Specific mating behaviors for this animal was not found, although it is thought to be monogamous like red brocket deer. (Huffman, 2004)
Reproduction appears to be year round, as spotted fawns have been found throughout the year. In some juvenile females, the ovaries were detected to have developing follicles indicating an early onset of reproduction. The age classes used were the same used for whitetail deer, placing these females around a one-year age class.
Does were found to be simultaneously pregnant and lactating. In captivity, the gestation period is around eight months. Usually a single young is born with twins being rare. The young are camoflaged in grass, very similar to whitetail deer (Odocoileus virginianus). (Stallings, 1986; Thomas, 1975)
The antler conditions of bucks also supports the notion that there is year round reproduction. Males with polished antlers were observed throughout the year. Bucks have been found in velvet in January, May and June and with polished antlers by May through November. The males of this species apparently shed their antlers every 18 months to two years but with great individual variability. (Stallings, 1986; Thomas, 1975)
The doe provides care to the fawn until weaned. The female feeds the fawn, but until it becomes older, the fawn stays hidden. The time to weaning or the duration of dependence on the doe is unknown.
- Stallings, J. 1986. Notes on the reporductive biology of the grey brocket deer (Mazama gouazoubira) in Paraguay. Journal of Mammalogy, 67: 175-176.
- Thomas, W. 1975. Observation of captive brockets. Int. Zoo Yearbook, 15: 77-78.