Thursday, March 20, 2008

Ivory-billed's little brother

I think everyone wants the Ivory-billed Woodpeckers to exist, in spite of growing suspicions that the entire, I don't want to call it debacle, but.., was perhaps based on faulty evidence. Certainly no indisputable and compelling concrete evidence has yet been produced, and that's what it's going to take to convince the non-faith-based ornithological community.

My experiences with the tropical Pale-billed Woodpecker in recent years have caused me to wonder about our Ivory-billed Woodpecker situation all the more. Pale-billed is a big woodpecker in the genus Campephilus, same genus as the I-B. And just as the I-B must have been, Pale-billed Woodpeckers are large, extraordinarily showy, and often quite obvious birds.

In the past three years, in Costa Rica and Guatemala, I've seen many Pale-billeds and heard many more. That's the key - heard - that makes me more doubtful about the continued existence of I-B's in our southern swamps. The woodpeckers in the genus Campephilus, like I-B and Pale-billed, make an astonishing loud double rap knock as a way of communicating. These knocks, made by smartly rapping a tree twice in rapid succession, carries a very far distance, especially if the bird telegraphs it from a suitably acoustic substrate. There have been times where I have heard Pale-billeds do this quite clearly, and they were probably a good quarter-mile off, maybe further. The raps carry very well through the forest, are often repeated with some frequency, and are hard to miss. We've found Pale-billeds on a number of occasions by tracing the knocks to their source.

It's hard to imagine that the I-B lost the ability to double rap. If not, someone should be hearing this non-vocal call, and making good recordings. And probably finding the woodpeckers. Most of the old literature I've seen on I-B describes them as rather tame and obvious, and prone to producing double-raps, and that describes the behavior of their close relative the Pale-billed Woodpecker to a T.


Pale-billed Woodpecker, Campephilus guatemalensis, seen in the Peten region of Guatemala, March 2008. Our group of about 25-30 people was able to approach the bird quite closely, and those with larger lens got much more stunning photos. I think we could have gone much closer without causing undue disturbance, but didn't want to risk spooking the woodpecker. Besides, through the scopes we had absolutely killer looks. These big woodpeckers are real show-stoppers!


Cropped in closer. This is the male, the female has the front of the crest black. Look carefully; he is wrestling with a massive grub, probably of some sort of beetle. It is every bit as big as one of the mandibles of the woodpecker's bill, and he spent several minutes trying to choke this thing down. The Ivory-billed Woodpecker subsisted primarily on similar large beetle larvae.

A bit later, the female came down the tree to join its mate. We probably got to watch these magnificent birds for ten minutes or so, finally leaving them be and still working this tree. I will admit these photos are not fantastic, especially taken as they were in the very early morning hours in a foggy and damp Guatemalan jungle. If only someone could produce their own poor photos of the ever-elusive Ivory-billeds...

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5 comments:

Anonymous said...

Where do we start?

The Ivory-billed or putative Ivory-billeds recently reported in the US (AR, FL, LA and SC) have often been heard knocking and double knocking with scores of these events recorded. Some of these knocks were recorded in immediate areas where kents also occurred with kents recorded. Some of these sounds were investigated and actual sightings were made with field notes.

SK, DKs, kents and sightings were not randomly distributed in the available habitat indicating a common animal......they were found to statistically occur in correlation to one another in the same few square miles of habitat and not in others, indicating a rarer animal.

Links below TO A FRACTION of the material and reports out there but appartently all completly misssed.

Its curious in your piece that no parallel was drawn of what would have happened to your Campephilus in the years <1 AD to >1950. If these birds were approached closely in the US as you did on your vacation in the above 2,000 years they would have been attacked, terrified and/or killed. Indians, settlers, trophy hunters, subsistence hunters, curiosity seekers, taxidermists, museum hunters , etc., killed thousands to tens of thousands of IBWO.

What would happen in CR to the frequency of PBWO sightings if your group alone had shot at all those birds with guns rather than cameras? Would even the next group get as many PBWO sightings?

Well multiply that phenomenon's affect over decades/centuries and see what you have left behaviorally produced by selection on the gene pool of PBWO. Would you be walking up to them? Would they be rarer? Would they be in those drive up and hikable parts of CR or in more remote areas? Would the frequency of Dks be lower in many/all parts of CR?

