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Interview 3:46 - 1:54:27 Play 3:46 - More
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John Fitzpatrick, Russ Charif  







Ivory-billed Woodpecker search; Autonomous Recording Units; Bioacoustics Research Program  

NPR/NGS Radio Expeditions
16 Aug 2005

  • United States
    New York
    Tompkins County
  • Cornell Lab of Ornithology
  • 42.4800624   -76.4514796
  • Stereo
    Sampling Rate
  • 48kHz
    Bit Depth
  • 16-bit
    Equipment Note
  • Stereo=1; Neumann KMR-81

DAT #1

John Fitzpatrick (Fitz)
Russ Charif (RC)
Mike Powers (MP)
Scott Haber (SH)
Chris Joyce (CJ)

1:22 ambi in room -some people talking about highlighting the events -do you have a notebook? Keep a sheet......which ones exported successfully (one man telling another what to do) .....

2:42 ambi -birds and some knocks in bg. Also sounds of computer..... lots of clicking on computer but off mic.

Chris talking in bg

3:54 Fitz and Chris setting up

4:02 Fitz -early in our days of ARUs you know, and we got those stuff back and I am saying you know pls anylze them as fast as you can. You know, guys are listening to them all day long. Week goes by and somebody runs down to my office and says Fitz you got to come listen to this. Jesus -they got it (in a whisper). And they say hey, put the headphones on, so I put the headphones on and I am listening and I hear a Carolina wren and then all of the sudden I hear: WHAT THE FUCK IS THIS! And for then next 60 secs or 2 mins these guys are saying this is something, I donna know that maybe the government has put out here. Could be a bomb -look its got some writing on it and they can barely read -it is the Cor -Cornell Lab or something. 5:08

CJ -this is LA?

Fitz -yes LA -so it was the first example of the hunters finding the ARU

More talk about ARUs and leaving them alone..... no batteries robbed.... one hit by a bear -describing how they know......talking with MIKE POWERS here.

MP -I am the acoustic analysis coordinator. So I am in charge of all of the data that comes back

Russ Charif -I am in charge of the entire acoustic survey and analysis project

JF -I am John Fitzpatrick. I am director of the Cornell Lab of Ornithology

I am Scott Haber, I am one of the acoustic analysts here going through some of the tapes from Arkansas.
I am Connie Bruce and I am director of the marketing and communications for the IBW project

CJ _ asking Russ a little bit of the history of -about this room....... why did you pick this room.... what has gone on in this room

8:32 RC -well, about a year ago when we started reviewing the recordings from the first season of recordings in Arkansas we were doing it in the main bioacoustics lab which is a big, open, communal analysis area. And we had an episode where one of our analysts was going through the recordings and found what sounded to him like an IBW. And in fact it was an IBW -it was actually a playback experiment that our search team had done in the field, but our analysts did not know that they had done-any of these. So, there was a certain amount of excitement going on about this and it took a few mins before the pieces came together and people realized that this was not something to get very excited about. But in the meantime there were other people in the lab that didn't really know about this project and they were saying what is going on. At that point we realized we can't do this in this place if we really want to try and keep this all under raps. So there was a sudden frantic search in this bldg for a room where we could sit 3 or 4 people and their computers and we could have 4 walls and could close the doors. And like most modern office bldgs, most of the office space in this place is open cubs. And both from the perspective of trying not to disturb the neighbors with playing sounds and trying to keep the project still a little bit under raps. So we had to scramble and there was this small conference room which one of our dept directors very kindly agreed to give up for an undetermined amount of time. We got the conf table out of here, we did some quick extra network and electrical rewiring and we turned it into our little secret analysis center. 10:14

10: 16 -CJ -let's talk about some of the hard do you get some of these computers to go through all of the tape you have

RC -we have about 18,000 hrs of recording and none of it is tape. All of it is direct digital recording. It is recorded by these autonomous recording units directly on to hard disks in the field and shipped back here. We now have a total of about 18,000 hrs from the research season that began in 2004 we have several thousand hrs. also that was done in the spring of 2004 around the time when the Luneau video was made. So it is over 20,000 hrs all together. So, it is obviously not feasible to listen to all of that -it adds up to several years of continuous 24 hrs recordings. And obviously even at a place like this we can't get people to go through all of that recording. So we have software that was developed here in the bioacoustics program which can go through dig recordings searching for sounds that resemble some prototype that you have given it. 11:48 so you basically have a series of recordings of what it is you are looking for and say to the program go find things that look like this. goes fasster than real time. identifies events that resemble the thing you gave it as a prototype. as prototype we have 35 recording from singer tract, we have that recording can use calls for prototypes for software. the other sounds the birds make are these double raps . . . loud double raps .. there are no known recordings of ibw double rp but do have roecridng of closely related species in new world tropics, make signsla muc like each othe rand likfe written descriptions from '35 so we use those two as protopyoes with softare that can scan thru and id items of interest.

