Cloacal Examination Research Articles

Sexual size dimorphism and sex determination by morphometric measurements in the Coscoroba Swan

The accuracy of morphological sexing and the occurrence of sexual dimorphism were analyzed in mature and immature Coscoroba Swans (Coscoroba coscoroba, Anatidae) near the Estação Ecológica do Taim, southern Brazil. On the basis of weight and 10 linear measurements of external morphology, multivariate analysis of variance showed that males were consistently larger than females (sex confirmed via genetic markers) and mature birds were consistently larger than immatures. Overall, 38% of immatures and 14% of mature birds were sexed incorrectly by cloacal examination when compared to genetic data. Therefore, we performed a discriminant function analysis of different age classes based on morphometric measurements. Mature birds were sexed with 96% accuracy using head and tarsus lengths as predictor variables, whereas immatures were sexed with 90% accuracy based on head and forearm lengths. Method validation conducted with data for additional mature sampled in a different year showed that the use of head length alone was as accurate for sexing (92% correct classification) than discriminant functions based on two characteristics (91%).

Evaluation of a New Technique for Determining Sex of Adult White-Winged Doves (Zenaida asiatica)

Abstract Previous studies have shown that determining sex of adult white-winged doves (Zenaida asiatica) by cloacal characteristics is highly reliable (90%), while using plumage characteristics and body weights are less so. The drawback of the cloacal technique is that the procedure requires use of a modified nasal speculum to probe the cloacal area, which could possibly cause injury to the bird. We hypothesized that females have a wider pelvis than males for the passage of eggs, which should be quantifiable, thereby providing a means of separating adult males and females. We measured pelvic spread (distance from tip to tip of pelvis) of adults (n = 249). Additionally, body masses were taken for a subset (n = 215) of the doves. Sex was positively determined by either cloacal examination of live birds or gonad examination of dead birds. Mean pelvic spread of males was significantly less than that of females. Whole body mass was not correlated with pelvic spread for either sex. Accuracy of the pelvic sp...

USe of morphometric parameters for the determination of sex of Adelie penguins.

The sex of Addie penguins, Pygoscelis adeliae, may be determined by cloacal examination during the early part of the breeding season. Later in the season it becomes increasingly difficult to determine the sex of penguins by this method as the structures used for identification regress. Discriminant analysis of morphometric characters has been suggested as an alternative. This technique was examined for breeding birds of known sex near Mawson Station, Antarctica. The sex of 89% of breeding birds could be correctly determined by comparing the discriminant score D = 0.582 Bl + 1.118 Bd + 0.219Fw, where Bl is bill length, Bd is bill depth and Fw is flipper width, with a mean discriminant score (MDS) of 55.39. In all, the sexes of 87% were correctly determined by means of length and depth only (D=0.601Bl+ 1.154Bd, MDS=44.96). The sex of juvenile birds could not be determined. Determination of sex by discriminant analysis is shown to give acceptable estimates of morphometric characters divided by sex where only the mean and variance of these variables but not the sexual identity of individual birds is required. Where absolute accuracy in sex determination is required, 80% of the birds in our samples would have to be discarded to be 90% confident of the sex of the remainder.

Response to Dufour and Ankney

Ankney, C. D. 1979. Does the wing molt cause nutritional stress in Lesser Snow Geese? Auk 96: 68-72. Bennet, J. W. and Bolen, E. G. 1978. Stress response in wintering Green-winged Teal. J. Wildl. Manage. 42: 81-86. Conroy, M. J., Costanzo, G. R. and Stotts, D. B. 1989. Winter survival of female American Black Ducks on the Atlantic coast. J. Wildl. Manage. 53: 99-109. Cox, D. R. 1970. The analysis of binary data. Chapman and Hall, London. Hochbaum, A. 1942. Sex and age determination of waterfowl by cloacal examination. Trans. N. Am. Wildl. Nat. Res. Conf. 7: 299-307. Krementz, D. G., Conroy, M. J., Hines, J. E. and Percival, H. F. 1987. Sources of variation in survival and recovery rates of American Black Ducks. J. Wildl. Manage. 51: 689700. , Hines, J. E., Corr, P. 0. and Owen, R. B., Jr. 1989. The relationship between body mass and annual survival in American Black Ducks. Ornis Scand. 20: 81-85. Reinecke, K. J., Stone, T. L. and Owen, R. B., Jr. 1982. Seasonal carcass composition and energy balance of female Black Ducks in Maine. Condor 84: 420-426. , Shaiffer, C. W. and Delnicki, D. 1987. Winter survival of female Mallards in the lower Mississippi valley. Trans. N. Am. Wildl. Nat. Res. Conf. 52: 258-263. Whyte, R. J. and Bolen, E. G. 1984. Impact of winter stress on Mallard body composition. Condor 86: 477-482.

