Wednesday, September 15, 2010

As the Temperatures Dip, Monarchs Glide In!

Monarch at Boyce Thompson Arboretum by Laura Miller
Last week the high temps released their grip on us for a few days - and monarch butterflies coasted into the Phoenix area. Bob and I found two monarchs in Mesquite Wash Friday morning. One looked very faded and frail; the other fresh and new. Tatsuyo called early Saturday morning reporting her first monarch of the season on South Mountain. (Funny thing - last year the first monarch arrived on September 11th, too.) We drove to Seven Springs north of Cave Creek and met Christine Lowe there. We spotted one monarch in excellent condition near the campground. When we came home I received an email from Ranger Rebecca at Rio Salado Restoration Habitat reporting two monarch sightings - one near the 7th Street bridge and another near the waterfall. Today Laura Miller found this new-looking male monarch in the Demonstration Garden at Boyce Thompson Arboretum. Slowly, monarch butterflies are moving in to the greater Phoenix area.

The cool window of last week flared into the blazing heat wave of today. Monarch butterflies struggle with high temps. Anything 104 and above is stressful with increasing mortality. Hopefully, the monarchs that are here will find a cooler place in the trees or near water to refresh them a bit. I contacted Dr. Karen Oberhauser at the University of Minnesota, a monarch expert, about the effect of our high temperatures this week, often exceeding 104 degrees. In the laboratory monarchs were studied at high temperatures for a full day, 12 hours of sustained heat, and they mainly studied immatures. Here in Phoenix, adult monarchs are exposed to high temperatures of 104 and above only three to five hours before cooling again. "The adults' lifespans will be shortened, but otherwise they may live/reproduce normally." That's good news for monarchs in the desert. But let's hope it cools before the main migration surge arrives in upcoming weeks.

Freshly eclosed female Queen butterfly
Even though the afternoons are hot, the mornings are not. If you're like me, it's time to get outdoors and garden. Continue watering milkweed well to encourage flowering for the migration rush. Plant monarch nectar plants if you can find them.  Maxmillian sunflowers will bloom soon and other sunflowers are already flowering. Lantana is a butterfly magnet as are zinnias. Avoid trimming Red Bird of Paradise or Baja Fairy Duster - monarchs are frequent visitors. Be careful pruning any bushes near milkweed! This morning I was trimming a Texas Sage that was intruding on a nearby Desert Milkweed when suddenly orange wings fluttered near the ground. A female queen butterfly recently emerged from her chrysalis hidden in the branches! I was frightened that I damaged her wings. So I reached down - when she jumped on my hand. She was fine....whew! Together we walked over to the Maxmillian Sunflowers where she continued to flex her wings to dry before flying off to enjoy her new life several hours later.

Finally, resist the urge to prune or scalp Desert Milkweed! Many landscapers and home owners love a neatly contoured plant. This milkweed was severely pruned last April right before it bloomed. As you can see it still hasn't recovered enough to flower and will likely not be on the monarch butterfly's "visitation list" when they swarm through the Valley during their main migration window. So, look for orange wings gliding above! September 29 through October 11th is the peak time of the monarch migration - but the leaders of the migration pack are visiting now.

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