Author Topic: Condors and lead  (Read 22843 times)

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Offline JoJoDapyro

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Re: Condors and lead
« Reply #105 on: November 12, 2015, 01:50:01 pm »
Abused, no. Allowed to be poisoned by lead, yes. Intentionally, Not really, but if you know you are doing something that isn't good, that is an issue. I don't see how after you posted that study in your defense that you could claim that they aren't being poisoned by lead.

a·buse
verb
əˈbyo͞oz/
1.
use (something) to bad effect or for a bad purpose; misuse.
"the judge abused his power by imposing the fines"
synonyms:   misuse, misapply, misemploy; More
2.
treat (a person or an animal) with cruelty or violence, especially regularly or repeatedly.
"riders who abuse their horses should be prosecuted"
synonyms:   mistreat, maltreat, ill-treat, treat badly; More
noun
əˈbyo͞os/
1.
the improper use of something.
"alcohol abuse"
synonyms:   misuse, misapplication, misemployment; More
2.
cruel and violent treatment of a person or animal.
"a black eye and other signs of physical abuse"
synonyms:   mistreatment, maltreatment, ill-treatment;
If you always do what you always did you'll always get what you always got.
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Offline iowabow

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Re: Condors and lead
« Reply #106 on: November 12, 2015, 02:19:41 pm »
Ok skeptics I guess you have a problem with clicking a link.
So here is the one I posted for you on page five.
 Now please stop chewing on my ankles.
There is a message for you at the end of page.


Bare in mind this study was done in 2008 so if they are still complaining
about the mortality and poisoning it must be because they continue to
subject the poor birds to that fate. Or the documentry was way old?
Please tell me your take on it.

I included the conclusion. I read the paper in it's intireity


Effectiveness of Action to Reduce Exposure of Free-Ranging ...



Dec 24, 2008 ... Condors were routinely recaptured and treated to reduce their lead levels as ... We simulated the effect of ending the existing lead exposure ...

 
 
We used a previously published population model [8] to assess likely long-term trends in the numbers of condors in the absence of further releases and without chelation and other treatment of birds with elevated blood lead concentrations. According to this model, the condor population would tend to decline under present conditions unless natural adult mortality was at the lower end of the likely range or reproduction was at the “maximum conceivable” level (Table 5). Since the assumptions of the “maximum conceivable” scenario are extremely unlikely to apply to any real population of condors, this indicates that the Grand Canyon condor population is unlikely to be self-sustaining at current levels of exposure to lead.



Rhys E. Green,1,2,* W. Grainger Hunt,3 Christopher N. Parish,3 and Ian Newton4
Tom Pizzari, Editor
Author information ► Article notes ► Copyright and License information ▼
Copyright Green et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
This article has been cited by other articles in PMC.
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Abstract
California condors (Gymnogyps californianus) released into the wild in Arizona ranged widely in Arizona and Utah. Previous studies have shown that the blood lead concentrations of many of the birds rise because of ingestion of spent lead ammunition. Condors were routinely recaptured and treated to reduce their lead levels as necessary but, even so, several died from lead poisoning. We used tracking data from VHF and satellite tags, together with the results of routine testing of blood lead concentrations, to estimate daily changes in blood lead level in relation to the location of each bird. The mean daily increment in blood lead concentration depended upon both the location of the bird and the time of year. Birds that spent time during the deer hunting season in two areas in which deer were shot with lead ammunition (Kaibab Plateau (Arizona) and Zion (Utah)) were especially likely to have high blood lead levels. The influence upon blood lead level of presence in a particular area declined with time elapsed since the bird was last there. We estimated the daily blood lead level for each bird and its influence upon daily mortality rate from lead poisoning. Condors with high blood lead over a protracted period were much more likely to die than birds with low blood lead or short-term elevation. We simulated the effect of ending the existing lead exposure reduction measures at Kaibab Plateau, which encourage the voluntary use of non-lead ammunition and removal of gut piles of deer and elk killed using lead ammunition. The estimated mortality rate due to lead in the absence of this program was sufficiently high that the condor population would be expected to decline rapidly. The extension of the existing lead reduction program to cover Zion (Utah), as well as the Kaibab plateau, would be expected to reduce mortality caused by lead substantially and allow the condor population to increase.

