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Status Survey and Conservation Action Plan Second Edition Crocodiles
Edited by James Perran Ross
IUCN/SSC Crocodile Specialist Group
Contributors:
Eduardo Espinosa (Caiman crocodilus, C. yacare)
Robert Godshalk (Paleosuchus palpebrosus. P. trigonatus)
Philip Hall (Crocodylus novaeguineae)
John Thorbjarnarson (Crocodylus intermedius, Melanosuchus niger)
Anton Tucker (Crocodylus johnsoni)
Luciano Verdade (Caiman latirostris)
Cover photo: Black caiman, Melanosuchus niger, Mamiraua, Brazil, where a substantial population of this depleted species is reported to be recovering. Photo by J. Thorbjarnarson.
Contents
The revised Action Plan for Crocodiles, provides concise summaries of the current status and recent information for all 23 species of crocodilian. The Action Plan supersedes the 1992 Crocodiles: An Action Plan for their Conservation. It reflects the ongoing activities of the Crocodile Specialist Group (CSG) membership, provides some guidance and describes priorities for immediate actions that address the most pressing current problems in crocodilian conservation.
An introductory section provides general information on crocodilian biology and outlines some general principles that are being applied to their conservation. The ecological and economical importance of crocodilians in their wetland habitats is noted. Conservation of wild crocodilian populations has numerous spin-off benefits for other species and local human communities. The application of sustainable use to crocodilian conservation is explained, and descriptions of national programs that demonstrate both the application and the effectiveness of these methods are included. The examples of the American alligator in the USA, the Nile crocodile in Zimbabwe and South Africa, and the Saltwater crocodile in Australia and Papua New Guinea are particularly compelling.
This revised Action Plan provides the first application of the new 1994 IUCN Red List Categories to crocodilian status assessment. In general, the assessments made using the 1994 categories agree with previous assessments, but in several cases the application of the new objective and quantitative criteria has drawn our attention to some significant gaps in our information and the need for a reconsideration of species status. The Critically Endangered status of Crocodylus mindorensis, Crocodylus siamensis, Alligator sinensis and Crocodylus intermedius is confirmed and these remain the highest priority for action. Three species, Tomistoma schlegelii, Crocodylus moreletii and Crocodylus cataphractus were evaluated to be Data Deficient. New information suggests Tomistoma may be Vulnerable and C. moreletii Lower Risk, conservation dependent. The application of the quantitative criteria and new information on status reassures us that Crocodylus rhombifer, Gavialis gangeticus and Melanosuchus niger are all showing slow recovery but remain Endangered. The maintenance of ongoing conservation action on these species should continue their recovery. Crocodylus acutus, Crocodylus palustris and Osteolaemus tetraspis are evaluated as Vulnerable. The remaining ten species of crocodilian are assessed to have a Lower Risk of extinction. This group includes the major species appearing in trade and subject to sustainable use and management.
The revised Action Plan provides an updated set of action recommendations for each species. The
recommended actions include: status surveys, the identification and protection of important populations
and habitat; the enhancement of conservation and management capacity of national authorities; the
development of national management plans for crocodilian conservation; captive breeding and restocking programs; and the development of economic incentives for crocodilian
conservation through well-regulated sustainable use. Those high priority projects applying to the most endangered species are analyzed and ranked as a guide to immediate needs.
The plan provides government agencies, management authorities, funding agencies, researchers, non-governmental organizations and other conservation interests with basic information and concrete recommendations for action that will promote the conservation of crocodilians and their habitats.
When Crocodiles: An Action Plan for their Conservation
was completed and went to press in 1990 we did not truly
expect that so many of the facts and recommendations it
contained would become obsolete within a short time. To
our surprise, and considerable pleasure, such is the case.
The period 1990–1997 has seen some tremendous advances
in our knowledge of the status of crocodiles and some
significant improvements in the status of some species.
The overall strategy of the CSG appears to be effective in
slowing, and then reversing declines in the various species,
and in encouraging proactive conservation programs to
ensure their continued survival.
This period has not been without controversy and some
setbacks. The CSG’s enthusiastic promotion of sustainable
use has drawn criticism from some quarters, largely by
those who are unaware of, or cannot bring themselves to
believe, its demonstrated success. In this period we have
also engaged in an extended debate over the relative
conservation merits of various forms of sustainable use for
crocodilians (ranching, closed-cycle farming and wild
harvest) and this Action Plan addresses the advantages,
disadvantages, and some important general cautions
applying to each. We have also continued to assist and
promote a variety of other conservation mechanisms,
including complete protection, captive breeding and
restocking. Our commitment to the conservation of wild
populations of all species of crocodilians remains
undiminished and we will recommend all the available
techniques and strategies to achieve success. This task is far
from complete but we understand that conservation is a
dynamic process that will require continued action.
The Crocodile Specialist Group draws its strength and
its effectiveness from its members. Their individual
contributions, summed over the numerous countries and
projects in which they are involved, provides the
information and action which this Action Plan outlines.
This revised Action Plan, like its predecessor, is intended
to be a dynamic document that will be revised again to
reflect changing conditions and knowledge. It provides a
concise and focused guide to the status of crocodilians and
the current actions needed for their conservation and will
be a general guide to our activities for the forthcoming
period.
