Abstract
Population dynamics, microhabitat use, space use, and competition in populations of the Key Largo woodrat (Neotoma floridana smalli), Key Largo cotton mouse (Peromyscus gossypinus allapaticola) and the introduced black rat (Rattus rattus) were investigated in four tropical hardwood hammocks on Key Largo, Florida. The hammocks represented three different age classes of hammock: medium (disturbed between 1940 and 1959), medium-old (disturbed between 1926 and 1940), and old (disturbed before 1926).N. floridana performed best in medium-old hammock where they had high population size, high female reproduction and R. rattus was absent. N. floridana performed poorly in old-aged hammock. In old-aged hammock, they had low recruitment, low female reproduction, seasonal male reproduction, and a larger home range compared to other sites. Also, N. floridana performed poorly in the presence of R. rattus with low population size, reduced survivorship, and a male biased population. P. gossypinus performed best in medium-aged hammocks, as indicated by their high abundance at those sites. The presence of R. rattus, caused P. gossypinus, to reduce their home range size. R. rattus was only present in a medium-aged grid, where it had high population size and recruitment.N. floridana presence at a location was predicted by characteristics of the understory, while their intensity of use of a location was predicted by canopy characteristics. The presence of P. gossypinus was predicted by characteristics of the canopy, while intensity of use of a location was predicted by understory characteristics. R. rattus intensity of use of a location was predicted by canopy characteristics.Male home range was greater than female home range in both native species. Home range of N. floridana was different among hammock age-class, but home range of P. gossypinus was not. In addition, P. gossypinus exploited the habitat at a greater spatial scale than N. floridana.Both N. floridana and P. gossypinus were engaged in intraspecific competition. However, only P. gossypinus was found to have a competitive effect on N. floridana.