INDEX
A
Aborigines, importance of seals to, 30
Adenohypophysis, cell types in, 390
Adolescent growth spurt, 155 . See also Juveniles
Adoption, of orphan pups, 18 –19
Adrenal gland, in newborns, 394
Adults
survival rate of, 91
time at sea of, 15
Aerobic dive limit (ADL), 253 , 265 –269, 350
Age
dominance rank and, 191
effect on diving patterns of, 240 –242
effect on reproductive effort of, 169 –200
effect on time at sea of, 14 –15
of females at primiparity and natality, 17 , 89
in relation to length, 162 –165
in relation to male reproductive effort, 188 –192
in relation to reproductive effort, 172 –173
weaning success and, 146
Age classes, biomass of, 102 –103
Age-specific male mortality curve, 166
Age-specific mortality, in the northern species, 124
Age-specific natality, 140
Age-specific reproductive effort, 196 –200
Age-specific survival.
See also Survival
calculating, 86
effect of weaning mass, size, and condition on, 128
in the northern species, 124
rates of, 122
Age-specific weaning success, 144
Age structure studies, cross-sectional, 81
Aggressiveness, female, 18 , 151 , 197 . See also Dominance hierarchy
Air pressure anomalies, effect on population of, 78
Albatrosses, decline in, 69
Allen, Sarah G., 29
Alpha male, 15
American Society of Mammalogists, 158
Animal movements, between dawn and dusk, 234
Annual cycle, 9 –14, 356
Año Nuevo Island, 1 , 38
age-specific survival at, 124
annual cycle at, 9
background of, 122 –123
breeding season at, 10 , 12
colonization of, 39
dominance hierarchy at, 16
increase in births at, 37
juvenile survivorship at, 121 –122
mean duration of stay at, 189
pup mortality at, 133 –134
sexually mature males at, 173 –174
shark attacks at, 21
survey of, 42
survivorship curves for, 125
survivorship rates at, 133
Antarctica, births at, 51
Antarctic fur seals, 69 , 104
Antarctic Polar Front, 257
prey in, 371
Antarctic seals, derivation of, 2
Antarctic waters, role in annual cycle of, 69
Anthony, A. W., 31
Antipodes Island, population in, 61 –62
Antonelis, George A., 211
Apnea,
See also Sleep apnea
length of, 20
physiology of, 343
Apnea tolerance, during sleeping and diving, 343 –352
Aquatic matings, 56 . See also Mating
Aquatic phases
of the northern species, 238
of the southern species, 254
Argos-compatible transmitter packages, 365
Arnbom, Tom A., 98 , 354
Asaga, Tomohiro, 310 , 328
Ascent angles, 333
Ascent velocities, 105 , 331
of northern species females, 317
Avian Island, population in, 57
B
Baleen whales, 69
Bartholomew, George, xii , 32
Basal metabolic rate (BMR), 284 . See also Metabolism
Beachmaster male, 15 , 16
Beat-to-beat heart rate analyzer, 348
Behavior.
See also Diving behavior; Fasting
mating, 15 –16, 89
during molting, 363 –364
of the southern species, 66
Benthic foraging, 246 , 261 , 299 , 337 , 367 .
See also Foraging
dives associated with, 261 , 264
Type E dives and, 324
Benthic prey, 76 , 218 , 246 –247
Bester, Marthan N., xiii , 85
Biomass
of age classes, 102 –103
estimates of, 102 –103
in the South Georgia population, 98 –114
Biopsies, 274
Birth.
See also Births
cold stress at, 388
mean mass at, 104
pineal size at, 392
pup mass at, 202
sex ratio at, 86
thyroid changes after, 391 –392
Birthplace, female return to, 19
Births
at the Año Nuevo colony, 122
after colonization, 39
estimates of, 40
1958–1991, 34 –35
rates of change of, 43 –44
Birth weight, 356
Blood oxygen
during sleep apnea, 350 –351
storage of, 283
Blood samples, 274
Blood volumes, 283
Blubber, benefits of, 20
Blubber oil yields, 52 , 53
Body composition
changes in, 375
of southern species females, 359 –362
Body fat, effect on insulin response of, 379 –380
Body mass
calculation of, 201 –202
fluctuations in, 199
losses in, 307
measurement of, 174 –176
reproductive effort and, 179 –185
Body reserves, drain of lactation on, 93
Body temperature, maintenance of, 388
Bottom time, of northern species females, 317
Bouvet Island, 50
population in, 57
Boyd, Ian L., 98 , 354
Bradycardia, 347 –348
Branding, 133
Breeding.
See also Mating
age at first, 138 –141
deferred, 151
intermittent, 139 –140
male weight loss during, 363
mass loss during, 193
Breeding competition, 155
Breeding fast.
See also Fasting
duration of, 179
male mass loss during, 188 –189
termination of, 192
Breeding females
haul-out pattern of, 61 , 238
at Macquarie Island, 68
size variation in, 356
Breeding intensity, of females, 141 –144
Breeding males
fasting among, 19
at Macquarie Island, 68
metabolic rates of, 104
Breeding season
body mass over, 201
of the northern species, 10
of the southern species, 13
Breeding sites, preferred, 9
Breeding unit, size of, 18
British Columbia waters, feeding in, 305
Brody function, 159 –160
Bryden, Michael M., 387
Bulls.
