Moving Out! Large Roosts Reported in North
Monarchs rested last week in Minnesota, Michigan, Wisconsin, and Iowa
during their long migration to Mexico. With over a thousand miles left
to fly they formed large roosts and waited for winds that would carry
them southward. A research team in Michigan watched a roost break up on
the morning of August 25th:
were around 400 monarchs on three different trees. Temperatures were
around 50 degrees that night, so the monarchs were slow to leave the
next morning. But, with perfect wind conditions, they started heading
south before noon. We could stand at the end of the peninsula and watch
the monarchs flying south over Lake Michigan."
of Overnight Roost from Citizen Scientists
What facts can you learn about the amazing overnight roosts that monarch
form during fall migration? Read the details people provided this week:
map of overnight roosts shows a cluster of roosts in the Upper Midwest.
Still not a single roost has been reported from Canada! There have been
14 roosts reported now, but last year at this time there had been over
80. Will sightings pick up over the next week as more monarchs grow into
adults and join the migration? Or are these true signs of a small population?
In July, monarch scientist Dr. Chip Taylor predicted the size of this
winter's population will be lower than last year's measurement of 4.61
do you predict this winter's population will compare? (See graph to right.)
Another Chance: New Generation in Southern States
Amid worries about a small monarch population comes this reminder:
Monarchs will lay eggs across the southern United States this fall. Those
offspring will grow into adults and join the migration. This will add
another generation to the population. Let's hope conditions will be just
right, with plenty of milkweed for the young monarchs to eat, and few
predators to eat the monarchs!
Report Your Sightings!
Watch for monarchs that are flying in "directional
flight," resting at overnight roosts, or refueling
at flowers in fields, gardens, or roadsides.