Tuesday, June 25, 2019

That Article About Raising Monarchs


Here we go again. Another sensationalist headline of sorts has the monarch world in an uproar.  There's a study - a very limited study - that says that raising monarchs in captivity is detrimental to their navigational abilities. Because of this news release, I've been bombarded with questions as to what I think about it.

First of all, let me state my personal disclaimer. Though I try to keep up on the latest research and am constantly learning, I am not a biologist, entomologist, etc. I have a Science degree, but it's in Dental Hygiene. Do I use some of what I learned in my microbiology, anatomy, chemistry, and other related classes when it comes to my experience with monarchs? Certainly. Do I use principles from studies I was a part of when I worked for a dental research company? Of course. But I come at this issue from a limited perspective with respect to my focused formal secondary education.

Now, to the issue. Here is one version of the article that's causing so much buzz:


https://www.theatlantic.com/science/archive/2019/06/hand-reared-monarch-butterflies-dont-migrate/592423/


Here's a link to the study:  https://www.pnas.org/content/early/2019/06/18/1904690116

And here are some of my thoughts on the information in the articles being circulated in mainstream media:

A spined soldier bug takes a monarch
caterpillar as its lunch in my garden.

We know that in the wild, less than 5% of monarchs will survive from egg to adult. (This is fairly typical in the insect world.) Logic tells me that saving just one female saves not just her, but the 400+ eggs she will lay. Play that out exponentially and it's definitely worth considering that the population will increase, given the number of people who now raise them.

I have never advocated the mass raising of monarchs, for a number of reasons, but what do botanists do when they're trying to bring back a plant that's in danger of extinction? They enlist the help of others in growing it in various hospitable locations. Case in point: Solidago shortii. I personally took part in this effort through the Cincinnati Zoo's CREW program. (http://cincinnatizoo.org/conservation/crew/what-is-crew)



Solidago shortii
'Solar Cascade' was once endangered, but thanks to the CREW
program at the Cincinnati Zoo and Botanical Gardens, it is now available commercially.

I'm not saying that because it worked in the plant world, it will work in the insect world, but there is food for thought there.

I have several issues with the study as well as the article itself (including the headlines that the media puts out there with it), not all of which I'm willing to state publicly. If we were having this discussion in person, I would be more inclined to say them. But one of my reservations with it is already proving to be true. People are reading the widely spread articles, coming to their own conclusions, and spreading those conclusions, even if they aren't necessarily true.  

Another thought I had - and at this point, it's just a thought - how does this study affect all the studies of monarchs being raised in captivity in universities for research? Does this mean that the results there are not entirely valid because the monarchs aren't being raised in their natural environment? (Some are, but some are not, even though they try to mimic it.)


People are reading the widely spread articles, coming to their own conclusions from them, and spreading those conclusions, even if they aren't necessarily true. 

The article has some good information and raises some questions, mostly about commercial breeding, but it's premature to be putting it out there in the media as if it were absolutely proven. The article states that the limited study isn't conclusive, but that fact will get lost in the noise and won't always be included in the message that will be the takeaway. *sigh*



I think two important points need to be made:

  • If raising monarchs is how we have to "save" them, we aren't really saving them. This model isn't sustainable. However, it may help get them over the hump until such a time that their population has increased enough that their numbers are plentiful and self-sustaining.
     
  • Just as their lower numbers are a result of numerous factors that have caused it, a number of things can be done to reverse it. This is a good thing, since not everyone can do everything, but everyone can do something. The results are cumulative.

Personally, I think the most important things we can do is to increase habitat and reduce the use of chemicals. And just as important is increasing awareness by speaking up about the problems that pollinators face and how we can help them. 

"Each one teach one" can be our mantra. We all have a mouth, so let's put it to good use by spreading the word about strategies we know that help and not harm. 


EDITED TO ADD THIS COMMENTARY ON THE ARTICLE AND THE STUDY:

Later today, after I published this blog post, Angie Babbit, of Monarch Watch, so beautifully said what many of us feel in regard to rearing monarchs at home:

We need to focus on keeping people connected to the monarchs in a positive way that lends itself toward conservation. I got a letter from a woman today that said she has been rearing fewer than 100 monarchs a year for a while, and her entire neighborhood has started turning green spaces into habitat because she announces how many she's successfully released each year. Now she's read this news and wants to know if she's doing more harm than good.

