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 What is a quick and easy way for a non-scientific person to identify a juvenile from an adult in species of ducks?
-Haygood Keadle
Answer:
Hi Haygood!
This is a great question, as I think it’s important to learn as much as we can about each bird we harvest.
There are actually three viable methods used to age waterfowl. These methods are internal aging, cloacal (anal vent) aging, and aging from the wing or tail feathers. Of these three methods, looking at the tail feathers for distinguished notches is the simplest and fastest way that any non-scientific person can identify a juvenile duck from an adult duck. Duckling’s start out covered by natal down, in which is eventually pushed out by a new developing tail feather. The natal down is actually the tip of the developing tail feather but this portion breaks off at the rachis (the tip of the feathers stalk), which gives the new tail feather a distinguished v-shaped notch. This notch is slightly hard to explain in words, but becomes very evident once you have the bird in front of you.
The other methods are a little more complex and require a longer time commitment. Internal aging obviously requires the bird to be dead and is done by measuring the presence and size of a ducks bursa of Fibricius. This is a specialized organ used for B-cell development and is situated on the dorsal side of anal pit region of the cloaca. This organ is present in juveniles, regresses as the bird matures, and is completely gone in adults. Examination of the size and shape of the oviduct and penis through the cloaca is the other viable aging method.
So your best bet is to examine the tip of the tail feathers for a v-shaped notch, as you can do this while still in the field. This is a popular and efficient method, especially at banding stations where time is limited. Hope this helps you Haygood, and good luck with you next bird!
Sincerely,
Carly Michie - Delta Waterfowl Biologist
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