Reproductive steroid (oestradiol and testosterone) levels were measured in the faeces of ten wild dugongs (Dugong dugon) from Moreton Bay Australia, using radioimmunoassay (RIA). All faecal samples, including from both genders and from both immature and mature dugongs contained detectable levels of oestradiol and testosterone. Faecal testosterone levels were high relative to oestradiol concentrations in all samples, regardless of gender. The highest levels of testosterone occurred in adults (body lengths ≥250 cm), in both males (1146.7 ng g-1 dry weight faeces) and females (691.1 ng g-1 dry weight faeces). The highest oestradiol levels were recorded in adult females (37.2 ng g-1 dry weight faeces). In mature dugongs, the ratio of testosterone to oestradiol was higher in adult males than in females, suggesting that this ratio may be a better indicator of sex than levels of individual steroids. This study represents the first step in an investigation into assessing the reproductive status of free-ranging dugongs.

Brown, J.L., Wasser, S.K., Wildt, D.E. and Graham L.H. 1994. Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured non-invasively in faeces. Biology of Reproduction 51: 776-786.
Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured non-invasively in faeces
Biology of Reproduction
, vol. 
51
 (pg. 
776
-
786
)
Brown, J.L. and Wildt, D.E. 1997. Assessing reproductive status in wild felids by non-invasive faecal steroid monitoring. International Zoo Yearbook 35: 173-191.
Assessing reproductive status in wild felids by non-invasive faecal steroid monitoring
International Zoo Yearbook
, vol. 
35
 (pg. 
173
-
191
)
Berkeley, E.V., Kirkpatrick, J.F., Schaffer, N.E., Bryant, W.M. and Threlfall, W.R. 1997. Serum and faecal steroid analysis of ovulation, pregnancy and parturition in the black rhinoceros, (Diceros bicornis). Zoo Biology 16: 121-132.
Serum and faecal steroid analysis of ovulation, pregnancy and parturition in the black rhinoceros, (Diceros bicornis)
Zoo Biology
, vol. 
16
 (pg. 
121
-
132
)
Heistermann, M., Finke, M. and Hodges, J.K. 1995. Assessment of female reproductive status in captive-housed Hanuman langurs (Presbytis entellus) by measurement of urinary and fecal steroid excretion patterns. American Journal of Primatology 37: 275-284.
Assessment of female reproductive status in captive-housed Hanuman langurs (Presbytis entellus) by measurement of urinary and fecal steroid excretion patterns
American Journal of Primatology
, vol. 
37
 (pg. 
275
-
284
)
Hirschenhauser, K., Mostl, E., Peczely, P., Wallner, B., Dittami, J. and Kotrschal, K. 2000. Seasonal relationships between plasma and faecal testosterone in response to GnRH in domestic ganders. General and Comparative Endocrinology 118: 262-272.
Seasonal relationships between plasma and faecal testosterone in response to GnRH in domestic ganders
General and Comparative Endocrinology
, vol. 
118
 (pg. 
262
-
272
)
Kirkpatrick, J.F., McCarthy, J.C., Gudermuth, D.F., Shideler, S.E. and Lasley, B.L. 1996. An assessment of the reproductive biology of Yellowstone Bison (Bison bison) subpopulations using noncapture techniques. Canadian Journal of Zoology 74: 8-14.
An assessment of the reproductive biology of Yellowstone Bison (Bison bison) subpopulations using noncapture techniques
Canadian Journal of Zoology
, vol. 
74
 (pg. 
8
-
14
)
Lanyon, J.M., Sneath, H.L., Kirkwood, J.M. and Slade, R.W. 2002. Establishing a mark-recapture program for dugongs in Moreton Bay, south-east Queensland. Australian Mammalogy 24: 51-56.
Establishing a mark-recapture program for dugongs in Moreton Bay, south-east Queensland
Australian Mammalogy
, vol. 
24
 (pg. 
