http://www.digitaljournal.com/news/environment/urban-areas-make-song-birds-ill/article/371580

Urban areas make song birds ill

Posted Feb 18, 2014 by Tim Sandle
People living in densely populated urban areas affect the health and fitness of native wildlife. A new study draws a link between the degree of urbanization and the prevalence of two parasites in wild house finches.
A blue tit (Parus caeruleus)
A blue tit (Parus caeruleus)
Maximilian Dorsch
The argument of the paper is that the loss of natural habitat may be a driving force behind increases in parasite infections in birds.
To draw this conclusion, a research team the team studied male house finches found at seven sites throughout Maricopa County in central Arizona. Each site varied in the number of people living within one kilometer : from nearly a dozen to more than 17,000 inhabitants. Researchers also considered whether the soil in each location had been disturbed and the vegetation cultivated or left in a natural state.
Next the researchers studied finches and collected samples. They looked at whether the degree of urbanization and parasitic infections were related and also whether increased infections are associated with increased stress levels.
The researchers found that the presence and seriousness of gastrointestinal parasitic infections were higher in more urbanized areas with land covered by compact soil and cultivated vegetation.
The research may have wider implications. Natural habitats and ecosystems have been dramatically altered from their original states, and there is rising concern about the spread of diseases that can be passed from urban wildlife to humans.
The research was conducted by Arizona State University and the findings have been published in the journal PLOS ONE. The research is titled “Parasites in the City: Degree of Urbanization Predicts Poxvirus and Coccidian Infections in House Finches (Haemorhous mexicanus).”