Monarch butterflies (Danaus plexippus) have long been known for their impressive migration abilities, with North American species traveling around 3,000 miles from the United States and Canada into Mexico or Southern California to overwinter. However, there has been a noticeable decline in these overwintering populations over the last few decades. This decline has been thought to be at least partially caused by habitat loss, a decline in milkweed availability, and a parasite called Ophryocystis elektroscirrha (OE), which is known to increase monarch mortality by weakening migrants' ability to fly.