Nav: Home

How zebra stripes disrupt flies' flight patterns

February 20, 2019

Scientists learned in recent years why zebras have black and white stripes - to avoid biting flies. But a study published today in the journal PLOS ONE probes the question further: What is it about stripes that actually disrupts a biting fly's ability to land on a zebra and suck its blood?

UC Davis Professor Tim Caro and Martin How of the University of Bristol led a series of new experiments to better understand how stripes manipulate the behavior of biting flies as they attempt to come in to land on zebras.

Taking place on a horse farm in Great Britain that kept both zebras and horses, the experiments entailed:
  • Close-up observation of zebras as flies attempted to land on them
  • Detailed videos to record flight trajectories as the flies cruised close to the zebras
  • Dressing the horses and zebras sequentially in black, white and then black-and-white striped coats.
STRIPES MAKE LOUSY LANDING STRIPS

In the study, flies were just as attracted to zebras as they were to horses, indicating that stripes do not deter flies at a distance.

"Once they get close to the zebras, however, they tend to fly past or bump into them," said Caro, a professor in the UC Davis Department of Wildlife, Fish and Conservation Biology. "This indicates that stripes may disrupt the flies' abilities to have a controlled landing."

Compared to rates at which flies landed on the white and the black coats, hardly any landed on the striped coats.

"Stripes may dazzle flies in some way once they are close enough to see them with their low-resolution eyes," said How.

ZEBRAS SWISH AND RUN, HORSES TWITCH

The study also noted that zebras and horses respond very differently to the presence of flies. Zebras swish their tails almost continuously during the day to keep flies off; they stop feeding if bothered by them; and if the flies are particularly persistent, the zebras will run from them. Horses, on the other hand, primarily twitch and occasionally swish to ward off flies. As a result, any flies that actually contacted zebras were soon dislodged compared to horses.

Researchers do not yet understand why zebras evolved these sophisticated defense mechanisms. A possible explanation is zebras may be highly prone to infectious diseases carried by African biting flies, although that hypothesis requires further study.
-end-
The study's co-authors include Yvette Argueta from UC Davis; Emmanuelle Sophie Briolat, Maurice Kasprowsky, Matthew Mitchell and Sarah Richardson of the University of Exeter; Joren Bruggink of the Netherlands' Aeres University of Applied Sciences; and Jai Lake from the University of Bristol.

University of California - Davis

Related Horses Articles:

Most modern horses are descendants of recently imported oriental stallions
Researchers who have analyzed the Y chromosomes of more than 50 horses representing 21 breeds have found that the paternal lines of nearly all modern horses trace to stallions brought to Europe from the Orient over the last 700 years.
Horses masticate similarly to ruminants
In contrast to ruminants, horses chew their food only once -- but with the same regu-lar, rhythmic movements as cows, who ruminate their food after eating, as demon-strated by researchers at the University of Zurich and the ETH Zurich.
How domestication altered the genome of ancient horses
Analyses of 14 ancient horse genomes reveal the significant selective pressures domestication put on these animals, and highlight a relatively recent loss in their genetic diversity.
Can aromatherapy calm competition horses?
Although studies suggest that inhaling certain scents may reduce stress in humans, aromatherapy is relatively unexplored in veterinary medicine.
Researchers find positive long-term colic surgery results in horses
Many horse owners and equine veterinarians find themselves facing a difficult decision when it comes to treating a horse surgically for colic, with concerns including postoperative performance and expense.
Climate change responsible for the great diversity in horses
Changing environments and ecosystems were driving the evolution of horses over the past 20 million years.
Ancient horse fossils hint factors driving evolution different than thought
A new study analyzing the evolution of horses suggests that patterns of migration and changes in environment drive the development of new traits, countering a theory called rapid phenotypic evolution that proposes the opposite -- that is, that development of traits is what allows a species to take over new niches.
When horses are in trouble they ask humans for help
A new study demonstrates that when horses face unsolvable problems they use visual and tactile signals to get human attention and ask for help.
Management of feral horses an ongoing challenge in the United States
Feral horses are free-ranging descendants of once-domesticated horses. All free-ranging horses in North America are feral horses, and between 2014 and 2015 the feral horse population in the United States increased 18 percent according to the Bureau of Land Management.
Ancient DNA evidence traces origin of horses' smooth ride
Ambling horses are particularly prized for their ability to travel in a way that's comfortable for riders, with a smooth, four-beat rhythm.

Related Horses Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".