The earlier pictures were taken on my wee compact Canon ixus 970IS, which involved sneaking up on the butterflies. This can be very frustrating when they fly off, but very rewarding when they don't!

Since 2012 I have been using a Panasonic Lumix FZ150, which allows me to zoom in to the butterflies from a couple of metres away.



Thursday, 17 October 2013

The Monarch - Danaus plexippus

I find the story of the Monarch butterfly amazing. Starting in Mexico in the spring, three generations make their way north up through the USA. Then the fourth generation, or super generation, makes it way all the way back to Mexico to the same bit of woodland its great grandparents left so many months earlier.
It is impressive enough that a butterfly can fly 2-3,000 miles, but how can the information about where to migrate to be transferred between generations like that?

Monarch seen in Lanzarote, 2011 
It is also interesting that this species, which is so strongly migratory in the USA has spread to other corners of the world where it remains sedentary. I don't remember seeing any Monarchs in the USA, but I have been lucky enough to see them in Portugal, Spain, Gibraltar, St Lucia, Lanzarote and Tenerife. They also occur in Mauritius and I believe Australia and New Zealand. In these countries it seems to have discovered the good life and it occurs and breeds there all year around.

Monarch seen in Gibraltar, 2012
This summer when I was in Tenerife I went walking in the area around a village called Masca. I walked along a path in the village where I saw a couple of Monarchs gliding on the thermals below the path. I tried, unsuccessfully, to take some pictures of them floating in the air.


I then noticed that they seemed to be attracted to some orange flowers beside the path. One of them would fly down and feed on them for a while and then fly up and settle in a palm tree. As I watched another Monarch , I realised that it was laying eggs! And then I noticed that there were eggs dotted all over the plant.



Even better, as I was looking for eggs, I suddenly realised that I was staring at a caterpillar and slowly it dawned on me that there were hundreds of them amongst the plants!


What I didn't know then was that the plants were Tropical Milkweed, Asclepias tuberosa.

Tropical Milkweed. When I enlarge the original of this picture I can make out nine caterpillars, one butterfly and several eggs!!
Having found three life stages of the Monarch, I was sure that there must be some chrysalises close by. After searching the cracks and crevices in the dry-stone-wall I eventually found some empty shells hanging in a doorway.


I was surprised not to find any occupied chrysalises, but having seen a few large lizards amongst the Milkweed, I suspected that many of them may have been eaten. I don't know if they would be toxic to the lizards. Just as I was about to give up, I saw one on the underside of a Canna Lily leaf.


I was so delighted to find it!! What a fun half an hour it had been. I have never found all four stages of a butterfly on the same day before.


Masca


Edit:
Thank you very much to Maria Firpi, a fellow blogger from Puerto Rico, who has sent me links to information about the Monarchs that occur in the Caribbean. It seems that in most Caribbean islands the Monarchs belong to a sub-species, Danaus plexippus megalippe. These have slightly different markings and less pointed wings. Maybe more obvious are the markings of the caterpillar, with the Caribbean sub-species having thicker black bands.
It isn't quite as simple as that, as in Puerto Rico and other northern islands the population is supplemented by the nominate form, when it migrates south from mainland USA.
Judging by my pictures of caterpillars seen in Tenerife, it would seem that the populations of Monarchs occurring in Europe originate from the USA migratory Monarchs (which is probably not surprising).
There is a picture of the caterpillar of Danaus plexippus megalippe on Maria's blog here.

16 comments:

  1. Great post Nick! I would have been over the moon had I found all four stages in one afternoon, so can imagine your excitement. It is remarkable how they are able to retrace the flight of their grand parents back to México.I hope that one day we will know how they manage to communicate! We used to see Monarchs every summer here on the farm. They were particularly attracted to a strain of grape called Uva Americana, American Grape, which we have in abundance, and would drink the grape juice. Sadly there have been no sightings of Monarchs for several years now.I miss seeing them!:(

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    1. Sonjia. It's sad that you don't get them there any more. They are a lovely butterfly with such a graceful flight. Maybe you should plant some Milkweed in case they fly in your direction in the future!

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  2. Wow! What a great find Nick! I can fully imagine your delight. I was so sad to not have one cat this year. Raising Monarchs has been a part of my every summer for over twenty five years now. I only saw three Monarch butterflies in the garden during late summer and fall. Great joy to see your post. ;>)

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    1. Thanks Carol. I have read a lot about this year being a bad year for Monarchs in the USA and a lot of speculation about what has caused the decline in numbers. I hope that it is just a temporary blip and that you are joined by clouds of Monarchs next year!

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  3. The last image is awesome. Nick, I was able to photograph the Monarch's pupation; but missed some of the starting points. They pupate very rapidly; and I had very low light. What frustration!

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    1. In P.R. we also get Caribbean Monarchs which do not migrate.

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    2. Thanks Maria. It was a real thrill to see all the different stages of the Monarch. It is an amazing butterfly. I suppose in Puerto Rico the weather is so nice all year around that the Monarchs don't feel the need to migrate. I wonder if the Caribbean Monarchs are now considered to be a separate sub-species from those in mainland USA?

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    3. Someone already noticed a difference in the caterpillars. Our caterpillars have wider black stripes than the American ones; but the butterflies are anatomically the same once they fly; they could be considered, however, to have slightly smaller wing size than the American ones.

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  4. There is actually a D. plexippus megalippe, which fits the description I just told you, but they have also found Danaus plexippus having these same stubbier wings and darker lines; so they are saying these two have interbred whilst migration (as some of them deviate towards Caribbean Islands along the Mexican route). The best article I found is this one, and it's not too much; so I think it's still under investigation: Here's the link again: (I still have trouble putting links in comments)
    Home

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    1. Maria,
      Thank you so much for the information. That article is really interesting. It makes me wonder how the sub species occurred if the nominate form is regularly interbreeding with it. Certainly the article says that more research is required. I wonder if the megalippe subspecies occurs in the southern islands and that Cuba and Puerto Rico have been getting a regular new supply from there, to keep the two different sub-species going. It also makes me wonder if the Monarchs occurring in other parts of the world will one day be considered to be a different subspecies. It seems the more I learn, the more I want to know!

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  6. What a productive day it must have been for you to be able to record all 4 stages. So far I have not been able to discover the egg. Its too tiny! The last photo is amazing in its clarity and composition.

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    1. Thanks Elsie. It was a fantastic day. More than I could have hoped for. It was funny that I didn't spot the eggs for ages, but as soon as I found one I noticed that they were all over the plant. Even more funny, as I was staring at the little eggs I didn't even notice the enormous caterpillars at first!!

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    2. From your photo which show how a single egg can be attached to the leaf surface, I shall look for them more closely. Strangely I've always thought that the eggs would be laid in batches. I must have missed lots of opportunities in spotting them. Thanks for showing the way.

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    3. It was strange that I didn't notice the eggs at first at all, even though I was watching the butterfly for a while on the plant. It was only after I realised that it was laying eggs, and saw where one of the eggs was, that I spotted the other eggs. Once I had seen one, I realised they were everywhere. They all seemed to be laid in the middle of the leaves on the upper surface. Yes, you generally expect the eggs to be laid under a leaf in a big cluster. I wonder if the eggs are toxic of bad-tasting.

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