Changes in body size in some bird species from the Yucatan peninsula since the Late Pleistocene
Por:
Silva-Martinez, Ana Frida, Zuniga-Vega, J. Jaime, Arroyo-Cabrales, Joaquin, Sanchez-Gonzalez, Luis A.
Publicada:
1 ene 2023
Ahead of Print:
1 mar 2023
Resumen:
During the Pleistocene, the Yucatan Peninsula reached its greatest
geographic extension, with 457,650 km(2), but the rise of sea level
after the Last Glacial Maximum (ca. 20,000-12,000 years ago) reduced its
area to 225,182 km(2) (50.8% reduction). These geographic extension
changes likely modified the extension of different habitats throughout
the peninsula, which may have also promoted morphological changes in the
species that inhabit this region. Here, we tested if the reduction of
the geographic size of the Yucatan Peninsula may have promoted changes
in the body size of three fossil bird species and two modern bird
species. We compared Late Pleistocene bird fossils specimens from
Loltun, Yucatan, Mexico (ca. 28,000-11,700 ya), San Josecito Cave and
Tlapacoya, and study skins of collected specimens. To assess the
area-scale ratio and to establish if body size changes occurred over
time from a large to a small body size, we relied on the ``island
rule'' as a framework; we also relied on Bergmann's rule, which
postulates a decreasing in size from north to south in homeothermic
species to recognize if these birds show a north to south cline. Based
on body mass and measurements of the tarsometatarsi, a reliable proxy
for the estimation of body size, we performed statistical analyses to
test for differences between fossil and non-fossil birds, as well as to
test a gradient in body mass north to south. We found a statistically
significant trend in body size changes through time, from small body
sizes in fossil birds to larger body sizes in non-fossil birds. These
results suggest that relatively recent ecological factors related to the
environmental carrying capacity may have promoted body size variations
in birds from the Yucatan Peninsula. We also found that modern
population of bird species follow Bergmann's rule.
Filiaciones:
Silva-Martinez, Ana Frida:
Univ Nacl Autonoma Mexico, Posgrad Ciencias Biol, Mexico City 04510, Mexico
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Biol Evolut, Museo Zool Alfonso L Herrera, Mexico City 04510, Mexico
Zuniga-Vega, J. Jaime:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Mexico City 04510, Mexico
Arroyo-Cabrales, Joaquin:
Inst Nacl Antropol Hist, Lab Arqueozool M C Ticul Alvarez Solorzano, Col Ctr, Mexico City 06060, Mexico
Sanchez-Gonzalez, Luis A.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Biol Evolut, Museo Zool Alfonso L Herrera, Mexico City 04510, Mexico
hybrid, Hybrid Gold
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