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And so Lonesome George passes away and the Pinta Island tortoise becomes extinct.http://www.galapagos.org/newsroom/the...
Lead Poisoning Blocks Recovery of California Condor Population.http://www.sciencedaily.com/releases/...
I am confused by the claim and the supporting evidence.Claim: Ammunition is the principle source of harmful exposure exposure to lead for California condors.
A later paragraph seems to contradict that claim.
"Efforts in California to address the problem of lead exposure have led to state regulations banning the use of lead ammunition in condor habitat. A partial ban went into effect in July 2008 and was later expanded. So far, however, researchers have found no evidence that the ban has resulted in a reduction in blood lead levels in condors."
If lead ammunition is the principle source of harmful lead exposure, one would expect that in 4 years of not using lead ammunition, or to be practical at least a greatly reduced amount of it, that there would be some commensurate reduction in the blood lead levels in condors. Therefore it seems the claim that lead ammunition is the principle source of harmful lead exposure must be false.
Also questionable is the vague term "ammunition". What specifically are we talking about here? Lead shot (bb's) or lead slugs from shotguns or lead bullets from hunting rifles or pistols? There are important distinctions here that the article does not discuss.
The study does not appear to firmly establish the presumption that "lead ammunition" is the principle source of lead exposure. Neither does it much discuss, consider nor rule out other possible principle sources of lead exposure. The report cites another study that contradicts the claim that ammunition is the principle source of lead exposure. Finally, the article fails to making important distinctions between types of "lead ammunition" and their use.
Either the study itself or just the report of the study is at at best poor. At worst they are highly suspicious of confirmation bias against hunting or hunting practices.
David, is it really good practise to claim that a study is biased and draws false conclusions based on a press release? It is true that this may be the only access you have to the findings of the study but press releases are by their very nature limited. Moreover, the issues you raise are readily answered in brief by the press release itself:
Re: prevalence of lead poisoning post-ban:
"Unfortunately, even if only a few people are still using lead ammunition, there will be enough contaminated carcasses to cause lead poisoning in a significant number of condors," Finkelstein said. "We found that over the course of 10 years, if just one half of one percent of carcasses have lead in them, the probability that each free-flying condor will be exposed is 85 to 98 percent, and one exposure event could kill a condor."
These findings suggest that greater regulation of lead-based ammunition may be necessary to protect condors, she said. Although alternatives to lead ammunition are available, regulations limiting the use of lead-based ammunition face stiff opposition from hunting organizations and gun-rights groups.
Re: 'ammunition':
They can ingest fragments of lead bullets from feeding on carcasses or gut piles of animals shot by hunters.
Re: lead ammunition as the principle source of lead exposure,
The UCSC researchers are able to identify the source of the lead in a condor blood sample using a "fingerprinting" technique based on the isotope ratios found in different sources of lead. Condors raised in captivity that have not yet been released into the wild have low blood lead levels, with lead isotope ratios that fall within the range of background environmental lead in California. Most free-flying condors, however, have lead isotope ratios consistent with those found in ammunition, and the higher a bird's blood lead level, the more likely that its lead isotope ratio matches the lead in ammunition.
Of course the paper itself goes into much more detail. On the subject of isotopic analyses, for example, the authors describe the consistency of the technique in the context of identifying deteriorating lead-based paint as a contaminant in one affected pair.
With regards to the suspicion of an anti-hunting bias, I would counter with the observation that at no point do the authors argue for the cessation of hunting, simply for the elimination of lead-based ammunition. The source of the ammunition, I should add, does not matter. What matters is that the lead is being ingested and poisoning the birds.
Re: prevalence of lead poisoning post-ban:
"Unfortunately, even if only a few people are still using lead ammunition, there will be enough contaminated carcasses to cause lead poisoning in a significant number of condors," Finkelstein said. "We found that over the course of 10 years, if just one half of one percent of carcasses have lead in them, the probability that each free-flying condor will be exposed is 85 to 98 percent, and one exposure event could kill a condor."
