Galapagos Frigatebird – a new split
But how shall you ID Galapagos Frigatebird when out of range?
In a recent paper from Proceedings of the RSPB, Hailer et al present convincing genetic data (although hard to follow as it is quite technical) that there is no geneflow between Galapagos populations of Magnificent Frigatebird and those on the mainland. This is very much in contrast with other populations that freely intergrade such as the Caribbean and the Pacific populations on both side of the Panama isthmus.
Morphologically the Galapagos populations are significantly larger than other populations of Magnificent Frigatebird, but the paper does not give any more data whether there are other plumage characters that would give away the identity. Banded birds from Galapagos have been found on the South American coast. Probably the new species represents an identification horror for birders. Frigatebirds are hard to ID to species as is.
Sometimes the form on Galapagos has been considered a race, but in most modern literature such as Handbook of the Birds of the World subspecies for Magnificent Frigatebird has not been accepted. To further complicate things the Galapagos form had ssp name magnifcens meaning that the remaining populations of Magnificent Frigatebird would no longer keep its Latin name. It would have to be rothschildi from now on.
Important is that the population of Galapagos Frigatebird is only around 1000 pairs, why it threat status must be reevaluated from the present least concern status. Climate change and natural disasters could easily decimate the population.
I’m going to take this as another ID challenge and reason to pay attention even if I can’t separate these 2 in the field. Our notions of species keep it challenge with all these newly-emerging cryptic species.
The paper makes no comment on splitting the Galapagos population as a subspecies or species. Also, while the morphological differences are statistically significant, they are hardly significant in the lay sense – a few millimeters to centimeters, wide variation relative to the difference, and small sample size. Certainly not useful for field identification.
No it doesn’t! One has to read between the lines. With no geneflow in
hundred of thousands of years as the paper suggest species status does not
seem unprobable. It goes in line with other endemic island populations such
as Ascension Frigatebird in the Atlantic and Christmas Frigatebird in the
Indean Ocean.
Wonder if there is anything on the females/imms can be used for ID.
Gunnar
Gunnar Engblom-Lima, Peru.
Gunnar’s Blog – updated frequently.
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The photo doesn’t show a Magnificent, but a Great Frigatebird!
Tack
I learnt so from one of the list servers… However I don’t have a
photo availble…
WIll try to change it..and search for a photo on the interhet
GUnnar
Gunnar Engblom-Lima, Peru.
Gunnar’s Blog – updated frequently.
https://www.kolibriexpeditions.com/birdingperu/blog/
Follow me on https://www.twitter.com/kolibrix
https://www.facebook.com/Gunnar.Engblom/
Hey Gunnar,
you’re wellcome to use my photo: https://ornit.dk/galleri/photo.php?photo=561&exhibition=22, which shows a ‘Magnificent’ Frigatebird from the Galápagos…
cheers,
Jorge
Jørgen Peter
I finally got around to update the photo on the web-site. Thanks for letting
us use your nice photo.
Jørgen Peter
I finally got around to update the photo on the web-site. Thanks for letting
us use your nice photo.