Population Studies of Deer (Odocoileus virginianus, Mazama americana) in Southern Yucatán, Mexico

Abstract

Aims: Estimate the population density of deer in the municipality of Tzucacab, Yucatán in the periods of 2003-2004, 2007-2008 and 2008-2009, determine the use of the habitat by these populations and the sustainability of the deer harvest from the estimated population densities.
 Study Design: A descriptive and vertical free-living deer population study was carried out in southern Yucatan, Mexico over a three-year period.
 Methodology: The map of the municipality of Tuzcacab was zoned in quadrants of 36 km2, completing a total of 36 quadrants; Unrestricted random sampling was applied to select seven quadrants in the period from 2003 to 2004 and 18 in each annual period between 2007 and 2009. Population samplings were carried out by applying three population estimation methods: direct sighting in a linear transect of 5 km in length, count of tracks in transect except period 2003-2004 and faecal pellets group count in plots. The evaluation of the use of habitat was carried out using the Bonferroni intervals, from the data of faecal pellets count. The evaluation of the deer harvest was carried out using the sustainable harvest model.
 Results: The population densities were different in each method, the density by the excreta count was 4.63 ± 2.49 deer / km2 in 2003-2004, 0.294 ± 0.198 deer / km2 in 2007-2008, and in the year 2008-2009 was 0.419 ± 0.0000085 deer / km2. Habitat use in 2007-08 and 2008-2009 was higher in the tropical forest, lower in agriculture and similar to that expected in secondary succession forest (acahual). The values of sustainable harvest, taking as a value the density per count of excreta in the plot because it showed the highest statistical precision, in the period 2003-04 it is sustainable, but in the period from 2007 to 2009 it is not sustainable.
 Conclusion: The population densities of deer (O. virginianus and M. americana) in Tuzcacab by means of the excreta count method, have decreased significantly. The habitat use preference is the tropical forest. The deer harvest in the period from 2007 to 2009 is not sustainable.