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Environmental Variation and Experimental Manipulation as Proxies for Disturbance
in Elephant Seals
Daniel Costa1, Lisa Schwarz1, Patrick Robinson1, Daniel Crocker1, Marm Kilpatrick1, Clive McMahon2, Mark Hindell3, Leslie New4,
Rob Schick5, Len Thomas4, John Harwood4, Jim Clark5
1 2 3 4 5
Costa, Crocker, Gedamke, Webb, Houser et al. 2003 JASA
102 dB
123 dB 135 dB
126 dB
104 dB
Burgess, Tyack, LeBoeuf, and Costa 1998. Deep Sea Res
Proven Experimental System
Elephant Seal
Beaked whales
Diving Behavior Comparable to Beaked Whales
Hooker et al submitted PRS
Elephant seals can be used as a Model Capital Breeder
Breeding Calving
Mig
ratio
n
Individual Prey patches Mesoscale feature
Linking At-Sea Foraging Behavior to Reproductive Success
Elephant Seal Migration
PCAD conceptual framework SOUND Frequency Duration Level Source Duty cycle + + +
BEHAVIOR CHANGE Orientation Breathing Vocalization Diving Mother-infant spatial- relationships Avoidance + +
LIFE FUNCTION IMMEDIATELY AFFECTED Survival Migration Feeding Breeding Nurturing Response to predator +
VITAL RATES Stage specific Survival Maturation Reproduction +
POPULATION EFFECTS Population growth Population structure Transient dynamics Sensitivity Elasticity Extinction probability +
+
+
0
+ + +
Connecting Reproductive Success…..
…With Foraging Success
…and Alterations in Foraging Success
An Elephant Seals Day at Sea
0 4 8 12 16 20 0
De
pth
(m
ete
rs)
-800
-600
-400
-200
0
0 4 8 12 16 20 0
De
pth
(m
ete
rs)
-800
-600
-400
-200
0
Response to Acoustic Disturbance
Body composition- Mass fat and lean Energy content At-sea migration track Trip duration & location Diving behavior Depth, Duration, Pattern Vital parameters Survived- Pregnant Pupped- mass
2004-2010 233 Adult females
4-14 yrs old
Female Elephant Seal Diving Pattern
Time (hr)
2 3 4 5 6 7 8
De
pt (
me
ters
)
-600
-400
-200
0
Processing dives
Foraging dives
Drift Dive Buoyancy Health
Matsumura et al 2010
Time
11:40 11:45 11:50 11:55 12:00
Dep
th (m
)0
100
200
300
400
500
Δ Drift Rate
PCAD conceptual framework SOUND Frequency Duration Level Source Duty cycle + + +
BEHAVIOR CHANGE Orientation Breathing Vocalization Diving Mother-infant spatial- relationships Avoidance + +
LIFE FUNCTION IMMEDIATELY AFFECTED Survival Migration Feeding Breeding Nurturing Response to predator +
VITAL RATES Stage specific Survival Maturation Reproduction +
POPULATION EFFECTS Population growth Population structure Transient dynamics Sensitivity Elasticity Extinction probability +
+
+
0
+ + +
Connecting Female Mass Gain to Reproductive Success & Pup Survival and Recruitment
Foraging Success (Mass) and Reproductive Output
Disturbance
300 400 500 600 700
5010
015
020
0
Maternal total mass (kg)
Pup
wea
n m
ass
(kg)
300 400 500 600 700
5010
015
020
0
Maternal total mass (kg)
Pup
wea
n m
ass
(kg)
Disturbance
At-sea
50 100 150 200
0.0
0.2
0.4
0.6
0.8
1.0
Pup wean mass (kg)
Sur
viva
l pro
babi
lity,
wea
ning
to 1
y
Survival is a function of weaning mass
No disturbance
50 100 150 200
0.0
0.2
0.4
0.6
0.8
1.0
Pup wean mass (kg)
Sur
viva
l pro
babi
lity,
wea
ning
to 1
y
Survival is a function of weaning mass
No disturbance Disturbance Disturbance
300 400 500 600 700
0.0
0.2
0.4
0.6
0.8
1.0
Maternal total mass (kg)
Pup
sur
viva
l pro
babi
lity,
wea
ning
to 1
yr
Integrated Response Maternal Mass Predicts Pup Survival
No disturbance Disturbance
PCAD conceptual framework SOUND Frequency Duration Level Source Duty cycle + + +
BEHAVIOR CHANGE Orientation Breathing Vocalization Diving Mother-infant spatial- relationships Avoidance + +
LIFE FUNCTION IMMEDIATELY AFFECTED Survival Migration Feeding Breeding Nurturing Response to predator +
VITAL RATES Stage specific Survival Maturation Reproduction +
