Post by Woody Williams on Jan 28, 2007 16:22:53 GMT -5
How to age a goose…
Interesting info from a Canadian biologist friend of mine..
There are 4 definitive ways to tell whether a goose is a juvenile or an adult. (1) The rectrices or tail feathers will show a tiny pin rachis at their terminus on hatch-year birds. This is the vestigial down plume that emerged shortly after leaving the egg (2) the bursa of fabricius is a small blind pouch near the cloaca (anus for all practical purposes) and gentle probing of the anterior wall of the cloaca about 1/2 inch in will show this pouch in young birds. It disappears in adults, (3) The internal testis/ovaries will be visible upon dissection for mature birds and basically invisible on immatures, (4) on males, one may evert the penis - yes, waterfowl have a small corkscrew like penis that goes external when palpated - in adult males it is present & 1/2 inch long; in immatures it is tiny an nub-like (not saying that 1/2 inch isn't tiny but it is COLD up here).
An experienced bio could probably tell from the beak size:body size whether the bird has grown into his hard structures, sort of like a teenager with huge feet - one rarely sees a 140 lb adult man with size 12 feet (insert wise assed comments here) & likewise one won't see a large-billed goose adult with small body . This is subjective as hell because there are some 17 sub-species of Branta canadensis. Yes, the cheek patches will be flecked with dark on young-of-year but not dependably or for their entire first year
Interesting info from a Canadian biologist friend of mine..
There are 4 definitive ways to tell whether a goose is a juvenile or an adult. (1) The rectrices or tail feathers will show a tiny pin rachis at their terminus on hatch-year birds. This is the vestigial down plume that emerged shortly after leaving the egg (2) the bursa of fabricius is a small blind pouch near the cloaca (anus for all practical purposes) and gentle probing of the anterior wall of the cloaca about 1/2 inch in will show this pouch in young birds. It disappears in adults, (3) The internal testis/ovaries will be visible upon dissection for mature birds and basically invisible on immatures, (4) on males, one may evert the penis - yes, waterfowl have a small corkscrew like penis that goes external when palpated - in adult males it is present & 1/2 inch long; in immatures it is tiny an nub-like (not saying that 1/2 inch isn't tiny but it is COLD up here).
An experienced bio could probably tell from the beak size:body size whether the bird has grown into his hard structures, sort of like a teenager with huge feet - one rarely sees a 140 lb adult man with size 12 feet (insert wise assed comments here) & likewise one won't see a large-billed goose adult with small body . This is subjective as hell because there are some 17 sub-species of Branta canadensis. Yes, the cheek patches will be flecked with dark on young-of-year but not dependably or for their entire first year
, this ones a female dad". Hope he doesn't do that to wimmins soon! 
