Could 2012 be the Worst Year in Monarch Butterfly Migration History?

The mild winter, well-timed rains, and record wildflowers of spring 2012 resemble a lost dream as this year’s Monarch butterfly migration looks like it could be the worst in history.

Parched Goldenrod on the Llano River

Parched Goldenrod on the Llano River will serve no use to migrating Monarch butterflies except as a rest stop.

For a recap of the challenging year so far, read this post.

A visit last weekend to the Llano River reinforced the depressing outlook:   many of the usual nectar sources that fuel the migrating insects have been stopped in their blooming tracks by a lack of, or ill-timed rains and brutal heat this summer.  Declining river flow and a lower water table have contributed to the nectar shortage.

Goldenrod, usually a magnet for migrating Monarchs this time of year, stood parched along the riverbank–brown, crisp, and useless to the absent migrants, except perhaps as a rest stop.  Some stalks still remained green and those on the “Chigger Islands,” as we call them, offered only a few blooms.  Any nectar plant more than a foot from the riverbank was dead, except for Snow-on-the-Mountain.

Frostweed, a Monarch butterfly favorite, was much more scarce than last year–surprising given our better rains.   In the “historic drought” of 2011, Frostweed still thrived, but I’m guessing the timing of our rains and the Llano’s failure to recover lowered the water table so dramatically that plant roots were left dry. The 2012 Frostweed crop looks to be half or less than last year.

Frostweed

Some Frostweed showed its blooms on the Llano River last weekend, but not as much as we usually see in September.

Swamp Milkweed, typically a favorite host to Queens and Monarchs laying eggs along the river, showed scrawny, wilted leaves with blooms mostly spent.   We did find some eggs, though, and brought them home for fostering.

In my San Antonio butterfly garden, Monarchs are scarce.  I’ve seen only five so far and tagged ONE.  Last year at this time I had seen many and tagged two dozen by now.

A recent visit to the San Antonio River Milkweed Patch resulted in two Monarch sightings.   “We’re not seeing anything here,” said Mary Kennedy, a Monarch Larvae Monitoring Project volunteer and former science teacher, of her Fair Oaks yard just west of San Antonio.

Monarch butterfly on Water Hemlock

Monarch butterflies opt for Water Hemlock when their favorite nectar sources are not available.

Dispatches from Facebook and the Monarch butterfly DPLEX list sound equally discouraging.  “I live on an acreage, and for the past 12 years, my small woods has been a roosting site,” wrote Anna Nicholas of Shell Rock, Iowa, on the DPLEX list, an email listserv that reaches hundreds of Monarch butterfly enthusiasts and scientists.

Nicholas relayed that in good years, Monarchs visited by the thousands. In bad years, only a couple hundred formed roosts. “So far… in the past week, I’ve seen three butterflies total,” she wrote.  “Throughout the summer, I seldom saw a Monarch. I never found a caterpillar on any of my milkweed. I’ve checked with friends and family members…all report the same thing. In various parts of Iowa, there simply are no Monarchs. It’s very sad.”

“Been seeing any Monarchs?” asked the Native Plant Society of Texas on Facebook recently. Answers were overwhelmingly no, and then this report from Shauna Feely of Dallas:

I have not….However, I’m in a section of Dallas county that was aerially sprayed [with insecticides] , due to West Nile virus. A definite lack of birds and bees around here….We had a very active garden, but the spraying has put a damper on things….

Aerial insecticide spraying creates an extra challenge for the migration.

And then we see isolated reports of record Monarch sightings, like this one from Pennsylvania:  “Observers at Hawk Mountain Sanctuary on the Berks-Schuylkill county line counted 2,806 monarch butterflies moving past the hawkwatch site on Monday,” reported the Pennlive website on September 11.  The tally set a one-day record at the sanctuary, Mary Linkevich, director of communications and grants, told reporter Marcus Schneck.

It’s still early in the season for the “Texas Funnel,” the strategic gateway through which all Monarch butterflies must pass en route to and from their ancestral roosts in Michoacan, Mexico.  So far, signs suggest a dismal year.  Continued rain like this weekend’s could change the forecast somewhat, perhaps coaxing late season Frostweed to push out more blooms, but nothing will resuscitate the crispy flower stalks we saw on the Llano.

