Researchers from the University of Queensland have been working with the Centre for Crocodile Research to develop a vaccine that protects crocodiles against West Nile virus (WNV).
WNV is transmitted by mosquitoes and birds, and can cause death in American alligators as well as skin lesions in Nile and saltwater crocodiles.
The vaccine was shown to produce:
- a protective antibody response; and
- protection against WNV infection.
The next step is to obtain Australian regulatory approvals for commercialisaton. This work is currently underway.
It is hoped that this vaccine will eventually be available as a human vaccine against WNV as well.
The last extant population of the Cuban crocodile is now restricted to the 300km2 area of Zapata Swamp in southwestern Cuba. Continuing to be classified as Critically Endangered according to the IUCN Red List criteria, population decline is continuing with only an estimated 2,400 adults remaining in the wild.
Although habitat extent and quality continues to decline, along with illegal harvests, the largest risk appears to be hybridization with the American crocodile and requires the foremost action.
New paper released on crocodilian multiple paternity…
Clutches of eggs sired by multiple fathers is well documented. However, this new study shows how poor study design can over-inflate the number of fathers estimated. Some studies have reported up to 10 fathers siring a clutch. But are they real?
Posted October 7, 2022
Knowing when to barrier spray to reduce mosquitoes and effectively reduce "pix" lesions is optimized by guided intervention during peak West Nile virus transmission periods. If you want to implement an mosquito monitoring program, contact us.
Posted 20th July, 2022
West Nile virus (WNV) is now well-recognized to cause disease and skin lesions in crocodilians. One method that crocodiles become infected with WNV is being bitten by mosquitoes. This posed the question of what other mosquito-borne flaviviruses are being transmitted to saltwater crocodiles?
This paper presents the first broader screening of flaviviruses in a crocodilian species thanks to our collaborators at the University of Queensland.
Posted 27th May, 2022
Members of the IUCN-SSC Crocodile Specialist Group have conducted global assessments of the American crocodile (Crocodylus acutus) and the saltwater or saltwater crocodile (Crocodylus porosus).
Crocodylus acutus has been assessed as Vulnerable under criterion A2cd with an inferred population decline of 30% over the last three generations (75 years) because of habitat quality decline and exploitation.
There are an estimated 5,000 mature individuals remaining but the overall global population trend for this species is increasing.
The global population of Crocodylus porosus is secure because of large populations, extensive habitat and effective management in Australia, Papua New Guinea and, to a lesser degree, Indonesia. There are increasing C. porosus populations in the Solomon Islands, Sarawak and Sabah due to effective protection measures, although management may require incentives derived from sustainable use in order to counter negative public attitudes towards them.
Posted 17th January, 2022
Posted 14th January, 2022
Saltwater crocodiles (Crocodylus porosus) lay clutches
of eggs deposited into nests. If left in the nest, few embryos survive, mainly due to flooding. But collecting the eggs and artificially incubating them can improve hatch rate. After
hatching, the crocodiles are grown to produce skins for the luxury leather
trade. Despite artificial incubation, substantial production losses from embryo
mortality still occur. Significant production gains could be made from
understanding, and avoiding, the risk factors that affect embryonic mortality.
In this chapter,
we provide an overview of saltwater crocodile reproduction and current industry
practices with a focus on the identified risk factors that contribute to reproductive
failure.
Further, the consequence of high nest embryonic
mortality on post-hatch performance of the surviving embryos has not yet been
fully explored. However, it is recommended that these two life stages
should not be viewed independently but rather as a continuum to provide some predictability
for producers to increase their production efficiency.