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Vol. 54, 2015
Niche partitioning
among three tree-climbing bird species in subtropical mountain forest
sites with different human disturbance
Carlos Lara1*,
Berenice Pérez1, Citlalli
Castillo-Guevara1 and Martín Alejandro Serrano-Meneses2
1Centro
de Investigación en Ciencias Biológicas, Universidad Autónoma de
Tlaxcala, Km. 10.5 Autopista Tlaxcala-San Martín Texmelucan, San Felipe
Ixtacuixtla, Tlaxcala 90120, Mexico
2Laboratorio de Biología Evolutiva, Centro Tlaxcala de
Biología de la Conducta, Universidad Autónoma de Tlaxcala, Carretera Tlaxcala-Puebla, Km. 1.5, 90062 Tlaxcala, Mexico
Abstract
Background: Closely related and
ecologically similar species that overlap in ranges can coexist through
resource partitioning without one pushing the others to extinction
through competition. Understanding resource partitioning among species
is essential to predicting how species decline can affect the
functioning of communities and ecosystems. In this study, we analyzed
niche overlap and resource partitioning of three tree-climbing bird
species in disturbed and undisturbed forest sites at La Malinche
National Park, Tlaxcala, Mexico. From January to December 2008,
resource partitioning between the three species was examined through
the frequency of sightings of individuals foraging in different sites
in the trees of both forest types. We characterized the pattern of
resource utilization by niche breadth and niche overlap. Finally, we
tested if these birds divide tree space differentially according to
forest type.
Results: Our results indicate that in undisturbed
sites, pygmy nuthatches had a high niche breadth (foraging
significantly more on the thin branches), while white-breasted
nuthatches and brown creepers had similar medium niche breadth values
(more often foraged in thick branches and lower trunk, respectively),
causing the last two to have a high niche overlap. In contrast, in
disturbed sites, niche breadth and overlap values were similar for all
three tree-climbing species. All observed overlaps for both forest
types were higher than expected, but expected values in disturbed sites
suggest the possibility of competition on these sites. Pygmy nuthatches
were more sighted than white-breasted nuthatches and brown creepers in
both forest types.
Conclusions: Our study shows that
differences in tree use suggest resource partitioning among the three
bird species, particularly at undisturbed sites. However, activities of
excessive logging and grazing in the disturbed sites resulted in niche
overlap among species. This could lead to changes in competitive
dynamics among them.
Key words: Brown creeper; Pygmy nuthatch;
White-breasted nuthatch; Niche overlap; Null models; Resource
partitioning.
*Correspondence: E-mail: laracar@posgradouatx.com.mx
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