now with somethig like this thee are two kinds of errors the softare can make.

missed deteciton, somethign you want and it misse,s the worset kind for htis projecgt, wse want to minimize that, the othe knid of error is false detection. it triggers on something you wdon't want ..we set threshold low its senstive
and not ver slective. so as resutls lets see we run this at 50 hours at a time and ffom that several thousand candidates detections per 50 hours.

cj: whose job to look at those r: we have a staff. software creates data logs that alow us to fairly queickly review these events. these guys can do aboug 500 events an hour ***


they are looking at a sound spectrogram, initially. it's similar to a musical score in that time runs left right and pitch vertically, high sounds are high, low are low. we can recogn a lot of false alarms can be recognized immediately, they don't look like ibw on the spectrogram. most of those thousnads of detections they dont' hav eto listen to and then they get one that does look Like ibw and then they have to look again.


scott haber
cj: you could recog ibw spectrogram in an instant.

sh: almost ,there are a few species that almsot very simliarly come across as being very similar, blue jays are very similar, red shouldered hawks white breasted nuthatches but the 35 recording has a distinct look

cj: do you dream about it?

sh: laughs ... i dont' know if it's gotten to that point but it's close. it's keyed in in your brain.

cj: as you look at screen your ewathicn ghtem come across .. not scrolling, you typically load about 15 seconds a time on screen and 10k at it. the software present you with a log of detections and you go from one to the next just skip to it. that's the beauty of this (russ talking) ..

cj: if thre's nobody in the forest and a tree falls.

r: 17:47 **** ou can hear a tree falling we have exmaple

sh: (laughter) sh: the other day when i was going through it and i had this
really huge distinct signal on spectrogram i had no idea blasted my ears had to turn the volume down and it was a tree falling so we manage to answer the age old question that trees make a sound in the forest when they fall and there is no one there.

cj: what other things have you heard. but first who first swa the spectrogram of the ark ird

r: we found double knocks first

18:50 **
i think the first person to find that wsasd beth howard, .... i walked in door and she was working here alone back in january feb some time, she said oh i found osething that sound spretty good here, she played withs one recoridng. now we had had other things before that sounded somewhat like double knowcks, but they didn't have the right resonance. people were learning as they went. mental tmeplate at first hadn't bee honed,

19:48 so tthere were some false alsraams as the were to look for it. there was thei double knock specrgraom shalyed it over speakers and i was blown away i said that's i and i left the room i went looking for fitz and whoever w se wa around .. that was an exicitng moment. seeral weeks later it was also beth who found the first of the series of kent like calls.

The ivory-bill call has been described as a childn't tin horn, was trancriped as kent , (he makes the sound) so we call them kent like calls. we found this series of kent like

and the sonde dpretty damn goof. first thing we did was check th elogs. we knew crew was planning to do some palybacks, we'd been burned the previous season people got really excigted about something that turned out to be a playback. so we 21:32
qucikcly went aorund and conslulted notes on when playbacks had been done .. turned out this reocing was made 3 or 4 days berfore any field use of recordings by our teams. the date of first recording oa kent like calls we found was jan 17 2005 in the white river natoional wildlife refuge. In subesquent days found four more episodes of virtually identical
calls recorded by the same aru over the next couple of weeks, between 17th and 31 of jan~

cj: double raps?

rc: 22:30 **
the double raps are widely distributed the first one we found was like a xmas present .. found several weeks later. but it was on xmas day. there are double raps in our record widely over long period can't give exact info on distribution.

the locations apear to be concentraegd i a few places .


in one particular area of white river and in a couple of areas in the cache river area. what's part. interesitn gis that a very preliminary analaysis"not sure of th is ..but suggest tht edoyble knocks seem to be consentrated in spots where we have other enticing evidence.

for e.g. the kent like calls form white river were made at one particular location, AND THERE ALASO SEEMS TO BE A concentration of double knocks there. cj: sam earu? rc: over that aru and others in that area. we have 24 phyusical instruments in field. they would be deployed, tied to tre eand left for two weeks or so. retrieced, data retrieved, then unit redelpoyed. wehad 153 separate aru deployments are differetn some cases a few meters apart.

