HELPING UNRAVEL MYSTERY OF WEST NILE'S SPREAD
- Research conducted by biologists at The University of Southern
Mississippi could help health officials piece together the puzzle
of West Nile Virus, a potentially fatal disease transmitted by mosquitoes.
For the benefit
of the Center for Disease Control, researchers in the Department
of Biology at Southern Miss recently completed a three-week experiment
on the migratory patterns of birds, which are believed to spread
the virus through their seasonal flight patterns.
is a lot of speculation about the role migrating birds might play
in the dispersal of West Nile Virus," said Jen Owen, doctoral
student and principal researcher for the experiment.
is a cycle between birds and mosquitoes. Birds are the amplifying
hosts; once they become infected the virus amplifies in their system.
Then when a mosquito bites the bird, it may contract the virus,
so it continues the cycle between the mosquitoes and birds."
Owen said CDC
researcher Nick Komar from the Ft. Collins, Colo., office contacted
the Southern Miss biology department about studying the migratory
pattern of infected birds. At issue was whether or not birds would
adhere to their instinctive flight habits once they were infected
with the virus.
question was whether a bird infected with West Nile Virus has the
ability and motivation to fly.
"You can't tell that by catching a bird in migration because
you don't know where it became infected. That's where our lab came
in. We wanted to find out if the birds with the disease still exhibited
Under the direction
of Dr. Frank Moore, professor and chair of the Department of Biological
Sciences, a team of student researchers studied and cared for the
birds for several weeks. Using three species - Swainson's Thrush,
Gray Catbird and Woodthrush - they developed a unique caged experiment
to observe the behavior of the subjects, which they infected with
WNV under strictly controlled conditions.
willingness to migrate is actually endogenous, meaning if you put
a bird in a cage it will still migrate," Owen said. "Even
in a cage it will display the appropriate behavior in different
seasons. In spring it will begin hopping, and the amount of that
hopping directly correlates to the distance it would have traveled
in the wild."
When a bird
is initially infected, Owen said, the virus amplifies and the bird
may become infectious for four to five days. During that time, a
mosquito must bite the infected bird to contract the virus. "But
will the bird continue to migrate when it gets sick?" Owen
asked. "Will it fly across the country?"
catch a bird in Florida with West Nile, there is no way of knowing
if it contracted the virus there or in New York," she said.
"A bird is capable of flying from New York to Florida in a
few days, so there is the potential a bird infected in New York
may still be infectious when it arrives in Florida several days
the transmission of West Nile Virus is restricted between birds
and mosquitoes. Infected mosquitoes spread the disease to mammals,
but individuals in most species of mammals do not get sick from
the virus. Therefore, mammals are thought to be "dead-end hosts"
because the virus does not amplify in their blood to levels high
enough to become infectious.
the test group and the control group for three weeks, researchers
observed that the infected birds appeared to maintain their normal
migratory habits, Moore said. However, it is still unclear whether
or not they were "sufficiently infected," he said. "At
this point we don't know if the levels were high enough (in the
birds) to infect a mosquito in the wild."
Data and blood
samples from the experiment have been sent to the CDC. The team
at Southern Miss is currently awaiting the results of blood tests
that will determine how infectious the WNV birds were during testing.
Owen will present the team's findings this summer at the American
Ornithologists Union Conference in Illinois.
in the research project included Rachel Bru, Julie Rich, Christina
Sykes, Michael Dodge and Nick Young.
of the attention about West Nile centers around public health issues,
there are other concerns, Moore said, namely how the virus will
permanently affect the wildlife population.
worried about how it might affect endangered species," he said.
"With small populations, a disease like this can have drastic
PHOTOGRAPHER TO LEAD WORKSHOP, PRESENTATION MARCH 10
-- Award-winning wildlife photographer Tom Ulrich will lead
two photographic events at the Gulf Coast Research Laboratory on
Wednesday, March 10.
He will present
a nature photography workshop from 8:30 a.m. to 4:30 p.m. and then
a talk and slide show called "Wildlife Images 2003" at
7 p.m., both at The University of Southern Mississippi GCRL.
the evening event is free and will be held in the Caylor Auditorium
at GCRL. The veteran photographer will feature photos from his 2003
photographic safaris abroad and in North America. He will answer
questions and sign his books during the reception following his
fee for the all-day workshop is $50 per person, payable to GCRL.
Registration includes a continental breakfast, light lunch and snacks.
Participation is limited to 20. Though the workshop is geared toward
beginners, Ulrich tailors the experience to meet needs for all degrees
will definitely benefit from the workshop, but I always help the
more advanced get something out of it also," Ulrich said. "I
lead many photo trips and always find a wide range of levels."
participants do not need to bring their photographic equipment unless
they need an explanation about some aspect of their equipment.
a brief review of the principles of photography, relationships between
shutter and aperture settings, fundamental elements of composition,
use and timing of fill-in flash, digital versus film photography,
techniques of close-up photography, and a brief discussion of slide
etiquette, the photography business and marketing.
up in South Chicago, graduated with a degree in biology from Southern
Illinois University and taught for four years before launching his
career as a freelance photographer. He has supported himself with
nature photography for the past 29 years.
of more than 300,000 transparencies includes birds and mammals from
all over the world. His photographs have been featured in publications
such as National Wildlife, Audubon, National Geographic, Montana
Outdoors and Life.
He has published
six nature books, including Mammals of the Rockies, Birds of the
Northern Rockies, Once Upon a Frame and his 2002 release, Photo
Pantanal. Dr. William E. Hawkins, GCRL executive director, said
Ulrich brings the scientific and artistic worlds together.
his living photographing wildlife all over the world," Hawkins
sad. "He is an outstanding observer and a biologist. His approach
to photography is to capture his subjects exhibiting their natural
The GCRL is
home to the university's Department of Coastal Sciences, the Center
for Fisheries Research and Development, and the Gulf Coast Geospatial
Center. The J.L. Scott Marine Education Center and Aquarium is also
a unit of the laboratory. The GCRL is part of the Southern Miss
College of Science and Technology. For more information, call the
laboratory at (228) 872-4200.