Abundance, microhabitat and feeding of Peromyscus yucatanicus and Peromyscus mexicanus in the Mexican tropics

Abstract

Introduction: Rodents influence the processes of succession and regeneration in tropical forests, functioning as important dispersers and predators of seeds and plants.  In this study, we describe aspects of the population structure and dynamics, and characterize the microhabitat and composition of the feces of the semi-tree-dwelling rodents Peromyscus yucatanicusand Peromyscus mexicanus in tropical forests of Quintana Roo and Veracruz, in Mexico. Methods: We trapped Peromyscus yucatanicus from September 2014 to February 2015, with 122 Sherman traps between 2 to 10 m of height in 62 trees.  Peromyscus mexicanus was trapped from March to September of 2015, with 105 Sherman traps between 0-11 m of height on 57 trees.  We characterized the microhabitat, identified the trees, and calculated the canopy openness in the sites where individuals were trapped.  We collected and analyzed the composition of the feces of each species. Results: We captured 48 individuals of Peromyscus yucatanicus at an average height of 2.58 m above ground level.  Its population density was 26.6 ind/ha, with reproductive activity in the dry season.  The average canopy openness was 7.75 %.  Their feces mainly contained seeds, fruit pulp and starch.  We recorded 54 individuals of Peromyscus mexicanus at an average height of 1.15 m.  Its population density was 20.83 ind/ha, with reproductive activity in both dry and rainy seasons.  The canopy openness was 4.78 % (dry season) and 4.5 % (rainy season).  Their feces mainly contained fruit pulp, starch and chitin remains in both seasons.   Discussion and conclusions: The captured of rodents were higher on trees with small diameters and low leaf litter percentage; the rainy season favored the captures.  Both species were mainly captured in sites with a covering of organic matter on the soil and in sites with higher vegetal cover and reduced canopy openness.  Conservation of a diverse tropical forest is fundamental for the conservation of both semiarboreal rodents.