Imagine my pleasant surprise when the Science section of the NY Times had an
article about Ivory-Bills being found in Florida (hey my home state!). Apparently
this putative population (when and if confirmed: about 100 miles due west of
Tallahassee) is quite a bit larger than the unconfirmed one in Arkansas from two
years ago:
I may just go out there this fall then one weekend; I have an odd way of attracting
odd wildlife to me (yes call me insane I’ve heard it all before). Wow.
Ah, but Arkansas says tythey’ve got 'em, too. Here, birdie, birdie, birdie
I think your thread title should be appended " . . . in the U.S.," because it’s my understanding that there are still IBWs in Cuba. So this Florida sighting is not too shocking, no?
Any possibility that even last year’s still-controversial sighting was an incursion from Cuba? No way to know that, of course, but has anyone raised that possibility?
Or is the Cuban population likely to be genetically different? I mean, to a significant enough degree that we can say they “don’t count”?
I’m just typing aloud . . .
(As a birdwatching kid in Texas in the sixties–Painted Buntings and Scissortail Flycatchers in my backyard!–the IBW was very much a mythological bird for me; it was my first grasp of the word “extinct.” It would thrill me to literal tears to see a live one in the flesh. And I actually did shed an angry tear when a doofus I was camping with in Northern Ontario shot and killed a Pileated Woodpecker just for giggles. Too close to my mythology.)
They aren’t migratory, and wouldn’t be able to cross the Florida straits (a hurricane may have
blown some US IBW’s to Cuba way back in prehistory). I think several Cuban searches in
recent years came up empty. If they are still in the US, they are remnants of the former US
population, managing to wait out the habitat loss (in small pockets) in the first 2/3rds of this
century.
This seems to have more of a factual answer (even if it is still uncertain) than a need for debate.
Off to GQ.
[ /Moderating ]
Yes, this is good news! I was in a meeting with the Secretary of the Florida Dept. of Environmental Protection yesterday when they got the news from Auburn. They’ve found them in the Choctawhatchee River Basin, and said they’ve been sighted over 40 times.
Unless there were several hundred hiding out, this just postones the extinction. Genetic drift and other problems (deterministic and stochastic factors) usually dooms small populations.
The reports from Arkansas are better confirmed than this one, since there actually are videos, although these are not accepted by everyone. As someone who regularly evaluates sight reports of rare species (I am the chair of the Panama Records Committee), I would regard the observations from both areas to be acceptable according to the standards by which such records are usually evaluated.
I believe the observations from both areas, which include detailed records by experienced observers, as well as recordings and other evidence, constitute evidence “beyond a reasonable doubt.” However, because the species has been believed to be extinct, some ornithologists are demanding evidence “beyond any doubt.” This can come only from a clear photograph, a fresh feather, or genetic evidence (e.g. from droppings).
I also regard a sight record from Louisiana some years ago to be credible. There have been other records from other areas over the years, but they have always been ignored or dismissed simply because the species has been regarded as extinct. It may well be that there are other pockets where the species may persist. Failure to detect a population in the areas of the Arkansas and Louisiana sightings may mean that those birds were wanderers from some undiscovered area where an actual population persists.
Not necessarily. The Chatham Island Black Robin in New Zealand was brought back from the brink of extinction, having been reduced to five individuals, of which only one was a breeding female. The Cheetah went through an extreme population bottleneck several thousands of years ago, but rebounded to become an extremely widespread and successful species despite its extraordinarily low genetic diversity. Certainly a small population presents problems, but it is very far from being a death sentence.
Well, like I said “usually”
http://scholar.google.com/scholar?num=100&hl=en&lr=&q=cache:tvng8ovdDOEJ:www.ace-eco.org/vol1/iss1/art6/ACE-ECO-2005-40.pdf+genetic+diversity+ivory-billed
"Second, the species at best exists as a critically small population. It will bedifficult to make the case that a viable population can be established without undermining the smallpopulation paradigm that underlies conservation strategies for many other species. "
http://links.jstor.org/sici?sici=0006-3568(197412)24%3A12<715%3APONDTP>2.0.CO%3B2-6#abstract
“Extinction coefficients are estimated from the rates of disappearance of bird species from islands severed from the Neotropical mainland at the close of the Pleistocene. These coefficients accurately predict the loss of species from Barro Colorado Island, Panama, over a recent 50-year period. Prescriptions are given for the preservation of six categories of extinction prone species.”
