Sunday, March 21, 2010

Where have all the Monarchs gone?

This morning Dr. Chip Taylor was featured on ABC's Good Morning America. He talked about the steep decline in Monarch butterfly sightings across the United States. Monarchs are a harbinger of the season, yet the numbers of Monarchs seen are 1/4 of usual. Why? Torrential rains in Mexico, climate change, habitat loss all contributed. Dr. Chip Taylor interview

While the record low numbers of Monarch butterflies returning from Mexico are startling, the news from California is grim, too.  Every year the Xerces Society conducts counts at the various overwintering sites during the week of Thanksgiving. The 2009 year numbers are not posted yet, but it is known that numbers are 30 to 40% lower than last year - and last year had the third lowest number of Monarch butterflies ever recorded at the California overwintering sites. Here is a graph I compiled of earlier numbers:
 (You can read about our November trip visiting the California Monarch overwintering sites California Monarch Overwintering Site Trip Blog)

It is well accepted among scientists that Monarch butterflies East of the Rocky Mountains migrate to the mountains near Mexico City for the winter. Those West of the Rockies overwinter along the Pacific coast of California. Chris Kline began the Southwest Monarch Study in 2003 to learn where Monarch butterflies in Arizona go, south of the Rockies - or if they go anywhere at all. While his study is still continuing, he has some interesting results thanks to many citizen-scientists monitoring Monarch populations around the state. Monarchs tagged in Arizona have been recovered in both Mexico and California, and a few stay for the winter.

 What about here in the Phoenix metropolitan area?  For the last four years a small number of Monarch butterflies overwintered at the Rio Salado Restoration Habitat and the Desert Botanical Garden. In the Fall it looked like this year's population would be higher than last year's, then fierce storms with high winds struck the Phoenix area decimating their numbers. In January, I only spotted one lone Monarch at the Rio Salado overwintering site. By early February the Desert Botanical Garden's population was reduced to five male Monarchs, who left the area shortly after mid-February likely searching for mates. 

I looked at my records from last year of Monarch sightings locally as a comparison. By mid-March most of the Monarchs left Rio Salado, likely due to lack of milkweed. (This year volunteers planted milkweed as a life-line host plant for female Monarchs to lay their eggs.) But the activity in March 2009 at the Desert Botanical Garden began to accelerate with mating and egg-laying on milkweed around the garden. By March 4th I noticed four Monarch caterpillars near the Butterfly Pavilion and by March 9th there were another seven. 

Within a few weeks the air erupted in fluttering orange wings dancing through the lavender and other nectar sources in the garden. April witnessed another mating frenzy and the last Monarch left the area in mid-May when temperatures began to rise over 100. Compare these numbers to 2010 when I only saw one lone female laying eggs on Tropical Milkweed last Monday, March 15. We are watching the three eggs she laid closely to see if they become caterpillars.

What are we doing in the Phoenix area to save the Monarch Butterfly?
  • Last weekend we worked with the Hassayampa Preserve, part of the Nature Conservancy, to learn about the Monarch Butterfly in Arizona and plant milkweed: Asclepias subulata, Asclepias linaria and Asclepias subverticilatta on the preserve.
  • Planted Desert Milkweed, Asclepias subulata, at the Rio Salado Restoration Habitat and are planning to have a workday to plant Narrowleaf Milkweed, Asclepias angustifolia, in the near future.
  • Planted milkweed seeds at the new Audubon Center along the Salt River.
  • Offered workshops on Monarch Butterflies and planting milkweed at the Veterans Oasis Environmental Center in Chandler.
  • Worked with the Desert Botanical Garden to encourage everyone to buy milkweed to provide rest stops for monarch in their home landscaping.
  • Offered workshops advocating Monarch Butterfly conservation and awareness at local and distant Audubon chapter meetings.

Thursday, March 18, 2010

Monarch Nectar Plants

What is the monarch butterfly's favorite food in Phoenix home gardens? Milkweed in bloom! So, be SURE to plant milkweeds - and you can see how beautiful they are in the previous post. It is amazing how many monarch and queen butterflies will appear when they are in bloom as well as other butterflies.

Now lets look at other nectar favorite choices. By far if you can only plant one other flower, plant Lantana.Maybe we get tired of seeing it everywhere, but butterflies of all kinds love it! Lantana is easy to grow and a low-water user. It blooms profusely in our summer heat and is a perennial most winters, although it can incur damage in a deep freeze. Lantana grows well in full or reflected sun. Plant several one gallon specimens close together for a mass planting to draw more butterflies. They seem to favor the orange and red varieties most, especially Lantana camari. Look for them at local garden stores and the plant sales at the Desert Botanical Garden and Boyce Thompson Arboretum.

