Condor Watch Talk

Red knees

  • inaspin by inaspin

    Hello Scientists - I've been trying to sort out whether the red knees appearing on some condors are related to their age or sex. Trouble being they are most often seen when the wing tag is not visible; they are most unhelpful birds! Is there any info. relating to this topic? Thanks

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  • zekazoo by zekazoo scientist

    Hi inaspin- As it stands now there is no documented relationship between leg color and age. But that doesn't mean there's no relationship, it just hasn't been verified yet. My best guess would be that sometimes the white urates are caked on the legs all the way up to above the "knee" and sometimes not, revealing the pink or red skin underneath. For more info on age-related color changes, I would suggest the Califonia condor species account on cornell's birds of north america online database: http://bna.birds.cornell.edu/bna/species/610/articles/introduction.

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  • inaspin by inaspin

    Thank you for the link. Shall check it out soonest.

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  • wreness by wreness moderator

    My input - take a look at the knees of a 12 year old, or a 21 year old Victoria's Secret Supermodel. Then we can glance down at our tired, well worn knees (well, some of us.) (I'm not naming names) and we are neither 21 nor Super Models anymore πŸ˜ƒ Ditto for elbows, knuckles...maybe condors are the same as us and since those are contact points they just get tired and worn out, too. Not very scientific but it's a point. Ah, to be 21 again πŸ˜ƒ

    It would be interesting to know if it's more common in breeding females - if nesting/having to sit and pivot on the rocky soil adds to the wear.

    Inaspin & anyone else - if you see any good examples, start a collection if you'd like. We can take a look at the photos and see if it turns up any data.

    Thanks for the info zekazoo! Always interesting!

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  • vjbakker by vjbakker scientist

    If CW can accumulate photos of knees, red and otherwise, and we can ID the birds and dates, we can investigate this. And maybe turn up something interesting.I love your energy you all!

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  • DZM by DZM admin

    Should I declare Project Condor Knees officially open? πŸ˜ƒ

    Perhaps someone should start a thread for collecting photos of... condor knees. Yep. Condor knees.

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

    I'm up for it! scanty observations so far, but will keep on it! It's a bit like the birds we see with the ill-fitting waistcoats where the breast bone is exposed (very cheeky) and it is as red as the faces. Haven't pinned that one down either. (Obviously too much time on my hands, or excessive interest in trivia!)

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  • wreness by wreness moderator

    Trivia rules. πŸ˜ƒ

    We've looked at Butts enough so why not knees? πŸ˜ƒ And after what we've seen on that poor jello horse nothing is sacred.

    I can solve the Waistcoat-Red-Thingie mystery for you! That's the crop which when empty sits tucked away behind the chest feathers. It's an inflatable pouch of muscle where they store extra food after gorging themselves much like a hamster will fill its cheeks with seed to eat at a later date. (This is also where they save the food to vomit up to feed their young) When you see Condor Floof Muffins sitting around, they might be chewing away on their crop stash like a cow ruminates on their cud where it's quiet and they're out of the feeding frenzy.

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  • zekazoo by zekazoo scientist

    Update: I just read this very informative sentence in Snyder and Schmitt's condor species account (below).

    Leg color generally dark gray, but often white during hot weather when legs become plastered with urinary wastes in thermoregulation (urohydrosis). A conspicuous small red patch at the bird’s β€œknee” is prominently displayed during strutting courtship activities.

    So let's see at what age this red patch shows up!

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  • inaspin by inaspin

    Great stuff wreness & zekazoo thanks! Realised when we had chicken that the knees should probably be referred to as ankles... never mind, we know what we're talking about. I'm going to start a collection of ID'd birds with this feature ASAP.

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  • DZM by DZM admin

    Wow, that is some fantastic information, @zekazoo ... have I mentioned how good it is to have the scientists active on Talk?

    Calling it now: Condor Watch-wide hunt for #redknees. Everyone with me? πŸ˜„

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  • wreness by wreness moderator

    Here's one for you - Red90 (female)

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  • DZM by DZM admin

    Did you tag it? πŸ˜„

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  • wreness by wreness moderator

    Nope didn't tag it. That's the 2nd one we found I think πŸ˜„ They're not real common. You can tag it if you want! I know InAspin was keeping a collection but don't know how far she got, either. (I bet no one will think to do it ;x)

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