Condor Watch Talk

lead poisoning

  • inaspin by inaspin

    I just had a look at the blog posting on lead poisoning - which answered my initial query. Glad to know it isn't always fatal. Are there any signs we could look out for whist we are checking the images?

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  • vjbakker by vjbakker scientist

    Great question. If a bird looks clearly unwell, you could mention it in Talk, but since these are archived photos, it wouldn't give us real time information. One of the things we are hoping to do with the current project is to identify indicators for lead poisoning based on the current set of classifications and on blood lead data concurrent with the photos. We are hoping that these indicators might be usable in real time in the future. For example, the field biologists have told us that sick/lead poisoned birds may change their dominance rank in the social structure of the pack. We are hoping to detect such changes from who hangs out with whom in the photos.

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  • inaspin by inaspin

    Are there any statistics on how many birds have been lost to lead poisoning since the programme began? Or how many birds from the original population are still alive and kicking?

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  • myraf by myraf scientist

    Hi Insapin, you might like this paper: http://www.peregrinefund.org/docs/pdf/research-library/2012/2012-Rideout-california-condors.pdf
    which discusses the causes of mortality for free-flying condors once the release program began and out how many birds were determined to die of lead poisoning, etc.. But to summarize, lead poisoning is the number one mortality factor for juvenile and adult free-flying condors. There is one bird from the 'wild' original population that is now free-flying, condor 21, he was captured in 1987 and then part of the captive breeding program for over 10 years and then released back to the wild. He is still alive today and you might see him in the photos. I need to check to confirm if any other of the original wild flock are still alive in the captive program.

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  • inaspin by inaspin

    Thanks myraf, I shall check out the paper. Sounds like there is a need for an "if you shoot it, you eat it" clause. Or bury it if the target species is not considered edible.
    I'll keep an eye out for condor 21

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  • myraf by myraf scientist

    I got the official tally and only one of the original 'wild' condors is free-flying currently:
    SB# 21 - male - captured 19 April 1987, released to the wild 1 May 2002. He has mated with SB# 192 from the Ventana flock. They have fledged a number of chicks.
    There are five five remaining still in captivity:
    SB# 20 - AC4 - male - captured 26 June 1985, Currently at the captive breeding program associated with the San Diego Zoo Global
    SB# 23 - Paxa - male, captured 5 Dec. 1982, Currently at the captive breeding program associated with the San Diego Zoo Global
    SB# 11 - Tama - female - captured 6 Sept. 1985, after being sent to the Oregon Zoo she was returned to CA, currently at the captive breeding program associated with the LA Zoo
    SB# 5 - AC6 - male - captured 21 April 1986. Too ill to be released, currently at the captive breeding program associated with the LA Zoo
    SB# 1 - TopaTopa- male, captured as 1(?) year old immature on 12 Feb.1967, too imprinted to be released, currently at the captive breeding program associated with the LA Zoo

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  • wreness by wreness moderator

    I think this is a pic of #21 - http://talk.condorwatch.org/#/subjects/ACW00007b5

    add: well this is weird....I'm adding this a few hours after first post - just got this now. Here you go, for sure!

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  • inaspin by inaspin in response to myraf's comment.

    So, #21 has some contemporaries, just not flying free. Good to know. Thanks for the amount of effort it must have taken to get all that together.

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  • Canmore1919 by Canmore1919

    A couple of lead related questions...
    Do eagles suffer a higher proportion of lead poisoning, gIven their dominance when eating or do they metabolize the lead in a different way from condors that allows them to safely consume some lead?
    Or do the condors and eagles eat different parts of the carcass perhaps with one part of carcass having a higher proportion of lead?

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  • myraf by myraf scientist

    Great questions! We don't know what proportion of eagles are lead poisoned to compare with condors because, as nearly every condor is monitored on a near daily basis, eagles are not. We do know that eagles also suffer from lead poisoning and existing evidence suggests that they are poisoned from ingestion of spent lead ammunition embedded in carcasses (as are condors). We just don't have comparable data to determine if eagles are poisoned more or less frequently than condors. We have no data that suggests eagles are more or less susceptible to lead poisoning. But, lead has been shown to extremely toxic across many vertebrate species.