Professor Harry Messel
This work could not have been completed without the
financial support generously provided by Utai and
Uthen Youngprapakorn and the Samutprakan
Crocodile Farm and Zoo. The editor wishes to thank
the contributors who provided drafts for the revision of
several of the accounts, but retains the full responsibility
for the final content and any errors. Professor Harry
Messel, CSG Chairman, provided the initial stimulus
for revising the Action Plan and continued to provide a
firm pressure that ensured its completion. John Polisar
and Sylvia Scudder contributed valuable support and
comments. The working draft was reviewed by Dennis
David, Phil Hall, Jon Hutton, Dietrich Jelden, F. Wayne
King, Grahame Webb, Hank Jenkins, Alvaro Velasco,
Lala Singh, David Evans, Enrico Chiesa, Norm Scott,
Andreas Schubert, Chris Banks, Mark Bezuijen, Walt
Rhodes, Indraniel Das, Gustavo Hernandez, Zilca
Campos, Myrna Watanabe, Alan Woodward, Paul
Ouboter, and Charles A. Ross. Copy-editing and
production assistance was provided by Alexandra
Zimmermann. Finally, it is a pleasure to acknowledge
the immense contributions of dozens and dozens of
CSG members, who by their day-to-day efforts and
particularly their communications with the CSG, keep
us active and informed about the progress of crocodilian
conservation throughout the world. Their work is the
firm basis on which the Action Plan is securely grounded.
James Perran Ross, Editor.
In the executive summary of Crocodiles: an Action Plan
for their Conservation (1992) the following passage
appears;
“The seven most critical species in terms of need for
conservation are, in order of priority: the Siamese
crocodile (Crocodylus siamensis), the Philippine
crocodile (Crocodylus mindorensis), the Chinese alligator
(Alligator sinensis), the Cuban crocodile (Crocodylus
rhombifer), the tomistoma (Tomistoma schlegelii), the
Orinoco crocodile (Crocodylus intermedius), and the
gharial (Gavialis gangeticus). Four other species are
endangered, the broad-snouted caiman (Caiman
latirostris), the black caiman (Melanosuchus niger), the
American crocodile (Crocodylus acutus), and Morelet’s
crocodile (Crocodylus moreletii). Because so little is
known about many of these species, emphasis is placed
on conducting population surveys to quantify the current
population status as a first step towards initiating
conservation programs.”
In the period following the publication of Crocodiles: An
Action Plan for Their Conservation, i.e. 1992–1995,
considerable progress was made on addressing the
conservation needs of the priority species. In the same
period the status of the other species also changed. These
changes were most clearly demonstrated in the papers
presented at the Second Regional Meeting of the CSG
in Darwin, Australia, March 1993, the 12th and 13th
Working Meetings of the CSG in Pattaya, Thailand, May
1994, and Santa Fe, Argentina, May 1996. Additional
new information was published in numerous project
reports, publications and CSG reports, some published
(e.g. Crocodile Conservation Action 1993) and others
distributed in both the formal and popular literature. For
some species, better information is allowing us to
make more effective decisions for conservation, while
for others conservation actions have shown beneficial
effects. In a few, the situation continues to be bleak. In
all cases it is clear that the Action Plan served its purpose
as a catalyst for action and a guide for priorities. The
situation has, therefore, sufficiently changed that it is
useful to revise the Action Plan to reflect new status
and altered priorities as they appear to the CSG at the
present time. We therefore undertook a revision of the Crocodile Action Plan with two main goals:
– To focus the recommended and priority actions for conservation more clearly.
The original Action Plan was intended to be a
dynamic working document. This revision and future
revisions continue to reflect the changing nature of the
status of crocodilians and the changing requirements
for their conservation.
The fundamental goal of the CSG remains unchanged,
to prevent the extinction of all crocodilians and to
encourage management and conservation of crocodilians
and their habitats at levels that ensure their ecological
integrity and preserve their resource value.
The objectives of this action plan are to:
With these objectives the Action Plan serves the dual
purposes of assisting government bodies, local conservation
groups and researchers to define their crocodile conservation
needs, and to stimulate and support fundraising for priority
projects.
Information on population status and management
programs was gleaned from published sources, unpublished
reports, and from direct communications with CSG
members and correspondents. Some of the accounts were
drafted by individuals who are listed as the revisers and
most of the accounts, and the organization of the whole
document, was directed by the editor. The priority
conservation programs were projects recommended by
CSG members, either specifically for this Action Plan or
as recommendations in published or unpublished
reports, or were projects deemed to be of particular
importance by the editor and revisers. Not all conservation
recommendations could be incorporated as specific
projects, rather the intent was to address the principal
areas of conservation concern and outline, in a very broad
sense, what needs to be accomplished. The most immediate
priorities are ranked based on urgency. These projects
represent an inventory of conservation needs; the details
regarding project personnel, budget and timetables are
left for future elaboration. A list of people to contact for
each project, country or species needs to be developed.
The revised Action Plan follows King and Burke (1989)
in recognizing 23 species of crocodilian, although where
there is taxonomic confusion or revision in progress this is
indicated in the species account. We have generally used
the scientific binomial names for crocodilians rather than
common names. The scientific names are unique,
unambiguous and internationally recognized, while each
species has a plethora of common and colloquial names
that can cause great confusion. We have inserted some
common names to orient the lay reader. A full review of
nomenclature of crocodilians is given in King and Burke
(1989). An exhaustive list of common, vernacular and
trade names is given in the CITES Identification Guide-Crocodilians
1995, Appendix 1.
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