See also Dominant bulls; Males
belligerence of, 15
dominance hierarchy among, 52
prime breeding years for, 16
weights of, 362
Buoyancy, control of, 370
"Burst diving," 333
Burton, Harry R., 66 , 253
C
California
births in, 40
colonization of, 29 , 38 –39
commercial exploitation in, 30 –32
origins of elephant seals in, 2 –3
California Marine Mammal Center, 123
California rookeries, growth at, 36
California sea lions, diving bouts of, 311
Campbell Island, population in, 61
Cape Arago, 41
Cape San Martin, survey of, 42
Cape San Martin/Gorda colony, 38
Cape St. George, 40 –41
Capillary tube depth recorders, 273 –274
Cardiac patterns, 347 –348
Castellini, Michael A., 343
Censusing programs, 81
Cephalopods, 105 –106.
See also Prey
bioluminescence of, 219
percent of occurrence and habitat of, 214
as prey, 212 , 213
Chambers, C., 354
Channel Islands, colonization of, 39
Chemical immobilization, 212
Circulatory alterations, during diving and sleeping, 348 –350
Civil twilight, 228
Climatic fluctuations, population changes and, 77 –78
Clinton, Walter L., 154
Coefficient of drag (CD), 105
Cohort variation, in the northern species, 126 –128
Colonization process, of the northern species, 39
Commercial exploitation, of the northern species, 30 –32
Commercial fishing operations
competition with, 114
population decline and, 76
Competition.
See also Intrasexual competition
effect on population decline of, 76
among females, 193
Condition, effect on age-specific survival of, 128
Cookiecutter sharks, 21
Costa, Daniel P., 169 , 328
Courbet Peninsula, population in, 58 –59
Covariance, analysis of, 176
Cows.
See also Females
mortality rates of, 91 –93
movements at sea of, 93 –94
Cox Proportional Hazards Model (CPHM), 141
Crabeater seals, 69
Crocker, Daniel E., 169 , 328
Cross-sectional age structure studies, 81
Cross-sectional studies, 72
Crustaceans, as a component of diet, 213
Cyclostomes, 246
as a component of diet, 213 , 220
D
Dawn
animal movements at, 234
equations used to predict, 234
Day length, measuring, 230 –231
Deep dives, functions of, 263 . See also Diving
DeLong, Robert L., xiii , 29 , 211 , 290
Demographic studies, 81
Density-dependent mechanism, population size and, 75
Depensation concept, 146 –147, 151
Descent angles, 333
Descent velocities, 105 , 331
of northern species females, 317
Deutsch, Charles J., 169
Diel pattern, of diving, 317 –321
Diet.
See also Prey
components of, 113 –114, 307
in the Georgia Island population, 106 –107
of the northern species, 211 –221
Diet
of the southern species, 254
studies of, 81
Disease, role in population regulation of, 75
Dive depths
of adult males, 245 , 264 , 298
of juveniles, 285
of northern species females, 317
Dive depth-duration ratio, 315
Dive depth profiles, 366
Dive durations
frequency distributions of, 281
transit velocity and, 333
Dive elements
correlation coefficients between, 319
interrelationships among, 317
summary statistics of, 318
Dive function, in northern species females, 328 –337
Dive parameters, variation in, 297
Dive records, free-ranging, 239 , chapters 14–17 passim
Dive segments, speed changes during, 333
Dive sequences, 313
characteristics of, 323
Dive statistics, postbreeding, 245 , 264 , 296
Dive types, 259 –263
classification of, 312 , 330
distribution of, 316
of females, 310 –325
frequency distribution of, 320
functions of, 333 –337
percentage in dive periods of, 315
schematic profile of, 313
schematic representations of, 330
sequence of, 321
temporal frequency of, 313 –315
two-dimensional shapes for, 334
Type 1 dives, 253 , 260 –261
Type 2 dives, 253 , 261
Type 3 dives, 261 –262
Type 4 dives, 262
Type 5 dives, 262
Type 6 dives, 262 –263
Type A dives, 312 , 315 , 317 , 321 , 324 , 325 , 330 , 333 , 334
Type AB dives, 333 , 335
Type B dives, 312 , 313 –314, 324 , 330 , 333 , 334
Type C dives, 312 , 315 , 317 , 321 , 324 , 325 , 330 , 335
Type D dives, 312 , 315 , 317 , 321 –325, 330 , 333 , 336
Type E dives, 312 , 315 , 330 , 336 , 337
Diving
apnea tolerance during, 343 –352
in bouts, 311
circulatory alterations during, 348 –350
depth and duration of, 263 –265, chapters 13–18 passim
developmental aspects of, 271 –285
effect of reproductive condition on, 242 –246
effect of sex on, 246 –249
generalizations about, 239 –240, chapters 13–18 passim
heart rate during, 348
implications of weight change for, 370
by juveniles, 240 , chapter 15 passim
metabolic changes during, 350 –351
physiology of, 344 –345
studies of, 254 , chapters 13–18 passim
time spent at, 105
Diving animals, geolocation of, 235
Diving apnea, similarity to sleep apnea of, 349
Diving behavior, 233 –234, chapters 13–18 passim
during first foraging trip to sea, 276 –282, 284 –285
instruments for recording, 273 –274
physiological implications of, 265 –269
during the postweaning fast, 273 –274, 276
"Diving biology," 343
Diving metabolic rate, 265 –267, 284
changes in, 278
of juveniles, 276
Diving patterns, 249 –250, chapters 12–18 passim
effect of age and mass on, 240 –242
free-ranging, 275 –276
of juveniles, 284 –285
male versus female, 246 –247
variations in, 237 –251
Diving physiology, sleep physiology and, 345
Dominance hierarchy, 15 , 16
Dominance rank
age and, 191
in relation to male reproductive effort, 188 –192
Dominance status, of females, 197
Dominant bulls, matings by, 89
Double tagging, 123
Drift net fishing, 131
Dusk
animal movements at, 234
equations used to predict, 234
E
Early-born offspring, fitness benefit of, 199 –200
Early life, species differences in, 8
Ear tags, 123 , 133
Elasmobranchs, 246
Elephant Island, haul out at, 13
Elephant seal milk, 379
Elephant seals.
