(Portland, OR) -- The Oregon Zoo needs help counting pikas in the Columbia River Gorge. Pika are small potato-sized members of the rabbit family, known for their squeak-toy alarm calls. Pikas are normally found in higher elevations, and this is the lowest elevation where the species is found. Scientists watch this group, because their habitat and temperature may make them especially vulnerable to global warming. The zoo is offering courses in May on how to take part in the count.