Discriminating the sex of birds: A study of brown teal (Anas aucklandica chlorotis)

Abstract The full methodology we used to produce a reliable method for morphometrically sexing individuals is presented. A linear discriminant function to separate male and female brown teal, on the basis of two body measurements, was developed from a multivariate dataset collected over 3 years by a number of observers. The two measurements were objectively chosen from the eight measurements initially collected and the final discriminant function correctly classified 92% of the birds measured. Each bird was initially sexed using the standard waterfowl cloacal examination technique; the accuracy of this was assessed for both naive and experienced observers. The effect of juvenile birds was minimal, compared to the effects of naive observers, and the discriminant function is recommended as a field check for the cloacal examination technique. The previously reported sexual dimorphisms in brown teal morphometry are not reliable discriminators.

Sex determination of monomorphic birds by fibreoptic endoscopy.

Fibreoptic endoscopy was performed in 1056 monomorphic birds of 144 different species belonging to 15 Orders. The purpose was to establish their sex by direct inspection of the gonads. The results suggest that although the technique involves surgical intervention it is generally more practical and accurate than chromosome analysis of lymphocytes or analysis of faecal steroids. Surgical anaesthesia is recommended on practical and humane grounds but this and the technique itself can be hazardous in old and fat birds, where a mortality rate of as high as 2 per cent was encountered. Cloacal examination of as high as 2 per cent was encountered. Cloacal examination is a more practical technique for sex determination in penguins.

Sexing ratite birds by cloacal examination.

Sexing ratite birds by cloacal examination.

Technical Note: Identification of Ovarian Follicles and Oviducal Eggs by Cloacal Examination of Live Australian Freshwater Crocodiles, Crocodylus johnstoni

Technical Note: Identification of Ovarian Follicles and Oviducal Eggs by Cloacal Examination of Live Australian Freshwater Crocodiles, Crocodylus johnstoni

Species, Age, and Sex Identification of Nearctic Goldeneyes from Wings

Species, Age, and Sex Identification of Nearctic Goldeneyes from Wings

Crane reproductive physiology and conservation

AbstractSome unique features of crane reproduction, management, and conservation are described. Because cranes are sexually monomorphic, sexing is difficult and must be accomplished using behavior, laparoscopy, cloacal examination, genetic techniques, or fecal steroid analysis. Although husbandry techniques for cranes are similar to those used with other nondomestic birds, a number of basic characteristics, such as extreme aggressiveness, imprinting by the crane chick on man, a delayed molt in the immature crane, delayed sexual maturity, and infertility, pose special problems for the propagator. Artificial insemination is a practical solution to crane infertility. Vigorous captive management and propagation efforts must become increasingly important if several endangered crane species are to survive the continuing decline in wild populations. The ultimate goal is the restoration of suitable habitat and sustainable native populations.

MORPHOMETRICS AND SEXING OF THE AFRICAN BLACK OYSTERCATCHER

Summary Hockey, P. A. R. 1981. Morphometries and sexing of the African Black Oystercatcher. Ostrich 52: 244–247. 109 African Black Oystercatchers Haematopus moquini were caught, measured and sexed by cloacal examination during the 1979/1980 breeding season. Six standard taxonomic variables were measured. Females were larger than males in all dimensions considered. The most dimorphic characters were mass and exposed culmen length. The data were subjected to stepwise discriminant analysis and a linear function was derived which allowed birds of unknown sex to be sexed. The function is D = −0,391x1 −0,016 x2 +0,218 x3 +0,714 x4 +15,946 where x1 = exposed culmen length (mm), x2 = body mass (g), x3 = length of tarsometatarsus (mm) and x4 = culmen depth at the gonys. Values of D from the above equation less than zero indicate a female while those greater than zero indicate a male. The greater the divergence of D from zero, the higher the probability of correctly sexing an unknown individual: once D> ± 1,2, p>0,99.

A MORPHOLOGICAL STUDY OF YELLOWBILLED DUCK AND REDBILLED TEAL

Summary Day, D. H. 1977. A morphological study of Yellow-billed Duck and Red-billed Teal. Ostrich Suppl. 12:86–96. Measurements were made of Yellowbilled Duck Anas undulata and Redbilled Teal A. erythrorhyncha (100 male and 100 female birds of each species) caught for ringing at Barberspan Ornithological Research Station 26 33S; 25 36E in the western Transvaal. The sexes (originally determined by cloacal examination) can be separated morphologically in the field. Males are larger than females in length and differ from females also in the colouration of the bill and extent of the speculum.