See also Northern species; Southern species
apnea tolerance in, 343 –352
appearance of, 4
cardiac patterns in, 347 –348
differences among species of, 4 –9
ease of study of, xi –xii
fasting among, xi , 374 –383
foraging ranges of, 69
land cycle of, 9 –14
nomenclature of, 3 –4
origins of, 2 –3
predator-prey relationship of, 79
production efficiency of, 111 , 113
time at sea of, 14 –15
tracking, 227
El Niño Southern Oscillation (ENSO) events, 37 , 38
effect on age of primiparity of, 139
effect on food resource distribution of, 80
effect on natality rates of, 140
effect on population of, 78
foraging during, 128
juvenile survivorship during, 121
survival during, 126
Emigration, of the northern species, 39
Endocrine changes, in newborns, 387 –396
Endocrine glands
importance to survival of, 394 –396
in newborns, 388 –394
Energy
acquisition, expenditure, and investment, 354 –372
expenditure and investment on shore, 356 –364
of foraging, 105 –106
of growth, 104
of molt, 104
of reproduction, 103 –104
Energy acquisition
interaction with energy expenditure of, 370 –372
at sea, 364 –369
Energy consumption, in the South Georgia population, 98 –114
Energy deficiencies, tolerance of, 199
Energy expenditures, in the southern species, 103 –107
Energy saving, apnea and, 20
Environmental change hypothesis, predictions from, 80
Environmental changes, effect on population decline of, 77 –79
Environmental conditions, exposure to, 388
Environmental patterns, large-scale, 77 –78
Epibenthic foraging, 299
Equilibration
effect on population decline of, 76 –77
predictions from, 79 –80
Equinoxes, 229 –230
Experience, weaning success and, 142 , 146
Exploratory dives, 262 , 263
Exponential growth curves, 159 –161
Extended surface intervals (ESIs), 313 , 325
Extinction, early presumptions about, 30 –32
F
Falkland Islands, 51
population in, 57
regulation of sealing by, 52 –53
Farallon Islands, 21 , 38 –42
studies of, 138
Fasting, xi
adaptation for, 379 , 382
benefits of, 20
hormones and fuel regulation in, 374 –383
as a life history trait, 19 –20
in males, 156
Fat growth, increase after birth of, 392
Fat oxidation metabolism, 379
Fat storage, capacity for, 20
Fecundity
female, 141 –144
male, 156
rates of, 86
Fedak, Michael A., 98 , 354
Feeding studies, 336 . See also Foraging
Female age, weaning success and, 142
Female aggression, 18
pup survival and, 151
Female life tables, 55
Female longevity, 87
Female mass
at parturition, 177 , 178
weaning success and, 17
Female molt
behavior and energetics of, 363 –364
in the northern species, 10
in the southern species, 13
Female mortality, 133
Female population, decline in, 77
Female pups, proportion at Marion Island, 89 . See also Pups
Female reproductive effort, influences on, 179 –188
Females.
See also Cows
access to, 15
age at first breeding of, 88 , 122 , 138 –139
age at primiparity and natality of, 17
body composition changes in, 359 –362
body mass and mass loss in, 174 –175
competition among, 193
costs of reproduction for, 140 –145
deferred maturity in, 17
dive patterns of, 246 , chapters 12–18 passim
dive types of, 310 –325
energy expenditure of, 108
foraging areas of, 257 –259
future fecundity and breeding intensity of, 141 –144
gross energy requirement for, 113
growth rate of, 155
intermittent breeding and natality of, 139 –140
maximum longevity for, 101
mean dive duration for, 267 , chapters 12–18 passim
migratory routes of, 248 –249, 300 –301, 302
postbreeding migrations of, 249 , 292 –293
postlactation trip to sea by, 15
reproductive cycle of, 16 –17
reproductive effort in, 170
reproductive success of, 17
reproductive value of, 172
site tenacity of, 139 –140
species differences among, 7
survival rate of, 90 –91
swim speed and dive function in, 328 –337
time spent on land and at sea by, 238 , 299 –303
tradeoffs in the life history of, 150 –151
weight loss during lactation of, 359
First breeding, age of males at, 155
First sea trip, dives during, 240 , 282 –283
First-year mortality.
See also Mortality
at Año Nuevo, 121
in the northern species, 124 –126
sea-level pressures and, 78 –79
First-year seals
prey of, 76
as targets for research efforts, 81
First-year survival, 88 –89.