These findings suggest that greater regulation of lead-based ammunition may be necessary to protect condors, she said. Although alternatives to lead ammunition are available, regulations limiting the use of lead-based ammunition face stiff opposition from hunting organizations and gun-rights groups.
Re: 'ammunition':
They can ingest fragments of lead bullets from feeding on carcasses or gut piles of animals shot by hunters.
Re: lead ammunition as the principle source of lead exposure,
The UCSC researchers are able to identify the source of the lead in a condor blood sample using a "fingerprinting" technique based on the isotope ratios found in different sources of lead. Condors raised in captivity that have not yet been released into the wild have low blood lead levels, with lead isotope ratios that fall within the range of background environmental lead in California. Most free-flying condors, however, have lead isotope ratios consistent with those found in ammunition, and the higher a bird's blood lead level, the more likely that its lead isotope ratio matches the lead in ammunition.
Of course the paper itself goes into much more detail. On the subject of isotopic analyses, for example, the authors describe the consistency of the technique in the context of identifying deteriorating lead-based paint as a contaminant in one affected pair.
With regards to the suspicion of an anti-hunting bias, I would counter with the observation that at no point do the authors argue for the cessation of hunting, simply for the elimination of lead-based ammunition. The source of the ammunition, I should add, does not matter. What matters is that the lead is being ingested and poisoning the birds.
Thon,Thanks for the response. I appreciate the defense of the study and the important work being done to protect the California condor. However, compared to the importance of the study, the report itself could be better and we would all do well to freely question everything from a press release to a scientific study from time to time.
Some clarification should be made here that the issues are not with the claims made in the report, but are of an editorial nature with the presentation and support of those claims. We should all demand higher standards when it comes to our news, scientific or not. Maybe if we all did this more often the fake news the media feeds us everyday would go away.
First, a "claim" of bias was not made but merely suspected due to some of the failings of the report. Also, false conclusions were not made but "shaky speculations" were proposed to illustrate some of the article's problems, most of which you addressed very well.
However, the main question that is still unanswered is how does one reconcile the recommendation for greater regulation of lead ammunition when according to the article, 4 years of of a ban on lead ammunition has had absolutely no impact?
An unaccounted for contradiction of a recommendation made in the same paper rather effectively removes support for the recommendation, don't you think?
I will help you out here. There is another report with a link on the same page as this one that makes the point with more clarity. http://www.sciencedaily.com/releases/... discusses two UC Davis studies indicates the following:
“One of the new UC Davis studies found direct evidence that lead levels rose in turkey vultures during deer hunts and in areas with wild pig hunts. This was the first-ever investigation of blood lead levels in free-flying turkey vultures.
The other study, the first to examine the effects of the 2008 law on any wild animals, found that the lead-ammunition ban in California condor range reduced lead exposure in golden eagles and turkey vultures in 2009.”
This article does several things:
1) Disproves the claim in the first article that a 4 year long ban on lead ammunition have had no impact.
2) Actually supports the suggestion that bans on lead ammunition work and should be expanded.
3) Reveals studies that demonstrate other species of scavenger birds are also impacted by lead exposure.
Also, please note: “lead levels rose in turkey vultures during [periods of hunting]” makes the point with much more clarity than, “. . .[condors] can ingest fragments of lead bullets from [large animals that were shot].” The first is a statement of fact. The second is only a possibility that only begs the question.
Regarding suspicions of anti-hunting bias, it is true that the authors do not specifically argue for the cessation of hunting. As pointed out however, the report does, “suggest that greater regulation of lead-based ammunition may be necessary to protect condors.” This suggestion is vague and it could have been more helpful if it were more specific with very little effort.
To expand on the issue of vagueness in the term “lead ammunition” there are two basic types of “lead ammunition”. Shot and bullets. Shot is generally used for smaller game, and bullets are more commonly used on the larger game the article cites as sources of lead exposure to condors. The article fails to take advantage of the differences in these types.
