“Somewhere, something incredible is waiting to be known.” ― Carl Sagan Current Biology

5th April 2014

Photo with 204 notes

Scientists solve the riddle of zebras’ stripes
A research team led by the University of California, Davis, has now examined why zebras have black and white stripes. Their answer is published April 1 in the online journal Nature Communications.

The scientists found that biting flies, including horseflies and tsetse flies, are the evolutionary driver for zebra’s stripes. Experimental work had previously shown that such flies tend to avoid black-and-white striped surfaces, but many other hypotheses for zebra stripes have been proposed since Alfred Russel Wallace and Charles Darwin debated the problem 120 years ago. These include:

A form of camouflage
Disrupting predatory attack by visually confusing carnivores
A mechanism of heat management
Having a social function
Avoiding ectoparasite attack, such as from biting flies

The team mapped the geographic distributions of the seven different species of zebras, horses and asses, and of their subspecies, noting the thickness, locations, and intensity of their stripes on several parts of their bodies. Their next step was to compare these animals’ geographic ranges with different variables, including woodland areas, ranges of large predators, temperature, and the geographic distribution of glossinid (tsetse flies) and tabanid (horseflies) biting flies. They then examined where the striped animals and these variables overlapped.

After analyzing the five hypotheses, the scientists ruled out all but one: avoiding blood-sucking flies.

"I was amazed by our results," said lead author Tim Caro, a UC Davis professor of wildlife biology. "Again and again, there was greater striping on areas of the body in those parts of the world where there was more annoyance from biting flies."
Caption: UC Davis scientists have learned why zebras, like these plains zebras in Katavi National Park, Tanzania, have stripes. Credit: Tim Caro/UC Davis

Scientists solve the riddle of zebras’ stripes

A research team led by the University of California, Davis, has now examined why zebras have black and white stripes. Their answer is published April 1 in the online journal Nature Communications.

The scientists found that biting flies, including horseflies and tsetse flies, are the evolutionary driver for zebra’s stripes. Experimental work had previously shown that such flies tend to avoid black-and-white striped surfaces, but many other hypotheses for zebra stripes have been proposed since Alfred Russel Wallace and Charles Darwin debated the problem 120 years ago. These include:

  1. A form of camouflage
  2. Disrupting predatory attack by visually confusing carnivores
  3. A mechanism of heat management
  4. Having a social function
  5. Avoiding ectoparasite attack, such as from biting flies

The team mapped the geographic distributions of the seven different species of zebras, horses and asses, and of their subspecies, noting the thickness, locations, and intensity of their stripes on several parts of their bodies. Their next step was to compare these animals’ geographic ranges with different variables, including woodland areas, ranges of large predators, temperature, and the geographic distribution of glossinid (tsetse flies) and tabanid (horseflies) biting flies. They then examined where the striped animals and these variables overlapped.

After analyzing the five hypotheses, the scientists ruled out all but one: avoiding blood-sucking flies.

"I was amazed by our results," said lead author Tim Caro, a UC Davis professor of wildlife biology. "Again and again, there was greater striping on areas of the body in those parts of the world where there was more annoyance from biting flies."

Caption: UC Davis scientists have learned why zebras, like these plains zebras in Katavi National Park, Tanzania, have stripes. Credit: Tim Caro/UC Davis

Tagged: ZebraStripesFliesBiologyScience

()

  1. lohikaarmo reblogged this from blacklionfish
  2. beardedvulture reblogged this from currentsinbiology
  3. brainsnotbones reblogged this from currentsinbiology
  4. scienceforscience reblogged this from currentsinbiology
  5. a-particular-proclivity reblogged this from buckysleftarm
  6. rialro reblogged this from buckysleftarm
  7. buckysleftarm reblogged this from kingarthurscat
  8. kingarthurscat reblogged this from currentsinbiology
  9. kaylaxvx reblogged this from currentsinbiology
  10. do-it-for-science reblogged this from currentsinbiology
  11. grackalacking reblogged this from currentsinbiology
  12. ethies241 reblogged this from currentsinbiology
  13. autumn-amber reblogged this from currentsinbiology
  14. secretporcupine reblogged this from currentsinbiology
  15. flowers-in-guns reblogged this from systema-naturae
  16. pfowolf reblogged this from systema-naturae
  17. systema-naturae reblogged this from currentsinbiology
  18. charliep242002 reblogged this from currentsinbiology
  19. sodintheseed reblogged this from currentsinbiology
  20. frosted-filly reblogged this from currentsinbiology
  21. lucythewalrus reblogged this from currentsinbiology
  22. skynoms reblogged this from currentsinbiology
  23. fadliuwaiselqorni reblogged this from sitinurb
  24. findingreasoninmadness reblogged this from currentsinbiology
  25. sitinurb reblogged this from currentsinbiology
  26. z00wh0 reblogged this from currentsinbiology
  27. joroan8 reblogged this from uh-eesha
  28. chipdawes reblogged this from currentsinbiology