See also Survival
calculating, 86
decline in, 76 , 79
food accessibility and, 80
influences on, 123
rates of, 90 , 91
studies of, 72
Fiscus, Clifford H., 211
Fisheries
competition with, 114
effect on survivorship of, 131
population decline and, 76
Fitness costs of reproduction, 197
Food
biomass consumed, 111 , 113
consumption in the South Georgia population, 110 –111
effect on population decline of, 76 –79
Foraging, 20
continuous nature of, 307
data gathering about, 364
on deep-dwelling prey, 76
energy expenditure of, 105 –106, 109
in first-year seals, 81
mixing of animals during, 249
in relation to oceanography, 371
sex differences in, 248 –249
success in, 365
time under water while, 335
Type D dives and, 321
Foraging areas, 69
distant, 371
dives in, 299
of Marion Island cows, 93
Foraging dives, 336 –337
Foraging ecology studies, 211
Foraging migrations, postbreeding, 290 –308
Foraging patterns, sex differences in, 336
Foraging trip, first, 276 –282, 284 –285
Fossil elephant seals, 2 –3
Free-ranging dive pattern, 275 –276
Fuel regulation, in fasting seals, 374 –383
Fuel turnover, studies in, 376
Fur seals, 2 , 69 , 104 , 155 , 311 , 325 , 378
Future research, directions for, 80 –81
G
Genetic variability, loss of, 41
Geographic location time-depth recorders (GLTDRs), 247 , 291 . See also Time-depth recorders (TDRs)
Geolocation
analysis software for, 87
by light levels, 227 –235, 248
recorders of, 81 , 291
Gestation, maternal investment during, 185
Gestation period, energy costs of, 92 –93
Giant petrel, decline in, 69
Global climate studies, 77 –78
Glucagon levels, 378 –379
Glucose tolerance tests (GTTs), 379 –380
Gompertz growth models, 101 , 159 –160
Gough Island, 50
population in, 57
Government-controlled sealing industry, 49 –63
Gray seals, 91
food consumption among, 99
mass change in, 193 –194
metabolic rates in, 246
Gross energy requirement, 111
Growth
energy of, 104
life history and, 165 –167
in males, 154 –167
measuring, in males, 158 –161
Growth functions, parameters for, 163
Growth hormone, in pups, 391
Growth spurt, in males, 166 –167
H
Habitat, terrestrial, 9
Halichoerus grypus. See Gray seals
Harbor seals
mass change in, 193 –194
metabolic requirements of, 268
studies on, 329
swimming efficiency of, 105
Harems.
See also Cows; Females
male positions in, 15 –16
organization of, 363
overcrowding of, 75
Harp seals
food consumption among, 99
heat increment of digestion for, 105
mass change in, 193
Harwood, J., 354
Heard Island, population in, 59
Heart pattern, 347 –348
Heat increment of feeding, 105 –106
Heat loss, reducing, 388
Hematocrit
determination of, 274 , 279
in Weddell seals, 348 –349
Hemoglobin
concentrations of, 283
determination of, 274 , 279
levels of, 348
Heterozygosity, findings on, 41
Hill, Roger D., xiii , 227
Hindell, Mark A., 66 , 253
Homing, translocation and, 249 –250
Hormones, in fasting seals, 374 –383
Huber, Harriet R., 29
Humans, predation by, 21
Hydrurga leptonyx. See Leopard seals
Hypophysis
development of, 388
in newborns, 389 –391
Hypoxia, defenses against, 329
I
"Ice seals," 68
Iles Crozet, population in, 60
Iles Kerguelen stock, 58 –60
Immigration, of the Northern species, 39
"Individual effect," in weaning success, 146 , 151 –152
Individual variation, significance for life history patterns, 145 –150
Injection method, remote, 87
Injuries
reproductive risk and, 176
sex differences in, 181 , 196
Insulin
protein synthesis and, 382 –383
secretion of, 378 –379
Insulin tolerance tests (ITTs), 380 –382
International Conference on Elephant Seals, xii
Intrasexual competition, 171 , 173 , 192 –193, 198
Isla Cedros, 38
Isla de Guadalupe, 30 –33, 36
Isla Natividad, 38
Isla San Martín, 38
Islas Los Coronados, 38
Islas San Benito, 30 , 33
Isotope dilution measurements, 355
J
Jameson, Ronald J., 29
Jolly-Seber mark-recapture analysis, 86
Juvenile haul-out
of the northern species, 12
of the southern species, 14
Juvenile males, social play among, 200 . See also Juveniles
Juvenile molt
of the northern species, 10
of the southern species, 13
Juvenile mortality, 92
at Año Nuevo, 131
population decline and, 77
predation as a cause of, 75
Juveniles
diving behavior of, 240 , 273 –274, 276 –282
diving pattern of, 284 –285
foraging locations of, 218
foraging trips of, 122
metabolic studies of, 275 , 283 –284
oxygen consumption in, 284
stomach contents of, 272
Juvenile survival
from ages 1 to 4, 128
at Año Nuevo, 131 –132
in the northern species, 121 –134
population regulation and, 80
rates of, 132
K
Kerguelen stock, 49 , 50 –51
decline in, 68
Killer whales, predation by, 21 , 75 , 131 , 262
King George Island, population in, 57
Kirby, Vicky Lee, 374
L
Lactation
body mass over, 201
duration of, 187 –188, 387
energy expenditure of, 92 –93, 103
female weight change during, 185 –187, 357 , 359
pup growth during, 356
Land
energetics on, 354 –355
first mating of females on, 16 –17
time spent on, 238
Latitude, determining, 229 –230
Laws, Richard M., xii , 1 , 49
Le Boeuf, Burney J., xii , xiii , 1 , 29 , 121 , 169 , 237 , 271 , 310 , 328
Length
effect on first-year survival of, 123 –124
measurement of, in males, 158 –161
as a measure of sexual size dimorphism, 178 –179
in relation to mass, 102
standard measurement of, 158 –159
of weanlings, 128
Leopard seals, 69
predation by, 21
Leptonychotes weddelli. See Weddell seals
Life history
male, 155 –158
in relation to growth, 165 –167
Life history parameters
differences in, 196
male, 154 –155
tagging studies to assess, 85
Life history patterns, individual variation and, 145 –150
Life history theory, 137 , 171
Life span, for males and females, 171
Life tables, 54 –55
for Año Nuevo, 124
calculating, 86
manipulation of data in, 89 –91
of Marion Island females, 88
for the southern species, 100 –101
Light-level curve, 235
Light levels
geolocation by, 227 –235, 248
measurement of, 232 –233
Lobodon carcinophagus. See Crabeater seals
Location, determination of, 228
Logistic function, 159 –160, 162
Longevity, female, 86 , 133
Longevity class, reproduction and, 146 –150
Longitude, estimates of, 229
Longitudinal studies, 72
Long Marine Laboratory, 275
Lowry, Mark S., 211
M
Macquarie Island, 49 , 50 –51, 60 –62
breeding females and males at, 68
breeding season at, 13
diving behavior at, 253 –269
female and juvenile molt at, 14
first-year survival at, 72
haul out at, 13
juveniles at, 14
population decline at, 67
population dynamics at, 80
post-year 1 survival curve for, 74
pup mortality at, 134
sealing at, 76
survivorship rates at, 66 , 133
Macrorhinus , 3
Maintenance metabolism, 193
Male life history
in relation to growth, 165 –167
review of, 155 –158
Male life tables, 55
Male molt
of the northern species, 10
of the southern species, 13
Male ranking, achievement of, 16
Male reproductive effort, 188 –192
age-specific, 173
effects of age class and dominance status on, 191 –192
Male reproductive energetics, 171 , 362 –363
Males.
