Narrowing Focus

The monarch butterfly (Danaus plexippus) population on the Mexican Monarch Reserve where they overwinter is the lowest since annual surveys began back in 1993. The oyamel fir forests provide a warm winter home for the monarchs, known for their great migration across North America. The population is down 59% from two years ago. In 1996, monarchs occupied 45 acres (18.2 ha) of forest. They now occupy 2.94 acres (1.2 ha).

Monarch butterfly wing Photo: Rare Giants

Monarch butterfly wing
Photo: Rare Giants

The entire migration process takes five butterfly generations to complete one full cycle, and over the past twenty years, fewer monarchs have been surviving the cycle to have their progeny return to the reserve.

The demise of the milkweed plant, mainly due to the use of glyphosate herbicides, means the butterflies are unable to find enough of their main food source. But extreme weather, deforestation and forest degradation, and regulatory rollbacks for protected areas also contribute to the dangers facing the species’ survival.

In Barbara Kingsolver’s novel Flight Behavoior, monarch butterflies disappear from Mexico almost entirely and find a new forest home in a completely unexpected location, alighting for a season before moving on. There’s always the hope that intensified efforts to replant milkweed and to strengthen protected migratory paths will help. And maybe, prior to the annual surveys, the monarch population experienced massive contractions that went unnoticed, only to recover again.

Mexican billionaire Carlos Slim has just announced a $100 million contribution to a variety of monarch programs. If there’s message here, it’s this: If you live in North America, go out and plant some milkweed. In your garden, on your balcony, on roadsides and byways. Sign a petition. Send a letter to your congressperson.

For now, the circle of monarchs retracts, a narrowing lens by which to observe these amazing creatures of long journeys on small wings.

Photo: Raul Gonzales

Close-up, monarch butterfly wing
Photo: Raul Gonzales

Milkweed Moment

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Antelope Horns Milkweed (Asclepias asperula), Texas Hill Country roadside. Photo: Monika Maeckle/Texas Butterfly Ranch

Anyone who has driven the long roads of the United States highway system has seen the variation possible along the roadside – trees, flowers, invasive plants. Everything from managed forests to clipped lawns line the massive acreage of the transportation system that is lost to farming or other development.

With the expansion of land that is intensively farmed rather than set aside for conservation, and the triumphal march of broad-spectrum herbicides, the room for native plants such as milkweed has dramatically decreased. With that shrinking, the insects which rely on those plants and flowers are suffering as well.

Case in point: the monarch butterfly. Even without the loss of its main source of nutrition during annual migration, the monarch population is in steep decline. Logging in Mexico has cut into the monarch’s breeding grounds, temperature fluctuation has affected its migration. Populations are down by 59% this year compared to the previous winter.

Trees with monarchs Photo by Jim Lovett/Monarch Watch

Trees with monarchs in Mexico
Photo by Jim Lovett/Monarch Watch

Monarch Watch, a non-profit organization that works to protect the monarch butterfly in North America, has a suggestion: Use roadside acreage along the migratory path of the butterfly to plant native plants and milkweed. Rather than plant or maintain large strips of grass, common in many states, highway roadsides and median strips could be used to conserve the plants that have disappeared due to agriculture and residential development.

This would also go some way toward protecting some of the creatures that rely on these plants. Monarch Watch also suggests planting milkweed plugs, i.e. plants that will blossom this 2013 season for the current migration, in any available patch or acreage that lies along the migratory path. According to the group, one major event or disaster – a bad season of temperature change, a particularly bad storm – could send the monarch population into a death spiral.

Roadside vegetation management has been under discussion for quite some time as a potential for conservation efforts.

Even in a time fiscal belt-tightening, the milkweed proposal seems like a good investment in highway beautification and wildlife conservation, even if there is a certain irony in creating a haven against habitat diminishment and climate change on the very byways of one of the main culprits, the road of the fossil-fuel based culture, by planting what are generally considered to be native weeds wiped out by another major culprit, successful and efficient agriculture.

Monarch and milkweed
Image: The Barnegat Bay Partnership

More:

TakePart article One Beautiful Thing You Can Do to Help Monarch Butterflies

Monarch Watch website, which also supplies milkweed seed and plugs, and a list of other suppliers.

Pollinarium Paddles

Pollinarium on a copper pennyPhoto: ophis

Pollinarium twins on a copper penny
Photo: ophis

These images are of pollinaria, the strange and wonderful fertilization saddlebags of the milkweed, among other flowering plants.

A pollinating insect, a monarch butterfly for example, stands atop the milkweed flowerhead. Usually there would be a layer of pollen dust waiting to catch a ride, but in this case, a wee pollinarium detaches from the flower and hooks itself to the leg or mouth or antenna of the insect to be transported to another milkweed, where it then detaches itself.

Milkweed plants are the main food source for monarch butterflies. Once common, milkweed has been eradicated across large areas of its former native habitat, mostly due to farming and pesticides.

Via: Monarchwatch.org

Via:
Monarchwatch

There’s a detailed description of how it all works here, but mainly, I like that the plant pollination structure looks like a paddle-legged insect itself.

Purple Milkweed (Asclepias purpurascens)

Purple Milkweed (Asclepias purpurascens)