Behold the monarch: King of insect migration

Roadside ditches provide habitat for Monarch butterflies, which is one of the reasons a series of meetings the Minnesota Department of Transportation is holding late this month and early next month likely will see heavy attendance.

The coming of spring brings good news and not-so-good news on the wildlife and habitats front, and center stage is the embattled monarch butterfly.

This familiar, taken-for-granted orange-and-black butterfly is our modern canary in a coalmine, and its fortunes are tied intimately to the fortunes of all upland and grasslands wildlife, such as cottontail rabbits, ring-necked pheasants, increasingly rare open-lands sparrows, and other such songbirds, and much more.

That is because we are facing increasing pressures to farm marginal, erodible land for corn to burn as ethanol out our tailpipes. Which in turn is causing devastating losses in wildlife-wonderful CRP set-asides, among other assaults on grassland/upland habitats. And because some states – led by ignorant, obstinate, backward Ohio state and local governments, insist on excessive rather than narrowly selective roadside mowing.

Monarchs must – must – have milkweed. They lay their eggs on it, their caterpillars eat its succulent leaves, and they hang in beautiful gold-flecked, deep emerald chrysalids to transform from caterpillar to butterfly. Only on milkweed, no other plant. Over-extended farming, right into or along the precipitous edges of ditches in some cases, with no runoff-absorbing greenways left, and overly zealous roadside mowing – way beyond any regard for traffic safety – have decimated milkweed patches across North America. So has the broadcast use of herbicides to force crops where they should not be grown.

The thing about milkweed that outdoors folk need to remember is that it thrives exactly where all kinds of other plants and grasses thrive, which are habitat critical to wildlife. Look are the size of cornfields and soybean fields nowadays – you can see for a mile or much more in many instances; not a shred of post-harvest habitat stands from ditch to ditch a mile away. A field mouse would have no cover there come winter in these manmade moonscapes.

So, that is why we need to be concerned about monarchs, the kings of insect migration. They winter as far north as southern Canada, but east of the Rockies they winter only – only – in a few hectares of thick oyamel fir forest in the Sierra Madre Mountains of central Mexico. Those forests, of course, have been under heavy assault from often-illegal logging that is as relentless as Big Agriculture’s monoculture assault on America’s farmlands. But enough such forest remains, under protection, to support many millions more overwintering monarchs than have done so recently. The winter of 2015 saw an all-time low for the annual monarch census in  Mexico – just 1.13 hectares, or less than 3 acres!

But a winter with favorable “El Nino” weather presented excellent weather conditions for eastern monarch breeding and migrating in the winter just now passing. This winter’s monitoring indicates that the population is occupying 4.01 hectares, an increase of over three times last year.

But, a soon-to-be published scientific paper shows that 6 hectares of area occupied in Mexico represents a large enough population to absorb losses (and still recover) during years where severe weather events or other factors that lead to declines in monarch numbers may come into play. That is 50 percent more area than monarchs currently populate in winter.

Good weather in the growing season in 2015 allowed production of a maximum number of monarchs given available habitat.  This same amount of habitat can also produce many fewer monarchs in a bad year. Which is why 6 hectares is considered the long-term minimum for monarch survival.

To reach a target of 6 hectares overwintering area occupied in Mexico, an estimated one billion additional milkweed stems spread across the Norther American summer-breeding landscape is recommended. The Monarch Joint Venture and 40-plus partner organizations have developed the 2016 Monarch Conservation Implementation Plan to help achieve the target through coordinated habitat restoration, research and monitoring, and education.

The take-home here is to plant and/or encourage milkweed wherever you can, including your own backyard. Moreover, Ohio has been identified as a priority state for monarch migration and fourth-generation monarchs. Fourth-generation monarchs are the individuals who will travel back to Mexico, spend the winter there, and then start their amazing life cycle all over again in the spring, ending back up in Ohio the next summer. 

In May 2015, the National Strategy to Promote the Health of Honey Bees and other Pollinators (The Pollinator Health Task Force) asked all states to work through federal, state, public and private actions in order to restore or create pollinator habitat with the goal of 7 million acres across the United States over the next five years. This state’s response is the Ohio Pollinator Habitat Initiative (OPHI).

OPHI is a statewide network of partners that work together to provide education, research, hands on conservation, native seed collection, and technical assistance to all that have an interest in pollinators and protecting our food supply.

The partners include the Ohio Department of Transportation, American Electric Power, Pheasants Forever, Ohio Department of Natural Resources/Division of Wildlife, U.S. Department of Agriculture, U.S. Fish and Wildlife Service Ecological Services Field Office, U.S. Fish and Wildlife Service Partners for Fish and Wildlife, Ohio Soil and Water Conservation Districts, Ohio Department of Corrections and Rehabilitation, Ohio State University Extension, Ohio State University School of Environment and Natural Resources, Wright State University Biological Sciences, and the Levin Family Foundation.

To learn more, and get on the milkweed wagon, look up OPHI on-line at https://u.osu.edu/beelab/ohio-pollinator-health-initiative/.

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