Posted
Nov. 22 - As Monarch butterflies migrate to Mexico's forested mountains in Michoacan, biologists fear droughts in the U.S. and Mexico will affect their numbers. Elly Park reports.
01:44
02:59
01:49
01:41
01:34
01:58
02:10
01:29
01:30
02:01
01:50
02:16
01:32
01:32
01:31
01:59
01:10
01:01
00:40
00:40
01:16
01:41
04:20
01:13
02:01
01:26
01:06
01:02
01:41
01:41
01:49
01:06
01:17
01:20
01:44
01:29
01:09
01:34
01:42
01:59
01:10
00:53
02:30
01:30
02:51
02:08
01:49
02:56
03:05
00:45
02:15
01:27
01:53
02:08
01:32
02:07