 Whenever I am at the Desert Botanical Garden I usually find queen and monarch butterflies on Fernleaf Lavender.This specimen grows easily with little care and blooms in the Fall through Spring. There are different kinds of lavender available, but by far Fernleaf Lavender is the number one nectar choice. At the DBG queen and monarch butterflies (when they are in town) roost in trees nearby so they are nearby for a morning nectar drink before they cruise around other parts of the garden.

Baja Fairy Duster is another favorite. There is a pink fairy duster, but monarchs prefer the red only.
The plants are drought tolerant and they also draw hummingbirds and other butterflies. 

 Sunflowers of any kind are a monarch favorite! 

There are other nectar sources that will draw monarch butterflies to your yard when they are in town, but these are easy favorites to plant this year. When you plant milkweed and nectar sources, you are helping the monarch butterfly keep its migration.

How serious is their migration threatened? We'll go into more detail in the next post. Are we alarmists? We are facing the reality that is before us - before its too late.

Wednesday, March 10, 2010

Your Milkweed Shopping List

Maybe its the "weed" in milkweed that scares people. You'll see by the photos that many members of the Asclepias family are beautiful in their own right, often with stunning flowers. Monarch butterflies and their cousins, the queen butterflies, use milkweed as their host plant. By host plant we mean that they will only lay eggs on a milkweed so their larvae can feed on them to eventually become a butterfly. With the local plant sales starting this week, here are a few to add to your landscape. By planting several in your yard you are helping to preserve the monarch butterfly's migration, but you may also be delighted by other butterflies who also enjoy the flower's nectar.

Desert or Reed Milkweed  Asclepias subulata
A delightful lady once stopped me while I was buying a Desert Milkweed at Boyce Thompson Arboretum's Fall plant sale. She was an artist and admired the unique and graceful shape of this plant as well as its muted color. As we talked, I learned to appreciate this desert-dweller in a new way. She also told me about a shopping center in East Mesa with rows and rows of A. subulata. Of course I stopped there on my way home and was delighted to see male monarch butterflies patrolling  and cruising the milkweed! I also saw many monarch caterpillars chewing on the flowers and stems.

Desert milkweed is a low-water plant that thrives in full sun. When first planted, water deeply twice a week. Once it settles in you can water deeply only once a week during the summer and little to none during our winters. How much better can it get in our Phoenix heat? The Spring plant sale lists at the Desert Botanical Garden and Boyce Thompson Arboretum show that the Desert Milkweed will be available at both locations usually in one and five gallon containers. This is a fast grower, so buy several one gallon plants and let them find their home in that sunny spot of your yard that is often a challenge to showcase. Then keep your eyes open and see who visits!

Tropical Milkweed or Bloodflower   Asclepias curassavica
While not native to Arizona, A. curassavica grows well in our desert climate. It is frost-tender and becomes an annual during those cold winters. But in our recent mild years it is a perennial that thrives on a fall pruning to help it become fuller with abundant blooms in the Spring. When you do cut back a branch or two because it is getting a bit leggy, stick it in a pot of fresh potting soil and it will easy root creating a new plant. Bloodflower also grows easily from seed.

This milkweed seems to be a favorite of monarch butterflies around the United States and it is often hoarded by monarch enthusiasts eager to draw monarchs to their yard. We are lucky that it often grows in the Phoenix area year round. Tropical milkweed is usually found with the popular orange and red flowers, but all-yellow varieties are also available. While this milkweed takes full summer sun, it grows best with some afternoon shade. It needs more water than the Desert Milkweed, so water deeply twice a week during summer's peak. Last year during a high heat dry spell I covered my Tropical Milkweed lightly with shade screen for a few weeks to helped protect it from those scorching days when we all cry for relief.

Asclepias currasavica is on the plant list for the Spring sales at both the Desert Botanical Garden and Boyce Thompson.

 Narrowleaf or Arizona Milkweed
Asclepias angustifolia

Have a shady spot but still want flowers? Narrowleaf Milkweed is just for you! One of the rare milkweeds that favors shade rather than sun, A. angustifolia draws monarch and queen butterflies as a place to lay their eggs. In the Fall, a monarch butterfly deposited her eggs on Narrowleaf Milkweed at the Desert Botanical Garden Herb Garden. Two caterpillars each formed their chrysalis on a nearby Agave. The weather then cooled, so their transformation took longer, but by Christmas two beautiful male monarch butterflies emerged and nectared on nearby Fernleaf Lavendar to the delight of visitors.