24:45 so we have lots fo arus at anyone time about 20 or more ..we've covered a lot fo area.

sometimes put arus back where we got interesting things. it was more art than scinece, where di dth ehabitat look good, sighting, someone heard somehting ...half a milllion acres to cover though. There's art science and whole lot of luck in getting anything

25:50 ***
JF: one of the most exciting things i think it was that xmas morning up in north, same site almost to within meter of palce where one of our field workeds a month beofer had heard double knocks form two directions over pierod of 10 mintues that was esp. ecciitng first logged ouble knock was right where we would have wished he had gotten marshall iliff. to his dying tday herad double raps form two difrrentt directgions only to learn he had left his microphone switch off. i dont' know if he wants it broadcast natioanlly.

29:00 rc: maybe we should start with th e35 rcording.

jf: these recording ar eamong the most famous bird recordings ever made, a mule wagon full of equipment made on movie film wiht sount rack, allen kellogg and tanner .. tanner ended up doign the study. they had found several nests, found one spot they could get this huge wagon set up point th ebig parabola up toward the tree.

jf: ***** 30:00 so what we're hearing is two birds at the nest hole probaly a little aggravated at the poele down below so .. they're probly birds a a slightly hier tha nomal metabolic rate, they are a little agitated. bu tyou'll clearly heare tow individuals calling.

CJ: this has texture unlike raps.

rc: lets go ahead and play this ... this si a segmetn form the '35 Arthur Allen recording in Louisiana the entire amt we have from then is about 5 minutes, this is a short piece of it.

ACT: 31:30 1935 KENT CALLS

russ: now that was made aat close range. . .the wre sitting very close th the tree .. the birds sounds perhaps altitle agitated. this is actualy an amazing reocifndg made 70 years ago, a little scrtachy, but coniserign they were in a swmap miles form anywahere had to transport batteries etc. it's amazing at the quality fo this. these guys aerew ere masters.

cj: fitz ..when you hear that .. how dist. form other sonunds ?

33:30 ***that is pretty unique sound i heard it whe i was 10 years old every birder has heard, ti's a reedy qualty yo can see on cpectrogram, very large nubmer of harmonics fo ra little flat note, not rough or whistle, very reedy quite unlike any othe rbird. *******
are couid e of toher birds that make nsal yank sound, white breatsted nuthatch in part. and we are alwyas worried about blue jay mimicry.

cj: campephilus in s.a. ?

jf: they all have distinct vocaliations each it's own and none like ibw. th eibw and th eimpoerioal woodpecker wre each others lcosest relatives and were quite distinct ..none has this single reedy note of the ibw. those other birds in centrla dn dsotuh america all have very distinctiv edoubl erap 35:25 that is dead ringer for what the ibw and imperiod use dto do.


russ: let's hear 1935 recofidng repaleyd thru th eofrst and rerecorded by aru, through cypress tupalo swmap over standin water. the reason for doing this. the ousnd changes as it travels thogh nay environment. obsiouysly it gets fainter.

but it cn also get filtered the frequency content of it can get changed by the trees and other obstacles it has to go aound the eis reverberation. you hear sort of an echoy cathedral Ike sound with big trees. we also need to know what would it sound liek if we hard that bird today form a ditance in the forest. so that peole here and th esoftware would know hat it was that we were really looking for.

37:45 you'll hear tin the backgroudn of this a sort fo faint high pitched hwinte ...not bird electronic artefact.

cj so this is 1935 braodcast thru th ewood.

russ: yes this is form a distance of 145 meters.
39:00 ****


39:30 fitz can see on spectroram many fewere harmonics t sound not as reedy or complext jsut a faint nasal knote ... taht faint nasal note is what we want to hear.

russ: here's origianl 1935 recording ... i'll stretch it out so we can see each not.e here are two notes t in uper panel we have wqve form t in lower t the specgrogram..
here are two notes of this

the series of parallel t bands t horizontal bands at differetn frequencies are different harmonics fot he sound t the llowest one if the fundamental that igves it it's pitch but the higher ones are what give it the sort of nasal reedy quality.


frequency of fundamental is usauly in low 600s about 633 cycles per secondt hertz.

the next above the fundemntal is twice that t spacing between the successive bans is the same as the frequ of the fundamental the bansds are separated by 633 hz.

