CONCERNED ABOUT TOO FEW MONARCHS IN YOUR GARDENS? NBC IS TOO!
By MARIANNA T. WRIGHT | Executive Director National Butterfly Center nationalbutterflycenter.org
As for the spring migration of Monarchs, we’ve observed several things, anecdotally:
- First — we began seeing Monarchs around the 1st of March, when normally we do not see them until March 10-14. We were paying extra attention this year because we had a documentary film crew arriving March 14. They planned according to reliable patterns from the past that, this year, definitely did not follow the predictable pattern.
According to Journey North, the Monarchs began departing the reserves about a week early this year. I think it was reported starting on February 24 or so, when normally this occurs at the beginning of March.
NOTE: Monarch Watch Director CHIP TAYLOR reports many Monarchs remained in Mexico as late March 23, but those should have arrived in the U.S. within 7-12 days–at the beginning of April.
- Second — March–at least in the Rio Grande Valley–was exceptionally hot (3 or 4 record-breaking days at 100º) and windy. We had tropical storm force winds at 50 MPH one day! This would literally blow the Monarchs away.
I am not sure what the weather has been like in Houston, but it’s been pretty extreme here. We also had approximately 9″ of rain over 4-5 days at the beginning of April, which would prevent visible Monarch activity, and likely cause diversion of their flight path, which can vary each year. As you know, everything about their spring and fall migration (timing, path, duration) is ruled by the weather!
- Third — Chip Taylor seems to be suggesting, from community observations, that the Monarchs chose to reenter primarily along the Rio Grande north via the Laredo – Del Rio region. I don’t know if this is the case because we are significantly south of there, but if you look at the Journey North map of reported spring sightings in the Hill Country area (San Antonio – Austin) and then up to DFW Metro, it seems as though this might be the case. Again, it’s hard to know for sure because the data is based upon community member observations and reports, but it tracks with our experience this spring.
- Finally — we did not see large quantities of Monarchs, typically dozens at a time, in the gardens and on the grounds at the National Butterfly Center this spring; rather, we saw 1 or 2 at a time. This may be due to decreased population numbers or perhaps they just passed over us in migration when the southerly winds were pushing them northward.
Any official statement from the North American Butterfly Assn. will have to wait until data is compiled from the July 4th Butterfly Counts across the country. You can read more about that on the NBC website homepage,
Here is a link to the peer-reviewed scientific research paper Dr. Glassberg and other published about Monarch population stability in summer breeding numbers: nationalbutterflycenter.org/images/Global_Change_Biology_2022_Monarchs_Crossle y_et_al.pdf
For those truly interested in helping the Monarch, we have three suggestions:
- Plant more milkweed (choose native to your region)*
- Do NOT spray herbicide or pesticide
- Leave them be, i.e. let wildlife remain wild.
EDITOR’S NOTE: Keep up-to-date on Monarchs:
- *Milkweeds native to Greater Houston area
- BECOME A MEMBER OF THE NATIONAL BUTTERFLY CENTER
- On Facebook: facebook.com/natbutterflies