Introduction
The California Condor (Gymnogyps californianus) became extinct in the wild in the 1987 when the last wild individual was captured and added to the captive flock, which then consisted of 27 birds. Since 1992, releases of these birds and their captive-bred progeny have re-established wild populations of condors in California, Mexico and around the Grand Canyon in Arizona and Utah. Individual condors in these populations have suffered from lead poisoning caused by ingested ammunition, which is the most frequently diagnosed cause of death among Grand Canyon condors. This holds despite intensive efforts to monitor blood concentrations of lead and to treat birds with high levels using chelating agents [1]. The condors in the Grand Canyon population range widely in Arizona and Utah and feed on carrion, a proportion of which comes from the carcasses of game animals shot by hunters using lead ammunition. Ingestion of shotgun pellets and fragments of bullets in flesh from such carcasses is the route by which lead poisoning occurs. Condors are located as frequently as possible using satellite tags and VHF radio tags and those that cease to move are recovered. Birds are also captured routinely and their blood lead concentrations measured. Any individuals with high levels are held for treatment to reduce the burden of lead in the body before release. Action is also taken on the Kaibab Plateau, Arizona to reduce exposure of condors to lead by encouraging hunters to use non-lead bullets and to remove potentially contaminated gut piles. The level of condor mortality caused by lead that would occur in the absence of chelation therapy and lead exposure reduction is of interest because it might not always be practical to locate birds daily and trap all condors routinely once or twice per year for blood lead monitoring, and implementation of lead exposure reduction schemes requires resources [2]. Could the reintroduced population persist if the lead exposure reduction and treatment programs ceased or were reduced in scope? What would be the effect of reducing exposure to spent lead ammunition throughout the range of this population? As a step towards addressing these questions, we report here a statistical model of blood lead levels in free-ranging condors, which extends previous analyses [3]. We took advantage of the unusually complete radio-tracking data, which allow the influence on blood lead of the location of condors within their geographical range to be assessed. Our objectives were to model the distribution of blood lead levels throughout the year in the absence of treatment, and then to estimate the mortality rates that would prevail. Finally, we used the model to explore the possible effects on condor mortality of withdrawing or increasing measures to reduce exposure of condors to spent lead ammunition.



Materials and Methods
Field studies
We used data for 2005, 2006 and 2007 derived from the monitoring of movements and blood lead levels of free-ranging condors [1]. The dependent variable in our analyses was the concentration of lead in the blood of a condor determined within five days after capture. Blood lead levels were determined using a portable field tester (LeadCare Blood Lead Testing System). Some blood samples were also analysed by atomic absorption spectroscopy at the Louisiana State University Diagnostics Laboratory using a Perkin Elmer Analyst 800. Levels of lead in the same blood sample measured using the field tester and in the laboratory were strongly correlated, but laboratory measurements gave significantly higher values (see Figure 2 of reference [1]). Using 99 cases in which the lead concentration in the same blood sample had been determined by both methods, we found that the mean concentration of lead measured in the laboratory was larger than that from the field tester by a factor of 1.914. In all analyses we therefore used a laboratory determination whenever one was available and otherwise adjusted the field tester measurement using this correction factor.