POPULATION EFFECTS Population growth Population structure Transient dynamics Sensitivity Elasticity Extinction probability +
+
+
0
+ + +
Effect of Disturbance on Lipid Mass Effect of Disturbance on Survival
Days of Disturbance Days of Disturbance
Sur
viva
l to
Age
1
Population Level Effect Li
pid
Mas
s (k
g)
Leslie New and PCAD Working Group
Measurements of Resilience to Disturbance
Bioenergetic Model
Disturbance
Bioenergetic Model
Disturbance
Effects time budget
Animal working harder or longer
31
Spring 1998 Summer 1998 Fall 1998
Spring 1999 Summer 1999 Fall 1999
Marine Habitats Are Spatially and Temporally Variable
SeaWifs Chlorophyll El niño
La niña
Year
1980 1984 1988 1992 1996 2000 2004 2008 2012
Mass g
ain
(kg
/day)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Year
1984 1988 1992 1996 2000 2004 2008 2012
Fo
rag
ing
tri
p d
ura
tio
n (
days)
60
70
80
90
100
110
120
El niño
Response to Interannual Environmental Variability
Acoustic Data Logger Decreased the Foraging Ability
Experimental Disturbance
Year
1984 1988 1992 1996 2000 2004 2008 2012
Ma
ss
ga
in (
kg
/da
y)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
23.2 + 9.3 MJ/day
9.2 + 7.3 MJ/day
Experimental Perturbation Decreases Foraging Success
Year
1984 1988 1992 1996 2000 2004 2008 2012
Fo
rag
ing
tri
p d
ura
tio
n (
days)
60
70
80
90
100
110
120
2011
Looks healthy with pup
Sighted with pup
Sighted, looks healthy with pup
Has not been sighted since instrument recovery
G1234 GM780
Females in Drag Experiment One Year Later 2010
Season mean = 85.5 (43-123 kg)
G1234: 21.5 kg mass gain
GX874: 32.2 kg mass gain
GM780: 32.2 kg mass gain
GX871: 50.1 kg mass gain
Future Directions What capacity do these animals have to compensate for lost foraging opportunities?
How does disturbance affect activity budgets (foraging, transit, rest, etc.)?
What are the energetic consequences (mass/lipid) associated with these changes in time-activity budgets?
Test predictions of the ONR-PCAD model against actual disturbance data (ENSO events, pup growth and survival, adult survival)
What is the threshold in female condition where they fail to reproduce? Blastocyst fails to implant Fetus aborts
How well do stress hormones correlate/predict body condition and foraging success over a foraging trip?
Non-Pregnant Seals
2004 2005 2006 2007 2008 2009 2010
Mas
s G
ain
(kg
± s.
d.)
0
100
200
300
400
Post-moltingPost-breeding
Natality R
ate
0.0
0.6
0.8
1.0
Reproductive Threshold
-10.0 0.0 10.0 20.0 30.0 40.0
Energy gain rate (Mj/day)
0.0
4.0
8.0
12.0
16.0
20.0
24.0C
ort
iso
l (n
g/d
L)
r2 = 0.51, p < 0.001
Condition Relates to Stress Hormones
Crocker et al unpublished
Spatially Explicit Model and Effects of Disturbance
Estimating resource acquisition and at-sea body condition of a marine
predator with implications for population health. Ecology in review R. S. Schick, L. F. New, L. Thomas, D. P. Costa, M. A. Hindell, C. R. McMahon, P. W. Robinson, S. E. Simmons, M. Thums, J. Harwood, and J. S. Clark.
Key foraging habitat of a mesopelagic predator of the northeast Pacific
Ocean: insights from a data-rich species, the northern elephant seal.
PLoS Bio submitted. Robinson, P.W., Costa, D.P.,Crocker, D.E., Gallo-Reynoso, J.P., Champagne, C.D.,Fowler, M.A., Goetsch, C., Goetz, K., Hassrick, J.L., Huckstadt, L.A., Kuhn, C.E., Maresh, J.L., Maxwell, S.M., McDonald, B.I., Peterson, S.H., Simmons, S.E., Teutschel, N.M., Villegas-Amtmann, S., Yoda, K.
The importance of non-independent tag loss in survival rate estimates
of southern elephant seals. in ms. L. K. Schwarz, M. A. Hindell, C. R. McMahon, D. P. Costa.
Environmental influences on demographic rates of Antarctic fur seals L. K. Schwarz, M. E. Goebel, D. P. Costa, A. M. Kilpatrick
Research Productivity
THANK YOU!
E&P Sound and
Marine Life Programme
Office of Naval Research