51
-
56
)
Larkin, I.L.V., Gross, T.S. and Reep, R.L. 2005. Use of faecal testosterone concentrations to monitor male Florida manatee (Trichechus manatus latirostris) reproductive status. Aquatic mammals 31: 52-61.
Use of faecal testosterone concentrations to monitor male Florida manatee (Trichechus manatus latirostris) reproductive status
Aquatic mammals
, vol. 
31
 (pg. 
52
-
61
)
Lasley, B.L. and Kirkpatrick, J.F. 1991. Monitoring ovarian function in captive and free-ranging wildlife by means of urinary and faecal steroids. Journal of Zoo and Wildlife Medicine 22: 23-31.
Monitoring ovarian function in captive and free-ranging wildlife by means of urinary and faecal steroids
Journal of Zoo and Wildlife Medicine
, vol. 
22
 (pg. 
23
-
31
)
Marsh, H. 1995. The life history, pattern of breeding and population dynamics of the dugong. In Population Biology of the Florida Manatee, edited by T.J. O’Shea, B.B. Ackerman and H.F. Percival. United States Department of the Interior, National Biological Service, Information and Technology Report 1: 75-83.
Marsh, H., Heinsohn, G.E. and Glover, T.D. 1984a. Changes in the male reproductive organs of the dugong Dugong dugon (Sirenia: Dugongidae) with age and reproductive activity. Australian Journal of Zoology 32: 721-742.
Changes in the male reproductive organs of the dugong Dugong dugon (Sirenia: Dugongidae) with age and reproductive activity
Australian Journal of Zoology
, vol. 
32
 (pg. 
721
-
742
)
Marsh, H., Heinsohn, G.E. and Marsh, L.M. 1984b. Breeding cycle, life history and population dynamics of the dugong, Dugong dugon (Sirenia: Dugongidae). Australian Journal of Zoology. 32: 767-785.
Breeding cycle, life history and population dynamics of the dugong, Dugong dugon (Sirenia: Dugongidae)
Australian Journal of Zoology
, vol. 
32
 (pg. 
767
-
785
)
New, N.P., Jakubowski, J.M., Stone, G.M. and Jones, R.C. 1998. Seasonal pattern of androgen secretion in the male platypus, Ornithorhynchus anatinus, in the upper Barnard River, New South Wales. Australian Mammalogy 20: 215-220.
Seasonal pattern of androgen secretion in the male platypus, Ornithorhynchus anatinus, in the upper Barnard River, New South Wales
Australian Mammalogy
, vol. 
20
 (pg. 
215
-
220
)
Schwarzenberger, F., Francke, R. and Goeltenboth, R. 1993. Concentrations of faecal immunoreactive progestagen metabolites during the oestrous cycle and pregnancy in the black rhinoceros (Diceros bicornis michaeli). Journal of Reproduction and Fertility 98: 285-291.
Concentrations of faecal immunoreactive progestagen metabolites during the oestrous cycle and pregnancy in the black rhinoceros (Diceros bicornis michaeli)
Journal of Reproduction and Fertility
, vol. 
98
 (pg. 
285
-
291
)
Schwarzenberger, F., Mostl, E., Palme, R. and Bamberg, E. 1996. Faecal steroid analysis for non-invasive monitoring of reproductive status in farm, wild and zoo animals. Animal Reproduction Science 42: 515-526.
Faecal steroid analysis for non-invasive monitoring of reproductive status in farm, wild and zoo animals
Animal Reproduction Science
, vol. 
42
 (pg. 
515
-
526
)
Vincent, I.C. and Mitchell, A.R. 1992. Comparison of cortisol concentrations in saliva and plasma of dogs. Research in Veterinary Science 53: 342-345.
Comparison of cortisol concentrations in saliva and plasma of dogs
Research in Veterinary Science
, vol. 
53
 (pg. 
342
-
345
)
This content is only available as a PDF.