size: 7451KB - Crocodile Specialist Group

Introduction and Conservation
Priorities
Crocodilians (crocodiles, aligato.s, caimans, and gharials) are crocodilians arc very effective aquatic predab6. Although
prominent and widespread occupants of tropical aquatic habitats.
The Sroup is ancieni, wilh hundrcds of fossil forms and temtlemture within narrow limits by behavior, basking in the
cro€odiles are reptiles, $ey can ofren mainrain their body
three major mdiations. Crocodilians are implicated in positive sun rvhen cool, seeking shade when hot. They are meabolically
effects in their environmonts as "keystone species" that maintain
eaosyslem structure and function by theiraclivities. Thes€ on land, where dey walk on erect legs, and in the wator, where
ellicien!, and have fast reflexes and effecdve locomolor ability
include selective predation on lish sf€cies, recycling nuEients, thcy swim Iapidly, driven by lheir powerful tails. Crocodilians
and maintenanc€ ofwet refugia in droughrs. Crocodilians have have complex behaviors including social interacrions, dominance
hicrarchies, vocalization, coordiMtod feeding, and well-
some unique aspects of natural history that create special
challenges for theirconseNation. They are the larges!prcdalors developed matemal behavior. Females deposil from 10 ro over
in their habiraB and can rhrcaten humans and deir livestock. 40 hard-shelled eggs inlo a ncst which is either a hole dug inlo
Many species arc exploired for rheir valuablo skin, which lhe ground or a pile of vegetation garhered by the female. Most
suppois an intemational trade woih ovcr U.S. p00 million females remain near $eir nest during incubation and may
annually. They are also heavily impacred by habitai 1o6s and prolect it from predators. Upon hatching, vocalizations made
pollution of aquatic habilats. l,oss of any crocodilian sp€cies by the hatchlings induce the fernale tio help $c hatchlings
rcpresen$ a significant loss of biodiversity, economic potential, emerge, and she may even carry thg tiny babies to tho watcr in
and ecosysr€m sabiliry. This acrion plan summarizes current hcr mouih. The hatchlings rcmain togelher near the mother for
slatus and priorily actions ne€ded !o cons€rve crocodilians. scveral months, deriving prolection from her proximity. As
The crocodilians are classified as belonging to three fafiilies liey gmw and become more widely dispersed and independenl,
and eight genera (see Table 2). There is a wide diversity of size, a large numb€r of the offspring perish, some eaten by orher
habitat, food prefcrence, reproducdve b€havior, and many crocodilians, The survivors grow and reach malurity after a
o$er aspecls of biology among the 23 crocodilian species. period of 5'15 years, depending on dle spccies. Females
However,all specie.s have dc following basic simildrities. AU generally grow more slowly and reach maturity a! a smaller size
than males, rrho continue growing and usually exceed females
in maximum size. Crocodilians can be long,lived in lho wild,
and therc are records of particular individuals resident for
Table 2. Classincatlon of Crocodlllans, afterKlng and
decades at somc locations. Adult males of s€veral species emit
Burk€ 1989.
loud vocalizations in association with fhe breeding season.
Delails of crocodilian biology as it pcnains ro thoir management
and conseryation can be found in Webb et al. 1987. These
biological characleristics give the potenrial of grEa! resiliency
Fanily Alllgatorldae
lo some crocodilian populations, enabling them to recover ftom
GeNs Alligatot (ruc .lligatoN-2 specict
population deplelion and susrain relatively high harvest rates.
cairoz (caimas 3 specis)
However, persistent killing of adulls can lcad to rapid populadon
depletion, panicularly if combined with habira! loss.
Meta@sachus (black caima 1 specict
Pa&rra.l/s (dw&f cainm-2 sp€is)
Crocodilians aie lhreatened by many human aclivides.
Farnlly Craodylidae
Commercial overexploiration and indiscriminaF killing have
Subfmily Crccodylinae
resulted in many species suffering drastic declines in nunbers
aeNsCreodyl6 (tue crocodilcs 12 spei6)
and, when combined with sevcrc habita! Io9s, have brough!
orreala% (dwdf docodile 1 sFcies)
severai spc.ies to the brink of extincrion. Amund $e world,
subimily Tohisrominae
AeNs Thinom (Ionbbfra-l
conservation inlerest has led to
species)
the developmenl of a number of
F:!nilJ Grvlalldae
Ccnus Calialts (shdial I species)
rccovery programs designed to improve the status of wild
populations. A number of lhes€ progmms, such as lhe work on
gharial in India and Nepal, have met wilh a de$e€ of success.
Today. with lhe heightoned interesr in conservadon rhrough