Importance of landscape heterogeneity to wood storks in Florida Everglades |
| |
Authors: | D Martin Fleming Wilfried F Wolff Donald L DeAngelis |
| |
Institution: | (1) Everglades National Park Field Station, National Biological Survey, 40001 State Road 9336, 33034 Homestead, Florida, USA;(2) Institut fuer Biotechnologie 3, Forschungszentrum Juelich, Postfach 1913, Juelich, Germany;(3) Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, 37831 Oak Ridge, Tennessee, USA |
| |
Abstract: | Declines in populations of and reproductive success of wood storks and other wading birds have occurred in the Florida Everglades
over the past several decades. These declines have been concurrent with major changes in the Everglades’ landscape characteristics.
Among the plausible hypotheses that relate to landscape change are the following: (1) general loss of habitat; (2) heavy loss
of specific habitat, namely, short-hydroperiod wetlands that provide high prey availability early in the breeding season;
and (3) an increase in frequency of major drying out of the central slough areas, which can affect prey availability late
in the breeding season.
These three hypotheses were compared using an individual-based model of wood stork (Mycteria americana) reproduction. This model simulated the behavior and energetics of each individual wood stork in a breeding colony on 15-min
time intervals. Changes in water depth and prey availability occurred on daily time steps. Simulation results showed a threshold
response in reproductive success to reduction of wetland heterogeneity. Model comparisons in which (1) only short-hydroperiod
wetlands were removed and (2) wetlands of both long and short hydroperiods were removed showed that, for the same loss of
total area, the specific habitat removal caused a much greater reduction in wood stork reproduction, indicating hypothesis
2 may be a more likely explanation than hypothesis 1. Reduction of initial prey availability in the central slough areas (simulating
frequent drying; hypothesis 3) reduced fledging success by an average of more than 90% in the model. |
| |
Keywords: | Computer simulation Wood storks Wading birds Everglades Individual-based modeling Landscape heterogeneity |
本文献已被 SpringerLink 等数据库收录! |
|