Reichard, D. G., Hahn, T. P., and Ketterson, E. D.

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This document is part of a collection that serves two purposes. First it is a public archive for data and 
documents resulting from evolutionary, ecological, and behavioral research conducted by the Ketterson- 
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 
Indiana University. The research was conducted in collaboration with numerous colleagues and students, 
and the objective of this site is to preserve not only the published products of the research, but also to 
document the organization and people that led to the published findings. Second it is a repository for the 
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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Female release of luteinizing hormone (LH) in response to short- and 
long-range song in a songbird, the dark-eyed junco (Junco hyemalis) 
Dustin G. Reichard1, Thomas P. Hahn2, Ellen D. Ketterson1 
1Indiana University, Bloomington; 2University of California, Davis 
Introduction 
• Male courtship signals affect female 
reproductive physiology and condition.1 
• In songbirds, hearing male song is 
known to activate HPG-axis leading to 
sex steroid production and follicle 
development in females.1,2 
• High-amplitude (loud) songs, also 
known as long-range songs (LRS), have 
been the focus of all research to date. 
• Males of many species also sing low-
amplitude (quiet) songs or short-range 
songs (SRS). 
• SRS can be directed exclusively towards 
females during courtship and are often 
strikingly divergent in structure from 
LRS.3 
Methods 
 
 
 
 
 
 
 
 
 
 
 
 
• Free-living females, early breeding season 
• LRS, SRS, or Silent Control 
• Blood Sample after 60-min stimulus 
• Plasma assayed for Luteinizing Hormone (LH) 
Results 
Discussion 
• Female juncos can upregulate circulating 
LH rapidly in response to male song 
• Lack of detectable difference between 
silence and playback birds may be due to 
o Small sample size 
o Variable Reproductive Condition 
of subjects (no brood patch to full 
brood patch) 
o Stress of capture  
• Both LRS and SRS appear to elicit LH 
release and SRS may be a more potent 
activator of the HPG axis than LRS. 
• Results highlight the importance of both 
SRS and LRS in studies focusing on female 
preference for male courtship signals. 
Future Directions 
• Replicate with captive birds and a larger 
sample with repeated measures design. 
• Measure female behavioral preferences for 
each song type. 
• Is a visual stimulus necessary to activate 
the HPG axis?  Possibly augment response? 
 
 
ABSTRACT 
Male courtship signals and displays can have strong stimulatory effects on female reproductive physiology. In songbirds, males use vocal signals, or songs, both to 
attract and stimulate females into a copulation or lasting pair bond. Previous research has shown that hearing male song can activate the hypothalamic-pituitary-
gonadal (HPG) axis leading to the production of sex steroids that drive reproductive development in both sexes. However, studies of the physiological impacts of male 
song have focused exclusively on high-amplitude, long-range songs (LRS) that project over long distances and overlooked low-amplitude, short-range songs (SRS) that 
occur during directed courtship. To test the effect of SRS on female physiology, we captured free-living, female dark-eyed juncos (Junco hyemalis), brought them into 
captivity and played 45 minutes of LRS or SRS, or left them in silence as a control. After an additional 15 minutes of silence, we collected plasma samples that were 
later assayed for luteinizing hormone (LH), the hormonal link between the pituitary gland and the gonads in the HPG axis. When focusing only on females with LH 
levels detectable by the assay, females hearing song had significantly higher circulating LH than controls. Also, a higher proportion of females hearing SRS exhibited LH 
levels above the minimum detection limit of our assay than did females receiving LRS or the silent control. These results suggest that females can rapidly elevate their 
circulating LH in response to male song and highlight the potential for SRS to elicit a larger release of LH and possibly sex steroid production than LRS. We conclude by 
arguing that future research on male vocal signals should focus on both LRS and SRS. 
 
Literature Cited 
1. Bentley et al., 2000. Horm. Behav. 37: 179-189 
2. Kroodsma, D.E., 1976. Science 192: 574-575 
3. Reichard et al., 2011. Am. Nat. 178: 478-487 
 
Acknowledgments - We thank the National Science 
Foundation, Mountain Lake Biological Station, Kristal 
Cain, Sarah Wanamaker, and Amy Dapper 
Long-range 
Song (LRS) 
 
or 
 
Short-range 
Song (SRS) 
 
Hypothalamus 
Pituitary 
Gonad 
45-min playback + 15-min silence 
GnRH 
LH, FSH 
Sex Steriods 
HP
G 
Ax
is 
Research Questions 
1. Do female dark-eyed juncos upregulate their HPG-axis in 
response to male song? 
2. Do females upregulate differentially to long-range song (LRS) or 
short-range song (SRS)?  
0.00
0.50
1.00
1.50
2.00
2.50
3.00
Silent Sound
LH
 (n
g/
m
L)
 
* P= 0.02 
5 16 
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Control LRS SRS
LH
 (n
g/
m
L)
 
5 6 10 
Treatment 
LH Levels Control LRS SRS 
Non-detecable 4 7 4 
Detectable 5 6 10 
Total 9 13 14 
NS, P=0.375 
Females receiving 
sound (LRS or SRS) had 
significantly higher 
circulating LH than 
females left in silence.  
Females did not 
detectably differ in 
circulating LH levels 
between treatments. 
SRS elicited detectable 
LH levels in a higher 
proportion of females 
than did LRS or 
silence. 


Female release of luteinizing hormone (LH) in response to short- and long-range song in a songbird, the dark-eyed junco (Junco hyemalis)

https://scholarworks.iu.edu/dspace/bitstream/2022/15373/1/5%20Reichard2012SICB.pdf

Female release of luteinizing hormone (LH) in response to short- and long-range song in a songbird, the dark-eyed junco (Junco hyemalis)

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