In
the Big City there has been the annual staging of the monarch butterfly
migration. The butterflies are on the
move for parts south. It is pretty cool and since the city apartment Jill and I
keep is immediately adjacent to a roost site a couple of times a year we
get to observe the migration action up-close and personal. If you haven't witnessed it before - it is quite cool.
There is a very active monarch
restoration network working hard in an urban environment to restore habitat and
support the migration. Photos, video and
more information about the Friends of the Monarch Trail here.
Anyone reading this blog also knows that,
Jill and I maintain a reasonably large pollinator habitat here at The Platz. It has been a terrific year for butterflies
of all types including the monarchs. Yet to
my eyes there hasn’t been much sign of departures on a migration. As a matter of fact the comings and goings
of the monarch butterflies seemed pretty normal with numbers what we have
become accustomed-to over the past few months.
click on images for a closer look
The photos in this post were taken last Sunday and Monday and include at least
three stages of monarch development.
Since none of these insects seemed to be in a
rush to beat it out of Dodge I was puzzled by this conundrum. Was it a consequence of northern latitude? A
milder clime on the peninsula? What
gives?
Talking to some of the people in
the Big City I was lead to believe that the monarchs were on their city roosts,
departing for parts south and there wasn’t an explanation for anything I
observed at latitude halfway between the equator and the pole.
Pre-emergent - you can see the butterfly within
Thursday morning I was chatting with a guy
setting-up a tripod and camera to photograph the city monarchs and he didn’t
believe a word I was sharing with him. All
the monarchs were in Wauwatosa – wasn’t it obvious to me? As far as he was concerned I might as well
have lived at the North Pole. I was either
nuts or making stuff-up.
Rescued from the composter and it pupated before my very eyes
So were the
monarchs observed here on the peninsula too late to the migration dance? What
was the backstory? Curious, I fired-off
an email on the subject to the Department of Etymology at UW Madison. I received a reply yesterday afternoon and
learned that the migration is both complicated and nowhere near over. From the experts was this:
Hi Tom,
Thanks for your inquiry about monarch life history. This is a
complicated time to sort out generations, life stages, and behaviors because so
many things are overlapping. Monarchs that emerge as adults after about the
third week in August will migrate, and not reproduce.
However, there are still
reproductive monarchs around that emerged earlier, some from the local area and
some from farther north. My guess is that you're seeing the immature stages
(eggs, larvae and pupae) that are the offspring of the last reproductive
monarchs of the season, and that the adults in your garden are a combination of
migrants and these late reproducers.
This
weird overlap goes on for about a month; you should stop seeing the immature
monarchs in a week or so, but will keep seeing migrants for a month or so
(especially since it sounds like you have great habitat for them). Thanks for all that you're doing to support
monarchs and the other species that use their habitat.
Just emerged and drying-out
So, there you have it. There is overlap and it is complicated. Raising a toast to science and a few more
weeks of monarchs to be enjoyed...