California Condor Making a Comeback

Discussion in 'California Flyway Forum' started by Tuck31, Sep 20, 2017.

  1. Phytoplankton

    Phytoplankton Elite Refuge Member

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    There are two issues here and they are somewhat related. (1) What caused the demise of the condor, and (2) what is hindering the comeback.
    The cause of both is man.
    (1) Much of the demise of the condor can be tracked back to fire suppression activities (I'll skip the part about ranchers and others wholesale shooting them back before {and after} they were protected). The condors favored range was open arid areas with patches of brush. The brush was kept in check by periodic fires, keeping the range open. Fire suppression allowed the brush to thrive, so what was once mostly open range with brushy patches became mostly brushy areas with patches of open range. So a condor finds a dead deer in the brush, it has to land in an open area and go into the brush to feed, often a considerable distance into the brush, when before fire suppression the area was much more open. Condors, like ruddy ducks, must run a considerable distance before taking off, this is especially true after ingesting several pounds of carrion. But this was not a problem when it was mostly open range, however as the brush encroached, it left the condors extremely vulnerable to predation by bobcats and coyotes, since they couldn't take off from the brushy areas.

    (2) Condors have a very low replacement rate, takes many years before they reach breeding age, and just like ducks, the first couple breeding/rearing attempts are usually unsuccessful. This coupled with the fact that they still have some of the fire suppression/habitat issue and major problems with lead poisoning (which is irrefutable) makes their recovery a slow process. Got to remember they are carrion eaters and opportunistic, they can pick up the smell of dead flesh in the parts per billion range (very few birds have a good sense of smell) gut piles and wounded animals that later succumb are easy pickings!
     
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  2. enzinn

    enzinn Senior Refuge Member

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    Interesting and it does seem intuitive. Did the amount of burning that the local Indians pursue on the marine terraces to keep them open, grassy and productive help with their numbers at all? Does it make any difference that they were hanging out during the Pleistocene when there were a lot bigger animals and more open grasslands near the coastline?

    I remember looking at the mortality charts back in the early 2000's and being struck by two things: 1. How few birds there actually were, making statistical analysis not super helpful regarding mortality and 2. The many different ways their death's had been documented - hitting power lines, hit by cars, killed by coyotes, killed by bobcats, poisoned, drowned in cattle tanks and our particular favorite, lead poisoning. it is a tough world here in central California for a Condor to survive. They really don't seem suited to the current regime of flora, fauna and activities of man.
     
  3. J.Bennett

    J.Bennett Elite Refuge Member

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    From the research that I've done, it doesn't appear that they were ever really abundant. While they were never abundant, they weren't exactly rare either prior to the mid 1800s and their range was much larger. I'll have to see if I can dig it up, but I remember reading an article that showed a strong correlation between the settlement and populating of the American west and a the rapid decline of condors. I do recall the article mentioning (as you did) that the burning practices of the Natives most likely benefited the condors in some areas, but the article also mentioned that given the range that the condors occupied at the time, it would be pretty hard to explain how changes to a relatively small portion of habitat within that range led to such a rapid decline from the mid 1800s to the early 1900s. Most likely it was a combination of factors... Changes in habitat, shooting by ranchers, poisoning carcasses (even if condors weren't the intended target), elimination of large predators like wolves and grizzlies, whaling (if man is killing all the whales, there are fewer of them to die and wash up on the beach), etc...

    It was a pretty interesting article (regardless of your opinion of condors). If I find the article, I'll post a link.
     
  4. Phytoplankton

    Phytoplankton Elite Refuge Member

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    You actually brought up one Major Factor I had forgot, poisoning. Ranchers routinely left out poisoned carcasses to kill wolves, coyotes, bobcats, mountain lions, and condors. Ranchers often observed condors feeding on the carcasses of newborn/young calves and mistakenly thought they were killing them. Given the condors ability to find "dead," poisoning contributed greatly to their decline. Poisoning carcasses was a commonplace practice into the 1960's and condors certainly paid a hefty price.

    The slow reproduction rate is a major stumbling block to recovery, they don't breed until they are at least 6 years (they can live to be 50), and normally only lay one egg every other year.

