Living Acres

Blog: Monarch Butterflies

Oct. 28, 2016
Monarch Numbers
Monarch Butterfly Population Numbers of 2016

Since 1993, butterfly researchers have been keeping records of the monarch population size. In 2013, an all-time low of 0.67 hectares (approximately 32 million monarchs) was documented. This record-setting low is likely the result of a cold period during the first three weeks of May 2013, which restricted movement of the monarchs into the northern breeding range.

To calculate monarch population size, scientists measure the area of forest covered by monarchs while they overwinter in the oyamel fir forests of Mexico. Researchers flag off the areas and determine the amount of hectares the monarchs are covering, which is then used for the official measurement.

In the winter of 2015-2016, good news came from Mexico. Researchers recorded 4.01 hectares of monarchs. This rise indicates nearly 200 million monarchs were blanketing the oyamel fir forests. This significant increase brought the 1994-2016 monarch population average to 5.91 hectares. For the monarch population to be considered stable, a consistency of 6 hectares must be met.

Unfortunately, it does not appear that this upward trend will continue. According to Monarch Watch, all of the data collected on current monarch populations suggest that 2016 will be a near repeat of 2014 due to a late spring weather event in Mexico that drastically reduced the number of adult monarchs making the journey north. They calculated a dismal number of 1.13 hectares. It is unlikely that the overwintering numbers will surpass 2 hectares.

The low number of monarchs that moved north from Texas in early summer, which resulted in these low-sighting numbers, reflect the mortality rates from a heavy sleet storm that swept through the oyamel forests in early March. While some butterflies had already started their migration north at that time, a majority of the overwintering population had not yet departed.

Rather than a discouragement, this decrease should act as a motivation. All landowners can still take steps to promote monarch development, including planting native milkweed in their gardens and non-cropland areas.

As the year goes on, check back for updates on the final overwintering number for the 2016-2017 winter. Stay informed by visiting living-acres.basf.us.

Aug. 26, 2016
Monarch on Milkweed
Maintaining Migration: What Matters When Planting for Pollinators

Each year, monarch butterflies take on an incredible journey in pursuit of survival. Millions of monarchs travel together to warmer regions like Mexico and California for the winter. Since many monarchs live in the Corn Belt, this trek can span across 3,000 miles. It’s easy to imagine that any monarch, that is traveling up to 100 miles per day, will build up quite the appetite along the way. Luckily, farmers can help fuel the travelers’ journey by planting nourishing pollinator plants along the route, and with a little upfront research, farmers can get a good start on supporting biodiversity in their communities.

Variety Matters

Like other pollinators, monarch butterflies count on a variety of vegetation as a source of food and shelter. A general variety ensures that monarchs receive the resources they need, but choosing the right variety is important for sustaining a specific region’s ecosystem.

Choosing native plant varieties when planting on a farmstead is important because the plants found naturally in the area are best suited for the local climate and wildlife. Non-native plants can quickly become invasive and endanger the wellbeing of other vegetation. Farmers should look up which varieties are native to their own region before planting.

Diversity Matters

Diversity in what farmers plant helps support a wide spectrum of pollinators and gives all species a range of nourishment. When choosing which plants to include in their efforts, farmers should take into account the lifecycle of each plant. A good mix of vegetation ensures that there will be plenty of plants in full bloom throughout the April to October growing season.

In addition to flowering plants, other natural resources should be considered when selecting what to include in a pollinator garden. Grasses can provide valuable ground cover that can help control weed competition and reduce soil erosion, ultimately supporting the longevity of the garden. A mix of trees, shrubs and other plants provides shelter and protection to visiting monarchs. Nutritional elements not supplied by nectar plants can be obtained by leaving fruit in the garden to rot and degrade into its core vitamins and minerals.

Methodology Matters

To establish the most impactful gardens for monarchs, certain planting techniques should be followed. Planting in tight groups rather than spread across a large area helps make it easier for monarchs to find the pit stop along their way.

Farmers should also research the best way to grow each plant. Some species can successfully emerge and develop from seed, while others require planting at a later growth stage. Research conducted in 2015 as part of the Living Acres initiative from BASF found that milkweed, a plant that provides valuable shelter for monarchs and food for their larvae, best grows from planted rootstalk.

Location Matters

Since much of the land beneath the monarch’s winter flight is a farmer’s acreage, pollinator plants can be incorporated right into the farmstead. Another research focus of Living Acres evaluates where farmers can establish supporting vegetation alongside their high-production operation. Non-cropland areas like roadways, ditches, and areas next to machine sheds and storage structures make great spaces to plant without encroaching on yield-producing real estate.

Now What?

After learning what monarchs need during their migration and how to best support their journey, it’s time to get started. There is a variety of resources available to help farmers take the first step:

  • This tool, developed by the Pollinator Partnership, generates a detailed report of plant varieties native to a region based on the zip code entered.
  • This webpage from BASF houses helpful videos, audio clips and print materials on monarch butterflies.
  • This marketplace from Monarch Watch connects farmers with milkweed varieties that are native to their region.

To learn more about the monarch butterfly population and efforts to support it, please visit living-acres.basf.us.

Aug. 17, 2016
The Problem

The monarch migration through North America is a natural phenomenon. As the only butterfly that makes an annual two-way migration, the monarch has captured the attention of scientists and nature enthusiasts across the continent. Butterfly experts began keeping record of population sizes in 1993 and have since seen a 68 percent decline in numbers, leading to the question, “What is happening to the monarchs?”

Multiple factors have contributed to this staggering drop in population, including changing weather patterns, the loss of overwintering sites in Mexico and the reduction of milkweed habitat in the United States. Over the last decade, massive Pacific weather systems have moved through central Mexico. These systems brought heavy rain, hail, high winds and even freezing temperatures in January and February of 2002, 2004 and 2010. The severe weather conditions ushered in mortality rates ranging from 50 percent in 2010 to 80 percent in 2002, devastating monarch overwintering populations.

Another issue facing the monarch population is the demolition of oyamel fir forests in Mexico, a common overwintering site for the butterflies. Monarchs prefer oyamel fir because it serves as a blanket and umbrella during the winter, protecting them from extreme cold and precipitation. According to Lincoln Brower, service professor of zoology emeritus at the University of Florida, the oyamel forests are the Achilles’ heel of the monarch.

While there are multiple government regulations and incentives put into place to preserve the oyamel firs, these efforts have not proven very effective. Illegal logging accounts for most the encroachment on monarch habitat. Even so, authorized extraction for firewood and timber adds to the overall loss of trees. Other strains on the landscape, including unregulated tourism and climate change, contribute to the decline of overwintering sites.

However, the biggest contributor to this decline may be the loss of milkweed habitat in the United States. Milkweed is essential to the monarch’s reproductive cycle. It serves as the location for mating, egg laying and larval feeding. Without milkweed, monarchs struggle to make their annual commute through America’s heartland.

Luckily, milkweed habitat loss is easy to fix and nearly every landowner can help make a difference. Living Acres, a research initiative from BASF, aims to increase the amount of milkweed habitat in non-crop areas on farms. Already, this initiative has led to the development of best planting practices for sustainable milkweed. For instance, though it is common to plant milkweed by seeding, only a small number of common milkweed seeds germinate. For this reason, researchers suggest that farmers establish milkweed through a planting process using root sections or transplanted seedlings. Following the seven steps outlined in the planting guide will optimize the success of milkweed habitat creation, allowing farmers to increase biodiversity while focusing on crop production.

To learn more, visit living-acres.basf.us.

 
 

©2018 BASF Corporation