One Queen Returns

| 16 Comments

Monarch butterflies are among the … um … well, monarchs of the lepidopteran world, at least in North America. Their numbers are declining. The decline is due in part to the loss of over-wintering habitat in Mexico caused by deforestation in the isolated forests in which migrating monarchs spend the winter clustered in trees, and in part due to the loss of milkweeds in North America, their sole breeding host plant, often regarded as a weed plant. As a result, whereas decades ago it was commonplace to see monarchs in roadside milkweed patches, today it is more and more of an ‘event’ to see even one monarch.

More below the fold

We keep a good portion of our land wild for the benefit of various two-, four-, six-, and eight-footed critters. Up at the north end there are a couple of patches of milkweeds that we don’t mow. Every year they reseed themselves, and the patches have slowly grown over the years. Up until fairly recently, every year we’d see half a dozen or more monarchs at a time in the milkweeds, feeding on the nectar of the blooms and mating and laying their eggs, one egg to a milkweed plant (at least that’s all I’ve ever seen on a single plant), stuck on its end to the underside of a new leaf high on the plant. Later we’d see the caterpillars chomping away on the milkweed leaves, in the process slurping up the bitter milky-white sap that gives them the noxious taste that protects them from bird predation. Last year, though, for the first time in 33 years, no monarchs appeared. Not one. While absence of evidence is not evidence of absence, seeing no monarchs last summer was depressing.

Today, though, about the time of year they’re expected, when the clusters of milkweed flowers are in full bloom, there was a female monarch pottering around in those milkweeds up on the north end, sipping nectar and frustrating the photographer by flitting away just about the time the digital camera decided it had a focus. Nevertheless, she was there:

You can tell it’s a “she” by the relatively thick wing veins and the lack of a pouch-like swelling on a vein on the hindwing.

Monarchs are not the only insects that are attracted to milkweeds. I saw fritillaries, red admirals, and a couple of kinds of skippers up there this afternoon. Honeybees (the few that have so far escaped the Varroa mites), bumblebees, various flies and beetles, and the hummingbird clearwing (a moth that thinks it’s a hummingbird) frequent milkweeds too.

When I was a kid living in a tiny village of 250 people in the upper midwest, farm country had ample uncultivated habitat for a variety of critters. In the 1950s, though, Ezra Taft Benson, Eisenhower’s Secretary of Agriculture, encouraged farmers to plant crops from fenceline to fenceline. Later Earl Butz, Nixon’s Secretary of Agriculture, urged farmers to “get big or get out”, a reference to the rise of industrial farming with its intensive use of herbicides and pesticides. As a consequence of federal policies that supported those exhortations, the weedy cover along fence rows was plowed and planted, sloughs and wetlands were tiled and drained, insects – beneficial bugs and crop pests alike – were indiscriminately poisoned, and wildlife became scarcer and scarcer. I haven’t heard or seen a meadowlark in more than a decade. In a way I’m glad I’m getting old – I don’t want to watch many more species killed off by the short-sighted stupidity of humans.

But that one monarch was there today. I hope she is a mated female, or that she soon finds a suitor out there in the milkweeds.

And my neighbor to the north, who has a wild-ish acre or so on his place, agreed to take some milkweed seeds this fall and see if he can get a couple of patches started. Every little bit .…

RBH

16 Comments

Reminds me of a Gahan Wilson cartoon, showing two men with butterfly nets in a field, with one man cowering. The first one says, “Dammit, Henderson, what kind of a lepidopterist are you? For God’s sake man, stand up to them!”

When I first moved to Minnesota in 2000, there were swarms of monarchs in the fall – clouds of them fluttering around specific trees. We even gave each student in our intro class a pile of tags and a net and sent them out to catch, mark and release them.

That was the last year that was feasible. Ever since, all I see in September is a few individuals here and there.

They have been rapidly falling in numbers world wide. I remember when there were hundreds of them on milkweed plants at my school. I used to play with the caterpillars (I thought they were cute, as a child, I harassed any insect or arthropod unfortunate enough not to get away). Now I just don’t see these insects anymore and in fact, they’ve even picked up a habit of spontaneously bursting through their exoskeleton so few survive these days. Really depresses me.

Who is destroying the habitat, and what can be done to stop said destruction?

We are of course, we’re brilliant at doing it as well. The larger amounts of pesticides being used in the environment and the removal of milkweed are just two ways we’ve done it.

I remember raising monarch caterpillars, marking them and releasing them in the Peace Garden when I was in third grade. There were these big maps out in the hallway for various migrating animals, one being the monarch. They seemed like they were everywhere around the country. I wonder what those maps would look like now… Perhaps I should make a visit to my elementary school next spring.

I also remember chasing a monarch through my house when I was around 4 or 5-years-old. I’ve been outside in the yard a lot this week and I haven’t seen one butterfly; just a lot of mosquitos and moths. Just one butterfly would be nice… Oh well.

Syntax Error: mismatched tag at line 3, column 115, byte 428 at /usr/local/lib/perl5/site_perl/5.12.3/mach/XML/Parser.pm line 187

Nice post RBH. An example of how an overemphasis on economic growth leads to a loss of intangible “resources”.