4200 when people talk about voiceprints its' spectrogram.. thsi is a voicepritn of an ibw. it's pretty distinctiv eonce you've lookeda t it and know hwat to look for there' snot much else that looks like this. other calls that sound liek this white breasted nuthatch or blue jays these nasal twangy kind of calls t and nasal bird sounds have is type of sturcure t a seeries of harmonics.

42:55 if no harmonics you'd have a pure tone more musical. or like whisltes.
let's look at this sound plaeyd back in the swamp. you can see its different you can see the fundamental down here . . . . you can see the fundmental down here around 630 to 650 h fo rfundamentla then anothe rstorng harmonic way up here close to 2000 herz btween a900 and 2000 herz. but inb etween you cn't see much of anyting. but if you 10k in the original recofing form 35 you've got two more harmonics, one at about 1260 hz and one at about 1900 hz and thoseafter the recording has been played back thru th eforest those are prettyt much gone.

44:30. it's a couple of things. the different harmonics in original clal each has differnt strength differnt amplitude. differetn harmonics can be, relative to each other, more or les sintense, ouder or quieter in relation to each other. part of what's goign on here, you can se in 35 recoridng, the seocn harmojnic betwen 1200 and 1300 hz is weaker yo can tell by image on spectgrogram is lighere tha nothers. so aprt of what's oging on this weak harmonic is not coming thru th eforest very well *** 45:19 and that's not surprising it's ewekaer to begin with and now 145 meters away. so you are seeing differtntial attentuation or los of harmoinci based on their original intensity but supeimposed on taht, yo also have filtering by the fores,t scertian frquencies go thru forest better tha others, what affets that is distribution fo tree truks and limbs of differnt sizes r3elfects and scatters differetn frequencies for the Original sound. so it slooks and sound sidfferen 140 meters away

cj; to fitz about this tehcnology

jf: i learne daobu tspectrogram from a bird book, but 1 started birdwathcing when i was six so no.

49:30 ...notice the marks in the forest appear to be longer in duration .. blurring off to the right. that is reverberation that comes through the ofrest.




** 51:15
plays 35 reocrding the original .. there's the 35 reocidng ACT ONE KENT; here's the same thing 150 meters away act one kent, and you can hear that it's go t a more drawn out soudn to it, that's more reverberation thru th etrees. you see this with any forest birds can hear a foresty like effect, and in specroram they have a smudge off to right. you dont' ge that with birds in grasslands. much crisper.

***52:20 RUSS: so let's jump to january 29th 2005 8:50 in the moring in the white river, it's rianing, you'll har sizzling soudn of water in swamp stign about 3 second into recoring you'll hear sereis of sounds similar to what we were just hearing.

russ; and that's what we've got. fitz: interspersed wiht a carolina wren. a much Isoer carolina wren.


CJ FITZ when you first heard that know that call by herat fitz; what i didn't know by heart as the arthur allen 35 sound played thru th eaforest and rcoded by the aru... there was a group of us here, we came down and immedatley the queiton was, what does the arthur allen sound .. they are faint but rpetty darned good. so back and forth we played the allen recording as played to the aru n the woods and palyed these recordings side by side back and forth. and looked at them on the screen toghetr ocmpraing the harmonics we continued to be impresse dby how similar these boht sound and look to one another.

cj: how long before yo were certain

fitz: 55:00 you have to step back and relaize hwat we are doing. we are trying document existnece of bird we tghought as extinct. and we so desperately want that to be true that from the very beinning *********** of this prohject at every step we are constnactly testing ourselves an dproving one another and aksin gis there a possibly we are confused. so that day, although our palms wer esweaty we remained cautious about itt so our big effort began right ther ein that room to say how can we liminate blue jay and nuthatch as possible deliverers of this song. that is literally what we were saying. we weren't all quielcy juping up and saying eurkea we froudn it we said then as we say now we have to make it sure these are not blue jays or


cj: is there a prof. reluctance t be first t go out on a limb?