The ban on “lead ammunition” is typically a ban on lead “shot”. This was brought about through the realization that lead shot often contaminates free standing water leading to lead exposure for many types of animals including fish. This realization lead to the development of non-toxic replacements for lead shot such as steel, bismuth, or tungsten.
Rifle or pistol bullets are generally not regulated. If the condors are being exposed to the offal of "larger" game as cited, then the article could have more helpfully suggested additional regulations concerning the configuration and content of specific lead "bullets" in addition to the current bans on lead shot. At the same time this would help explain why the current bans on lead “shot”, most commonly used on smaller game, have had little or no impact in reducing lead exposure.
Instead the article leaves the reader with the vague suggestion of additional regulations against “lead ammunition”. In all honesty, without considering the different types of ammunition, what additional regulations would the typical reader assume? What solution is the typical reader going to assume in light of the fact the article indicated the current bans on lead ammunition have had no effect?
Identifying ammunition as the principle source is much less of a problem to accept. However, with the devil being in the details I am curious to examine this study. Obviously the explanation of those details falls outside the scope of this news report. Fingerprinting lead contamination to ammunition based on the ratios of only 4 stable lead isotopes seems an intriguing study indeed. Mr. Holmes would approve of a catalog of such information. I wonder if this fingerprinting is precise enough to identify when and by whom it was manufactured?
Emma wrote: "Richard Dawkinas and E. O. Wilson seem to be having a bit of a tiff over some of the evolutionary theories in E. O. Wilson's new book. Perchance one for us to get our teeth into.http://www.guardi..."
Yeah, I just printed off a stack of reviews of Wilson's book, will have to read it soon. Mark Borrello has also recently written a book on the history of 'group selection'.
David, thanks for taking the time to reply. With your leave I'll occasionally use excerpts from your post, prefaced 'D:' to ground this response.
Your second paragraph, "Some clarification...", is on point. Too often press releases and reports of scientific studies in popular media are sub-standard. I wouldn't agree that this is so with regards to the release in question. It could certainly do with greater editorial control but there are no significant issues. But that’s by the by.
With regards to the claim of bias, that was poorly worded on my part. As to the 'false conclusions', I was referring to your sentence: "Therefore it seems the claim that lead ammunition is the principle source of harmful lead exposure must be false." This is indeed 'shaky speculation'. My initial point in this regard, that you claim the study draws false conclusions based on a press release, stands.
D: "...how does one reconcile the recommendation for greater regulation of lead ammunition when according to the article, 4 years of of a ban on lead ammunition has had absolutely no impact?"
By using a term such as 'reconcile', you suggest a dichotomy where none exists. The study describes lead ammunition as the primary source of lead poisoning in condors, leading one of the principal researchers to suggest that greater regulation of the ban may be required. It's not an inappropriate suggestion. Also, the article does not state that the band ‘had absolutely no impact’; see below.
D: "1) Disproves the claim in the first article that a 4 year long ban on lead ammunition have had no impact."
The article does not make this claim. It states that "researchers have found no evidence that the ban has resulted in a reduction in blood lead levels in condors." This is not the same thing.
D: "2) Actually supports the suggestion that bans on lead ammunition work and should be expanded."
The contexts here are the focal species. It does not necessarily follow that if a practise is effective with regards to species X and Y that it will also be effective with regards to species Z. In the context of condors the data suggest that the ban is inefficient or insufficiently enforced.
D: "This suggestion is vague and it could have been more helpful if it were more specific with very little effort."
This is true. But a request for more explicit detail depends on such detail being available. It also requires the commenter to consider the provision of such detail to be necessary. In this instance I would suggest the former to be more likely, the detail in question being methods of regulation. This may rankle but beyond being an irritant for some, there is no inherent problem.
