Reichard, D. G., and Ketterson, E. D.

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Nolan research group. The focus of the research is an abundant North American songbird, the dark-eyed 
junco, Junco hyemalis, and the primary sources of support have been the National Science Foundation and 
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works of Val Nolan Jr., who studied songbirds in addition to the junco: in particular the prairie warbler, 
Dendroica discolor. This site was originally compiled and organized by Eric Snajdr, Nicole Gerlach, and Ellen 
Ketterson. 
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Decoding an enigmatic signal: short-range song in 
Dark-eyed Juncos (Junco hyemalis) 
Dustin G. Reichard and Ellen D. Ketterson 
Indiana University, Bloomington, IN 
The study of song has largely focused on high amplitude, long-range songs (LRS) associated with male-male 
interactions and mate attraction. In addition to LRS many species also sing a low amplitude, often more complex 
short-range song (SRS) during courtship that is distinct from LRS and can exhibit substantially different structure. 
Little is known about the standing variation in SRS between males or its importance in mate choice and female 
stimulation. We presented mated, free-living male Dark-eyed Juncos with a caged female conspecific placed near 
the nest and playback of a female precopulatory trill to elicit courtship behavior and SRS. During the female 
presentation and playback we recorded SRS from the focal male and later quantified both frequency and temporal 
characteristics of SRS. We also estimated repertoire size for each male and determined the amount of shared and 
unique song types within the individuals sampled. These results will be discussed in the context of mate choice and 
signal design. 
ABSTRACT 
INTRODUCTION RESULTS 
-Birdsong can be divided into 
two distinct classes: high 
amplitude songs and low 
amplitude songs 
-These two song classes can 
differ substantially in structure 
and function, however, low 
amplitude signals have received 
much less attention1 
-Low amplitude songs 
experience relaxed selection on 
sound transmission and 
production, which can promote 
an increase in complexity1,2 
-Dark-eyed Juncos sing two 
distinct songs: high amplitude, 
long-range song (LRS) and low 
amplitude, short-range song 
(SRS)3 
-Previous work has shown that 
repertoire size is substantially 
larger in SRS, but no significant 
differences exist in frequency 
range of LRS and SRS3 
 
 
 
- No significant difference in 
maximum or minimum frequency 
based on previous data 
(n(LRS)=13; n(SRS)=4). 
-Significant difference in maximum 
and minimum frequency based on 
this study (p<0.001, n=10) 
-Smaller repertoire size for SRS in 
this study 
-Majority of song sharing in SRS 
occurs with less than three other 
individuals 
 
METHODS 
-SRS was recorded by 
presenting free-living, territorial 
males with a caged female lure 
and a playback of a female 
precopulatory trill 
-Spectrograms were analyzed 
for minimum frequency, 
maximum frequency, and 
repertoire size using Adobe 
Audition 1.5 
-Repertoire sharing was 
assessed by visual inspection 
and comparison of song types 
present in a 60 sec recording 
from each male sampled 
DISCUSSION 
-The frequency range of SRS is 
substantially different from LRS, 
which contradicts previous work. 
-We found a smaller average SRS 
repertoire in our study, but this is 
likely related to different recording 
methodology 
-Low song sharing indicates a high 
level of variation between males 
and a low likelihood of universal 
song types 
-SRS is transmitted over relatively 
small distances (< 5 m), thus 
selection on song transmission is 
likely limited 
-The increase in complexity during 
SRS may be attributed to a 
relaxed production constraint 
associated with low amplitude 
singing 
-Females may also be selecting 
for elaborate SRS which is sung 
most often during courtship 
-Little is known about geographic 
variation in SRS… 
 
LITERATURE CITED 
1Dabelsteen, T., et al. 1998. Bioacoustics. 9:89-105.      
2 Cardoso, G., et al. 2007. Behavioral Ecology. 
18:1051-1057. 
3Titus, R. 1998. Auk. 115: 386-393. 
2Mila, B., et al. 2007. Proc Roy Sci B. 274: 2653-2660. 
HYPOTHESES 
-SRS will contain a significantly 
wider range of frequencies and 
a larger repertoire size due to 
relaxed selection on song 
transmission and/or production 
-Song sharing in SRS of free-
living juncos will be limited 
based on the high diversity of 
song types observed 
Photo Courtesy of Ted Dapper 
Long-range Song (LRS) 
Short-range Song (SRS) 
Junco spp. Distribution 
3Mila et al, 2007 
ACKNOWLEDGEMENTS 
We thank Mountain Lake Biological Station and the 
United Junco Workers for assistance in the field. 
Photo Courtesy of Ted Dapper 
0
5
10
15
20
25
Max Frequency Min Frequency Repertoire Size
Fr
eq
ue
nc
y 
(k
H
z)
 o
r N
um
be
r 
LRS (Titus)
SRS (Titus)
4 4 4 13 13 13 
0
5
10
15
20
25
Max Frequency Min Frequency Repertoire Size
Fr
eq
ue
nc
y 
(k
H
z)
 o
r N
um
be
r 
LRS (Titus)
SRS (Titus)
SRS (Reichard)
13 13 13 10 4 10 4 10 4 
LRS v. SRS 
0
10
20
30
40
50
60
Shared Shared with 1-3 Shared with >3
Pe
rc
en
ta
ge
 (%
) 
10 10 10 
NS 
NS 
* 
* 
LRS v. SRS (Titus 1998) 
LRS v. SRS (New Data) 
Repertoire Sharing 
Recording SRS 


Decoding an enigmatic signal: short-range song in Dark-eyed Juncos (Junco hyemalis).

https://scholarworks.iu.edu/dspace/bitstream/2022/15375/1/11%20Reichard2009AOU.pdf

Decoding an enigmatic signal: short-range song in Dark-eyed Juncos (Junco hyemalis).

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