Figure 2Hypothetical changes in blood lead concentration over time for California condors moving between zones with high and low daily risk of ingesting lead.
We modeled the blood lead level in each free-ranging condor in relation to the locations it had used before it was recaptured for testing. During the study period, roost locations of condors marked with VHF or satellite tags were determined on the majority of days for all tagged condors, and attributed to one of the following five zones; Paria (Vermilion Cliffs), Colorado River Corridor, Kaibab Plateau, South Zone and North Zone (Utah). A location was taken to be a roost location if it was obtained later than16.00h. local time. Condors are known to range widely, even within a day [3], so the ideal analysis would take into account the bird's location at several times during each day. However, only the data for satellite tagged birds would permit this. Roost locations were recorded for as many days as possible during the period beginning with the initial release of each bird, or its release after capture for blood lead monitoring and ending with another capture at which blood lead concentration was determined. For days on which the roost location was not recorded, we interpolated the roost zone used by assuming that it was the same as that on the nearest day with data available. Overall, it was necessary to interpolate the roost zone on 27.2% of days, with the range of this proportion for individual birds being 11.1% to 59.9%. We had eligible data derived from 60 individual condors consisting of 322 pairs of blood lead measurements preceded by periods comprising, in total, 41,230 bird-days with known or interpolated roost locations.

Numbers of deer, elk and buffalo reported as killed by hunters in each zone in 2005–2007 were obtained from the Arizona Game and Fish Department and the Utah Department of Natural Resources. We estimated the number of carcasses and gut piles potentially contaminated with lead and left in the field for scavengers by using information collected on the proportion of kills made with lead ammunition and the number of lead-killed animals from which gut piles were brought in by hunters for safe disposal. We also assumed that in addition to the number of animals reported as killed with lead bullets, an additional 10% of that number were wounded and died unrecovered soon after, thereby becoming available to condors.

Analysis and statistical modeling of blood lead data
We assumed that, with no further ingestion, the relationship between blood lead concentration and time after ingestion of fragments of metallic lead could be described by a simple three compartment model, with one-way movement of lead between successive pairs of compartments. Although this model is a simplification, it has the advantage of requiring the estimation of only two parameters and seems likely to capture the main features of real changes in blood lead. We assumed that a constant proportion of the ingested lead enters the blood from the gut per unit time and that fragments are not expelled from the gut within the period that significant absorption is occurring. Hence, the proportion of the lead ingested that remains in the gut at time t (in days) since ingestion is given



 since ingestion is given by exp(−k1t), where k1 is a constant, and (1−exp(−k1t)) is the proportion of lead ingested that has moved from the gut to the blood by that time. We also assumed that a constant proportion per unit time of the lead present in the blood was lost to another compartment, such that the amount in the blood would decline by a proportion (1−exp(−k2)) per day in the absence of absorption. The quantity of lead in the blood, as a proportion of that ingested, is then given by the function

(1)
Assuming that blood volume is constant, blood lead concentration is proportional to g(t). Note that this expression approximates to g(t) = exp(−k2t) when k1 is much larger than k2. That is, when absorption from the gut is very rapid, blood lead concentration declines exponentially with time since ingestion. The model is illustrated for a single value of k2 and three values of k1 in Fig. 1.

Figure 1Models of the relationship between blood lead concentration and time since ingestion of metallic lead in California condors.
We next used the function g(t) to explore how the concentration of lead in the blood of an average condor would be expected to change over time, given the possibility of ingestion of lead on more than one day. We assumed that the condor spends some time in areas where there is a high risk each day of ingesting lead and some time in low risk areas. We imagined a large number of condors, all showing the same movement pattern. On each successive day, the average quantity of lead ingested by the birds would, if it was all absorbed immediately, increase the

When you report back after reading this I will post the rest after I quiz you

Zuma
is this the documentary?
(:::.) The ABO path is a new frontier to the past!

Offline Zuma

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Re: Condors and lead
« Reply #107 on: November 12, 2015, 04:55:30 pm »
Jojo I didn't know that was a verb. :embarassed:
Thanks

Iowa-- no does it look like a TV program?? ???
I am sure you will have more and more questions.
I hope they are more challanging.
Are you ready to take the quiz?
Do you think letting Condors eat lead is ethical?
Would you let a Condor eat lead?
If you are a good detective the past is at your feet. The future belongs to Faith.

