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Evaluating headstarting as
a management tool: Post-release success of green iguanas (Iguana
iguana) in Costa Rica
Ricardo A. Escobar1, Edsart Besier2
and William K. Hayes1
1Department
of Earth and Biological Sciences, Loma Linda University,
Loma Linda, CA, 92350, USA.
2
Green Iguana Foundation, P.O. Box 30-7304, Puerto Viejo,
Limón, Costa Rica.
*Corresponding author. E-mail:
rescobar@llu.edu.
Accepted
21 May, 2010 |
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Headstarting has become a popular tool employed by wildlife
managers to help animal species, specifically those lacking
or providing minimal parental care-offset extinction.
However, many researchers challenge the conservation value
of headstarting and urge proponents to monitor headstarted
individuals following release into the wild to evaluate the
success of headstart programs. As part of an experimental
headstarting program managed by the Iguana Verde Foundation
in Costa Rica, we conducted a 1.5-month radiotelemetry study
of 11 headstarted 2 year old green iguanas (Iguana iguana)
following their release into the wild at the
Gandoca-Manzanillo Wildlife Refuge. Headstarted iguanas were
compared to their wild counterparts (two radiotelemetered
and 18 opportunistically-encountered) with respect to
changes in growth, arboreal microhabitat use, social
aggregation, activity ranges and movements. Male and female
headstarted iguanas exhibited similar behaviours and
headstarted iguanas were similar to wild iguanas for most
variables measured. Thus, the headstarted green iguanas were
clearly capable of short-term (1.5-month) survival in the
wild and their apparently normal behaviours reflected the
suitable conditions under which they were raised. The
results provide insight into the ecology of green iguanas
and will help guide headstarting and reintroduction programs
for iguanas at this location and endangered iguanas
elsewhere.
Key
words:
Captive-breeding, conservation, headstarting, home range,
lizard, radiotelemetry, reptilian, spatial use.
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