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  • wreness by wreness moderator

    Canmore1919 - sent you a message with some details after talking to a friend who volunteers at an eagle rescue center in Vancouver, B.C. I figured since it wasn't "condor" talk I wouldn't post the whole thing 😃

    Short and sweet version - Hawk (his real name! He's Native American - Nez Perce and Blackfoot. His whole famil are named after birds. I'm envious he gets the cool names!) said that close to 25% of the eagles they rescue are ill or injured as a direct result of lead poisoning or injuries related to becoming ill from lead (drowning, flying into power lines, getting hit by cars, attacked by other animals, etc)

    The same sad story as our condors. He also detailed the food chain horror that goes on with lead used in fishing and how it's contributing massively to poisoning in eagles and other birds of that area.

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  • myraf by myraf scientist

    thanks Wreness! I didn't get the message - I sent one back to Canmore 1919 to try again. But yes, lead poisoning of eagles is widespread and also very tragic and preventable.

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  • rowena71 by rowena71

    Just wondering if there is a statistically significant difference between the incidence of lead poisoning between male and female condors? Just from reading the bios it seems like males may be more likely than females to be affected.

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  • wreness by wreness moderator

    Hm..interesting question!

    I took a look at what's listed in all Bios for the birds (except for those that haven't been entered into the system yet, being too recent). There have been a few recently 😦 The scientists can fill you in better when they post.

    From what I grabbed from 2007 to as current as listed there are 13 female, 11 male whose cause of death is listed as lead poisoning.

    However, lead poisoning can also play a role when another "cause of death" is listed, too.

    A bird who is sick from or poisoned by lead can become so weak that they don't have the strength to fly so may get hit by cars or become victims of eagles or other predators, drown or meet with other accidents.

    Hopefully this is a bit of an answer for now... great question!

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  • myraf by myraf scientist

    Yes, great question! We are currently looking at many variables (age, sex, etc.) and if they are related to a condor's risk of lead exposure and we have not seen a significant difference between males and females. Wreness brings up an important point that a condor that is suffering from lead poisoning might be at greater risk to being hit by a car or perhaps killed by a predator.

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  • Canmore1919 by Canmore1919

    A stream of PB related thoughts and questions.

    First off can condors eliminate Pb from their internal system- do they have any natural mechanisms to recover from Pb poisoning by themselves or is chelation the only means for recovery?

    Does feeding carcasses to condors having a positive effect on Pb poisoning rates? ie. does dropping off more carcasses or setting up eating areas result in lower Pb levels or poisoning events? Obviously more carcasses, could be create a dependence on a food supply but it may aid in lower Pb poisoning rates...

    A related question would be how much food (unknown or naturally occurring carcasses) do condors eat? HOw much of their diet consists of the known carcasses.

    Last questions - Given that GPS wing tags are employed on birds, what are the findings wrt spatial distribution of poisoned birds? What is the range of the birds are there certain geographic regions that they like to habitat? Do they focus on "wild" remote areas or regions near people? Is there a higher propensity to contact Pb when birds fly into a certain geographic region? If so, then blitizing that region with a aggressive campaign to use copper or brass bullets could be effective.

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  • vjbakker by vjbakker scientist in response to Canmore1919's comment.

    Such excellent comments and questions Canmore! Our science team is actively working on these questions as part of a multiyear study. In fact, many of your questions read like our original proposal. We don't have all the answers yet, and I can't give specific numbers because we are currently writing up for publication, but some general answers:

    First off can condors eliminate Pb from their internal system- do they have any natural mechanisms to recover from Pb poisoning by themselves or is chelation the only means for recovery?
    Myra is the ecotoxicologist on the team, and she says: "Yes they can survive a lead poisoning event but the long-term effects of their lead exposure are not really known as even though the bird’s tissue lead concentrations are reduced, the lead has caused irreversible damage. For children, there is no safe level of lead exposure – even levels less than 10ug/dL have been related to decreased cognitive function. When Pb poisoning is detected by managers, the bird will be chelated and provided supportive therapy, often at the LA Zoo, to aid in its survival. We are currently looking at how these repeated lead exposure events might be affecting the long-term health of individual condors. The question of whether chelation therapy is helpful in terms of reducing an individual’s lead body burden (as opposed to just removing the exposure source) is a current research project we have just started in collaboration with Pinnacles National Park

