TicoTyler
Tyler Wenzel
I wanted to see if anyone here could help clarify a bit of a confusing situation I have with the Galapagos Petrel. For context, I photographed one on a pelagic tour out of Cabuya, Costa Rica back in January. (eBird report) I believed it was the northernmost report for this species and have been working on writing up a note about the observation for Costa Rica's Journal of Ornithology (Zeledonia). However, as I've been researching the topic for the note, I've run across a series of seemingly contradictory and confusing data points.
The Birds of Central America has an extensive bibliography of historical reports that I consulted. It lists a handful off the coast of Panamá and Costa Rica, including the first photographic report by Jim Zook, who was with me on this trip, back in 2009. However, I've seen some places list its range as extending farther north than Costa Rica. For example, Birdlife's map shows it going as far north as Central Mexico. And Avibase includes it on the checklist for Guatemala. However, after consulting with some contacts in northern Central America who are quite active in pelagic birding there and none of them are aware of any reports north of Costa Rica.
A paper published in The Condor includes population estimates of several pelagic species based on 22 cruises between 1980 - 1994 and its map seems to indicate sightings between 10 and 15 degrees North and 95 - 100 degrees West (our sighting was at 9 17' N 85 00' W). However, no specific data is provided, and some people I've shared it with seem to think this is a projection rather than based on actual sightings in that region. But it seems to me like it is based on actual observations.
Adding to this confusion is a report from the Advisory Committee of the ACAP that indicated that: "However, according to Proaño (et al. in prep.), based on satellite and geolocation data, during the non-breeding season, the marine habitat widely extends from the South coasts of Central America (2º NE of the Archipelago) and does not reach Mexico, as mentioned by Birdlife (2011), and through the South of Chile (-14º SE)." I have been unable to locate the publication so it may not have been published.
Does anyone have any thoughts?
The Birds of Central America has an extensive bibliography of historical reports that I consulted. It lists a handful off the coast of Panamá and Costa Rica, including the first photographic report by Jim Zook, who was with me on this trip, back in 2009. However, I've seen some places list its range as extending farther north than Costa Rica. For example, Birdlife's map shows it going as far north as Central Mexico. And Avibase includes it on the checklist for Guatemala. However, after consulting with some contacts in northern Central America who are quite active in pelagic birding there and none of them are aware of any reports north of Costa Rica.
A paper published in The Condor includes population estimates of several pelagic species based on 22 cruises between 1980 - 1994 and its map seems to indicate sightings between 10 and 15 degrees North and 95 - 100 degrees West (our sighting was at 9 17' N 85 00' W). However, no specific data is provided, and some people I've shared it with seem to think this is a projection rather than based on actual sightings in that region. But it seems to me like it is based on actual observations.
Adding to this confusion is a report from the Advisory Committee of the ACAP that indicated that: "However, according to Proaño (et al. in prep.), based on satellite and geolocation data, during the non-breeding season, the marine habitat widely extends from the South coasts of Central America (2º NE of the Archipelago) and does not reach Mexico, as mentioned by Birdlife (2011), and through the South of Chile (-14º SE)." I have been unable to locate the publication so it may not have been published.
Does anyone have any thoughts?
