by Kendra Bauer
From 1994 until 2007, Charles Foerster was the primary researcher of the Bairdís Tapir Project in Costa Rica. Charlie has been studying tapir interaction, and has been working to determine the homerange size of Baird's Tapirs in Costa Rica's Corcovado National Park. He has been monitoring the population with radio telemetry and direct observations. He has discovered some of the basic knowledge about the tapir that has allowed us to ask more in-depth questions about the tapir's involvement in the ecosystem. Below are a few of the things he has learned:
Baird's Tapirs have babies about every 20 months. The babies stay with the mom for about two years. The gestation period of a wild tapir is about 13 months. Each baby weighs about 15 pounds.
Juvenile Dispersal Behavior
Juvenile dispersal appears to be dependent on the reproductive behavior of the mother. Offspring will stay with the mother until one or two months before she gives birth again. Then the offspring starts to move independently of the mom. It will, however, remain within its maternal homerange for another two or three years. Between three and four and one-half years of age, juvenile tapirs explore territories outside of the parents' range. Finally, between four and one-half and six years of age, the juveniles move completely away to establish their own territories.
Thus far, six juvenile tapirs have been monitored during the dispersal process. Four females dispersed an average of 18 kilometers from their original homeranges. Some moved as little as five kilometers, while others ranged as far as 30 kilometers. One male traveled 16 kilometers and another 5 kilometers. However, these males have not yet become completely established and may yet disperse to different locations.
Offspring and Adult Sex Ratios
Sixteen offspring have been born to five radiocollared females. The sex ratio of offspring has been eight male, five female and three unknown. No consistent birthing season has been noted.
Offspring and Adult Survival Rates
|Female (2000)||Likely died of old age|
|Male (two and one-half years old)||Fell in canyon|
|Adult male (2001)||Unknown cause|
|Adult male (2002)||Unknown cause|
Average homerange size for all adult tapirs is about one square kilometer. No significant differences have been noted in homerange sizes between seasons or between sexes. As expected, home ranges of juveniles, which average 67 hectares, are much smaller than those of adults.
Based on adult home range size alone, the population density of tapirs in the Sirena area is estimated at 0.88 tapirs per square kilometer. However, when homerange overlap is considered, the density estimate increases to 2.54 tapirs per square kilometer. The population needs to be monitored for more time to increase this dataset.
The results of this study can be directly applied to other tapir populations and will influence new and existing conservation programs such as reintroduction, translocation, and the designation of new protected areas. In addition, we are collecting data on site-specific parameters (homerange size, habitat use, etc.), which will be vital for management plans for tapirs in Corcovado National Park.
About the author:
Kendra Bauer is a doctoral student at the University of Texas in Austin, Texas.
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