See also Bulls
annual cycle of, 157
biomass of, 98
body mass and mass loss in, 175 –176
decline in population of, 77
dive depths of, 241 , 298
dive patterns of, 246 , chapters 14 and 16 passim
energy costs of reproduction in, 104
energy expenditure of, 107 –108
foraging areas of, 248 , 257 , 303
growth curve for, 166
growth pattern in, 159 –160
injury risk for, 179
mating effort of, 189
mating success of, 16
measuring length and growth in, 158 –161
postbreeding migrations of, 248 , 293 –294
reproductive effort in, 170
resource consumption by, 114
secondary sexual characteristics of, 4
sexual aggressiveness of, 15
sexual maturity of, 362
sexual selection and growth in, 154 –167
survival rate estimates for, 101
threat vocalizations of, 8
time spent on land and at sea by, 238
Male survival, costs of reproduction and, 156 –158
Marion Island
juvenile survivorship at, 132
population decline at, 85 , 87 –89
population ecology of southern species at, 85 –94
population in, 59 –60
survivorship rates at, 133
Mark-recapture analysis, 86
Mark-resighting programs, 81
Mass
determination of, 274
effect on diving patterns of, 240 –242
in relation to age, 102
in relation to male reproductive effort, 188 –192
in relation to nose-tail length, 102
Mass loss
over the breeding season, 179
calculation of, 201 –202
of lactating females, 93 , 185 –187
measurement of, 174 –176
Maternal age, reproductive effort and, 179 –185
Maternal investment
correlation with parturition mass and age of, 186
effect of pup sex on, 181 –185
measures of, 182 –183
pup birth mass and, 185
pup mass gain and, 187
weanling mass and, 188
Maternal mass, lactation duration and, 187 –188
Mating
behavior during, 15 –16
competition for, 155
effort of, 170
success of males in, 158 , 174
Maturation, male, 154
Mature cows, mortality rates of, 91 –93. See also Cows; Females
Maturity
male, 156
male growth after, 163
Maximum depth recorders (MDRs), 274
McCann, T. S., 354
McCann formula, 40 , 54 –55
McConnell, B. J., 354
MCT velocities, swimming at, 331 –332
Mean dive duration
changes in, 282
as a function of time at sea, 279 –282
Mesopelagic habitats, 307
Mesopelagic zone, feeding in, 306
"Metabolic overhead," 187
Metabolic rate.
See also Metabolism
of breeding males, 104
decrease in, 283 –284
during fasting, 375
after feeding, 336
increases in, 367 –369
of pregnant females, 244 –246
during sleeping and diving, 350 –351
of southern species females, 103
Metabolic studies, 275
during the postweaning fast, 276
Metabolism
fuel storage for, 376
swimming velocity and, 329
thyroid gland and, 391
Mexican Islands, survey of, 43
Mexico
births in, 40
new colonies in, 38
population increase at, 36
Microprocessor-based event recorder, 290 , 291
Microprocessor TDRs, 275 . See also Time-depth recorders (TDRs)
Migration.
See also Foraging
determining routes of, 247 –249
postbreeding foraging, 290 –308
satellite monitoring of, 251
Milk thieves, 18 –19
Mirounga , xi , 3 . See also Elephant seals
Mirounga angustirostris. See Northern species
Mirounga leonina. See Southern species
Mock fighting, 200
Molt
energy expenditure of, 104 , 109 –110
process of, 4
in southern species female, 363 –364
Monk seals, 3 , 4
Morris, Patricia, 121
Mortality.