Aging Small Canada Geese by Neck Plumage

The neck plumage method, a new technique for separating immature from adult Canada geese (Branta canadensis) in the hand, was evaluated by comparison with the notched tail feather and cloacal examination methods. Two (1.4 percent) of 141 geese examined were misaged, resulting in a 6 percent error in the immature-adult ratio obtained by the neck plumage method. The neck plumage method is a rapid aging method and reasonable accuracy (94 percent) can be obtained. It can also be used to dif- ferentiate immatures from adults on the ground at distances up to 175 yards, but was almost impossible to use when geese were in flight. As yet, the neck plumage method has only been tested on the subspe- cies (B. c. hutchinsii-parvipes complex) in the Tall-Grass Prairie population of small Canada geese. AGING SMALL CANADA GEESE BY NECK PLUMAGE KENNETH F. HIGGINS, South Dakota Cooperative Wildlife Research Unit, Brookings1 LYLE J. SCHOONOVER, Sand Lake National Wildlife Refuge, Columbia, South Dakota Abstract: The neck plumage method, a new technique for separating immature from adult Canada geese (Branta canadensis) in the hand, was evaluated by comparison with the notched tail feather and cloacal examination methods. Two (1.4 percent) of 141 geese examined were misaged, resulting in a 6 percent error in the immature-adult ratio obtained by the neck plumage method. The neck plumage method is a rapid aging method and reasonable accuracy (94 percent) can be obtained. It can also be used to dif- ferentiate immatures from adults on the ground at distances up to 175 yards, but was almost impossible to use when geese were in flight. As yet, the neck plumage method has only been tested on the subspe- cies (B. c. hutchinsii-parvipes complex) in the Tall-Grass Prairie population of small Canada geese.

Identification of Sex of Day-Old Quail (Coturnix coturnix japonica) by Cloacal Examination

EARLY determination of the sex of Japanese quail (Coturnix coturnix japonica) is desirable when these birds are raised for experimental purposes. Sexual dimorphism does not become obvious until the contour feathers emerge when the quail are 2 to 3 weeks of age. The birds usually are sexed by the difference in color of the breast feathers, the male having brownish-red feathers and the female characteristically having tan (gray) feathers with black speckles.In some mutant stocks, color of the feathers remains identical in both sexes even after sexual maturity, e.g., the “ghost bar mutant” and other types of albinos. In these stocks, identification of the sex is possible by observing the development of the cloacal gland after the birds were 4 weeks of age. This gland is located in the dorsal wall of the cloaca and becomes hypertrophic in sexually active males.The above two methods are not satisfactory for …

Mallard Age and Sex Determination from Wings

Aldo Leopold (1933:22) defined productivity as: . . the rate at which mature breeding stock produces other mature stock, or mature removable crop. Since sustained hunting must subsist on this annual crop, measuring productivity is one of the basic steps required for the management of any game species. At present, the U.S. Bureau of Sport Fisheries and Wildlife conducts waterfowl production surveys (Crissey, 1957; Stewart, et al., 1958), but does not measure directly the productivity of individual species. A serious problem encountered in gathering waterfowl productivity data has been the lack of a method applicable to sampling randomly over large areas. The only reliable field technique for determining the age and sex of waterfowl, cloacal examination (Hochbaum, 1942), could be applied by relatively few persons. Techniques, however, have been developed that permit age and sex of gallinaceous game birds to be determined from detached wings or other body parts collected from hunters (Ammann, 1944; Leopold, 1939; and Petrides, 1942). Procedures for gathering data in this manner and some possible applications have been summarized by Blouch and Ammann (1952) and by Dow (1954). Because the Bureau obtains addresses of a sample of waterfowl hunters from its annual mail

Sexing Mature Columbiformes by Cloacal Characters

WHILE there is a pronounced sexual dimorphism or dichromatism in some species of the order Columbiformes, in most others there is not. Until recently we have known of no simple and reliable method for sexing living individuals of these latter species. Various techniques which have been used are: observation of slight quantitative differences in the coloration on the head, neck, and breast of the Mourning Dove, Zenaidura macroura (Petrides, 1951); slight differences in the contour of the head and neck of the domestic pigeon, Columba livia, (Levi, 1941); differences in behavior; and others. For a number of years, sexing by internal examination of gonads (by laparotomy) has been frequently used in the department of Genetics, University of Wisconsin. This is a delicate and time-consuming operation. Iwata (1926) described a method in which differences of the shape of the lips of the vent of Columba livia are used to distinguish the sexes. This technique has not to our knowledge been verifiable in this country (Levi, 1941). The objectives of this paper are three-fold: (1) to describe a simple method for sexing living adult doves and pigeons by cloacal characters and to present data on the reliability of the method; (2) to list the diverse species in which we have tried this method; and (3) to present data from brief experiments which indicate that the development of these characters is under endocrine influence. We believe the method to be quite reliable and as simple to use as the cloacal examination method for sexing ducks (Hochbaum, 1948) or the widely used method of determining the age of birds by the bursa of Fabricius (Gower, 1939).

Sex Determination of Turkey Poults

HAMMOND and Marsden (1937) described a method for determining the sex of day old turkey poults by cloacal examination. They also prepared wax models, one illustrating a common male type and the other an obvious female. Marsden and Martin (1946) presented photographs of more detailed drawings illustrating one male and one female type. The above were of great value since they demonstrated for the first time that the principles underlying the sexing of day old chicks could also be applied to poults.The demand for sexed poults among commercial growers is increasing as some operators find it advantageous to raise operators find it advantageous to raise the males and females separately or occasionally, as in the case of specialty producers, only one sex is desired. As a consequence of this demand many chick sexers are being called upon to work on poults as well.To aid in this transition it .