    Does feeding carcasses to condors having a positive effect on Pb poisoning rates? ie. does dropping off more carcasses or setting up eating areas result in lower Pb levels or poisoning events? Obviously more carcasses, could be create a dependence on a food supply but it may aid in lower Pb poisoning rates... Yes, something that we think a lot about, and yes, overall birds that feed more at proffered feeding stations have lower lead exposures. Individuals are more dependent on proffered feeding stations when they are young, and earlier in the condor program, the entire flock was more dependent on feeding stations. However, individuals increase their home range and exhibit more natural foraging behavior as they age. In addition, the flock appears to have become more wide ranging and exploratory as it has grown and as the collective experience has increased. Given the budget for condor management, unfortunately, I don't think there is any way to provision carcasses across the landscape in a way that prevents lead exposure. There are also aesthetic considerations -- the desire that California not be an open air zoo for condors. The goal is to have a wild free-flying, self-sustaining population, and ultimately, that will require a safe non-provisioned food supply across the landscape.

    A related question would be how much food (unknown or naturally occurring carcasses) do condors eat? HOw much of their diet consists of the known carcasses. In terms of how much a condor eats, our team estimated that California condors feed on between 75 and 150 carcasses per year based on the estimate in the work by Snyder and Snyder that a condor needs to feed every 2–3 d to maintain a healthy weight. We are also actively working on using stable isotope analysis to determine what condors actually eat. In general, a substantial amount (a surprising amount really) of the diet for most individuals comes from non-proffered (non feeding station) food, including wild deer, pig, etc, domestic cattle, etc, and marine mammals.

    Last questions - Given that GPS wing tags are employed on birds, what are the findings wrt spatial distribution of poisoned birds? What is the range of the birds are there certain geographic regions that they like to habitat? Do they focus on "wild" remote areas or regions near people? Is there a higher propensity to contact Pb when birds fly into a certain geographic region? If so, then blitizing that region with a aggressive campaign to use copper or brass bullets could be effective. We are literally working on the space use of condors and the spatial distribution of Pb risk right now. Condors can fly up to 200 miles in a single day, GPS locations are generally recorded hourly, and lead exposures are very episodic, making the spatial analysis of risk challenging, but clearly important. As you suggest, one motivator is to be able to better target management, both in terms of closer monitoring of the health of at-risk birds as well as more effective targeting non-Pb outreach. All 3 condor management organizations have a big focus on non-Pb outreach currently and they try to target effectively.

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  • wreness by wreness moderator

    An add to the lead information:

    "The Peregrine Fund offers this description:

    "When a California Condor suffers from severe lead-poisoning, the digestive system paralyzes, unable to pass food or water through the system. The bird is hungry, losing weight, dehydrated, and continues to forage and feed, despite the distended crop full of rotting meat. It will continue to pack food in, because despite the greater than 3lbs of food it possesses in the crop, it feels starved and becomes anemic. This condition, we call crop-stasis, is usually the last telling sign that the bird is withering away, and it will not be long before it dies."

    An incredible story about lead poisoning can be found on this Blog by one of condorwatch's Scientists myraf "The Tragic Fate of Condor 401" who we know better as White 1. (also wore tag Black 01 Underline and Black 1) who died June 4, 2014

    If you can stand to see a heartbreaking video, this short shows the severely lead poisoned condor collapsing in the treatment center http://goo.gl/fbVXm6

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  • donsa by donsa

    Story about Miracle (BLK 38) being treated at Oakland Zoo. One of the pictures shows her weight at 16 lbs. http://www.contracostatimes.com/breaking-news/ci_28238140/condor-named-miracle-treated-at-oakland-zoo-lead
    Also covered on local TV.

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  • wreness by wreness moderator in response to donsa's comment.

    Thanks for posting that, donsa!

    We have seen this bird a lot here - she's also seen on Condor Watch as Black 38 Underline

    You can watch live video of her treatment and recovery, and any sick or injured condor's treatment at Oakland Zoo's Steve and Jackie Kane Condor Recovery Center

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