Jack Bowling wrote:

>** Dennis Paulson wrote -
>>
>> I thought readily apparent El Nino effects were limited to oceanic
>> creatures such as fish and birds. They are affected by changes in oceanic
>> food resources brought about by temperature changes and are big enough to
>> be noticed. One might consider a Brown Booby a likely vagrant from these
>> changes, although I hadn't noticed an increase in booby records in
>> California recently. Has there been a booby incursion farther south? And
>> how far are birds likely to vagrate (to coin a new verb) under these
>> conditions? Brown Pelicans, Heermann's Gulls, and Elegant Terns have always
>> flown north during their nonbreeding season, and the terns are merely
>> following a normal pattern but flying farther when they come up our way,
>> perhaps because they don't find enough to eat in California.
>
>A narrow view of things, Dennis. I am sure the floods in Africa, the drought in
>Australia, and the smog from forest fires in Indonesia are all "readily
>apparent
>El Nino effects" to the inhabitants of the affected areas, both human and
>otherwise. As for the vagrancy of Elegant Terns, etc., it is not the fact that
>their is an annual vagrancy, but the statistically significant increase in
>numbers of vagrants during an El Nino. I believe Mike Patterson has already
>crunched some numbers for his section of Oregon.

Sorry, I shouldn't be in such a hurry. My sentence should have read
"Effects that we can perceive *in this region* having to do with
macroscopic animals and apparently attributable to El Nino seem limited to
oceanic fish and birds." Notwithstanding hurricanes on the W coast of North
America, the changes in our weather due to El Nino are not outside the norm
for this particular region. I do indeed know about these other effects, but
my comments were intended to refer to the pattern of bird occurrences under
discussion.

Of course Elegant Terns increase during El Ninos. That's what I said. Their
normal postbreeding migration is to move north along the California coast
in summer, then back to Baja in fall. They are just going farther in El
Nino years.

>> We've had some pretty severe El Nino years in the past decades without any
>> apparent vagrancy, right?
>
>I would imagine so due to the fact that one El Nino is always different in some
>respect than another. There is just too much chaos in the system to expect
>that the same exact conditions would ever repeat themselves.

Yes, but the effects are, in fact, rather predictable in the Northeast
Pacific--rising water temperatures and according crashes in some of the
food webs. I haven't read or heard of any other (again) readily apparent
effects having to do with wildlife.

>> Am. Oystercatchers might be affected by changes in intertidal food
>> resources, but I had not heard of El Nino causing this to occur, and this
>> species has remained rare in California even with the increase in birders
>> there over the years. Nevertheless, I see it as a real possibility. Some of
>> you may not know about the record from Idaho in April 1981, a really
>> shocking occurrence. It would be great if the Marysville bird could be
>> relocated and photographed to be sure of the subspecific (and even the
>> specific) identification. I don't suppose the observer thought of
>> distinguishing between American and Eurasian as this surprising bird flew
>> past.
>>
>> Of course, caracaras and hummingbirds wouldn't be affected by marine food
>> resources.
>
>Unless there were Caracaras which subsisted on seaside carrion...

Are you writing this tongue in cheek? There's a lot of seabird (and fish?)
mortality during El Nino years, so I would think a caracara would do just
fine staying where it was.

>> El Nino, of courses, also changes weather on a broad scale. Is there
>> anything about weather patterns in, say, northern Mexico, that would
>> increase the likelihood of vagrancy?
>
>Well, "Nora", for one, brought 300 mm of rain in 24 hours to the southern Baja
>when it crossed. The return period for such an occurrence is likely at least
>100 years. And many west coastal sections of Mexico were inundated by floods
>last summer. Perhaps a historical food source of either the hummer or caracaras
>was affected.

But surely not enough to make them move >1,000 kilometers! I can't believe
the first hummingbird feeder to be encountered by a moving XAHU would be in
BC! And caracaras eat just about anything.

So, yes, a caracara or a Xantus' hummer might migrate up here, but I can't
for the life of me see how this could be tied in to The Child.

>> Parenthetically, with the abundance of Caribbean hurricanes, and the high
>> frequency of Caribbean and Atlantic seabirds being seen up and down the
>> Atlantic coast and even inland (see the last Field Notes), I don't recall
>> reading about a single West Indian *land bird* turning up north of Florida
>> on the Atlantic coast. The Bahamas are full of land birds that don't occur
>> in the U. S. Does anyone know of such records? Perhaps this should be our
>> clue?
>
>Hurricanes are usually a boreal late summer and fall occurrence. At that
>season,
>most boreal-breeding migrants are on their way south, not north. In fact, in
>El Nino years the Atlantic hurricane mechanism is suppressed while the east
>Pacific basin enjoys an increase in hurricanes - exactly what happened in the
>summer and fall of 1997. I take it you mean the Field Notes edition which
>summarizes the fall of 1996 season (spring 1997 edition).

I'm not talking at all about boreal-breeding migrants, but resident endemic
West Indian birds, none of which--to my knowledge--has *ever* been reported
north of Florida, right next to the Bahamas. With the number of West Indian
land bird species that might be picked up by a hurricane, and there have
been many, and reported by the birding community because they weren't
species normally seen in the area, I think that's pretty strong evidence
against hurricanes transporting land birds *away from where they are
resident.* (emphasis intended). Of course they carry land birds that are
migrating over water at the time; they've got no choice. You said yourself
that land birds ground purposely during heavy weather." So how did the
caracara and hummer (not to mention oystercatcher, which also wouldn't be
flying out over the water somewhere when a hurricane came) get here?

Sorry I'm not reading the comments of others, too, but I appreciate Jack's
forwarding his message to me. Let me know if you're tired of my popping in
unannounced from time to time!

Dennis

Dennis Paulson, Director phone 253-756-3798
Slater Museum of Natural History fax 253-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416
http://www.ups.edu/biology/museum/museum.html