    I don't believe that they were ever abundant, but they had a much bigger range than they do now, and there is some evidence that the extinction of the megafauna at the end of the last ice age did contribute to reduction of their range: "At the time of human settlement of the Americas, the California condor was widespread across North America; condor bones from the late Pleistocene have been found at the Cutler Fossil Site in southern Florida.[29] However, at the end of the last glacial period came the extinction of the megafauna that led to a subsequent reduction in range and population. Five hundred years ago, the California condor roamed across the American Southwest and West Coast. Faunal remains of condors have been found documented in Arizona,[30]Nevada,[31] New Mexico,[32][33] and Texas.[34] The Lewis and Clark Expedition of the early 19th century reported on their sighting and shooting of California condors near the mouth of the Columbia River.[35][36](Wikipedia)"
     
  5. Phytoplankton

    Phytoplankton Elite Refuge Member

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    More dis-information, I can tell you categorically that being shot with lead pellets does not cause lead poisoning, how do I know? I've been carrying about 80 #4 lead pellets in my body for the last 15 years. As a precaution for about ten years I had my blood lead level checked and it is well within normal levels. Finally the doctor told me it was unnecessary (I had demanded it). Lead is a very stable element, it will dissolve in a strong acid (like in your stomach), but blood is near neutral, so it is benign when it comes lead, it will not dissolve it. The body sees the lead pellet as a foreign body, puts a little cyst around it and there it sits, doing no harm. If the condor has a blood lead level it is not from being shot, it is from ingesting lead.
     
    Last edited: Sep 28, 2017
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  6. J.Bennett

    J.Bennett Elite Refuge Member

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    Yeah, well you're probably an Alt-left, anti-gun, anti-hunting, UCSC alumni, propagandist, so what do you know?

    If I cared to take the time to educate you or if I thought your liberal brain could handle it, I'd show you the study that proves that the lead in your body is really from the fire watch tower and not lead shot.
     
  7. Phytoplankton

    Phytoplankton Elite Refuge Member

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  8. Specktacular

    Specktacular Senior Refuge Member

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    Well then how do you explain the findings of the study? The embedded pellets in the bird were documented as was the elevated lead concentration. So, either the data is a lie or the lead serum concentration came from something else. Which is it???
     
  9. J.Bennett

    J.Bennett Elite Refuge Member

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    Please direct us to the study that links embedded pellets to the elevated blood lead levels.

    I think you are making huge leaps again... Condors have been found with pellets embedded. Many condors have elevated blood lead levels (from ingesting lead). Some of those condors might also have pellets embedded in them. No where is there a link between embedded shot and condor blood lead levels, except the one you created with your huge leap.
     
  10. Specktacular

    Specktacular Senior Refuge Member

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    OK. How bout this...

    "Directly linking an observed feeding and/or recovery of ingested ammunition fragment(s) from a lead-poisoned condor is uncommon, largely because condors can fly over 200 km and traverse their entire range in a single day (35), but their feeding episodes can last less than 1 h (36). Since 2007, in part because of increased efforts by condor biologists and veterinary staff, there have been six cases where a lead-containing metal fragment (or in one case, buckshot) was recovered from a lead-poisoned bird or a condor was observed feeding on a carcass that had been shot with lead-based ammunition. In all six of these cases, isotopic analysis showed that the fragments/ammunition and condor blood had highly similar (difference ≤ 0.22%) lead isotope ratios (207Pb/206Pb) (Fig. S3), establishing that the recovered lead-containing fragment (or ammunition from the carcass on which the bird was observed feeding) (22) was the cause of the lead poisoning."

    Not only do they acknowledge that observed feeding events of Condors are uncommon, but then they magically were able to supposedly directly observe 6 feeding events on documented "lead-shot" game, despite the fact that lead ammunition was outlawed in the study area. They DOCUMENT only 1 case of an actual lead-based ammunition fragment(a single "buckshot") and make no mention of the other documented lead ammunition found. Wonder why. First, who uses buckshot??? No one, unless they're shooting traditional muzzleloaders. Second, it's already been shown in a previous study that one lead 00 Buckshot doesn't even minutely elevate the serum lead concentration to a remotely toxic level. So, they claim to have observed Condors feeding on carcasses shot with lead when not only is the observed feeding event highly unlikely but the presence of lead in the carcass suspect as well. Then, they go on to make the extreme stretch of the claim that a single buckshot and the other "lead fragments" that they did not prove were from ammunition caused elevated lead levels in those birds. How fast does ingested lead cause elevated serum concentrations, Phyto?? After all, you claim to be the expert on this. Certainly not fast enough for it to be elevated in the short period of time that the birds were supposedly observed feeding and then captured for testing.


    Need another one?

    The data provided regarding pre-release lead concentrations and post-release concentrations of lead and their respective isotope signatures shows a substantial crossover in sources. Given the small sample number, anyone with any scientific credibility would not reach the "conclusions" they claim based on this data unless it suited their agenda.
     

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