See also Juvenile mortality; Pup mortality
age-specific, 122
first-year, 124 –126
growth rates and, 167
male, 155 , 156
at Marion Island, 88 –89
preweaning, 18 , 90
of three-year-old females, 91 –93
Mother-pup separation, 18
Multicomponent logistic growth functions, 166
Muscle samples, 274 –275
Myctophids, as a component of diet, 105 , 113 –114
Myoglobin assay, 274 –275
N
Naito, Yasuhiko, 310 , 328
Natality
age at, 17
measurement of, 138
National Marine Fisheries Service, 231
National Meteorological Center, 247
Nelson Island, population in, 57
Neonate mortality, 124 , 133 –134
Neritic zone, feeding in, 218
Newborns
adrenal gland in, 394
endocrine changes in, 387 –396
endocrine glands in, 388 –394
pineal gland in, 391 –394
thyroid gland in, 391 –392
Noncephalopod prey, 220
percent of occurrence and habitat of, 215
Nonforaging dives, 262 –263
Northern Hemisphere colonies, mixing among, 132 –133
Northern species (Mirounga angustirostris )
ancestry of, 30
colonization process of, 39
commercial exploitation of, 29 –32
diet of, 211 –221
differences from the southern species, 4 –9
dive depths of, 239 –243, 245 –246, 292 –298, chapters 13–15 passim
dive types of, in females, 310 –325
extinction presumptions about, 30 –32
female life history strategies in, 137 –152
future growth in, 40 –41
isolation of, 2
juvenile survivorship rate among, 121 –134
land cycle of, 9 –13
population increase in, 79 –80
population size of, 40
postbreeding foraging migrations of, 248 , 290 –308
prehistory of, 30
pup diving in, 271 –285
pup mortality in, 18
recent trends and present status of, 33 –39
recovery of, 41
sexual selection and growth of, in males, 154 –167
subtropical breeding locations of, 4 –7
survivorship curve of, 128
swim speed and dive function of, in females, 328 –337
threat call of males of, 8
time at sea of, 14 –15
variation in reproductive effort in, 169 –200
variations in diving patterns of, 237 –251
North Pacific, the northern species in, 40
North Pacific Transition Zone (NPTZ), 307 –308
North transits, 292
Nose-tail measurements, 101 –102
of males, 158 –159
Notothenids, as a component of diet, 105
Nur, Nadav, 137
Nursing, 18 –19
female fasting during, 19
growth rates during, 167
pup mass gain during, 188
of unrelated pups, 18
weight gain during, 375
Nursing period, length of, 272
O
Obstructive apnea, 349
Ocean circulation, effect on food resources of, 80
Ocean environment, effect on population decline of, 77 –79
Oceanography, in relation to foraging, 371
Odobenids (walruses), 2
Oil
sealing as a source of, 67
yields of, 52 , 53
Ommatophoca rossi. See Ross seals
On-shore energy expenditure, 356 –364
Orphan pups, adoption of, 18
Ortiz, C. Leo, 374
Otariids (fur seals and sea lions), 2
compared to phocids, 332
swim velocities in, 331
"Overshoot" hypothesis, 76 –77. See also Equilibration
Oxygen storage
capacity for, 274 , 283
diving performance and, 272 –273
P
Pacific whiting, as prey, 212 , 213 –217, 219
Parasite infestations, 75
Parental effort, 170
Parturition.
See also Birth
body mass at, 201
prior, 141 –142
Patagonia, population in, 57
"Paucity of males" hypothesis, 89
Pectoral girth, 102
Pelagic foraging dives, 261 , 263 –264
Pelagic prey, 76
Pelagic red crabs, as prey, 213 , 219
Penguins, 69
Península Valdes, population at, 57
Petrel populations, decline in, 69
Philopatry, 19
Phoca groenlandica. See Harp seals
Phoca hispida. See Ringed seals
Phoca vitulina. See Harbor seals
Phocids (the true seals), 2
annual food consumption estimates for, 99
compared to otariids, 332
mass change in species of, 193 –194
origins of, 2 –3
oxygen storage capacity in, 283
reproductive energetics in, 171
status in the Southern Ocean of, 69 –72
Photogrammetric technique, 175 , 191
Physiological variables, over the first eight months of life, 276
Physiology
diving behavior and, 265 –269
of phocids versus otariids, 332
role of melatonin in, 394
of sleep-associated apnea, 345 –351
Pineal gland
in newborns, 391 –394
in the northern species versus the southern species, 394
Pinnipeds, 2
diving in, 311 , 344
energy requirements of, 98 –99
growth pattern of, in males, 155
Placental mass, 104
Plasma glucose levels, in pups, 376 –377
Plasma hormone levels, 378 –379
Plasma metabolite levels, 376 –378
Point Reyes Headlands colony, 38
survey of, 43
Polar animals, pineal gland in, 392
Polygyny, 19
Population
difficulty in estimating, 68
increase in, 29
at Marion Island, 85 –94
in the South Georgia stock, 54 –58
Population biology studies, of the southern species, 72
Population biomass, estimates of, 113
Population decline, 67
causes of, 62 –63
characteristics of, 73 –75
commercial fishing and, 76
at Marion Island, 85
"overshoot" hypothesis of, 76 –77
Population growth, estimates of, 40
Populations, total energy requirements of, 99
Population size, of the northern species, 40
Population trends, of the southern species, 67 –72
Postbreeding migrations, 248 –249, 290 –308
dive depths during, 293
of females, 87 , 292 –293
of males, 293 –294
Postnatal life, melatonin concentration during, 393 –394
Postweaning fast, 122
development of diving during, 272 –273
diving behavior during, 273 –274, 276
duration of, 8
metabolic studies during, 276
Predation, 20 –21