Narrowleaf Milkweed will require more water than the Desert Milkweed, so twice a week deep watering in the summer will help this shade-lover flourish. Fortunately, since it is protected by shade, the evaporation rate isn't as high as other plants.

Unfortunately A. angustifolia isn't on the Spring plant sale list of either the Desert Botanical Garden (where it was in the Fall) or Boyce Thompson. But do ask at local nurseries if they will order it for you. Its a great find!

Pine-needle Milkweed   Asclepias linaria
  Pine-needle Milkweed also grows well in our desert and flourishes in full sun with little water. Once established, a weekly deep watering suffices.

Let us know if you find monarch caterpillars on A. linaria. The Southwest Monarch Study finds that they are a common monarch host plant at East and Southeastern Arizona locations, like Boyce Thompson Arboretum. But in the Phoenix area monarch butterflies seem to prefer other milkweeds. We don't know why that is or if it is true at all, so more data is needed. Pine-needle Milkweed will be available at the Boyce Thompson Arboretum Spring plant sale.

Sunday, March 7, 2010

The news is grim...

If you love monarch butterflies, the news is grim. This is the time of year we look forward to the beginning of their return from their over-wintering grounds in California and Mexico. But this year monarchs may be harder to see. The sheer number of monarchs everywhere nose-dived this past Fall to the lowest ever recorded in Mexico and California. Then, compounding the issue, fierce storms and flooding pummeled the monarchs' winter home in Mexico. While the exact number of losses are unknown, the news isn't good.

Why the low numbers? Scientists suggest the weather was one culprit. The Midwest had a cool, rainy summer which resulted in lower numbers of monarchs reproducing. In the West, no one has speculated as to the cause this year. But it is well known that the number of monarch butterflies has dropped over time for several reasons. Habitat loss, increased pesticide use, urbanization, roadside spraying of milkweed, and weather changes all play a role. How significant is this? Some scientists say the monarch butterfly will lose its magnificent migration in less than 25 years if something doesn't change.The World Wildlife Fund placed the monarch butterfly on its Top Ten Endangered list primarily because its migration is an endangered phenomena.

So, how can we help? Create a monarch habitat in your yard. Plant milkweed. Better yet, encourage your friends, relatives, too -- and your city parks and churches. Think "monarch" with gifts of milkweed plants for Easter or Earth Day, April 22. Plant monarch-attractive flowers for nectar. There are many websites with great information about creating monarch-friendly gardens. But for those of us who live in the Sonoran Desert, especially in the Phoenix metropolitan area, the types of flowers and planting times are a challenge.

First, are there monarchs in the desert? You bet! Last year the Southwest Monarch Study tagged over 2,000 monarchs in Arizona! The first monarchs of the season were seen early in July in the Southeastern portion of the state and along the Little Colorado River near Springerville. Monarchs were spotted in the Phoenix area on September 10 on South Mountain and the next day at the Desert Botanical Garden. Soon they were seen around the area, especially in the East Valley, nectaring and laying eggs on Asclepias subulata, Desert Milkweed. It was formerly thought that Desert Milkweed was too coarse for monarch caterpillars to chew or that it supplied insufficient nutrition, possibly causing deformities. But, to the contrary, monarch caterpillars thrive on Desert Milkweed! The caterpillars are robust and the new monarch butterflies are strong and healthy.

The goal of this blog is to share information about monarch butterflies in our unique desert environment. But first, mark your calendar today for upcoming plant sales in the area that will offer milkweed and monarch friendly plants. Over the next days we'll explore what a healthy monarch refuge can look like.

Plant Sales
Desert Botanical Garden, Phoenix
Member Day:  Friday, March 19
General Public:  Saturday, March 20 to Sunday, March 21

Boyce Thompson Arboretum, Superior
Member Day: Friday, March 12
General Public:  Saturday, March 13 through Sunday, March 28

Upcoming Monarch Workshops
I will also be leading the following classes on creating monarch habitats:

Hassayampa River Preserve, The Nature Conservancy
Unraveling the Mystery of the Monarch Migration
Saturday, March 13 from 1 to 3 PM
Contact (928) 684-2772 for information and registration

How to Create a Monarch Oasis
Environmental Education Center at Veterans Oasis Park, Chandler
Contact (480)782-2890 for information and registration