That wasn’t the main part of your post I was responding to. You also said:
This is quite incorrect. Positive conservation action can, and has, brought back species with extremely small populations. Even if there are only a few pairs of Ivorybills remaining, I wouldn’t write them off.
Colibri, can you comment on the likelihood of bird species in general evading detection? To put this another way, if the IBW has evaded detection for decades, is it possible there are other bird species in North America that have similarly evaded detection? I’m sort of asking you to prove a negative, but I figure you can give an informed opinion based on what you know of the history of species discovery.
It depends very much on the kind of bird it is and its general ecology. The Ivorybill could have escaped detection because, although large, it lived at low densities in habitats difficult for humans to access, such as old-growth swamps. In other parts of the world, several deep forest species have been rediscovered after many decades without any confirmed records. The Solitary Eagle has only been seen in Panama about 8 times in the past 130 years (one of the records is mine), even though there is pretty certainly a resident population. I have seen Harpy and Crested Eagles, and a number of other rare forest species, only a couple of times each in decades of birding in areas where they are well known to occur.
Regarding the other North American species thought to be extinct:
Passenger Pigeon: No chance. It is believed that part of the reason it became extinct is that it required very high density colonies in order to breed successfully. Individuals would likely roam over wide areas, and fly in the open, so it could not have escaped detection. Some resemblence to Mourning Dove, but pretty easy to identify.
Carolina Parakeet. Extremely unlikely. Like the Passenger Pigeon, a flocking species that occurred in open areas. Easy to identify.
Heath Hen. (Actually a subspecies of Greater Prairie Chicken). No chance. Occurred in relatively restricted open habitats. Easy to identify.
Labrador Duck. Exteremely unlikely. Migratory species found in open habitats, and easy to identify.
Eskimo Curlew. Possible. Nested in remote tundra areas, and migrated over vast differences. Difficult to identify, or to pick out among large flocks of similar species.
Bachman’s Warbler. Possible. Small and fairly inconspicuous. A very small population could easily escape detection, both in the US and in its migratory range, especially since they prefer a habitat difficult to survey (canebrakes and marshes). The wintering area of Kirtland’s Warbler in the Bahamas, the next rarest North American warbler, was only recently discovered.
I am not Colibri- but there aren’t a lot on North American non-insular bird species that have gone extinct. (In fact according to Jared Diamond, there have been 171 species & sub-species of bids that went extinct since 1600. 155 of these were from islands!)
The “Big two” are the Passenger Pigeon and the Carolina Parakeet. Both of these traveled in huge flocks, and went extinct more or less all at once- no “dwindling”. It is thus supposed that these species NEEDed crowds to survive. Thus, any hope for these is very small, in fact I’ll say 0.
The Labrador Duck, *Camptorhynchus labradorius * , went extinct around 1878 under mysterious circumstances. It wasn’t heavily hunted. Since sea ducks are large and aren’t shy, this bird is likely gone forever also.
The Heath Hen (Tympanuchus cupido cupido) was a subspecies of the Greater Prairie Chicken, Tympanuchus cupido- which is still around, though with much reduced habitat. It’s possible, I guess. :dubious: Personally, I’d be really surpised.
We still don’t know if Bachman’s Warbler is extinct, or just really rare. This is a good species to try and find, IMHO.
The Eskimo Curlew is/was a medium-sized New World shorebird, whose flocks once numbered in the millions. It is believed to be extinct. Here is another bird where there is a decent (but very small) chance at finding one.
The dusky seaside sparrow, Ammodramus maritimus nigrescens is a subspecies, declared extinct as of 1990. There’s still hope here too. Not much, though.
Interesting- a simulpost with nigh complete agreement!
