20 September, 2013

Island Girl Begins Her Next Southbound Migration

Welcome back to the Southern Cross Peregrine Project everyone. Here we go again, following the migration of an adult female peregrine for the tenth time!

Don McCall called in this morning with the news that Island Girl had departed Baffin Island yesterday (19 September 2013). He just got the signals this morning.

She has now finished her breeding season on Baffin and is heading back south to Chile.

We had expected her to leave Baffin Island at any time. Last year, she left on 25 September, her latest departure date so far. These dates have now ranged from 21, 22, 20 to 25 September respectively. This year, she left 24 hours earlier but still within a six day period. Always something different with her...

She is engaged in her fifth full migration since we tagged her back in 2008 with a GPS, solar powered transmitter. This remarkable unit has been operating for almost five years now. Let's hope it lasts all the way back to Chile once again. Pretty sure that this is a record for both distance and longevity for a satellite tagged peregrine, so a special thanks is due to Paul Howey and Microwave Telemetry crew too.

Team member Kathryn Gunther first caught Island Girl in Chile as a full adult peregrine in 2008. However, we did not put on her transmitter until the following year on 15 March 2009 when Kathy caught her a second time. Nice job Kathy...woo...hooo!

Since Island Girl was fully adult in March 2008, she is now a minimum of seven years old. However, since she had no apparent juvenile feathers at that time (i.e. she was fully molted, no brown feathers anywhere), I think it is more likely that she is at least eight years old.

Keep in mind that when Kathy first caught Island Girl in 2008, this falcon had already completed at least two previous full migrations without a radio. She had to have made her first trip to Chile as a juvenile and the second migration in her first adult plumage.

Thirteen migrations of approximately 9,000 miles from Baffin Island to Chile and back add up to over 117,000 miles just during her migrations alone, minimum. And that is considering a relatively straight flight path, dot to dot, not taking into account all of the ancillary flights and detours she takes during her typical migration day, like hunting flights, searching for roosts, etc.

I figure that she has probably flown well over 150,000 miles (240,000 km) during these migrations alone. 

Obviously, she also flies an undetermined number of additional miles during the breeding season (June, July, August) in the arctic and wintering in Chile (December, January, February and March). 

No one has any idea of how far they fly during those periods, but I am thinking that 150,000 miles is probably a very low estimate for her total lifetime miles.

In South America, Island Girl used to perch regularly on a tree stump located on a small island near the mouth of the Rio Mataquito in coastal Chile. Since Kathy caught her, she also had the honor of naming her. That is where the name, "Island Girl" came from originally.

There you have it.

Extraordinary birds.

Good luck this season,

PS Most of you probably already know this but I just read in Thor Hanson's excellent book Feathers: The Evolution of a Natural Miracle (2011) that on 3 August 1971, Apollo 15 astronaut, David Scott, carried a peregrine feather to the moon. They used it for an experiment to honor Galileo (dropping objects in a vacuum). This feather, from the Air Force Academy mascot, remains there still, the only bird feather known to be on the moon. And, incidentally, the name of their lunar module was "Falcon".

2 comments:

Alastair said...

Great data - the best there is for an individual peregrine. What will we learn this time I wonder?

Allen Gardner said...

It is still very hard to comprehend this incredible adventure. Time is always and forever....to be present during this segment of "always and forever" is a very humbling experience
Thank you again Bud. Seeing these secrets of life being unraveled before our very eyes is the gift that keeps on giving. Just glad I'm here to see it!

Allen Gardner