Monarch Watch issued its periodic Monarch Population Status Report August 30, predicting the Monarch butterfly population this year “might be the largest since 2003– perhaps 6-7 hectares” if the weather cooperated.  Or, they speculated, we would see “another overwintering population in the 2-3 hectar range,” the worst since records have been kept.

I hope I’m wrong and am sad to say that I think it will be even worse.

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9 thoughts on “Could 2012 be the Worst Year in Monarch Butterfly Migration History?

  1. I haven’t had any Monarch eggs on my milkweed yet. I had two queens earlier in the summer. Actually, I haven’t had any swallowtails either which is really strange.

    As I was driving yesterday I noticed some green milkweed on the side of the road near my home. I’m going to go check it out to see if there are any there. I thought that as my garden matured I’d get more and more caterpillars but they’re absent this year, even though I don’t use chemicals in my garden.

  2. We have had a low but steady influx of Monarchs this season, but not nearly as many as last year. We released 3 that we fostered and tagged and have 4 more that went into chrysalis last week. We also currently have 5 tiny caterpillars in the “nursery” (sunroom) of our north-central Austin home.

  3. I think we may have seen 4 so far this season in our yard, Mission, Texas (about 5 miles nor) We have plenty of milkweed that we have been watering to keep tender. They don’t normally peak here until the end of October. Hoping! Thank you for the blog.

  4. I’ve seen four so far in my yard. We have a small Monarch habitat with 4 Milkweed plants and some blue mistflower. I’m pretty sure I saw a female laying eggs on the Milkweed. I’m keeping my fingers crossed.

  5. I am in California. There have been 21 births since 8-14-2012. I have been away for a week and have missed some. My mom filled in for me as best as she could. We have also had a heat wave here. One day it reached 106 very hot for Fullerton Ca. We have taged 247 monarchs since January 2012. There have been more males born than females. Not as many eggs as I have hoped for. Way to many praying mantis 80 and counting. They love the dry weather and so do the wasps. They have been stealing my monarch eggs. My garden milkweed is doing well. Hope to see more caterpillars soon. So far I do not think we are spraying for west nile virus.

  6. While it’s true 2012 will be the worst migration in history through the Central Texas Flyway, the causes are not “massive aerial spraying”, “drought”, “heat”, etc. The cause is something much less glamorous that scientists do not monitor and measure: predation of monarch eggs and young caterpillars by ants, spiders, hemipteran bugs, assassin bugs, earwings, wasps, lady bugs and many others. The long time monarch observers in the upper midwest like this one http://monarchwatch.org/forums/viewtopic.php?f=6&t=2973 and this one http://www.learner.org/jnorth/sightings/query_result.html?record_id=1339711657 will tell you that in spite of a high number of female monarchs seen in early summer, large caterpillar were scarce. And that’s because the monarch eggs and small caterpillars were being decimated by predators. A high tachinid fly parasite population also cause alot of mortality of large caterpillars and chrysalids.. A warm winter in the upper Midwest followed by an exceptionally warm spring likely boosted predator and tachinid fly parasite populations to above normal levels.

  7. If I’m not mistaken, this past week was supposed to be San Antonio’s migration week, but I’ve seen very few through my yard, and only saw one on my sad, struggling milkweed. I have TONS of Queens all over my mist plants and a few on my milkweed plants as well. Also have lots of Painted Ladies, Tawney Emperors, Red Admirals and even Tropical Buckeyes, Black Swallowtails, Gulf Fritillaries, Question Marks and tons of various skippers. But Monarchs…not so much.

  8. I’ve had tons of monarchs and various other butterflies fluttering around my garden. Have had alot of eggs this season, but something was getting them. So I’ve raised a dozen or so monarchs on my enclosed backporch. I still have 4 monarch crysalids and was surprised when two queens hatched from the milkweed i cut for my monarchs! I’ve been collecting milkweed seed and have discovered milkweed roots really well in water. So I should have a good start nest year! I was thinking about tagging next year. My question is when is it too late for the monarchs in North central texas? Dalllas/Fort Worth area? I wouldnt want to release butterflies only to die in the cold.

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