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Record(?) monarch tag recovery distance set last year from Nova Scotia, Canada

Greetings all,

Last fall, something very cool happened in the monarch world, and it happened without anyone knowing about it. A tagged monarch flew all the way from Nova Scotia, Canada to the overwintering site in central Mexico, a distance of 4,330km or 2,690miles. In this blog entry, I'm going to delve into this event in detail.

The person who tagged this monarch was Mr. Larry Bogan, who lives in a small town in Nova Scotia (very near where I'm originally from, actually). Larry has been actively tagging monarchs on his property for about 10 years, and apparently, this was the first of his tagged monarchs to be recovered in Mexico. Actually, Larry has become very involved with monarch conservation, and has become a resource for folks in that part of the Province. There was a newspaper article written about him in the Provincial paper (link here to see it). He even set up a website documenting his monarch adventures and providing background information on monarchs - I encourage my readers to check it out, particularly to view the pictures of his milkweed field, which is massive - link here.

The monarch in question was tagged last fall (2015) and recovered this past winter at the El Rosario site in Mexico. Larry himself actually didn't even know about this recovery until recently. The following is what Larry wrote about this on the Nova Scotia nature listserve (NatureNS), which is how I learned of his discovery:


"I finally got around to checking the Monarch Watch list of tags found in Mexico for the 2015 season. We have been tagging for several years and have never had a return BUT this year one of our tags was retrieved in El Rosario, Mexico. (The El Rosario Butterfly Preserve is 110 km west Mexico City)

Monarch UGL-881 was released on 29 August 2015 from our home at Brooklyn Corners, Kings County, Nova Scotia along with four other Monarchs. It was a female. Her tag was recovered on 6th of March 2016. We had tagged four of the five Monarchs that day. All total we tagged 50 Monarchs of 75 raised last year. UGL-881 was the ninth Monarch we released last year and the seventh one tagged. Interestingly, our tags ranged from UGL-875 thru UGL-824 and UGL-881 was the only UGL tag found this year. The distance between our home and the El Rosario Reserve is a great circle distance of 4,330 km .

This answers some questions that we have had. Do our Monarchs go all the way to Mexico or head for Florida? Can they make it all the way to Mexico from Nova Scotia? Are we really contributing to the maintenance of the migration of Monarch?

This has encouraged us to continue our yearly efforts in raising Monarch above and beyond what can survive in the wild."


Andy here now - so I find this tag recovery to be very interesting, because from my calculations, this could (and should) represent a record-setting migration. If you've been around the monarch community for a while, you probably know that the current official world record, which is recorded in the Guinness Book of Records, is 'held' by legendary tagger, Don Davis (though I guess the monarch Don tagged is the real 'holder' of the record). Don lives in Ontario, Canada, and has been tagging since the time of the Urquharts (the scientists who first developed monarch tags, and who's efforts led to the discovery of the Mexican overwintering sites - though Lincoln always corrects me - they didn't actually make the discovery). Basically, Don has been tagging forever, and apparently, one of his tagged monarchs was recorded in the Guinness Book of Records. BUT - I've always thought that the exact nature of that record is a little wonky though - you should read it for yourself before reading further, because I'm going to discuss it next - link here to see the record.

Now I love Don and all he does for monarchs, but if you read through that record carefully you can see what I mean about something wonky - the butterfly in question was tagged in Presqu'ile Provincial Park in Ontario (in the fall), then recovered in Houston, TX in the following spring. To calculate the distance this butterfly flew, they (not sure who) assumed the butterfly flew from Presqu'ile Provincial Park, to the overwintering sites in Mexico, then back up to Houston in the spring, for a grand total of 4,635 km (2,880 miles). I can think of two problems with this whole scenario - first, we don't know for sure if this butterfly actually made it to Mexico that fall - it could have traveled only to Houston, stayed for the winter, and then no one found it until the next spring. Second, even if we assume the butterfly actually did make it to Mexico, the record people are really combining two journeys (fall and spring) into one trip to come up with the 4,635km distance.

The reason I'm going through all of this about Don's monarch is that I think Larry's monarch from last year has Don's beat, if you really think about it. Because of where Don is located in Ontario, Don's monarch would have traveled 3,429km (2,131miles) to reach the Mexico sites during that one fall trip in 1989. Meanwhile, Larry's monarch from last year traveled 4,330km (2,690miles) during one fall trip - AND, we know for sure it reached Mexico. Below is a map comparing both journeys, based on the tag locations. You can see what I mean about Don being beat here - sorry, Don.

To be fair, perhaps this is just a matter of semantics - i.e. what do we consider an actual 'migration'? Is it the complete journey all the way south, plus the return journey back - which is the original idea behind Don's record? Or is it the one-way trip, in which case, Larry clearly has Don beat. If it's the latter case (which I'm leaning toward), then what we have here is a new record for a one-way trip for a monarch. At least, this is the longest trip that I know of.

I'm going to leave it here. Take care all.

And by the way - you'll notice that the MonarchScience site is updated now and that there is a new way to post comments via facebook. Unfortunately, when I made these modifications it removed all of the prior comments on the other blog entries. They are still in my system, I just need to figure out how to put them back on the posts...


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The science of monarch butterflies

A blog about monarchs, written by a monarch scientist, for people who love monarchs

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