. Characters of age, sex and sexual maturity in Canada geese. Canada goose; Birds. Jr^ % IbK^ / Fig. 8. — Wing of yearling mule Canada goose, A, and of an adult male, B. The enlarged, knoblike portion of tlie car- pometacarpus of the adult is conspicuous. THE CLOACA Within the past quarter century, characters of the cloaca have become widely recognized as criteria of sex and age in waterfowl (Gower 1939; Hochhaum 1942; Elder 1946; Hanson 1949). A Canada goose can be most easily subdued for examination of the age and sex characters of the cloaca if the goose is held upside down on the operator'
. Characters of age, sex and sexual maturity in Canada geese. Canada goose; Birds. Jr^ % IbK^ / Fig. 8. — Wing of yearling mule Canada goose, A, and of an adult male, B. The enlarged, knoblike portion of tlie car- pometacarpus of the adult is conspicuous. THE CLOACA Within the past quarter century, characters of the cloaca have become widely recognized as criteria of sex and age in waterfowl (Gower 1939; Hochhaum 1942; Elder 1946; Hanson 1949). A Canada goose can be most easily subdued for examination of the age and sex characters of the cloaca if the goose is held upside down on the operator's lap and the breast of the bird is firmly tucked under the operator's chest. The goose can be readily placed in this position if the operator grasps the bird across the humeri with one hand so that the front of the bird is toward the op- erator. The bird is in position to be placed on the operator's lap with a half-turn of his hand. If the bird is first held so that it faces away from the operator, it must be turned end over end to be in position for examination. It is awkward to handle a goose in this manner, and the abrupt change in position causes the bird to increase its struggles. Tlie struggles of a bird being held can be greatly minimized if its head antl neck are tucked under one wing. Internal examination of the cloaca with the aid of a nasal speculum, Fig. 9, is relati\ely simple proxicUxl the goose is securely held. A metal rod about 2 mm in diameter and with a smoothl\ rounded tip shouKI 8 be used as a probe. Extending the cloaca greatly fa- cilitates probing for the bursa. The o\iduct attaches to the left wall of the cloaca about 15 mm below the sphincter muscle. To explore the cloaca for an open- ing to the oviduct, the operator should hold the specu- lum at right angles to the axis of the bird's body. The site of attachment of tlie o\iduct is most easily in- spected if the probe is held nearly parallel to the left wall of the cloaca and moderate lateral pressu
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Keywords: ., bookcentury1900, bookcolle, bookpublisherurbana, booksubjectbirds