population decline and, 75
Predator-prey relationship, 79
Pregnant females, dive duration in, 242 –246
Preweaning mortality, 75 , 90
Prey, 76
categories of, 216
diel vertical migration of, 218 –219
energy cost of warming, 369
index of consumption of, 212
secondary, 220
size of, 220
Primate growth models, 165
Primiparity, age at, 17 , 89 , 138 –139, 171
Prince Edward Island, population in, 60
"Processing" dives, 335
Production efficiency, 111 , 113
Puberty, male growth near, 165
Pup birth mass, 185
Pup counts
on Antipodes Island, 61 –62
on Campbell Island, 61
on the Courbet Peninsula, 58 –59
on Heard Island, 59
on Iles Crozet, 60
as an index of population growth, 40
on Macquarie Island, 60 –61
on Marion Island, 59 –60, 86
on Prince Edward Island, 60
on South Georgia Island, 56
Pup mass, 202
maternal investment and, 187
Pup mortality, 18
at Año Nuevo, 126 , 133 –134
density-dependent, 75
Pupping period
at Ano Nuevo, 10
at Macquarie Island, 13
of the southern species, 14
Pup production, estimates of, 62
Pups
developmental aspects of diving among, 271 –285
fat content at birth of, 104
growth hormone in, 391
growth of, 356 –359
hematocrit in, 349
molt differences in, 8
plasma glucose levels in, 382
respiratory pattern in, 345 –347
sex ratio of, 88
swimming and diving experience of, 271 –272
tagging of, 123
weight changes in, 357 , 358
Pup sex, reproductive effort and, 181 –185
R
Radioactive metabolic tracers, 350
Radio transmitters, for recording dive duration, 273
Range, of Marion Island cows, 93
Rapid eye movement (REM) sleep, 348
Reilly and Fedak equation, 103 , 104
Reiter, Joanne, 121
Remote injection method, immobilization using, 87
Renewable resources, rational utilization of, 63
Reproduction, 15 –19
age at first, 86
benefit of experience in, 200
costs associated with, 137 –138, 140 –145
effect of injury on, 176
energy expenditure of, 103 –104, 110
fitness costs of, 197
male, 155 , 156 –158
rate of investment in, 194 –195
in southern species males, 362 –363
Reproduction-survival tradeoff, 199
Reproductive condition, effect on diving of, 242 –246
Reproductive cycle, of females, 16 –17
Reproductive effort (RE), 170
age-specific, 196 –200
duration of, 195
female, 179 –188
magnitude of, 200
measurement of, 193
male, 188 –192
male mass loss during, 191
male variation in, 191
in relation to age, 172 –173
sex- and age-related variation in, 169 –200
sex comparison of, 179 , 192 –196
variation in, 195
Reproductive history, weaning success and, 146 –150
Reproductive rate, at Marion Island, 89
Reproductive season, 356
Reproductive success, xii
at Año Nuevo, 16
of females, 17
variation in, 195 –196
Research directions
deciding, 79
future, 80 –81
Research programs, 67
Resource allocation, to reproduction, 172
Respiratory costs, 113
Respiratory patterns, during sleep, 345 –347
Resting sites, preferred, 9
Richards function, 154 , 159 –160, 162
Ringed seals, 103 , 104
Risk, of reproduction, 176 , 196
Rockhopper penguin, 69
Rookeries, 4
Rookery density, weaning success and, 144 –145
Ross seals, 69
S
Sakurai, Haruo, 310
San Clemente Island, 38
San Miguel Island, 11 , 13
immigration from, 39 , 132
increase in births at, 36 –38
juvenile survivorship at, 121 , 134
survey of, 41
San Nicolas Island, 11 , 13
increase in births at, 37 , 38
survey of, 41 –42
Santa Barbara Island, 13 , 42
Santa Cruz Island, 40
Santa Rosa Island, 38 , 40
survey of, 42
Satellite geolocation equipment, 63
"Scabby molt," 12
Scientific Committee on Antarctic Research (SCAR), 62
Scotia arc, colonies in, 50 –51
Sea
cow movements at, 93 –94
energetics at, 355
energy acquisition at, 364 –369
first foraging trip to, 276 –282
first mating of females at, 16 –17
first pelagic trip to, 272
first trip to, 284 –285
first-year mortality at, 124
time spent at, 238
weight gain at, 371
Sea-level pressure, first-year mortality and, 78 –79
Seal Fishery Ordinance (Falkland Islands), 52 –53
Sealing, 1
divisional quotas for, 54
effects of, 53 –54
eighteenth- and nineteenth-century, 51
at Macquarie Island, 76
of the northern species, 8 –9
Southern Hemisphere, 21
of the southern species, 49
at South Georgia, 52 –58
Sea lions, 2 , 311
Sea Mammal Research Unit (SMRU), 355
Sea-surface temperature measurements, 304 –306
Seawater temperature, latitude and, 231 –232
Secondary prey items, 220
Secondary sexual characteristics, male, 174
Sedation procedure, 255
Sex
effect on diving of, 246 –249
effect on reproductive effort of, 169 –200
effect on time at sea of, 14 –15
Sex differences, 170 , 171
Sex ratio at birth, 86
Sexual behavior, at Marion Island, 89 . See also Mating; Reproduction
Sexual dimorphism, 4 , 177 –179
Sexual selection
for body size, 165
male growth patterns and, 155
in males, 154 –167, 155 –156
Shallow dives, 262 , 299
Shark attacks, 20 –21
Sigmoidal curve, 160 , 165
Signy Island, 14
haul out at, 13
pup molt at, 8
pup mortality at, 18
Site fidelity, 19
Size
effect on age-specific survival, 128
variability in, 177 –179, 371 –372
"Skipping," 138 , 139 –140
Sleep
apnea tolerance during, 343 –352
circulatory alterations during, 348 –350
metabolic changes during, 350 –351
patterns of, 20 , 343 –345
polygraph recording of, 346
respiratory pattern during, 345 –347
Sleep apnea.
