10.5061/DRYAD.68J14
Niederhauser, Joseph M.
Florida Atlantic University
DuBois, Adrienne L.
University of Miami
Searcy, William A.
University of Miami
Nowicki, Stephen
Duke University
Anderson, Rindy C.
Florida Atlantic University
Data from: A test of the eavesdropping avoidance hypothesis as an
explanation for the structure of low amplitude aggressive signals in the
song sparrow
Dryad
dataset
2019
Melospiza melodia
signal degradation
May 2015
eavesdropping avoidance
song sparrow
low amplitude
soft song
2019-02-01T00:00:00Z
2019-02-01T00:00:00Z
en
https://doi.org/10.1007/s00265-018-2469-7
285088 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Low amplitude signals function in private exchanges of information between
signalers and nearby receivers. The eavesdropping avoidance hypothesis
proposes that selection favors quiet threat signals in order to avoid the
costs of eavesdroppers. If true, then selection should favor other
acoustic traits in addition to low amplitude that lead to quiet signals
transmitting less effectively through the environment compared to
broadcast signals. The “warbled” soft songs of male song sparrows differ
from “crystallized” soft songs and from broadcast songs in a number of
acoustic traits, suggesting that these songs may transmit less
effectively. We tested this prediction in a field experiment by playing
broadcast songs, crystallized soft songs, and warbled soft songs through a
loudspeaker at the same amplitude and recording the propagated songs at
five distances, at two heights, and in two different habitat types.
Counter to our prediction, we found no evidence that either form of soft
song transmits differently than broadcast song when all were played
loudly. If anything, soft songs transmitted more effectively when all
songs were played quietly. Our results do not support one prediction made
by the eavesdropping avoidance hypothesis, although the possibility
remains that reduced amplitude alone is sufficient to reduce
eavesdropping. The question of why warbled soft song differs in acoustic
structure remains unresolved.
SOSP-Test of EAH-DataData from the song transmission analysis of song
sparrow broadcast songs, crystallized soft songs, and warbled soft songs.
All data were collected using SigPro 3.25.
Pennsylvania