Monarchs (Danaus plexippus
) began departing from northern U.S. and Canada a few weeks ago (mid- to late-August). Several dozen individuals have been observed at Lakefront and Huntington reservations along the shoreline.
It is surprisingly difficult to forecast a date that a “fall out” may be observed, though this website attempts to offer such a prediction by entering your latitude (Cleveland is 41° N): http://monarchwatch.org/tagmig/peak.html/
. A fall out is when the regional temperatures and dynamics of wind are such that more and more in-bound individuals join a grounded population. The result is absolutely astonishing. This past season (late-summer 2015) provided such a fall out.
| Monarch butterflies finish up their evening rest along the Lake Erie shoreline at Lakefront Reservation Cleveland Metroparks. Hoping each morning for warmer and sunnier conditions than the last, each day added another 500-1000 individuals from Canada. On this day however, by mid-morning, these and thousands of other individuals were already in flight to Mexico.
The monarchs only fly by day, preferring sunny and/or warm days. The butterflies actually fly closer to the ground in the morning because warm columns of air (thermals) aren’t yet raising them up higher into the sky. If a warm day is accompanied by sun, you can expect the monarchs to be flying at such high altitudes that our eyes lose sight of them. In other words, morning time provides the best viewing opportunity. This is because the butterflies are either flying close to Earth’s surface or have not yet departed their evening roost site. It’s easy to spot a thousand monarchs clinging to a tree!
Wendy Park on Whiskey Island is an outstanding place to spend a few monarch mornings. The butterflies make their way south across Lake Erie and then rest overnight on the cottonwood trees at the shore. As the sun and temperature rise, the butterflies begin to warm up and take flight. For more on this bizarre journey, visit www.monarchwatch.org/
Here's a glimpse at the magic witnessed Sept-2015 at Wendy Park:
Rocky River Nature Center