56:38 ****
fitz: when we get a recoding of ibw that is 8 to 10 feet away and yacking away on the turnk sounds like 35 reocing we'll jump up and down. the probme is now we've got severla exampel sa a bird uknown hundreds of meters awsay that has sounds that are tantalizingly close and os it makes us say that' sound pretty darn good but onc eagain we're aware of fact we want it to be true t so our job is .. to be as cautious as we can...the sound and the videohave a lot in common. there are skeptics re video many of sketpics when they've heard sound they've said those sounds are better evidnec ethan the video. cj: what do you think i tthink it's al a body oa feivndece gthat says it sth ebirdt and that body is extneisve now t lot of doubl eknock soudns t some kent like sound and some geographic clustering of soudns in bio~l right places t suggsting couple fo centers of activity.

here's what i want ot do i want to go out and lay my.~ binosuclars on a tree. that's what i wnat to do. 58:42

let's play 35 thru forst and then ark back to back.

1:00:53 ******************************
russ: so first we'll play the known reocrind gas played thru th eswamp about ten seconds .. breif pause then go into this recoridng made jan 29 in the white river refuge.

ik starign with known iveroy bil reocfindg.

act: 35 thru woods ...then the ark recording with the carolina wren.

russ: soudn pretty good? fitzi i love listeing to it every time, same enthsuaim that first day .. i also have to say i keep having the same trpeidation i hope that litlle kent is not diagnostic of a blue jay

there are features of 35 and th eark that are identical.

russ: yes the pattern 0 delivery are prtty distinc.

now regarding the blue jay thing a lot of experts birders have said is that yes i could imagin e a blue jay making a sound like that but not dleivering it in that knd of pattern over time, that would be unsual. fit> one reaosn we're so carefu about vlue jay thing in this area and others poele have tlaked about blue jays making sound sreminiscent of ivory bill. we got a recording by one of our poele a good reocrder he waked int othis rom and said i got it i've got the lbue jay mamign teh kent call in the white river. we put it on and looked at each other and said that's a blue jaYi russ: that's not it.

1:04: 23 heree's a known blue jay. several mmembers of our team have rpeortted blue jays making this sound in wht ewhite river. they got excited and said i went after it and found it to be a blue jay. (tells ben clock story of getting the blue jay sound) .

1:05:35 he went out into the wood and he got it and this is what he plaeyd for us

105:42: *** act blue jays In forest.

russ: in that recoding there's acrowd of blue jays some making typical blue jays, and then therese other sounds that are not typical. they are more like ivory bil they are not exactl like ibw and not like what twe got on aur. so this doesn't solve the mystery. **

here' our suspect *** 1:06:47.

act ark ibw with wren: here's ben's recording of blue jays: act. it's not the same. the individual notes are not the same and the pattern is not the same

cj; it's not but it's tough.

fitz. IT'S TOUGH, CRUDELY SPEAKING they are similar. but you can see some difference son the spectrogram ... dodne multivariate statist'cs. we don't have a single blue jay reocrding form our entire library that have some resemblence to ibw wuality inlcuidng ben's reocrding. subjected to multivariate test. clustered well awy form 35 recording and th eark recording.

cj; in what way differe?

russ: 1:08:34 for e.g. the funamental in blue jays is around 800 hertz. that's higher tlian ibw recording. The distribution of energy among harmonics is different. the fund. is actually very rfaint you can barely see it .. the second fourht an dfith harmonics and qite stonr.g int eh known ibw and aru reocirding you see iffernt partten a lower frequ fund. and the fund is alway slcealry visible, the second harm. is fainter and higher ones more prominent.
1:09:29 so when ou first ear ait yo know to untrianed ear. yeah that's kind of similar but hwen you srart to pick it apart it doesn't stand up as w el.

fitz: also chevron shape to n te of blue jay that is not there in 35 and aru. so the hape of the note and the disgrition fo weak versus ron gharmonics are differnt. and hat jibes with birders w 'v elistened , they say that's interesting but tha't s fintiely lbue, t

russ: sloewed down yo can tell the pitch drop toward the end. o

plays 1:10:30
may be more appr t is we go to quarter speed.

act plays at quarter speed.

russ: you can ear it drop in pitch. now here's sound form our aru here's at quarter speed.

act: aru at quarter speed:

its very constant it eosnt' drop it goes UUUUUHHH kind of sounds like a foghorn.