By the way how many Guans did you see in CR outside protected areas?...thats your corollary not unhunted, admired and PBWO that are in some respect ignored by Ticos for hundreds of years and worshipped by visitors.

There is much more on the IBWO subject available on these matters.

Please reconsider your piece. Bloggers have a journalistic responsibility also to keep it balanced ...I believe. To keep it mild your post is disappointing.

tks

the AUFV

http://www.auburn.edu/academic/science_math/cosam/departments/biology/faculty/webpages/hill/ivorybill/FieldNotes2006.pdf


http://www.auburn.edu/academic/science_math/cosam/departments/biology/faculty/webpages/hill/ivorybill/Updates.html

Anonymous said...

Your Maths and English are hopeless 'AUFV' but still better than your science.

You mean >1AD and <1950AD, and there are several grammatical errors.

Mildly disappointing but totally expected.

Anonymous said...

Anon, AU is correct and of course you avoided every question with a poor grammatical review of a quickly tapped out blog post instead of addressing the science.

The blog owners post used a seemingly good comparison set (to the uniformed), Pale billeds' density in Guatemala and CR, to compare acoustical data he asserts is uncollected in the US. Logical fallacies and biases are not hard to find in this reasoning.

He asserts that Ivory-billeds if in the US must/should knock and kent and be easily found since PBs are. He never says kent, probable doesn't realize what they are known to do. He then infers that there have been no putative kents and knocks recorded and reported recently.

He seems unaware that several people/teams that actually get into the field (novel idea to most skeptics) to collect data have found compelling evidence that the Ivory probably exists.

He uses as his comparative set Pale-billed woodpeckers which have little if any history of persecution especially when compared with Ivorys. Also vocalizations and knocks for most species decrease when population densities decrease.

He also makes no adjustment to the data set for relative population of the two disjunct sets before he makes sweeping comparisons.

Science that takes the form:

Species A is the species most like sp B

B is encountered in the field quite easily.

So therefore sp A must be encountered quite easily.

...this is simply not a valid form.
It may come up with a correct or partially correct conclusion in some instances...but that was by chance.

In this case the blog owner has by chance come up with a partially true conclusion. Ivorys should be
detectable by listening for them. Field results/data do indicate that IB may be kenting and knocking in some sections of some habitats. In addition field reports come in from reputable searchers. This data fits well a hypothesis that a few IBs are extant. Its does not fit well various skeptical hypotheses.

And so you feel at home and away from science.....Why did you capitalize math?

Also reading comprehension has many books in some libraries...but granted not all. First rule do not add words not there. You changed AU's original joiner word "to" to an "and" in your following remake of his/her sentence.

Anon said
>>>>You mean >1AD and <1950AD, and there are several grammatical errors.<<<<<

AU said < 1AD to > 1950AD. Since the exact dates of when persecution /hunting had started or ended, are not known AU was clearly trying to show that with his correct usage of the less/greater than symbols.

Do not add your ill-informed interpretations to sentences and change words...good to read whats there...only. Can't wait to see your field reports, with things arbitrarily added or subtracted.

There are reports of IB being shot after 1950 (FLORIDAFish and Wildlife)and finding IB in middens before 1AD...therefore AUs correct symbols.

>>>>>Your Maths and English are hopeless 'AUFV' but still better than your science.<<<<<<

>>>>You mean >1AD and <1950AD, and there are several grammatical errors.<<<<<

Must go.

peace all

Julie Zickefoose said...

You're not the first blogger to have his eyebrows singed off by mentioning the Lord God bird, or opining on its status. Welcome to the club!

Here's the news: Blogging isn't journalism. It can be, but it doesn't have to be. Blogging is a free service, and readers are free to partake of the information and images provided in a blog. But commenters should remember this simple fact, and rein themselves in well short of disrespect to the provider.

Bill said...

It's been a while since I've checked in, Jim. Loved the posts! I've never known you to draw such ire and correction but hey...!! I have enjoyed several trips to Dawes for the "salamander migration." It is truly one of the neatest phenomenon of Ohio nature.
Carry on the good work. I'll be checking back during the spring.