Are we really going to tell her that her efforts to rally her neighborhood are misguided? Are we really going to tell people to stop bringing in caterpillars to show their grandchildren the miracle of metamorphosis? This is a sociological phenomenon that's tied to a biological phenomenon that's tied to conservation. A hands-off approach to conservation is going to kill conservation and send thousands of school kids into programs of virtual dissection kits and online atrophy-based education.

“In the end, we will conserve only what we love; we will love only what we understand and we will understand only what we are taught.” ― Baba Dioum

Sincerely,

Angie Babbit
Communications Coordinator
Monarch Watch
The University of Kansas


AND

In reponse to an organization writing to Dr. Karen Oberhauser, who was quoted in the news article:

I talked to the reporter about the inside rearing a fair amount, but he didn’t include that information in the article. It is important to note that the inside rearing in the experiment was done in incubators in which the experimenters could control temperature and light exactly. As a result, the monarchs were not exposed to any natural light or temperature fluctuations; the lights went on and off, and they were kept at a constant temperature. In your exhibit hall, there are windows and diurnal temperature fluctuations which provide exposure to more environmental cues. I’m actually not surprised that they didn’t migrate after being in an incubator. There are plenty of examples of monarchs collected at different stages of development, being reared inside, and successfully migrating.

While I think that the study was really interesting, I’m sorry that this feature of the rearing conditions was not included in the paper itself or in the media reviews.

In my opinion, what you are doing is great. We’re doing the same thing at the UW-Madison Arboretum.

All my best,
Karen


AND

From Dr. Orley "Chip" Taylor of Monarch Watch:


A response to the PNAS paper regarding captive-reared monarchs, by Dr. Chip Taylor
Yes, induction of a non-reproductive condition and migration is fragile. That is known. No one to my knowledge has been able to completely replicate the conditions that result in reproductive diapause and migration in the laboratory.

The system is resilient, complicated and still full of unexplained attributes – as well as unexplainable outcomes – e.g. indoor raised monarchs in FL that were tagged and released in San Antonio with 9 (not 5 as stated in the paper) recovered at the overwintering sites in Mexico. Those rearing conditions (12h day/night, 80F constant temps, with dim light through a small window in the door of the rearing room) fit none of the parameters suggested by experimentation or observation that are thought to lead to either diapause induction or migration.

One might get the impression from the paper that few reared, tagged and released monarchs reach the overwintering sites in Mexico. That is not the case, 33.5% of the recoveries in Mexico from 2004-2015 were of reared, tagged and released monarchs. Wild caught and tagged monarchs have a higher recovery rate 0.9% - vs – 0.5%. There are probably many reasons for this difference.

1. Reared butterflies tend to average smaller – putting them at a glide ratio disadvantage, etc.

2. Taggers tend to tag all monarchs they rear including some that obviously have a low probability of reaching Mexico due to size or condition.

3. The reared monarchs experience a wide range of conditions prior to maturity that may determine whether they are able to become non-reproductive or migrate.

4. Reared monarchs are often released late in the season which reduces the chance of reaching MX [Mexico] and many are reared in the east at latitudes and longitudes with low recovery rates by virtue of distance alone.

5. On the other hand wild caught individuals are in effect a pre-selected group having been on the wing for days or weeks before they were caught and tagged.

The bottom line here is that wild caught and reared monarchs are populations with different morphological and physiological characteristics and therefore different outcomes.

Some who rear/tag and release have figured this out and have increased their recovery rates by rearing monarchs outdoors on living plants with the intention of tagging only the largest and earliest of the monarchs to emerge in late August and early September.

The article gives the impression that many of those who rear, tag and release get their stock from breeders. That’s not the case.

A lot of the rearing appears to be inspired by what could be called “monarch rescue”. It is known and widely reported that 98-99% of all monarch eggs and larvae fail to become adults due to predation, parasitism and other causes. This observation has led many to “save” monarchs by collecting eggs and larvae and rearing them indoors, etc. Aside from enjoying the experience of rearing these interesting butterflies, many justify the practice with the supposition that their efforts are contributing to the population. While there is evidence that some of their efforts result in monarchs reaching MX, the idea that rearing, tagging and releasing monarch will lead to a significant increase in monarch numbers is misguided.

This paper will likely be used to denigrate commercial breeders, However, only one breeder is represented in this study – one who evidently maintains a continuous stock that is quite unique due to origins or inbreeding. There are only a few breeders who maintain monarchs throughout the year. Most start new stocks as early as possible each spring.



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