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Updated: Aug 15, 2026

Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making
Published on: March 2, 2011
Testosterone levels in the Tasmanian bettong (Bettongia gaimardi)
1Zoology Department, University of Tasmania, Australia.
Abstract:
The Tasmanian bettong (Bettongia gaimardi) is a small macropodid marsupial that is a continuous breeder. This study has partitioned testosterone into three fractions that vary to some extent throughout the year, coinciding with peaks and troughs in breeding, body weight, and testes volume. The three fractions determined were free, albumin bound, and sex hormone binding globulin (SHBG) bound testosterone. Concentrations of both albumin and SHBG varied significantly throughout the year with peaks in SHBG coinciding with lowered levels of free testosterone. Testosterone was also measured during maturation of male bettongs. There were significant regressions between weight or testes volume and the combined free and albumin bound testosterone. Maturity started near age 30 weeks and a body weight of 1.5 kg and was accompanied by a brief surge in testosterone levels.
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