Date post: | 22-Aug-2015 |
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Songbird Odor Predicts Reproductive Success
Danielle J. WhittakerNicole M. GerlachEllen D. Ketterson
Photo by Marine Drouilly
Preen oil is an odor source
Oil secreted from the uropygial gland contains volatile compounds that give birds an odor
Volatile compound concentration increases during breeding season
1-Dec
anol
1-Und
ecan
ol
1-Dod
ecan
ol
1-Trid
ecan
ol
1-Tet
rade
cano
l
1-Pen
tade
cano
l
1-Hex
adec
anol
1-Hep
tade
cano
l
1-Oct
adec
anol
0
2
4
6
8
10
12
Breeding Non-breeding
Co
nc
en
tra
tio
n
Soini et al 2007, J. Chemical Ecology
Whittaker et al 2011, J. Chemical Ecology
Odor varies with sex and population
MANOVA
Sex p<0.001
Population
p=0.022
Sex * Population
p=0.03Whittaker et al. 2010, Behavioral Ecology
Photo by Flickr user Enjoy Every Sandwich
Dark-eyed Juncos (Junco hyemalis)
Seasonal breedersSocially monogamous~30% extra-pair
fertilization (EPF) rate
Females incubate eggs, both males and females feed nestlings
Field Methods
Mountain Lake Biological Station, VA
Summer 2008Captured birds for
measurements, blood samples, and preen oil
Monitored nests
Photo by Dustin Reichard
Photo by Dawn O’Neal
Lab Methods
Genotyped at 8 microsatellite loci to assess parentage
Analyzed chemical composition of preen oil with GC-MS
15 volatile compounds
Photo by Flickr user wvsawwhet
Relative proportions of volatile compounds
Previous studies found relationships between relative proportions and sex, population differences
More “male-like” and “female-like” blends due to different proportions
PC1 PC2 PC3 PC41-Decanol 0.131 0.927 -0.078 -0.1421-Undecanol 0.257 0.925 -0.081 -0.1381-Dodecanol 0.63 0.663 -0.251 0.11-Tridecanol 0.805 0.123 0.115 0.0151-Tetradecanol 0.663 -0.548 -0.292 -0.0781-Pentadecanol 0.486 -0.402 0.425 -0.141-Hexadecanol 0.494 -0.801 0.016 -0.012-undecanone -0.043 -0.081 0.066 0.9712-dodecanone -0.112 -0.075 0.156 0.962-tridecanone 0.147 0.009 0.89 0.2842-tetradecanone -0.008 -0.016 0.727 0.6182-pentadecanone 0.193 -0.162 0.935 -0.049DodecanoicAcid -0.955 -0.05 -0.156 0.187TetradecanoicAcid -0.98 -0.041 -0.147 0.029HexadecanoicAcid -0.964 -0.036 -0.172 0.029VARIANCE EXPLAINED 32.82 22.11 17.70 16.29
Principal Components Analysis: Relative Proportions
-1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.60
1
2
3
4
5
6
7
8Female Odor and Reproductive Success
PC3 (Relative Proportions)
Nu
mb
er
of
off
sp
rin
g p
rod
uc
ed
Pearson’s correlation = -0.639, p = 0.019n = 13
-1.5 -1 -0.5 0 0.5 1 1.5 2 2.50
1
2
3
4
5
6
7
8Male Odor and Genetic Reproductive Success
PC3 (Relative Proportions)
Nu
mb
er
of
Off
sp
rin
g S
urv
ivin
g t
o F
led
gin
g
Pearson’s correlation = 0.572, p = 0.005n=22
PC1 PC2 PC3 PC41-Decanol 0.131 0.927 -0.078 -0.1421-Undecanol 0.257 0.925 -0.081 -0.1381-Dodecanol 0.63 0.663 -0.251 0.11-Tridecanol 0.805 0.123 0.115 0.0151-Tetradecanol 0.663 -0.548 -0.292 -0.0781-Pentadecanol 0.486 -0.402 0.425 -0.141-Hexadecanol 0.494 -0.801 0.016 -0.012-undecanone -0.043 -0.081 0.066 0.9712-dodecanone -0.112 -0.075 0.156 0.962-tridecanone 0.147 0.009 0.89 0.2842-tetradecanone -0.008 -0.016 0.727 0.6182-pentadecanone 0.193 -0.162 0.935 -0.049DodecanoicAcid -0.955 -0.05 -0.156 0.187TetradecanoicAcid -0.98 -0.041 -0.147 0.029HexadecanoicAcid -0.964 -0.036 -0.172 0.029VARIANCE EXPLAINED 32.82 22.11 17.70 16.29
Principal Components Analysis: Relative Proportions
Male Female-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
Sex
PC
3 S
core
Volatiles contributing to PC3 are associated with sex differences.2-tridecanone2-tetradecanone2-pentadecanone
More “male-like” males have higher RS
More “female-like” females have higher RS
-1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6
0
1
2
3
4
5
6
7
8
PC3 (Relative Proportions)
-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
0
1
2
3
4
5
6
7
8
PC3 (Relative Proportions)
Nu
mb
er
of
Ge
ne
tic
Off
sp
rin
g
*One-way ANOVA, p = 0.04
Photo by Flickr user wvsawwhet
Absolute measurements of volatile compounds
Concentrations change seasonally
Total amount may convey information 1-
Decan
ol
1-Und
ecan
ol
1-Dod
ecan
ol
1-Trid
ecan
ol
1-Tet
rade
cano
l
1-Pen
tade
cano
l
1-Hex
adec
anol
1-Hep
tade
cano
l
1-Oct
adec
anol
0
2
4
6
8
10
12
Breeding Non-breeding
Co
nc
en
tra
tio
n
-2 -1 0 1 2 3 40
1
2
3
4
5
6
7
8
Male Odor and Apparent Reproductive Success
PC1 (Absolute Concentration)
Nu
mb
er
of
So
cia
l O
ffs
pri
ng
Su
rviv
ing
to
Fle
dg
ing
Pearson’s correlation = 0.512, p = 0.015n=22
Volatiles associated with RS in males (Absolute concentrations)
PC11-Decanol 0.2031-Undecanol 0.2831-Dodecanol 0.4861-Tridecanol 0.6951-Tetradecanol 0.8641-Pentadecanol 0.8841-Hexadecanol 0.9292-undecanone 0.082-dodecanone 0.0852-tridecanone 0.6752-tetradecanone 0.6752-pentadecanone 0.815Dodecanoic Acid -0.003TetradecanoicAcid -0.034HexadecanoicAcid 0.017VARIANCE EXPLAINED
32.145
}
}But what are these?!
Associated with “maleness” – more “male-like,” more RS!
Photo by Flickr user Super Bay
Pearson’s correlation = 0.558, p = 0.025n=16
-1.5 -1 -0.5 0 0.5 1 1.5 20
1
2
3
4
5
6
PC3 (Absolute Concentration)
Nu
mb
er
ex
tra
-pa
ir o
ffs
pri
ng
in n
es
t
Male Female-0.5
0
0.5
1
PC
3 (
Ab
so
lute
)
Odor predicts paternity loss
More “female-like” males lose more paternity
*One-way ANOVA, p < 0.001
PC3Dodecanoic Acid 0.911Tetradecanoic Acid 0.952Hexadecanoic Acid 0.928VARIANCE EXPLAINED
19.699
Photo by Flickr user Dave W
ConclusionsOdor is a strong
predictor of RS in both males and females
Females may evaluate potential social mates and EPF mates using different cues
No other traits correlated with RS