Re: 'lead ammunition'
Allow me to return the offer of assistance. The methodology contains the following: “Ammunition samples were obtained through several means, including an ammunition exchange program in central California, donations from hunters, recovery from shot carcasses, or previously published information (26), whereas lead shot/fragments were recovered from lead-poisoned condors.” The authors also cite several sources when they speak of lead ammunition. The first, Walters et al. (2008), states: "Generally condors are exposed through feeding on carcasses or gut piles of animals shot with lead bullets or lead shotgun ammunition". Evidently this is not made explicit in the press release but then your comment on the whole begs the question of how much detail you would have required the press release to contain.
D: "the article could have more helpfully suggested additional regulations concerning the configuration and content of specific lead "bullets" in addition to the current bans on lead shot" (and other associated comments thereafter)
This was not the purpose of the article nor was this discussed in the paper. Indeed, the paper is an analysis of lead poisoning in condors; the authors make no explicit recommendations based on their conclusions.
Walters JR, et al. (2010) Status of the California condor (Gymnogyps californianus) and efforts to achieve its recovery. Auk 127:969–1001.
Your second paragraph, "Some clarification...", is on point. Too often press releases and reports of scientific studies in popular media are sub-standard. I wouldn't agree that this is so with regards to the release in question. It could certainly do with greater editorial control but there are no significant issues. But that’s by the by.
With regards to the claim of bias, that was poorly worded on my part. As to the 'false conclusions', I was referring to your sentence: "Therefore it seems the claim that lead ammunition is the principle source of harmful lead exposure must be false." This is indeed 'shaky speculation'. My initial point in this regard, that you claim the study draws false conclusions based on a press release, stands.
D: "...how does one reconcile the recommendation for greater regulation of lead ammunition when according to the article, 4 years of of a ban on lead ammunition has had absolutely no impact?"
By using a term such as 'reconcile', you suggest a dichotomy where none exists. The study describes lead ammunition as the primary source of lead poisoning in condors, leading one of the principal researchers to suggest that greater regulation of the ban may be required. It's not an inappropriate suggestion. Also, the article does not state that the band ‘had absolutely no impact’; see below.
D: "1) Disproves the claim in the first article that a 4 year long ban on lead ammunition have had no impact."
The article does not make this claim. It states that "researchers have found no evidence that the ban has resulted in a reduction in blood lead levels in condors." This is not the same thing.
D: "2) Actually supports the suggestion that bans on lead ammunition work and should be expanded."
The contexts here are the focal species. It does not necessarily follow that if a practise is effective with regards to species X and Y that it will also be effective with regards to species Z. In the context of condors the data suggest that the ban is inefficient or insufficiently enforced.
D: "This suggestion is vague and it could have been more helpful if it were more specific with very little effort."
This is true. But a request for more explicit detail depends on such detail being available. It also requires the commenter to consider the provision of such detail to be necessary. In this instance I would suggest the former to be more likely, the detail in question being methods of regulation. This may rankle but beyond being an irritant for some, there is no inherent problem.
Re: 'lead ammunition'
Allow me to return the offer of assistance. The methodology contains the following: “Ammunition samples were obtained through several means, including an ammunition exchange program in central California, donations from hunters, recovery from shot carcasses, or previously published information (26), whereas lead shot/fragments were recovered from lead-poisoned condors.” The authors also cite several sources when they speak of lead ammunition. The first, Walters et al. (2008), states: "Generally condors are exposed through feeding on carcasses or gut piles of animals shot with lead bullets or lead shotgun ammunition". Evidently this is not made explicit in the press release but then your comment on the whole begs the question of how much detail you would have required the press release to contain.
D: "the article could have more helpfully suggested additional regulations concerning the configuration and content of specific lead "bullets" in addition to the current bans on lead shot" (and other associated comments thereafter)
This was not the purpose of the article nor was this discussed in the paper. Indeed, the paper is an analysis of lead poisoning in condors; the authors make no explicit recommendations based on their conclusions.
