Laysan Albatross - band returns/biology/population

Alvaro Jaramillo
 

Hello all,

     This season we have had five encounters with Laysan Albatross off Half Moon Bay, and Bodega Bay. We were able to get color band details from three of the birds. One of those was a bird seen off Half Moon Bay that was seen the following day off Bodega Bay, and we were able to identify it as the same individual based on distinctive plumage patterns. We have been in contact with the folks working on Laysan Albatross in Mexico, specifically Julio Montoya and Yuliana Bedolla. They confirmed that all of our birds were banded on Guadalupe Island, Mexico as part of their project. They confirmed that the birds were all juveniles, as we had identified them in the field. Interestingly, there are four colonies in the Guadalupe Island archipelago, two on the main island, and two on islets adjacent to Guadalupe. ALL of our birds were specifically from “Isla Zapato” which is the islet to the S of Guadalupe. Isla Zapato had over 300 nests in 2013, and that number has grown. The Guadalupe Island population of Laysan is recent, with the first nests detected there in 1983. Growth has been steady in the colony and now hundreds of nests are found there. Growth in the colonies cannot be explained solely by the fledging rates, suggesting that some birds from Hawaii are being recruited to the local population. The colony growth rate is perhaps the highest for any albatross colony known. So we should expect that Laysan Albatross will become more common on pelagic trips in the coming years. Certainly Half Moon Bay has been a great port for finding this species, and we already knew that Bodega/Cordell Bank is an albatross hotspot.

              It is interesting that all of our birds were juveniles, but this may be the norm. Steve Howell commented to me that most of the Laysans on pelagics at this time of year are juveniles. Band data from the past has also clarified that most CA Laysans are from the Mexican, not Hawaiian population (at least in recent years of course). Our birds hatched in February, they were banded in May, and fledged in June so they had only been on the wing for a few months. They won’t return to the colony until they are 6-7 years old, so these guys may not be seen again for a few years. Tracked adult Guadalupe Laysan Albatross during the breeding season mainly forage off Baja California, with some movement up to central CA at or near the continental shelf edge, with extensive wandering in offshore areas as well. So we are well within the normal range of Guadalupe Laysan Albatrosses. Another thing we have learned is that underwing pattern is quite variable in juveniles and with good photos it may be possible to plumage match individuals. Or it can be used to identify if multiple observations of a Laysan on a pelagic trip pertains to one or more individuals, on the 25th we did see another individual with a very pale underwing confirming that two different Laysan had been seen that day.

     

Photos of the birds are here:

Aug 17, 19 off Half Moon Bay

https://ebird.org/view/checklist/S59076654

Aug 24, 19 off Half Moon Bay

https://ebird.org/view/checklist/S59282454

Aug 25, 19 off Bodega Bay

https://ebird.org/view/checklist/S59260963

Sept 2, 19 Half Moon Bay

https://ebird.org/view/checklist/S59470843

 

If you are keen on trying to see a Laysan Albatross this Saturday we are going out of Half Moon Bay into good water for them. Note that we now offer a discounted youth price for birders 19 and under. Our boats have seen a lot of youthful energy recently, and it is nice to see!

http://alvarosadventures.com/boat-trips/pelagics/

 

good birding,

Alvaro

 

Alvaro Jaramillo

alvaro@...

www.alvarosadventures.com

 


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