Red Cross, Red ShieldAll you see is a bright streak of red as the Northern Cardinal flits across the

Red Cross, Red ShieldAll you see is a bright streak of red as the Northern Cardinal flits across the backyards of North America with their classic bird call carrying on. These birds are relatively common and according to new research, they might be playing a big role in keeping ecosystems, including our own, healthy.Scientists from Atlanta, Georgia, wanted to find answers to why more humans aren’t infected with the West Nile Virus. This mosquito-borne illness is zoonotic, which means the virus can be spread between us and other animals by a “bridge vector.” In this case, that is the Culex mosquito.The West Nile Virus has become the country’s most common zoonotic disease carried by mosquitos since it was introduced to the United States in 1999. WNV is responsible for more than 43,000 infections and 1,911 deaths since then, though it seems to affect people in certain areas more than others.Birds tested for the disease in Georgia showed nearly 30% infected, as compared to 18.5% infected birds in the Chicago, Illinois region. Yet 383 human cases of WNV were reported throughout Georgia since 1999 compared with 2,214 human cases reported in Illinois.The reason for such a difference prompted a 3-year study carried out by a team of scientists from the University of Georgia, the Georgia Department of Transportation and Texas A&M University. Collecting mosquitos from various places across Atlanta, testing them for WNV and analyzing the DNA from their blood brunches, the scientists could find out which birds the mosquitoes were biting.Lead author Rebecca Levine, who also works with the U.S. Centers of Disease Control and Prevention, explained, “We found that the mosquitoes feed on American Robins a lot from May to mid-July but for some unknown reason, in mid-July, during the critical time when the West Nile Virus infection rate in mosquitoes starts going up, they switch to feeding primarily on cardinals.”There seems to be something in the blood of the American Robin that amplifies WNV once the bird has become infected. This can potentially pass the disease more efficiently to new mosquitoes when bitten. Northern Cardinals, however, seem to do the opposite. Researchers describe these birds as “super suppressors” of WNV as their blood doesn’t hold the same likable qualities of the American Robin as far as the virus is concerned. Similar effects have been seen in birds from the Mimidae family, including Brown Thrashers and Gray Catbirds, both common in Atlanta. Researchers have yet to find the exact reason for all of this, though they did notice that patches of old forest harbored fewer infected birds altogether, compared to secondary forests. Both forest types held about the same rate of infected mosquitoes, however. “These are really complex ecosystems, so we cannot single out the specific reasons for these findings,” Levine goes on to say, “They suggest that there is something unique about these old-growth forests and how they affect avian systems in Atlanta.”Atlanta just happens to be nicknamed ‘the city in a forest.’ It’s one of only 7 cities in the United States with 47.9% urban tree cover along with their high population – approximately 3,154 people per square mile (1,232/square kilometer) reported by the 2010 United States Census. Chicago has only 11% of that area’s original tree cover.Many more studies are needed to understand the reasons behind why cardinal’s bodies act so differently with WNV than the robin’s bodies, why primary forests hold fewer infected birds than secondary forests and why mosquitoes switch from robins to cardinals in mid-July. There is so much information we can gain from researching among old-growth forests, as well as paying attention to native creatures from around the world. The real question maybe, will we have enough time to study our long standing forests?–MiImage Credit –http://bit.ly/2btMSQ4Sources –http://bit.ly/2aSMFYshttp://bit.ly/2bANkMl -- source link

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