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Vol. 48 No. 1, 2009
Testosterone Levels in Male Formosan Reeve,s Muntjac:
Uncoupling of the Reproductive and Antler Cycles
Kurtis
Jai-Chyi Pei1, Kerry Foresman2, Bing-Tsan Liu3,*,
Long-Hwa Hong1, and John Yuh-Lin Yu4
1Institute
of Wildlife Conservation, National Pingtung University of Science and
Technology, 1 Hseuh Fu Rd., Neipu, Pingtung 912, Taiwan.
E-mail:kcjpei@mail.npust.edu.tw; hlh@single.url.com.tw
2Division of Biological Sciences, University of
Montana, Missoula, MT 59812, USA. Email:foresman@mso.umt.edu
3Department
of Animal Science, National Pingtung University of Science and
Technology, 1 Hseuh Fu Rd., Neipu, Pingtung 912, Taiwan
E-mail:tml19@mail.npust.edu.tw
4Institute of
Cellular and Organismic, Academia Sinica, 128 Academia Rd., Sec. 2,
Nankang, Taipei 115, Taiwan
E-mail:johnyu@ccvax.sicina.edu.tw
Kurtis
Jai-Chyi Pei, Kerry Foresman, Bing-Tsan Liu, Long-Hwa Hong, and John
Yuh-Lin Yu (2009) Cervid
species are generally assumed to be seasonal in their reproductive
activity, and species that develop antlers also do so in a seasonal
manner in conjunction with this annual puberty. As gonadotropin
endocrine support for reproductive activity wanes, the resultant
lowered testosterone levels initiate antler casting. Male
Formosan Reeve’s muntjac (Muntiacus
reeves micrurus)
exhibits an annular antler cycle with growth initiating in early May,
velvet shedding and antler hardening by early Sept., and casting the
following May. This cycle was correlated with fluctuating
testosterone levels in a manner somewhat similar to that observed in
other cervids. However, this species remains reproductively
active year-round with spermatozoa present in the testes and
epididymides, with no variation in their quantity or quality.
These findings suggest that the testosterone threshold required for
antler development in this muntjac may be set higher than that required
for spermatogenesis, or conversely, that spermatogenesis might be
controlled by other hormones in addition to testosterone.
Key words: Antler
cycle, Formosan Reeve,s muntjac, Fecal testosterone, Muntiacus reevesi, Seasonal levels.
*Correspondence: Tel: 886-8-7703202 ext. 6198. Fax:
886-8-7740148.
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