ftiz: that's very very cool that's the first time i've hard that that's amazing *** 1:11;21

russ: let's go back to one of the allen recordings in the sswmp and let's do one of those.

again quarter speed.

act: quarte spedd good.

fitz: that si someithgn to do next week russ, those three (those two and then the blue jay that's sooo clear. ***

russ: act known iveroy bill that's a known ivory bill.

act: this is the aru and then here's a blue jay, act:

fitz: that's really interesting. and the wuesion is it's the challenge us to hext season besides finding a roost hole is to get recordings of blue jays if they exists that are mor eexactly replicate of ivoery bill ... right now we don't have blue jays that match.


white breadsted nuthatches form a distanc ein the owods can sound a lot to an exitged field biolgoist liek a possible ibw, as you get lcoser thos it's clealry nuthatch, but we've had to do same analysis to eliminate nuthatch form these. there are a few osunds that can be viewed as ambiguoyss.

(that was fitz)




APART. they go back to normal behavior.

1:16: 40
scott: blue jays mimic a lot but boht th epatten of dleivery is off and then ofater a few nontes they'll regress back into normal blue jay call no matter how good their orignakl form is.

cj; if blue jyas are doing this .. if ibw extinct .. how woujld thye fitz: 1:17:35 aren't they just immicking ibw. they mimic nasal things like coopers hawks and red shouldered hjawks. thats interesting idea but not much to say th'ats proof that blue jays are imitating ivory bill. i study scrub jay, they can share behavior socially and learn form others, jnot inconceibab Ie to me that there dould be an ibw mimicry in southern blue jay pouplaiton that has bene pased culturally thorugh generations of blue jays even in absence of mimics. that would be belieable. for me the idea of a model out there i don't buy it. carrying the signal in the forest behond the bird. ibw like calls form blue jays have been descrbied in south, as far anorth as new jersey.

fitz: we mentioned th esounds in the apirl scinece aper ...but no detial bec. had not done cf with other species and not much analysis. we felt exciting enough to mention in the article. our intention than and now is to take next step and dispaly to scinetiric public what we can say to the professionala at the aou meeting. tha'ts when we'll realese the sounds

russ; that wonlt be last word. we still havve seerla thousand hours to review looking for kent like call. we have done ocmplete first pass thru the 18,-000 hours for double knocks and still looking once more, but still quite a lot of time to examine looking for kent calls ..

1:22:29 r .. itls still posiskbe th ekiller recording that fitz spoike of befor ehtalt sboing to make us jump up and down and make us open the champagin is still on our server. fitzx: welre still unwrapping the presents.

fitz we hae new detectors too. better.

1:25:25. RUSS: if we have a harmonic here. a darker greay band, this is the aru recording of the sounds we like. hre you cansee one of the clals. a series of gray parallel bands, a faint harmonic down here aroudn 650 hz a dlighlty stronger one up here. a third one up here louder.


1:28:10 letls starat with some known double knocks fitz: letls go to south america.

russ: ok letls look at campephius pollnes, the powierful woodpecker. this is a bunch of indiviaul double knocks that have been. pulled ou t or recording form macauly librayr, this is not how they wre delivered .. just to give an idea of what they douns like.

one of the things thatls striking about these is how similar they are among specie.s

act: 1:29: 30 double knock: lousy one.

1:29:43 thatls more typical

1:30:23 another one .. not so good. three stirkes hrels some doubles.

1:31: 18 these are clzassic double knocks. (canlt use)

1:312:35 thse are clsassic doulb eknows the first a little louder than the second **

russ: let's look at rubricalus

1:32:20 .. and again 1:32:30 better.

that ws red necked woodpecker.

russ: then thre is campephilus guatemalensis, the pale-billed..

fitz this is the class ic one.

1:33:15 several double knocks but low volume

russ:hears a louder one>

1:33:31 ... ***** best ones.

russ: what's stirking about these ...we listened to three species, to untriane dear hard to tlel the three apart. the sounds are virualy identificl anlthough wwe don't have reoridn gof ivory bill making this sound but we have written desc. and thes to compare.

cj; th epurpose of call

fitz: it's a standard long distnace display call announcing terriroty almost all woodpeckers have riuatlized drumming as a territorial display announcing presence, often double rap givne by both members of a pair to let each other know where they are. very common in tropics to hear a distanct sinle double knock.