See also Apnea
duration of, 345 –347
physiology of, 345 –351
studies of, 351 –352
Slip, David J., 66 , 253
Slow wave sleep (SWS), 348
Social organization, 15 –16
Social play, benefits of, 200
Solar equations, 229 –230
Solar navigation, 228 –229
South African fur seals, 325 , 378
South American colonies, 51
Southern California rookeries, 13
immigration to, 133
Southern Hemisphere, sealing in, 21
Southern Indian Ocean, population decline in, 66 –81
Southern Ocean ecosystem, 67
food resource distribution in, 80
predation of squid and fish in, 254
status of phocid in, 69 –72
Southern Pacific, population decline in, 66 –81
Southern species (Mirounga leonina )
annual cycle of, 254
annual energy budget of, 107 –110
breeding distribution of, 50
breeding season of, 14
decline in, 56 , 66 –81, 85 , 99
demographic data for, 72
description of males of, 7
diet composition of, 106 –107
differences from the northern species, 4 –9
dive patterns of, 259 , chapters 14 and 20 passim
diving behavior of, 253 –269
dominance hierarchy in, 16
endocrine changes in newborns, 387 –396
energy of foraging in, 105 –106
energy of growth in, 104
energy of molt in, 104
energy utilization in, 103 –107, 354 –372
estimated population of, in 1990, 58
explanation of population trends for, 73 –79
explanations of behavior of, 66
female molt in, 363 –364
food consumption in, 99
foraging areas of, 78 , 255 –257
history and present status of, 49 –63
hunting of, 66 –67
land cycle of, 9 , 13 –14
main stocks of, 49 , 50 –51
male reproduction in, 362 –363
at Marion Island, 85 –94
mean dive duration and depth for, 266
population biology studies of, 72
pup mortality in, 18
reproductive season and annual cycle of, 356
in South Georgia, 98 –114
status of, in the Southern Ocean, 70 –71
threat call of males of, 8
time at sea of, 15
total world population of, 49
South Farallon Islands colony, 38
survey of, 42 –43
South Georgia Island, 49 , 50 –51, 52 –58
biomass and energy consumption at, 98 –114
decline in population at, 68
demographic data about, 72
first-year survival at, 72
harem organization on, 363
managed exploitation at, 77
numbers breeding at, 356
nutritional status of cows at, 93
population parameters at, 100
post-year 1 survival curve for, 74
pup mortality at, 18
sealing at, 51 –52
South Orkney Islands, 4 , 50
population in, 57
South Sandwich Islands, 50
population in, 57
South Shetland Islands, 50
haul out at, 13
South transits, 292
Species
developmental differences among, 8
differences and similarities among, 4 –9
Speed changes, during dive segments, 333
Sperm whales, dive depths of, 311
Squid.
See also Prey
biomass consumed, 110 –111, 112
as a component of diet, 105 , 307
Standard metabolic rate (SMR), 103
Standard seal length, 158 –159
Stewart, Brent S., xiii , 29 , 211 , 290
Stomach lavage, 212
Stomach samples, examination of, 106
Storms, pup mortality and, 131
Subadult males, mating success of, 200
Subadults, reproductive effort of, 197 –198
Sub-Antarctic fur seals, 69
Suckling, mean duration of, 103 –104. See also Nursing
Suckling pups, stealing of, 18
Sudden infant death syndrome (SIDS), 352
"Superweaners," 18 –19
Surface intervals (SIs), 313 , 317 . See also Diving of northern species females
Surface-seawater temperature (SST), 235
Surface swimming, 311
Survival, 55
age-specific, 86 , 90
annual, 100 –101
determining rates of, 133
of parous females, 140 –141
recording of rates of, 123
sex differences in, 122 –123
of weanlings, 126
Survival analysis, 141
Survival curves, post-year 1, 74
Survival/fecundity schedule, 92
Swim distances, calculation of, 330 –331
Swim speed
comparison of, 331 –332
of juveniles, 284
measurement of, 329 –330, 331
metabolism and, 329
in northern species females, 328 –337
reduced, 335 –336
Swim speed-distance meter (SSDM), 329 –330, 333
Sydeman, William J., 29 , 137
T
Tagged seals, movement patterns of, 39
Tagging, xi
of pups, 123
Tagging studies, at Marion Island, 85
Tag loss, 123 , 133
rates of, 86
Teeth, age estimates from, 54 , 81
Terrestrial habitat, 9
Thorson, Philip H., 271
Threat vocalizations, 8
Thyroid gland, in newborns, 391 –392
Time-depth recorders (TDRs), 87 , 227 , 235 , 247 , 254 , 275 –276, 310 , 312
deployment and recovery of, 255
technology of, 328
Time-depth-temperature recorders, 99
Total body gross energy (TBGE), 103 , 104
Total food consumed, estimates of, 114
Townsend, C. H., 31 , 32
Tracking studies, 63
Transit dives, 324 , 333
Transit velocities, comparison of, 332 –333
Translocation, homing and, 249 –250
Trauma-starvation syndrome, 18
Two-component logistic function, 154 , 161 , 162 –164
Type III survivorship curve, 128
U
Underwater survival, 344
V
Vancouver Island, 41
Variation
cohort, 126 –128
in dive parameters, 297
in dive patterns, 237 –251
individual, 145 –150
in reproductive effort, 169 –200
in reproductive success, 195 –196
in size, 356
in weaning success, 146
Vertically migrating prey, 218 –219, 306 –307
Virgin females, breeding of, 56 . See also Females
Vocalizations, male threat, 8
W
"Wallows," 364
Walruses, 2
Wandering albatrosses, 69
Weaner count
on Marion Island, 59
on Prince Edward Island, 60
Weaning
tagging at, xi
weight at, 359
Weaning mass, 202
effect on age-specific survival of, 128
maternal investment and, 188
Weaning success, 17 , 142
in relation to age, 172
variation in, 146
Weaning time, 17
Weanlings
fasting among, 19 , 375
isotope-labeled fuel metabolite studies in, 376
length classes of, 130
survival rates of, 126
weight classes of, 129
Weather patterns, effect on food resources of, 80
Weddell seals, 69
aerobic dive limit in, 285
dives of, 343
diving bouts of, 311
mass change in, 193 –194
metabolic cost of diving in, 351
metabolic requirements of, 269
metabolic studies on, 329
studies on, 344
Weight
effect on first-year survival of, 123
of weanlings, 128
Weight change
effects of, 370
implications for diving of, 370
of lactating females, 359
in newborns, 387
White sharks, predation by, 20 –21, 131 , 272
Wildlife Computers, 87 , 235 , 255
Wilkinson, Ian S., xiii , 85
Y
Year, effect on survival rates of, 126
Yearly growth rates, in males, 161 , 164 –165
Yochem, Pamela K., 29
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