Earth Science News  





. Could Global Warming Be Crushing Blow To Crocodiles

Nile crocodiles are among the fiercest predators in the Okavango Delta, Botswana, yet their population has shrunk due to habitat loss and hunting. Dr. Alison Leslie of University of Stellenbosch suggests that climate change will be a further setback to crocodile numbers. Credit: Oscar Baldomero.
by Staff Writers
Stellenbosch, South Africa (SPX) Nov 28, 2006
With global temperatures generally on the rise, crocodiles may have a harder time finding mates. For crocodiles, gender is not determined genetically, but rather by embryo temperature during incubation, notes Earthwatch-supported scientist Dr. Alison Leslie, of South Africa's University of Stellenbosch.

In an interview with three teenagers on a mission to find out about their planet, the subject of the new film A Year on Earth, Leslie explained how global warming could affect crocodile populations worldwide.

"A difference of 0.5 - 1C in incubation temperature results in markedly different sex ratios," says Leslie, principal investigator of Earthwatch's Crocodiles of the Okavango Delta project. Research shows that nest temperatures of about 32-33 degrees Celsius result in males, while temperatures higher and lower result in females. Temperatures within a nest can vary from the top to the bottom of the nest, and can result in mixed-gender hatchlings.

"More female hatchlings due to the cooler or hotter incubation temperatures could lead to eventual extirpation of the species from an area," says Leslie.

The three teens, Jamie (18), Arsen (17), and Tyler (16), visited Leslie at her camp in the Okavango Delta, Botswana, where they acted as field research assistants on Leslie's Earthwatch-supported research expedition. Their participation was part of a feature-length documentary, A Year on Earth, that will air on the Discovery Kids Channel in December.

The teens helped Leslie trap and examine Nile crocodiles big and small to monitor their diet, health, movements, and reproductive biology. Crocodile populations have dwindled dramatically in Botswana, due to overexploitation by hide hunters and conflicts with nearby communities.

"Even though crocodilians have been around for millions of years, and as important as these creatures may be in the systems they occupy, they are a much understudied species," says Leslie. For more than eight years, in both Botswana and South Africa, Leslie has been working with the support of Earthwatch Institute to change that.

In 2007, Leslie will leave behind her Okavango research camp (in the capable hands of staff member Sven Bourquin), and will embark on a new study of the crocodiles along Zambia's Zambezi River. Earthwatch volunteers will continue to assist her as she assesses the conservation needs of this population and surveys local villagers about crocodile impacts.

Related Links
Earthwatch Institute
Darwin Today At TerraDaily.com

Ethiopia's Famed Black-Maned Lions Being Stuffed For Lack Of Cash
Addis Ababa (AFP) Nov 22, 2006
Dwindling finances and shrinking zoo space are reducing already declining population of Ethiopia's famed black-maned Abyssinian lions, the country's national symbol, to mere stuffed mementos. Despite concern among by conservationists, Addis Ababa's historic lion zoo, built nearly 60 years ago, has begun selling lion cubs to taxidermists because it is unable to feed the big cats and lacks room for their increasing numbers.

.
Get Our Free Newsletters Via Email
  



  • Red Cross Calls For Disaster Cash Boost
  • Red Cross Calls For Stronger Alliances To Fight Disasters
  • NIST Test Fans The Flames For High-Rise Fire Safety
  • UN Official Laments Darfur Aid

  • Lessons Learnt From Drought Deaths 40,000 Years Ago
  • 'Divided' Countries Could Leave Climate Deal In 'Tatters'
  • Seven-Year Stabilization Of Methane May Slow Global Warming
  • Dutch Bask In Warmest Autumn In Three Centuries

  • 'Enact Space Law To Govern Use Of Remote Sensing Data'
  • European Space Agency And Google Earth Showcase Our Planet
  • GeoEye-1 Will Use SGI Technology To Process Image Data
  • SciSys Wins Software Role For CryoSat-2 Mission

  • China Moves Ahead With Project To Rival Three Gorges In Size
  • East Asian Countries To Cut Dependence On Conventional Fuels
  • Complex Order Parameter In Ruthenate Superconductors Confirmed
  • Putting Plant Life In The Energy Pipeline

  • Setting The Stage To Find Drugs Against SARS
  • Pattern Of Human Ebola Outbreaks Linked To Wildlife And Climate
  • UGA Researchers Use Laser, Nanotechnology To Rapidly Detect Viruses
  • 26,000 Russians Contracted HIV Since Start Of Year

  • Could Global Warming Be Crushing Blow To Crocodiles
  • Ethiopia's Famed Black-Maned Lions Being Stuffed For Lack Of Cash
  • Looking At Life In Lyon
  • Extraordinary Life Found Around Deep-Sea Gas Seeps

  • Chinese Pollution A Rising Health Threat
  • UN Seeks Help To Clean Up Deadly Ivorian Toxic Waste Dumps
  • Man Jailed In China For Dumping Chemical Waste
  • Police Fire Teargas To Break Toxic Waste Demo

  • First Map Of Structural Variation In The Human Genome Under Construction
  • Genetic Variation Shows We're More Different Than We Thought
  • Neanderthal Genome Sequencing Yields Surprising Results
  • Dad Inspired 'Jurassic Park,' Son Inspires 'Jurassic Poop'

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement