| dc.description.abstract | The Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri), a
subspecies of marsh rabbit endemic to the Lower Keys, Florida, is threatened with
extinction due to extensive coastal development of salt marsh habitats. LKMR recovery
is limited by habitat loss and degradation from brush encroachment, predation by freeroaming
cats (Felis catus) and raccoons (Procyon lotor), sea-level rise, and hurricanes.
This study sought to determine local and landscape factors that influence LKMR
metapopulation ecology and dynamics and to evaluate strategies for their recovery. I
evaluated the influence of patch and landscape characteristics on LKMR densities,
extinction, and colonization rates following Hurricane Wilma, and the response of
LKMRs and salt marsh habitats to prescribed fire. I used estimates of population change
based on annual monitoring data to validate vital rates, constructed a spatially explicit
demographic model to evaluate various levels and spatial configurations of recovery
scenarios implemented throughout the LKMRs range, and validated expected changes in parameter estimates using measures of habitat degradation and raccoon activity from
known LKMR populations.
I found LKMR densities were higher in patches with greater numbers of
bunchgrasses and forbs and less edge and lower in patches with higher measures of
raccoon activity. In response to a hurricane, I found the distance between LKMR
patches and the coast had a negative influence on extinction probability; the distance
between an extirpated and occupied LKMR patch had a negative influence on
colonization probability and patch size had a positive influence. Adult LKMRs
increased as woody cover <0.5 m decreased, herbaceous cover <0.5 m increased, and
food availability increased in at least one site following prescribed fire. Model results
indicated habitat management actions that improve carrying capacity of local rabbit
populations and juvenile survival and control raccoon populations to increase rabbit
reproductive rates are effective population recovery strategies. In total, my results
provide a conservation planning tool that can be used to select recovery strategies and
locations that will maximize benefits to LKMRs, thus improving their viability and
recovery. | en |
