Friday, April 12, 2013

Where Are The Monarchs?

Picture by Patrick Coin
When we recently drove to Colorado, we carefully checked the weather to decide when to leave and avoid the bad kind.  It turns out that monarch butterflies' migration is weather dependent for a different reason. Their travel plans are temperature dependent and they probably don't use the Weather Channel.

Lisa Bakerink* sent this interesting link which follows the monarch spring migration.  Last spring, the warmest on record, the monarch migration was much further north by now.  Their progress is linked to the growth of milkweed.  If you are a monarch momma, you need to wait for the milkweeds to emerge before laying your eggs.  These eggs will produce the next generation which will then arrive in Missouri.

The maps below show the effect of temperature change on migration.  This year's cool spring has slowed the first appearance of many wildflowers and insects.  The ticks we have been pulling off for over a month have been the exception.  Under magnification, some seem to be wearing tiny Under Armour suits to keep warm.  (Editor's note- that is just his cataracts).

This all serves as a reminder that monarch butterflies need help.  With increasing lands being converted to agriculture, fragmentation of land and more extensive use of Roundup ready crops decreasing native "weeds" like milkweed, their numbers are way down.  Plant milkweed.

* Lisa Bakerink is president of Friends of the Garden whose Butterfly House will open on May 10th.  The Butterfly Festival will be July 20, 2013,  from 9:00am to 3:00pm.