10.5061/DRYAD.26087
Clay, Natalie A.
University of Oklahoma
Lehrter, Richard J.
University of Oklahoma
Kaspari, Michael
University of Oklahoma
Smithsonian Tropical Research Institute
Data from: Toward a geography of omnivory: omnivores increase carnivory
when sodium is limiting
Dryad
dataset
2017
Ants
Trophic ecology
Hymenoptera: Formicidae
National Science Foundation
https://ror.org/021nxhr62
NSF DDIG DEB-1210336
2017-09-01T14:34:04Z
2017-09-01T14:34:04Z
en
https://doi.org/10.1111/1365-2656.12754
73437 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Toward understanding the geography of omnivory, we tested three
hypotheses that predict the proportion of animal tissue consumed: The
Sodium Limitation Hypothesis predicts that omnivores increase animal
consumption in Na-poor environments because Na bioaccumulates from plants
to predators; thus, heterotrophs are Na-rich sources. The Nitrogen
Limitation and Habitat Productivity Hypotheses use the same logic to
predict more animal consumption in N-poor and productive environments
respectively. 2. Omnivory is a common trophic strategy, but what
determines the balance of plant and animal tissue omnivores consume is
relatively unexplored. Most of what we know comes from single populations
at local scales. Here we quantitatively test these three hypotheses at a
large geographic scale and across 20 species of omnivorous ants. 3. We
tested each hypothesis using N stable isotopes (δ 15 N) to quantify the
degree of carnivory in ant populations in 20 forests that span 12°
latitude from Georgia to Maine, USA. We used the difference in δ 15 N
between 20 ant conspecifics in 10 genera between two paired forests (10
pairs of 20 forests) that consisted of a coastal and inland forests on the
same latitude to determine if the proportion of animal tissue consumed
could be predicted based on Na, N or NPP. 4. Sodium gradients accounted
for 18% of the variation in δ 15 N, 45% if one outlier ant species was
omitted. In contrast, the Nitrogen Limitation and Habitat Productivity
Hypotheses, which predict more animal consumption in N-poor and more
productive environments respectively, failed to vary with δ 15 N. 5. Our
results reveal a geography of omnivory driven in part by access to Na.
Ant_dN_Field_Lab_Data_201715N stable isotope, chemistry, and NaCl and
Sugar usage data for ants species from 20 forests from Georgia to Maine,
USA.
United States