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Vol. 52, 2013
Foraging guild structure and niche characteristics of
waterbirds in an epicontinental lake in Mexico
María
José Pérez-Crespo1, Juanita Fonseca1,
Rubén Pineda-López2, Eduardo Palacios3 and Carlos
Lara4*
1Maestría
en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, Km 1.5
carretera Tlaxcala-Puebla s/n, Colonia La Loma Xicohténcatl, Tlaxcala
90070, Mexico
2Universidad Autónoma de Querétaro, Cerro de las
Campanas s/n, Colonia Las Campanas, Querétaro, Querétaro 76010, Mexico
3Centro de Investigación Científica y de Educación
Superior de Ensenada, B.C. (CICESE), Unidad La Paz, Miraflores 334
entre La Paz y Mulegé, Fracc. Bellavista, La Paz, Baja California Sur
23050, Mexico
4Centro de Investigación en Ciencias Biológicas,
Universidad Autónoma de Tlaxcala, Km 10.5 Autopista Tlaxcala-San Martín
Texmelucan, San Felipe Ixtacuixtla, Tlaxcala 90120, Mexico
Abstract
Background: It was suggested that
ecological patterns can be used to infer the nature of ecological
processes (i.e., competition) that structure communities. Analysis of
patterns of resource partitioning under the classical niche paradigm
(competitive niche differentiation in exploiting limited resources) has
traditionally been used to understand the structure of communities. On
the contrary, neutral theory states that patterns result from neutral
processes such as stochasticity and dispersal abilities. Thus, if any
ecological process gives rise to a characteristic ecological pattern,
the comparative study of patterns with appropriate neutral models may
reveal the magnitude of that process. In this study, we analyzed
patterns of resource utilization of a waterbird community in Lake
Acuitlapilco, an epicontinental lake in central Mexico. In February
2011 to January 2012, we recorded foraging behaviors of waterbird
species in two niche dimensions or axes: feeding technique and foraging
habitat. The pattern of resource utilization was characterized by niche
breath and niche overlap.
Results: Results showed that waterbird species in
Lake Acuitlapilco were specialists in resource utilization patterns and
therefore were vulnerable to fluctuations in resources, particularly
feeding habitat. Niche overlaps were generally largest among species
belonging to the same guild. To test competition as an ecological
process that plays a role in the community structure, observed niche
overlaps were compared with niche overlaps generated with null models
of communities in the absence of competition using the RA4
randomization algorithm. Habitat and observed bidimensional overlaps
were higher than those of randomly generated communities.
Conclusions: Our study suggested
that other processes can be used to predict resource utilization
patterns instead of competition alone, as suggested by neutral theory.
Future studies analyzing the mechanisms that structure waterbird
communities should include the use of null models to support their
conclusions.
Key words: Communities; Feeding behavior;
Habitat use; Niche overlap; Null models; Neutral theory.
*Correspondence: E-mail: laracar@posgradouatx.com.mx
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