Walters JR, et al. (2010) Status of the California condor (Gymnogyps californianus) and efforts to achieve its recovery. Auk 127:969–1001.
Thon,Well cool, it seems I’ve found a kindred spirit that shares the joy of being a gadfly, not to simply argue and disagree, but to improve understanding.
I will borrow your notation for excerpts:
I will have to catch you on a technicality. I did not commit to any claims because I hedged here and qualified it using the word “seems”
D: “Therefore it seems the claim that lead ammunition is the principle source of harmful lead exposure must be false.” No claim is being made here other than one could draw this conclusion as the article seems to allow it.
The Effectiveness of the Ban on Lead Ammunition Problem
It seems you catch me on a technicality too and that is a very good thing.
T: The article does not make this claim. It states that “researchers have found no evidence that the ban has resulted in a reduction of blood lead levels in condors,”. This is not the same thing.
We may be splitting hairs here but that is quite Ok. Let us go with, “No evidence” that the ban has resulted in a reduction of blood levels in condors. This sets up the following non-sequitur.
1. A ban on lead ammunition will result in a reduction of blood lead levels in condors.
2. There is no evidence that the ban has resulted in a reduction of blood lead levels in condors.
3. Therefore, These findings suggest that greater regulation of lead-based ammunition may be necessary to protect condors
I must re-assert there is definitely a problem here. There is no evidence that banning tans-fats from McDonalds has resulted in a reduction of blood lead levels in condors, either, but according to the logic that this article must be using maybe greater regulation of trans-fats are necessary to protect condors?
Again, this is simply a problem with this specific article. Other articles that we have both found point to some success in lowering blood lead levels in condors and other birds as a result of the ban on lead ammunition.
T: The contexts here are the focal species. It does not necessarily follow that if a practise is effective with regards to species X and Y that it will also be effective with regards to species Z. In the context of condors the data suggest that the ban is inefficient or insufficiently enforced.
You are absolutely right. Not only may the effectiveness of certain actions have different levels of impact for different species, Condors may be more sensitive to lead than other scavenger birds. However, nowhere does either article mention varying effectiveness of the ban on lead ammunition or varying sensitivity to lead exposure among scavenger birds. Without information from sources outside of these two articles we don’t we are left without this useful knowledge. The reader is left to assume (or not) the same effectiveness of actions and the same sensitivity to lead exposure of all scavenger birds are equal. This could easily be cleared up in a sentence or two from other studies that shed light on this question.
T: “. . . how much detail you would have required the press release to contain?”
As you most awesomely pointed out, “Walters et al. (2008), states: "Generally condors are exposed through feeding on carcasses or gut piles of animals shot with lead bullets or lead shotgun ammunition",. Shot, bullets, and slugs, all three mentioned. This would have been good. But instead the article hurt itself by specifying “large” animals, lead fragments (assuming bullets here), where everywhere else they were vague about the types of ammunition, and leaving out simple details of the current ban.
As an aside I wonder if this would be an alternate or additional action to aid affected animals: Antioxidants Can Reduce The Toxic Effects Of Lead http://www.sciencedaily.com/releases/... Maybe condors should eat more blueberries?
Finally:
T: “. . .the authors make no explicit recommendations based on their conclusions.”
You are absolutely right, again. However they do say, “These findings suggest that greater regulation of lead-based ammunition may be necessary to protect condors.” They might not make “explicit” recommendations, but they do make recommendations based on their conclusion.
I profess I generally accept the claims as well as their suggestions made in this report, but not from this report as much as others I have seen. I don't know, but it seems to me they just could have avoided some criticism and spend less time defending it by being a little clearer in making their point.
Anyway, thanks for the additional info from the other study. I will see if I can find it or others like it. I think we’ve beat this dead horse enough though for now. For two people who seem to agree with the spirit of the report we should hang our hats up on this one and practice our gadflying on another one in the near future. What will we do if we ever get one that we actually disagree on? I suspect we both may learn something.
