My life is about living with nature – here you can live it with me!

Understanding the bird’s wing!

Osprey in flight (from March 2007)

Birds use the ability to fly for finding food, escaping from predators and even migrating to areas that can better support them when there are fewer resources available. Obviously their feathers are not permanent to their body and they need to replace their older (worn) feathers with new (sturdy) feathers. The molting (loosing and growing new feathers) patterns on the wing of the bird can help us banders understand the age of the bird (well sometimes).

Young Naturalist J’s most recent birdQUIZ!

The biggest problem with looking at the wing to identify their age is that most species have a different wing molt pattern! Majority of the passerines will replace some but not all of their juvenal wing feathers when going into their 1st prebasic molt (molting into their adult plumage their first summer before migration). The following summer the passerine will then do a complete molt replacing all of their wing feathers and then officially becoming an adult. Some species like the blackbirds and Cardinals will go thorough a complete molt when coming out of their juvenal plumage and then unable to age them (well, unless they accidentally retain one juv feather by mistake). Confused?? Bird banders can also be confused with the molt limit location! That’s why we use the Identification Guide to North American Birds Part 1 that tell us about where to look for the molt limit in each of the birds. There is a new molt photographic guide that should be coming out soon and will be even more helpful with aging birds for us that need an arrow pointing to the exact location of the molt limit in each hatch year birds.

Wing of the Northern Saw-whet Owl

“Many” non-passerines or “near-passerines” will regularly retain their flight feathers when going through their molt. If the bird looses too many flight feathers (like the Canada Goose) they will not be able to fly and then unable to find food! Lucky most ducks/geese are in the water with their goslings and don’t need to fly at that point (finds food on the ground/water) so molting all their feathers isn’t a problem. There are many other reasons for some species not to be going through a complete molt and has to do with amount of energy required to molt new feathers! Of course the energy problem is truer with our larger birds (who have larger feathers) than with smaller birds like hummingbirds.

Wing Molt
This photos shows 3 generations of flight feathers in this Saw-whet!

Currently many of the wings that I have been looking at the past few months are the Northern Saw-whet Owls wing. Lucky some fellow banders have discovered that by using a black-light on the Saw-whet’s wing (currently the only species I know that this method works with) will result in showing newly grown feathers glow pink in color. Looking at the below picture . . . . you will notice that the whole wing is pink making this fluff ball a hatch year bird. If it had been an adult owl . . . . the wing pattern would show the older feathers whiteish in color. Even with the numerous recaptured Saw-whet that us banders have recaptured, we are still struggling with understanding the age of birds older than third years of age.

Young Naturalist J’s black-light photo!

Hope I didn’t confuse everyone but I am off from work this week and stuck with snowy weather (unable to band owls). I am just in the blog babbling mood (well in-between watching The Price-is-Right, etc..) !

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31 responses

  1. Birdbander11

    The age of the bird I left what I thought it was on a comment on the picture on my Flickr. The wing chart idea was great! The picture of the Osprey was is incredible. The picture under the black light turned out I thought pretty well. That bird quiz is so mean also. I don’t know if anyone is going to get it. Do you even know what it is?

    6 November 2007 at 7:38 pm

  2. @ Birdbander, I sure do know what it is! 😉

    6 November 2007 at 7:40 pm

  3. Powerbirder

    Well I am not going to guess at the quiz – unless AMGO is a guess – because I will be wrong. May I copy the bird wing schematic to use in my wildlife biology class? I think it is great! I wish the weather would turn so you could band. And D and I could visit so I could keep my promise!

    6 November 2007 at 8:07 pm

  4. John, the bird quiz does have a yellow body but nope with being AMGO!

    6 November 2007 at 8:29 pm

  5. Powerbirder

    Give us a hint?

    6 November 2007 at 8:37 pm

  6. what a great post, very informative. ~nita~

    6 November 2007 at 9:55 pm

  7. More fantastic photo’s, and information!!
    I love visiting here, I can learn something new every day, and enjoy it!!
    Thanks for sharing!!
    Have a great week!!

    6 November 2007 at 11:02 pm

  8. I love learning this kind of information. You’re a great teacher!

    6 November 2007 at 11:45 pm

  9. Excellent post. The blacklight photo is cool – I had heard about such an effect but not seen it.


    7 November 2007 at 12:00 am

  10. winterwoman

    How is Price-is-Right with the new host?

