoo in July 1977, augmented the breeding population
of 12 females and 2 males (Bacon 1978, Fritts 1978).
The first successful reproduction by Española tor-
18 NOTICIAS DE GALAPAGOS No. 50
toises in captivity was in 1970-71.
The f1rst hatchlings reared in the
center were repatriated to Españo-
la (at El Caco) in 1975 (Fig. 1).
Thus the oldest repatriates were
nearly 20 years old in November
1990. The two females that
showed evidence of having nest-
ed (Nos. 57 and 61) are both from
the 1973-74 cohort, and were re-
patriated to El Caco in March
1978. They were nearly 17 years
old when theynested. Whetheror
not their nests are successful will
be determined at the end of the in-
cubation season. Based on the
November 1990 observations, Es-
pañola tortoises first reproduce
between the ages of 16 and 19
years.
The breeding, rearing, and repatriation program
of the GNPS and the CDRS has been very successful
in increasing the threatened tortoise populations to a
level of security. Rowever, until the repatriated tor-
toises begin to successfullyreproduce on theirislands
of origin, the ultimate success of the program is not
assured. Although the only hatchlings found had
been eaten by hawks, their appearance on Española
is a major indicator of the ultimate success of this
long-term program and the possibility exists that oth-
er young have escaped the notice of hawks and
scientists alike.
LITERA TURE CITED
Bacon, J.P. 1978. A tortoise goes home. ZooNooz
51 (2):4-7.
Fritts, T.R. 1978. Española tortoiseretums toGalápa-
Figure 1. Tonoise no. 27, one of the tonoises hatched in captivity in 1971 and
retumed lO Española at the age of four, moves across thc rock tcrrain in 1985 as a
young adult ma1elOnoise. Tortuga no. 27, una de las tortugas criadas en cautiverio
en 1971 y devuelta a Española a los cuatro años de edad. aparece aquí en 1985 en
terreno rocoso como un mocho subadulto.
gos. Noticias de Galápagos 28: 17-18.
MacFarland,C.G.,J. Villa, and B. Toro. 1974a. The
Galápagos giant tortoises (Geochelone elephan-
topus) part II: conservation methods. Biological
Conservation 6:198-212.
MacFarland, C.G., 1. Villa, andE. Toro. 1974b. The
Galápagos giant tortoises (Geochelone elephan-
topus) part 1: status of the surviving populations.
Biological Conservation 6: 118-133.
Márquez, C., S. Rea, and F. Llerena. 1990. Repro-
duction and rearing of giant tortoises and land
iguanas in captivity. pp.71-75 in CDRS Annual
Report 1986-87.
Cruz Márquez, German Morillo, and Linda J.
Cayot, Charles Darwin Research Station, Isla
Santa Cruz, Galápagos, Ecuador.
REVIEW: PORTRAITS OF GALAPAGOS
Authored By: Tui De Roy and Mark Jones
Published 1990, First Edition, 98 pages, Imprents Mariscal, Quito, Ecuador.
Reviewed By: Gay Ver Steeg
This new "coffee-table" volume of photographs
of the animals of Galápagos is a sensitive effort by
Tui De Roy and Mark Jones, both permanent resi-
dents of Galápagos. It is primarily a photographic
collection of close-ups by species of the most com-
mon land animal s (various birds, giant tortoises, land
iguanas, and lizards) and sea animals (marine igua-
nas, sea lions, fur seals, sperm whales, harnmerhead


A 25-year management program pays off : repatriated tortoises on Española reproduce

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A 25-year management program pays off : repatriated tortoises on Española reproduce

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