David,
I do indeed strive to maintain an open mind during debates so that I might gain greater understanding of the matter at hand. I also generally agree that there is little point in making this a prolonged discussion centred on finer details. That said, I would, with your forgiveness, like to offer one correction.
The tripartite non-sequitur you highlight and the subsequent analogy are fallacious. In constructing this argument you missed out a key observation:
2 (your ‘2’ being re-classified as 3). Analyses described continued high blood lead levels in condors, the primary source of which was lead-based ammunition.
Thus the argument logically reads: hypothesis; results; conclusion; recommendation. Inclusion of this observation effectively deals with what you perceived to be a flaw. It follows that to make your analogy directly applicable, one must be able to identify McDonald’s-based trans-fats as the source of trans-fats in condors.
Okay, I'm done gadflying.
I do indeed strive to maintain an open mind during debates so that I might gain greater understanding of the matter at hand. I also generally agree that there is little point in making this a prolonged discussion centred on finer details. That said, I would, with your forgiveness, like to offer one correction.
The tripartite non-sequitur you highlight and the subsequent analogy are fallacious. In constructing this argument you missed out a key observation:
2 (your ‘2’ being re-classified as 3). Analyses described continued high blood lead levels in condors, the primary source of which was lead-based ammunition.
Thus the argument logically reads: hypothesis; results; conclusion; recommendation. Inclusion of this observation effectively deals with what you perceived to be a flaw. It follows that to make your analogy directly applicable, one must be able to identify McDonald’s-based trans-fats as the source of trans-fats in condors.
Okay, I'm done gadflying.
Thon,One act of forgiveness - granted. Although you will have to return the favor. After this, I promise to quit debating, no matter how awesome your inevitable reply is. :)
Hopefully Emma will post something else we can debate before we get bored and start discussing this one again?
How does your suggestion to modify the non-sequitur make things better?
1. Hypothesis
A ban on lead ammunition should result in a reduction of blood lead levels in condors.
2. Results
[Post-Ban] analyses described continued high blood lead levels in condors, the primary source of which was lead-based ammunition.
3. Conclusion
There is no evidence that the ban has resulted in a reduction of blood lead levels in condors.
4. Recommendation
Therefore, These findings suggest that greater regulation of lead-based ammunition may be necessary to protect condors. [Still does not follow]
Inserting 2. as suggested only seems to emphasize 3. by establishing a little temporal order, ie., there is no evidence of improvement in blood lead levels AFTER the ban. Now 2. and 3. both kill any chance of causation between "bans" and lower blood lead levels so cause cannot be established.
Note: to be clear it is not being suggested that lead ammunition is not the primary cause of toxic blood lead levels in condors, but there is only a lack of evidence indicating that the "ban" on lead ammunition has improved blood lead levels, which the article flat out states. (you are quite correct earlier by alluding to the idea that a an absence of evidence is not evidence of absence. This doesn't always hold up but it seems to in this case)
It is a good thing we know 3 is false, otherwise some of the less responsible might use the article to go back to using lead.
It still "sounds" a little insane to me, you know, doing the same thing over and over and expecting different results? (kind of like this discussion..LOL Kidding) I suppose to keep ones sanity they will have to keep in mind that "greater" regulations are not the same as regulations in the same sense that doing more of the same thing in greater amounts is not the same thing as doing the same thing. What do you think?
Since you enjoyed [tearing apart] my other wonderfully witty analogy, I will try a simile to let you know I understand your point of view. Increasing the regulations is like turning on a radio but not hearing it clearly until you increase the volume to an audible (effective) level. Now, so you understand my point of view, the article could have more easily justified the suggestion of modifying the ban but made the ban sound like a broken radio where no amount of twisting the volume knob is going to make it audible. Or, maybe I just need a hearing-aid. :)
The End. I promise...maybe.
http://www.guardian.co.uk/science/201...