    7 November 2007 at 5:29 am

  11. Lisa at Greenbow

    Very interesting post. The quiz is difficult. That little hint of yellow reminds me of Northern Flicker. ??

    7 November 2007 at 5:56 am

  12. Wow… so interesting, but I hope there’s not a quiz to come as I’d fail miserably!

    7 November 2007 at 6:57 am

  13. Marg

    This is a neat post Mon@rch-you can ramble all you want we love it! Was that link on Pyle a hint? I guess I better take it

    7 November 2007 at 9:37 am

  14. @ Nita – thanks
    @ Catherine – thanks and glad you enjoy it here!
    @ Erie – glad you enjoyed it!
    @ Nick – thanks and blacklight is very helpful!
    @ Jen – Drew continued asking the contestants “what”! when they gave a price, etc.. Besides that, good!
    @ Lisa – thanks and this is a smaller sized bird! I do agree it is a hard one!
    @ Jayne – thanks and I get quizzed with every bird that I capture! Lucky many are easy to age!
    @ Marg- It is cheeper at if you do plan on getting Pyle!

    7 November 2007 at 10:25 am

  15. Sherri

    Great information Tom – thanks for sharing.. and the photos of the wings are amazing!

    7 November 2007 at 11:25 am

  16. Great information, Tom. I agree with Jayne – I’d fail a quiz for sure.

    Take some photos of the snow. I rarely see it anymore. Enjoy the Price is Right. LOL!

    7 November 2007 at 2:30 pm

  17. banderparents

    I’m guessing a CSWA – don’t ask me to age it.

    7 November 2007 at 3:02 pm

  18. Owww! My head hurts! You are such a good teacher, Tom, it’s not about you. It’s about me as a student. I think my eyes glazed over. Very interesting, and yes, I fail!

    7 November 2007 at 3:53 pm

  19. @ Sherri – thanks and enjoyed them for sure!
    @ Mary – thanks and will work on that photo and this post was more about letting people know about molts of birds. Confusing stuff for sure!
    @ Banderparents – it is a common bird we handle but isn’t a CSWA! This bird has more yellow in it!
    @ Trixie – This isn’t easy stuff and as long as you get the point that birds have different aged feathers in their wings that help us banders age them (you got what I was saying)!

    7 November 2007 at 4:27 pm

  20. Amazing stuff.

    7 November 2007 at 4:54 pm

  21. I’m haven’t really learned about all the various featheres yet, so this was informative. It’s one thing to try to read a chart in the field guide but it makes more sense when you see it on the bird.Stunning Osprey photo!

    7 November 2007 at 9:18 pm

  22. That was really interesting! I had no idea…and the pictures were so helpful, too. I agree. You’re a good teacher! Thanks for sharing!

    7 November 2007 at 9:51 pm

  23. @ Zen – thanks!
    @ Larry – what is great about birds is that we can always learn from them!
    @ Rondi – thanks and glad you learned from this!

    7 November 2007 at 10:47 pm

  24. great post… I don’t think I could get that close to our owls here but it was great info. We have a pair of Great Horned Owls that make enough racket to wake the dead at night.

    They compete for space with the others close by. Our poor finch feeding birds at the feeder during the day are quick to take cover with the Coopers Hawk and Red Tails around.

    Thanks, Scott

    7 November 2007 at 10:49 pm

  25. your black light discovery that is just amazingly cool!

    8 November 2007 at 2:03 am

  26. This is pretty cool stuff – especially the black light side of things.

    8 November 2007 at 9:17 am

  27. Very informative post Tom, thanks for sharing the info with us 🙂

    8 November 2007 at 1:47 pm

  28. I’ve always been so fascinated with birds’ wings, and this is such a great, informative post, Tom!

    Back when I had my Quaker Parrot, Scooter, he used to love having head scratches when he was molting. 😀

    8 November 2007 at 2:37 pm

  29. @ Chipseo – thanks and I love noisy owls like that!
    @ aullori – wasn’t my discovery but I do take advantage of it when banding Saw-whets! Thanks
    @ Marty – thanks
    @ Bernie – thanks and glad you enjoyed it!
    @ Lisa – thanks and birds do love having their feathers scratch when molting!

    8 November 2007 at 5:33 pm

  30. Tomek

    Very well explained.

    9 November 2007 at 3:44 pm

  31. Grace

    Your photoshoppped owl wing is great. I was there when you had J counting feathers. Now I know what it was all about. Great post.

    12 November 2007 at 10:46 am

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