1:35:48 let me play for you the first we heard form xmas day
4:30 pm dec. 25 2004 in the cache river area.

act: double knock:
fitz: that's a gunshot with it.
rus: you hear th etwo stikce,s then aloud boom which is a distanct gunshot, i'll play that again.

can tell it's a gunshot from the spectrogram. most of their energy is very very low in gunshot. and then a reverberation smudlge. like sail of sailboat. and very abrupt onset. then tapers off. in case ouf doubl eknocks you don't have mast of sail going to bototm peak enrgy in differtn palce and reverberation energy is up a few hundred herz.

1:39:30 ****** these are just plain perfect double knocks there's no specialist in american woodpeckers or birds would listen to and not say that sound a lot like the double knock of Campephilus woodpecker .. it's a double knock you or i could it but it doens't carry th amount of information as vocalization's but it's perfectly timed, about 70 milliseconds apart ...

russ: it's 70 to 80 though some variation, some at 100 milliseconds. there's a relationship with body size, the larger the woodpecker the longer the gap very slightly. . . . some of what we've found is up around 100 ms separation.

Fitz: sometimes Campephilus goes triple.


russ: we know from tanner .... arus have detected some 1000 double knocks .. soe of them are foraging woodpeckers ...gets logged as double knock. we didn't hear that with the aru ibw. we look fof ambient sounds aroudn to see if we can explain the doulbe knock with something else. ---fitz.

1:43:35 russ: when ou listen to 18000 hours you hear a lot of sounds.

1:43:52 russ: this was also recorded in the white river just ove a ~from kent call~ we hard before, this was not very far off in time we wre recording the kent calls, kent like calls, this was jan 24 6:45 in morning, you will hear throughout this recording sort of a clucking sound, alarm clal of a robin in backgroun and avbout 5 seconds into it a not very loud distnat doulbe knock and about three and a half seconds later a second apparently closer louder one.


thewse are about 100 millseconds apart. about km away from kent calls jan 24, right smack in midle of period of kent calls, they were got 17 to 31 january.

fitz: starting to look kinda good isnt ' it. 1:46:00

russ: this area .. peole were interested in this area, habitat looks good, nobody saw the bird there. there are cavities. fitz: we did very extensive inventory of th enorthern part of the study area, significant amount of work in white river looiing for nest holes. in both th top quality holes ... there were good quality holes found, none wiht bird going in and out of them. there are some holes that do appear to us gorund huggers to be big enough and shaped appropriately to be ivory bill holes.

(AOU meeting just describing acoustic sound and video)

(talk about holes)

fitz: 1:49:55 well i think ther are ibw out there i've been comfortable with that for man months, when i get carefl about dclaring sometehing about a sound it's becuase i canlt yet definitevely say a sound is definitnely that but twith th ebody of evidenc enow in front of us, veginning wit the sightings by gene himslef ...and tim eand obby's sighting .. and th enumbr of quite convincing sightings by peole who saw specific field marks thru binocs and the video evidence although it is poor that video does contina a sign. amt of information an di thin that video is an ibw. plus we now have kent like vocalization and even mor eexiciting to me the double knocks displayes of htis bird bec. that is such a dist. camp. behavior i'm coinvinced there are ibw in those woods, what i don't knwo is breeing populations, last remnants? occasionaly maknig noise. that's still uknonwn and i wonlt be satisfied like the skeptics til welre wathcing a pari of birds or a bird at a nest hole. tha'ts what welre after, we're after information abou thsi bird, there are lots of mysteries to solve. but to the qe wstion do i think there are ibw's in arkansas, yes. 1:52:07

cj: you predicted there wpould be doubters. has this palyed out as tyou exptecgted.

fitz: yes but the thing that hasn't played out is that i thought by saturating the palce with cameras we'd get beter picture and we didn't do that. given that all we had was video, yeah i knew there wre poeple who'd say it's not good enough it understand that. there are very good ornithologists who stil lsay i don't think that's an ivory bill. still. the one's stil in extreme doubt are, we haven't had a long chance to go over frame by frame as we've don e since public doubt was expressed, looked at frames more, and frnakly our analysis convinces us even more that we are right about the
id. others dont have the

1:54:00 others don't ahve the time or oppty to do that, they will eventually i'm hoping over next few months it will al lbe moot. i'm hoping someone will nail that time magazine photo.

end tape

russ what's stirking about

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