The importance of rice fields for glossy ibis (Plegadis falcinellus): Management recommendations derived from an individual-based model
Authored by Richard A Stillman, Gregorio M Toral, Simone Santoro, Jordi Figuerola
Date Published: 2012
DOI: 10.1016/j.biocon.2012.02.001
Sponsors:
Regional Government of Andalusia
Platforms:
MORPH
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Artificial wetlands provide alternative habitats for waterbirds. The
Donana rice fields (SW Spain) are extensively used as a foraging site by
the glossy ibis (Plegadis falcinellus). The aim of this study was to
develop an individual-based model to predict the possible effects of
glossy ibis' population growth, reductions in the rice cultivated area, and changes on the phenology of the management processes of the paddies
on the mortality rate of the glossy ibis population. We test the
hypothesis that the glossy ibis breeding population of Donana can obtain
its energy requirements during the non-breeding season by feeding on
rice fields alone. Our results show that the glossy ibis population
growth is not currently limited by rice field availability. However, a
reduction of 80\% would cause mortality rate increases above the
observed mortality (5.9\% per year), with values around 10\% per year
for populations between 50,000 and 100,000 birds. A reduction of 90\% of
the rice field area would cause mortality rate increase above the
observed value for populations greater than 20,000 birds, reaching 60\%
per year with a population of 100,000 birds. Cultivated area in Donana
suffers temporary reduction on its area during drought periods. Taking
into account the fact that the glossy ibis population for 2011 may
exceed 22,900 birds, large scale changes in the area of rice fields due
to habitat transformations and/or drought periods may have important
effects on the viability of the glossy ibis population in Donana. (C)
2012 Elsevier Ltd. All rights reserved.
Tags
birds
Populations
Environmental-change
Communities
White-fronted geese
Mississippi alluvial valley
Limosa-limosa-limosa
Natural wetlands
Southwest spain
Waterbirds