Just published in Science: a new perspective highlighting recent advances in our understanding the monarch butterfly’s declining population. Check it out here! See also commentary in today’s Washington Post.
Insects on Plants, Chemical Ecology, and Coevolution
Website of the Phytophagy Lab at Cornell University, led by Anurag Agrawal, James A. Perkins Professor of Environmental Studies
Just published in Science: a new perspective highlighting recent advances in our understanding the monarch butterfly’s declining population. Check it out here! See also commentary in today’s Washington Post.
I understand that the Mexican forests are being logged. I appreciate and agree with LinclonBrower’s assessment that the loss of Mexican Habitat poses a serious risk to the overwintering population, in the event of a winter storm.
However, I continue to see it as a risk and not a cause of the population decline. Again and again, including the Washington Post article based upon your article, I see the logging identified as a primary driver of the observed decline. Often, in the media, it is stated as the primary driver of the decline.
Could you please point me to the evidence? Where are the piles of dead butterflies caused by winter storms in unprotected overwintering colonies? Where are the scientific papers documenting the death of millions of butterflies in the colonies?
Perhaps the best evidence is this paper by Thogmartin et al. Nonetheless, I agree with you that there is not rock-solid quantitative data on the importance of the Mexican habitat. It is a bit unclear how it could be shown beyond a reasonable doubt. I think most agree that the overwintering grounds are tiny, very important for the annual migratory cycle, and have shrunk substantially over the past 4 decades. Talk soon, -Anurag
I noticed that the Washington Post article claimed that Monarchs are a “widespread pollinator.” Do you think maybe you should set them straight?
yes, thanks for the nudge. -AA
The eastern monarch overwintering population has actually exhibited stability the past 8 years: https://imageshack.com/a/img923/3720/nb8gWN.jpg And since the summer breeding population in the upper Midwest and Great Lakes regions this summer has been extra large (so far as of July 27), the midwestern fall migration this year should be extra large as well as should the overwintering population in Mexico.
Hi Paul, two main events have occurred since 2003 that have determined the promoted overwintering monarch populations. 1) The World wildlife Fund started counting them and they obviously changed the counting system as explained at the bottom of the following monarch watch population graph https://www.google.com/search?q=monarch+watch+population+graph&rlz=1C9BKJA_enUS758US758&hl=en-US&prmd=insv&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiR1IP9qsLeAhVxTd8KHVm5A4AQ_AUIEigB&biw=1024&bih=653&dpr=2#imgrc=4iE47NdvwsvOaM 2) the catastrophic drought that occurred between 2010-13 on the eastern range, the only catastrophic drought that has occurred since monarchs have been counted in Mexico https://en.m.wikipedia.org/wiki/2010%E2%80%932013_Southern_United_States_and_Mexico_drought Hopefully, despite the adverse weather events during the migratory period south, monarchs will complete their rebound to average numbers this winter proving there’s sufficient milkweed on the eastern range to support a minimum 5 hectare population, the average over the last 15 years. The spike surrounding the 1996-97 was nothing more than a abnormal spike many butterfly species intermittently experience when weather conditions are perfect and predators are at minimum levels. Of course, the liberal administration of 2014 and monarch NGOs took advantage of this dip to initiate a government funding scheme to support their liberal environmentalist supporters. Native milkweed’s are drought and cold tolerate plants that rebound putting on stems and leaves after drought conditions subside rebounding monarch and all polllinator populations. No life on earth would exist if this weren’t true. Fortunately the 100s of millions of dollars spent on this scheme raised awareness of monarchs and pollinators and consequently the pollinator population will benefit through citizen involvement through enthusiasts planting pollinator gardens and raising and releasing monarchs and other butterflies to protect pollinators when the next catastrophic drought occurs.
I agree with you that there is not rock-solid quantitative data on the importance of the Mexican habitat. It is a bit unclear how it could be shown beyond a reasonable doubt. I think most agree that the overwintering grounds are tiny, very important for the annual migratory cycle, and have shrunk substantially over the past 4 decades
Readers should know that the author sells insecticides.
I’ve spent a lot of time studying Monarchs and witnessing their decline in Michigan. I am convinced that Bt food crops combined with our foolish biofuel policies account for most of the decline.
RethinkEthanol.com has many good articles on this topic.
Note sure why you think “author sells insecticides” — I am a university professor and have never worked for pesticide companies or sold insecticides?!
Darn I hate it when people post False News.
Please respect others who are genuinely trying to carry on an intelligent dialogue about something we genuinely are concerned about. Thank you.