Offline iowabow

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Re: Condors and lead
« Reply #108 on: November 12, 2015, 05:01:33 pm »
Jojo I didn't know that was a verb. :embarassed:
Thanks

Iowa-- no does it look like a TV program?? ???
I am sure you will have more and more questions.
I hope they are more challanging.
Are you ready to take the quiz?
Do you think letting Condors eat lead is ethical?
Would you let a Condor eat lead?
I was waiting to get the name of the doc. I really did want to watch it before I made a judgement. You said this was about that now so I just want to be up to speed. What was the name of the documentary?
« Last Edit: November 12, 2015, 10:35:35 pm by iowabow »
(:::.) The ABO path is a new frontier to the past!

Offline Marc St Louis

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Re: Condors and lead
« Reply #109 on: November 12, 2015, 06:06:01 pm »
Actually the body does get rid of lead over time.  I know a few die hard competition pistol shooters who were told by their doctors that they had to stop shooting for awhile so the lead levels in their blood could drop below a certain level.  Another tidbit of information, too much lead in your system makes you impotent.
Home of heat-treating, Corbeil, On.  Canada

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Offline mullet

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Re: Condors and lead
« Reply #110 on: November 12, 2015, 09:19:47 pm »
Wow! This would be good if Ancient Tech would check in.
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Offline bubby

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Re: Condors and lead
« Reply #111 on: November 12, 2015, 09:41:14 pm »
Wow! This would be good if Ancient Tech would check in.




Lol not sure how he would fit overshot technology into the mix
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Offline sleek

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Re: Condors and lead
« Reply #112 on: November 12, 2015, 10:07:52 pm »
After reading this I have removed all the lead from my archery equipment. 
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Offline Zuma

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Re: Condors and lead
« Reply #113 on: November 12, 2015, 11:28:30 pm »
Thanks Marc for your informative post
Iowa it was on a public TV station. WVPT I think?
Zuma
« Last Edit: November 13, 2015, 05:33:32 am by Zuma »
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Offline iowabow

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Re: Condors and lead
« Reply #114 on: November 13, 2015, 07:33:02 am »
Thanks Marc for your informative post
Iowa it was on a public TV station. WVPT I think?
Zuma
what state and city?
(:::.) The ABO path is a new frontier to the past!

Offline iowabow

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Re: Condors and lead
« Reply #115 on: November 13, 2015, 07:47:10 am »
So their numbers now are 400? Half in the wild. This is pretty cool considering they were in the 20s
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Offline Zuma

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Re: Condors and lead
« Reply #116 on: November 13, 2015, 12:09:11 pm »
So their numbers now are 400? Half in the wild. This is pretty cool considering they were in the 20s

Harrisonburg or Front Royal Va
 Do you think the documentary will help you to decide whether
 the birds are abused?
Just remember the last scene. The handler releases the Condor
back to the wild after being captured and processed for lead
 poisoning. For what? To go back and eat more lead? BA
Really not great statistics considering the losses and
suffering of the ones that were and continue to be sacrificed.

I am going to lock the thread 8 pages and no resolve.
Please respond to the other thread. Reprehensible.
Zuma
If you are a good detective the past is at your feet. The future belongs to Faith.

Offline JW_Halverson

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Re: Condors and lead
« Reply #117 on: November 13, 2015, 03:56:11 pm »
Talked with several prominant wildlife rehabilitators about why the condors have been released. Some of the reasons include:

