Top Pictures of the Week

<div class="meta image-caption"><div class="origin-logo origin-image "><span></span></div><span class="caption-text">In this photo taken April 18, 2012, provided April 19 by the Chicago Zoological Society, a pair of Mexican gray wolves are seen at Brookfield Zoo?s Great Bear Wilderness exhibit in Brookfield, Ill. Through a study of Mexican gray wolves, researchers hope to aid in conservation efforts of the endangered species, and determine whether a type of nasal tumor is more prevalent in wolves or domestic dogs. The Chicago Zoological Society, which manages Brookfield Zoo, is embarking on a study to determine the occurrence of nasal carcinoma in Mexican gray wolves using CT &#40;CAT&#41; scans. &#40;AP Photo&#47;Chicago Zoological Society, Jim Schulz&#41; (AP Photo&#47; Jim Schulz)</span></div>
December 23, 2013 5:30:16 AM PST