I agree- want to find an “extinct” species? Go for Bachman’s Warbler.
Or, I suppose, if you like larger game, how about Bigfoot?
IMO, extremely unlikely. There is a tiny possibility a very small population could exist in a very remote area; however, all the supposed sightings near populated areas are surely bogus. In this case we also have the probability that physical evidence, such as bones, skin, etc, should have been found by now, besides just footprints, which are very easy to hoax.
I should make it clear that my previous post refers to the probability that a population could have escaped detection if it did exist, given its supposed characteristics. There are many other arguments against the possibility that the species could exist at all.
The only mammal on the cryptozoology pages I have any hope for is the Thylacine. aka the Tasmanian Wolf or Tas. Tiger.
I am not sure what to think about Ursus arctos piscator, (more commonly known as Bergman’s bear).
http://en.wikipedia.org/wiki/Bergman’s_Bear
The problem with subspecies is that they might never have existed at all. Some of the very rare subspecies may have simply been populations or just a varient, as with animals that have only been seen a few times, we really do not know how/if/when they interbreed as perhaps their breeding habits have never been researched.
*Members of one subspecies differ morphologically from members of other subspecies of the species. Subspecies are defined in relation to species. It is not possible to understand the concept of a subspecies without first grasping what a species is. In the context of large living organisms like trees, flowers, birds, fish and humans, a species can be defined as a distinct and recognisable group that satisfies two conditions:
Members of the group are reliably distinguishable from members of other groups. The distinction can be made in any of a wide number of ways, such as: differently shaped leaves, a different number of primary wing feathers, a particular ritual breeding behaviour, relative size of certain bones, different DNA sequences, and so on. There is no set minimum ‘amount of difference’: the only criterion is that the difference be reliably discernable. In practice, however, very small differences tend to be ignored.
The flow of genetic material between the group and other groups is small and can be expected to remain so because even if the two groups were to be placed together they would not interbreed to any great extent.
Note the key qualifier above: to be regarded as different groups rather than as a single varied group, the difference must be distinct, not simply a matter of continuously varying degree. If, for example, the population in question is a type of frog and the distinction between two groups is that individuals living upstream are generally white, while those found in the lowlands are black, then they are classified as different groups if the frogs in the intermediate area tend to be either black or white, but a single, varied group if the intermediate population becomes gradually darker as one moves downstream.
This is not an arbitrary condition. A gradual change, called a cline, is clear evidence of substantial gene flow between two populations. A sharp boundary between black and white, or a relatively small and stable hybrid zone, on the other hand, shows that the two populations do not interbreed to any great extent and are indeed separate species. Their classification as separate species or as subspecies, however, depends on why they do not interbreed.
If the two groups do not interbreed because of something intrinsic to their genetic make-up (perhaps black frogs do not find white frogs sexually attractive, or they breed at different times of year) then they are different species.
If, on the other hand, the two groups would interbreed freely provided only that some external barrier was removed (perhaps there is a waterfall too high for frogs to scale, or the populations are far distant from one another) then they are subspecies.
Note that the distinction between a species and a subspecies depends only on the likelihood that (absent external barriers) the two populations would merge back into a single, genetically unified population. It has nothing to do with ‘how different’ the two groups appear to be to the human observer.
As knowledge of a particular group increases, its categorisation may need to be re-assessed. The Rock Pipit was formerly classed as a subspecies of Water Pipit, but is now recognised to be a full species. For an example of a subspecies, see Pied Wagtail.*
I live in Vernon, Florida on Holmes Creek, which is part of the Choctawhatchee River Basin (I’m not far up the creek from the Choctawhatchee River). There was a dead tree on my property (before Hurricane Ivan toppled it) upon which I once spotted a very large woodpecker. I can’t say for sure if it was an Ivory-billed woodpecker or a pileated woodpecker, but that bird was enormous and it was making the Ivory-billed’s characteristic double-tap knock on the tree.
I haven’t seen it since the tree fell, but I have definitely heard the double-tap on occasion coming from the cypress slough on the other side of the creek.
So, in answer to the OP, definitely maybe.