Some scientists say iron deposits in the ground interfere with the
brids' ability to sense the earth's magnetic field, which they use to navigate, but no magnetically-sensitive bird organ has yet been found.
ARB'S stringent clean air rules have effectively forced the auto industry to produce new generations of low-emission vehicles, including gas-electric lay
brids and so-called Partial Zero-Emission Vehicles (PZEVs), which are environmentally responsible versions of regular gasoline cars like the Honda Accord, Ford Focus, Toyota Camry and Dodge Stratus.