TAPIR FIELD VETERINARY MANUAL - Tapir Specialist Group

9. Reproduction
9.1. Brief Reproductive Physiology Review
Male and female tapirs reach their sexual maturity when they are approximately two years old.
In the wild, occasionally the one year-old calves are sighted accompanied by their mothers.
The adult males have a small and pendulous scrotum, and the testicles are located near
the perineum. To urinate they move the extremity of the penis backwards, in order to
hurl the urine far away. Like in the domestic horse, the tapir’s urethra finishes with a
small prominence in the lower side of the gland. From the penis morphology in erection, it
may be deduced that the ejaculation occurs inside the uterus, like in equines.
The females have a pair of mammary glands on the inguinal area and the uterus presents
two horns, the placenta is epiteliocorial. The vaginal mucous produces a lipid secretion
that provides vulvar lips adherence, making the vaginal environment not only isolated from
the external medium but protected when the animal stays in the water.
The tapir estrus is very difficult to determine. In general, female tapirs are annual
polyestrical and the estrus, in general, lasts 1-4 days and is repeated each 28-32 days.
Fertile estrus is possible 9-27 days after the calf birth. However, the estrous cycle for
tapirs should be approached individually for each species as well as the gestation length.
9.2. Hormones during Estral Cycle and Gestation
Hormone screening is used to monitor the estrous cycle and hormonal status in both
captive and free-living animals. Because of the stress produced by immobilization, blood
samples are not reliable for these studies, so fecal, urine and salivary samples are the best
choices, because the collection of these samples is much less invasive for the animals and
the hormonal concentration can be measured more accurately given that the animals are
not stressed out by the capture process. The most widely employed technique is the
radio-immunoassay, for the detection of the hormone metabolites. For the determination
of pregnancy in captive tapirs, samples must be collected at least every week, in order to
project the fluctuations of progesterone serum levels.
In captivity, animals can be trained for the collection of saliva and urine. Fecal samples
are the best choice for field studies, but the collection must be performed right after the
defecation. The samples can be stored in a container with ethanol 90% and the precise
time of collection must be recorded. The sample can be dried in an oven, sunlight, or a
lyophilizeror extracted in the field as mentioned earlier.