Friday, October 19 , 2018, 7:28 am | Fair 49º

 
 
 
 

Research Links Diversity Among Birds to Lower Threat of West Nile to Humans

A UCSB biologist and undergraduate student produce the largest-scale application yet of the 'dilution effect.'

A biologist and an undergraduate student at UCSB have discovered that what’s good for an area’s bird population is also good for people living nearby.

The research, by John Swaddle and Stavros Calos, to be published Wednesday in the online peer-reviewed journal PLoS ONE, indicates that areas that have a more diverse bird population (biodiversity) show much lower incidences of West Nile virus infection in the human population. West Nile develops rapidly in bird populations and can be passed to humans or other animals through a vector mechanism, often a mosquito.

Swaddle completed the work while a Sabbatical Fellow at the National Center for Ecological Analysis and Synthesis at the UCSB. NCEAS supports integrative research that synthesizes existing data and makes these data and inferences available for management and policy applications.

Swaddle and Calos’ research is the largest-scale application to date of the “dilution effect,” a pattern whereby increased biodiversity in wildlife results in lower risks of humans becoming infected by animal diseases. The dilution effect was first reported in Lyme disease, but Swaddle and Calos are the first to demonstrate the dilution effect in a disease that has bird hosts. Swaddle said that other infectious diseases of concern, such as avian flu and bubonic plague, may fit the dilution effect as well.

“We don’t yet know the precise mechanism that drives this pattern, but it’s likely to be due to diverse areas having relatively few of the bird species that are particularly competent hosts and reservoirs for the virus,” Swaddle said.

Host competence, he said, refers to a set of qualities that make a particular species of bird best able to contract the disease and pass it on through a vector. The highest levels of host competence are found in crows, jays, thrushes and sparrows-the very birds that tend to thrive when avian biodiversity is reduced.

Swaddle, back in residence as associate professor at the College of William and Mary, points out the implications of his research. Very small changes in land management, he said, could attract more bird species, with the increase in biodiversity paying off in the form of lower human infection rates during outbreaks of West Nile or other diseases in the bird population.

“Biodiversity is giving us a public health service that people have rarely considered and the value of this service should be considered when developing land and managing bird populations in the future,” Swaddle said.

Margaret Connors is an outreach coordinator for UCSB.

 

Support Noozhawk Today

You are an important ally in our mission to deliver clear, objective, high-quality professional news reporting for Santa Barbara, Goleta and the rest of Santa Barbara County. Join the Hawks Club today to help keep Noozhawk soaring.

We offer four membership levels: $5 a month, $10 a month, $25 a month or $1 a week. Payments can be made using a credit card, Apple Pay or Google Pay, or click here for information on recurring credit-card payments and a mailing address for checks.

Thank you for your vital support.

Become a Noozhawk Supporter

First name
Last name
Email
Select your monthly membership
Or choose an annual membership
×

Payment Information

Membership Subscription

You are enrolling in . Thank you for joining the Hawks Club.

Payment Method

Pay by Credit Card:

Mastercard, Visa, American Express, Discover
One click only, please!

Pay with Apple Pay or Google Pay:

Noozhawk partners with Stripe to provide secure invoicing and payments processing.
You may cancel your membership at any time by sending an email to .(JavaScript must be enabled to view this email address).

  • Ask
  • Vote
  • Investigate
  • Answer

Noozhawk Asks: What’s Your Question?

Welcome to Noozhawk Asks, a new feature in which you ask the questions, you help decide what Noozhawk investigates, and you work with us to find the answers.

Here’s how it works: You share your questions with us in the nearby box. In some cases, we may work with you to find the answers. In others, we may ask you to vote on your top choices to help us narrow the scope. And we’ll be regularly asking you for your feedback on a specific issue or topic.

We also expect to work together with the reader who asked the winning questions to find the answer together. Noozhawk’s objective is to come at questions from a place of curiosity and openness, and we believe a transparent collaboration is the key to achieve it.

The results of our investigation will be published here in this Noozhawk Asks section. Once or twice a month, we plan to do a review of what was asked and answered.

Thanks for asking!

Click Here to Get Started >

Reader Comments

Noozhawk is no longer accepting reader comments on our articles. Click here for the announcement. Readers are instead invited to submit letters to the editor by emailing them to [email protected]. Please provide your full name and community, as well as contact information for verification purposes only.