Thursday, April 06, 2006

ENV: Texas Coastal Gannets

Posted to TexBirds today:

Jon McIntyre's post reminded me of a phenomenon i once witnessed that i think should be watched for -- it's probably annual, but i don't think the data exists to prove that -- perhaps John Arvin (especially from his offshore platform days) or Ted Eubanks (from this same experience or his book) could elaborate.

one day while birding Galveston Island and Bolivar Peninsula i was looking for migrant scoters and gannets for a day list when i started noticing numbers of gannets well offshore but clearly visible by scope, apparently slowly moving northeastward while feeding. intrigued i spent the rest of the day scoping them. as memory serves (no way i can find notes right now) i ended up with an estimate in the 750 range (this is likely documented in The Spoonbill, and maybe Ted has details on date etc from his new book). i'm guessing it was in March or mid April and probably in 1981 or 1982. and i believe i was alone, but it's quite possible someone was with me (sorry, this memory thing is tricky, especially after a couple thousand birding trips).

anyway, i ran across Ted late in the day, and as i recall i couldn't wait to tell him about the Gannets, when he came up to me wide-eyed and said "have you seen the gannets?!" he had similar numbers.

i vaguely remember another TexBirds post about really large numbers of gannets but in a search i was unable to locate it. most of the reports i did find of double-digit gannets, usually in the 10-30 range, were in March, but there were some also into mid-april.

so, while you're out birding the coast, you might consider stopping every once in a while and scoping way out in the gulf. gannets are pretty obvious even at distance. -- tony gallucci

I think this may have been the post i remember seeing . . .

Posted in response to TexBirds:

Hi Tony and Texbirders,
Last year on Feb 5th I had an amazing number of N. Gannets offshore North Padre Island. (See original post below.) I also remember that after making that post the Gannets continued to stream past and my notes indicated I counted over 100 Gannets in less then 2 hours. I didn't have any longer to count them so the total number migrating north could have been much larger. -- Gary Hodne, North Padre Island / The Woodlands

Original Post from Texbirds on February 5, 2005
Hi Texbirders, Right now (8:30-9:30am) there are a large number of Northern Gannets moving north past my deck overlooking the Gulf on North Padre Island near the Packery Channel. In the past hour I have counted about 60+ streaming by. Almost all are juvenile birds but I did see one full adult plumaged bird. Some have also been sitting on the water for a while but I haven't seen any diving although some circle around a bit. Points along the coast further north may want to keep an eye out. This is the largest number of Northern Gannets I have seen in Texas at one time. -- Regards, Gary Hodne, N. Padre Island, Corpus Christi, and the Woodlands, TX

And the other responses:

Tony, I am not certain that this movement occurs annually, or at least drifts close enough to shore to be detected by birders. The date you are referencing is 22 March 1982, when you and I (in separate parties) found hundreds along Bolivar Peninsula. A similar movement occurred 26 March 1989, also along Bolivar. Accompanying these gannets were good numbers of jaegers as well. -- Ted Eubanks, Galveston

Tony, I observed many dozens of gannets with the naked eye and binoculars very close to shore on February 23, 2002. I was on the surfside jetty and many of the gannets were between the shore and the end the jetty. There were both adults and juveniles and they were moving northeast, stopping now and again to feed. I didn't scope out to sea at all, but at any one moment I could see a dozen or more gannets with the naked eye. They appeared to be moving in groups, as well. I would see a group and a few minutes later another group would go by. I have never seen that many gannets on the Texas coast before, usually it is just sporadic single birds. I didn't count on this day, but I'm sure I could have tallied triple digits of gannets if I watched for more than the 20 minutes I was there and had looked a little further out to sea. I wondered if it was a mass migration, although late February seems early. I have also never seen gannets so close to shore in Texas. -- Chris Harrison, San Antonio

I mentioned to Chris Harrison that i had vaguely remembered a similar thing from Florida or the northern Gulf that was published in a journal. i was unable to locate it in a search at SORA, but did find some things that are related, including one by our own Terry Maxwell. Here are the titles linked to pdfs of the articles for those who are interested. -- tony gallucci

POPULATION SIZE AND STATUS OF THE NORTHERN GANNET SULA BASSANUS IN NORTH AMERICA, 1984

GANNETS IN NORTH AMERICA: PRESENT NUMBERS AND RECENT POPULATION CHANGES

SPRING MIGRATION OF THE GANNET IN FLORIDA WATERS

SPRING MIGRATION OF THE GANNET IN SOUTHEAST FLORIDA

Have seen these large flights along the coast between High Island and Crystal Beach many times. Almost always during the last few days of March and the first week in April. They fly right along the "blue water-brown water" line. When the line (usually scope distance off) is in close to shore, you can pick them up, easily, with binocs. Not just Gannets, but the occasional Brown Booby, also. Rollover Pass is a good place to search. -- David T. Dauphin

I haven't actually witnessed the large coastwise movements of Northern Gannets seen by others. When I spent the spring of '98 80 miles offshore on an oil platform Northern Gannets were fairly common until about mid April at which time they disappeared and I never saw another all season. Unlike my experience with gannets from the beach, the vast majority of individuals around the platform were adults. In fact I only saw the all brown first year birds once or twice. There may be some habitat segregation along age lines of wintering gannets if these differences are typical. -- John C. Arvin

On the morning of March 9th, 2005, I drove the beach at Surfside from the first public access to very close to San Luis Pass. During that drive I estimated that I saw a minimum of 350 to 400 Northern Gannets. These were not scoped birds, but ones that were near enough to see with the naked eye. There would be a bird or two show up right outside the surf line, and start diving, within a few minutes there would be 70 to a hundred birds there. The numbers estimate is probably very low, as I drove the beach both ways, and did not count the ones I saw on the return trip, when I saw the same thing. I remember thinking that the water they were diving into could not have been very deep. -- Charlie Brower

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