There is a strong connection to creationism and the rampant destruction of the environment. For exaample, consider the following:

My responsibility is to follow the Scriptures which call upon us to occupy the land until Jesus Returns.” –James Watt to the Wall Street Journal as quoted in “James Watt & the Puritan Ethic.” By Colman McCarthy. Washington Post, May 24, 1981. PAGE L5

“I was taught in school that acres of rain forest were being destroyed by the second, and yet we still have rain forests. Honestly, I don’t believe them. And if they are right, I’m not to worried about it anyway. The Bible says that this earth will be destroyed by God anyway. We can take care of what we’ve got now, but I’m not going to let what some scientist thinks is going to happen worry me.” June 2005, Rapture Read BB.

“The reason why I don’t worship the earth like Liberals do is because I know Jesus is coming back.Most liberals believe that the earth will end because of global warming,when in fact the earth never ends,just ask Jesus.” June 2005, Rapture Read BB.

Creationists encourage a disregard for the environment, and a distain for science in general.

Good news: Prince Charming appeared today and they mated. No pics, unfortunately (or perhaps fortunately!). Now I gotta look under all those milkweed leaves for eggs.

RBH

“While absence of evidence is not evidence of absence”

It’s unfortunate that Carl Sagan popularized, and numerous people mindlessly accept, this erroneous claim. A correct statement would be “absence of proof is not proof of absence”. Evidence, though, is in a different ontological category entirely, and absence of evidence makes an absence hypothesis more plausible, and this is (weak) evidence of absence. And absence of evidence after an extensive search for evidence is very strong evidence of absence.

> Evidence, though, is in a different ontological category entirely

Oy. Make that “epistemological”. The thought of trying to ontologically categorize proofs and evidence is very scary.

I hate to come across as the complete curmudgeon here, but I believe that reports of the imminent demise of the monarch are significantly exaggerated. Like many insects, monarch population numbers vary widely from year to year. The very low numbers encountered last season were not unexpected, and absolutely not confined to the monarch. Like most temperate species of butterflies, monarchs experience high mortaility and low reporoductive success during extended periods of cold or wet weather. These were exactly the conditions that prevailed over much of the upper Midwest last spring and early summer. The Illinois Butterfly Monitoring Network had one of it’s slowest years ever, not just for the monarch, but with just about everything. With this summer’s drought, many species of butterflies are actually doing quite well. I suspect that the parasite load is also down this year because of the bad year in 2004. I will go out on a limb and predict that, barring a dramatic change in the summer’s weather or a real intensification of the drought, people will be expressing surprise that the monarchs are doing so well come migration time this August and September. This has happened repeatedly following well-publicised snowstorms on the wintering grounds in the past. It has been (and continues to be) documented by programs such as the Illinois Butterfly Monitoring Network www.bfly.org and the Ohio long-term butterfly project http://www.ohiolepidopterists.org/bflymonitoring/

I don’t doubt at all that there is substantial year-to-year variability in the numbers (remember the Hudson’s Bay Company lynxes and rabbits). The large Monarch pop decline decline in 2001 was reversed the next year.

But it also clearly the case that habitat is being lost on both ends of the migration, the upper midwest (heir to the migrants’ offspring bred in the southern U.S.) and Mexico. I haven’t looked at (and in a fast search couldn’t find) good deep pop count data to do any stats on it. Anyone know where it is?

Being a long-time member of one of the sponsoring organizations I’m aware of the Ohio butterfly monitoring program. I applaud their efforts even though I don’t participate in them, preferring to tend my own patch of milkweeds. But I do deplore their use of variably trained people to do butterfly tagging, with the attendant mortality of the six-legged victims of the well-intentioned. After attending a tagging workshop supposedly adequate to prepare one to do it in the field I concluded that for some it is primarily a feel-good exercise that often cripples butterflies.

RBH

I’m not aware that either the Ohio program nor the Illinois does tagging (I can say with certainty that the Illinois program does not). Both use Pollard transect type protocols. I also question the loss of habitat statement, at least at this end up here. The habitat is changing, yes, however one of the reasons that the monarch is doing so well is that it, unlike many other species of butterflies, is well-adapted to many of the changes that have taken place in the modern landscape. Several of its host plants, particularly Asclepias syriaca, are very common weeds that can be found in a wide variety of disturbed habitats- urban lots, road cuts, railroad rights of way, etc. This feature is shared by most of the butterflies that remain abundant today- they rely on very weedy host plants that thrive on disturbance. I always get a chuckle when people suggest that we need to take some sort of conservation steps involving milkweed. It’s doing just fine with no particular effort on our part.

Count me with DougT on this issue. Monarch populations are notoriously volatile. The host plant thrives in disturbed habitats, and may be around in greater abundance than before the Europeans invaded and created the vast network of roadside and marginal habitat that the Monarch’s prefer.

Habitat loss in Mexico is certainly of concern, but here in CA where some western populations overwinter the butterflies actually do ok in suburban areas, clustering in non-native Eucalyptus trees in people’s back yards.

About this Entry

This page contains a single entry by Richard B. Hoppe published on July 8, 2005 8:45 PM.

More on the New Republic piece was the previous entry in this blog.

Victim of the Wedge? is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.

Categories

Archives

Author Archives

Powered by Movable Type 4.361

Site Meter