1) Placeholding.  Without a population, another vulture species will expand into that niche making it exceedingly difficult for the condor to be reintroduced.  Food resources, nesting resources, and other necessities will be scarcer due to competition and put the condor into an exponentially more difficult position.
2) Culture.  Believe it or not, vultures are intelligent enough that they pass along learned lessons, the definition of culture.  In the case of these birds, culture is nesting territories, feeding strategies, and cohabitative strategizing (birds sharing the same core territory take cues from each other's soaring patterns to signal the presence of food, etc) that improves survivability.
3) Wildness.  Birds raised in captivity do not learn how to process what their instincts tell them to do. From choosing a mate, to nesting techniques and nest site choice, imprinting, territorial imprinting, and likely hundreds of other things they do not learn in the captivity as they are raised by parents in the wild.  Not being properly "wild" leaves the bird with a lesser set of survival skills.
4) Supporting wild populations with captive raised allows the captive birds to "school" off the wild birds greatly increasing their chances of survival.
5) Natural genetic selection for hardiness and survival.  Captive breeding will not improve the stock and only add to the deselection for hardiness.  This was an issue in the early days of peregrine reintroduction.  Artificial insemination may have worsened things as quite a number of captive bred peregrines produce sterile eggs. (My first peregrine was a breeding coop reject that did not provide a viable egg in 7 years of breeding despite being a solid flyer and hunter).

These are just the first three people that have responded to my request from the community that deals with these issues on a daily basis.  As further responses come in, would you like me to post those as well?  Or would you rather just contact the persons that are actually working with condor recovery to ascertain the answers you are asking to receive? I bet I can get an email address for you pretty quick.
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Offline Zuma

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Re: Condors and lead
« Reply #118 on: November 13, 2015, 05:16:13 pm »
Thank you very much JW. Makes good sense. :)
Please don't think this is negativity. :o

Although these are solid ideas for what I may think
of as a normal reintroduction (like into a lead free area)

Can you assure us that the folks you talk to can
justify the losses and stress the birds endure?
I would be interested to see Who will do that?
Not a individual but the organization they represent.
Also it would be nice to know how long it might take
to have a lead free enough environment to sustain
the present and future population.
I would suggest at least slowing or moving the studies to
places void of the lead problem. I don't know if that
is possible? What I alone, think will make zero impact
 one way or the other. But by good efforts like yours
JW and others of your ilk. I think these big birds plight
will improve. I hope so. It would be my pleasure and I
am quite sure other members to, if you would post
whatever information you can find out, concerning Condors
and lead. I also think there are quite a few folks here that
would go out of their way to help you if they could. I would.
Zuma
 I'll keep this thread open as long as you all like, if the
resopnses are  meterd and informative. thanks
If you are a good detective the past is at your feet. The future belongs to Faith.

Offline JW_Halverson

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Re: Condors and lead
« Reply #119 on: November 13, 2015, 05:59:14 pm »
6) Expense.  Keeping these bird in captivity is extraordinarily expensive.  And if you remove all of them from the wild to caretake them, then you have to go get all the Kansas skipper butterflies, the red nosed dace, the stonerollers, the prairie moccasin orchids, etc, etc. 
7) Lead free hunting zones and voluntary lead ammo exchanges are expanding and increasing.  If the birds are not there, then when do they know the range is lead free for them?

I am heartened by how public opinion favorable to voluntary choice to go lead free and the number of people taking the ammo exchange has increased in the last few years.  Personal anecdotes from people having success using the copper solids/hollowpoints is helping shift the load, especially.  And despite how it shares the name with a certain Kennebago driver, I am a huge fan of my Barnes TSX rounds.  Puts the game in the DRT (dead right there) category.

Moving the study to another area that is lead free?  Where is that, pray tell?  Considering they can be 200+ miles further down the road in just a day, basically we would need to start with a Federal ban on all lead ammunition in the southwestern 1/4th of the continental United States as well as forcing a foreign country to adopt our laws on the issue.  Considering the luck we have had getting Mexico's help in the war on drugs, I doubt much traction will come with that idea. 

For years I have opposed a Federal ban on lead ammunition because it is an ultra-wide brushstroke where a pencil line would suffice. If hunters switch to nontoxic for the actual hunt, the problem goes away.  It is a conservation issue, not one where we want legislation coming in ham fisted.
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.