The emergence of the genus Homo is widely linked to the colonization of "new" highly seasonal savannah habitats. However, until now, our understanding of the possible impact of seasonality on this shift has been limited because we have little general knowledge of how seasonality affects the lives of primates. This book documents the extent of seasonality in food abundance in tropical woody vegetation. It then presents a systematic analysis of seasonality's impact in food supply on the behavioral ecology of non-human primates and ultimately applies its conclusions to primate and human evolution.
Author(s): Diane K. Brockman, Carel P. van Schaik
Series: Cambridge Studies in Biological and Evolutionary Anthropology
Publisher: Cambridge University Press
Year: 2005
Language: English
Pages: 606
Cover......Page 1
Half-title......Page 3
Series-title......Page 4
Title......Page 7
Copyright......Page 8
Contents......Page 9
Contributors......Page 11
Preface......Page 15
Part I Introduction......Page 17
Introduction......Page 19
Activities......Page 21
Seasonality in cover and day length......Page 24
Social life and life history......Page 25
Seasonality and reproduction in primates......Page 26
Seasonality and habitat structure......Page 28
Implications for primate ecology......Page 30
Seasonality and deep time......Page 31
Seasonality and the hominin enigma......Page 33
References......Page 34
Part II Seasonal habitats......Page 37
Introduction......Page 39
Seasons in the Sun: tropical climates......Page 40
Phenology data......Page 42
Climate data......Page 44
Analyses......Page 45
Some climate patterns relevant to tropical phenology......Page 46
Does climate affect community-level phenology?......Page 49
Climatic and phenological seasonality......Page 52
Relative timing of flushing and fruiting peaks......Page 55
Switch in food items......Page 56
Spatial variation......Page 57
Between-year variation......Page 59
Phenology–climate relations......Page 61
Behavioral ecology......Page 63
Geographic variation......Page 64
Masting......Page 66
References......Page 67
Part III Seasonality and behavioral ecology......Page 71
Introduction......Page 73
Responses to food scarcity......Page 74
Framework for interpreting ranging and dietary flexibility......Page 77
Ranging flexibility......Page 78
Dietary flexibility and morphology......Page 79
Behavioral flexibility and biogeographic particularities......Page 80
Behavioral flexibility and resource seasonality......Page 81
Methods......Page 82
Biogeographic regions and clades......Page 83
Subtle and variable dietary switching......Page 86
Critical dietary switching......Page 87
A closer look at habitat shifting......Page 90
General patterns......Page 94
Biogeographic regions and clades......Page 96
Response options......Page 98
Dietary flexibility......Page 99
Tracking resources......Page 102
Ranging flexibility......Page 103
Dietary flexibility......Page 104
Behavioral flexibility among biogeographic regions......Page 105
Where do we go from here?......Page 106
Implications for hominin evolution......Page 108
References......Page 109
Introduction......Page 121
Primates, predation risk, and seasonality......Page 123
Cathemerality as an anti-predator strategy in seasonal habitats......Page 125
Study site and subjects......Page 128
Behavioral and phenological data collection......Page 129
Anti-predator behavior of E. mongoz and E.f. fulvus at Ampijoroa......Page 130
Seasonal activity rhythms in E. mongoz and E.f. fulvus......Page 131
Seasonal changes in canopy cover and lemur behavior......Page 132
Cathemerality as a response to seasonal changes in predation risk......Page 133
Predation risk and canopy cover in diurnal primates......Page 136
Conclusion......Page 137
References......Page 138
Introduction......Page 145
Discussion......Page 146
Heat production......Page 148
Torpor......Page 149
Body reserves......Page 157
Behavioral mechanisms......Page 158
Acknowledgments......Page 159
References......Page 164
6 Seasonality and long-term change in a savanna environment......Page 173
Introduction......Page 174
Hypotheses about seasonality of foraging behavior......Page 175
Hypotheses about seasonality in social behavior......Page 176
Baboon ecology......Page 177
Amboseli ecology......Page 181
Ecological and research history of the Amboseli baboon population......Page 183
Acknowledgments......Page 184
Focal sampling......Page 185
Time budgets......Page 186
Analysis of variance in time budgets......Page 189
Time spent making a living changed with season and changed over time......Page 190
Social time was unaffected by season but changed over time......Page 193
Baboon diets had seasonal components but showed relative stability across seasons......Page 194
The "fallback foods" strategy versus the "high-return foods" strategy......Page 199
Baboon foraging as a "handoff" strategy that mitigates seasonality......Page 200
Baboons contrasted with vervet monkeys......Page 201
Costs of fallback foods......Page 202
The "dispensable social time" hypothesis versus the "social glue" hypothesis......Page 203
Seasonal change versus habitat change as a selective force in primate evolution......Page 204
References......Page 207
Introduction......Page 213
Methods......Page 216
Thermal constraints on behaviour......Page 217
Seasonal analyses of behavior......Page 219
Cross-populational determinants of resting time......Page 221
Discussion......Page 223
Acknowledgments......Page 226
References......Page 227
Introduction......Page 231
Gombe......Page 233
Mahale......Page 235
Taï......Page 238
Ngogo......Page 240
Baboons......Page 244
Acknowledgments......Page 246
Discussion......Page 248
Future research and implications for human evolution......Page 251
References......Page 254
Introduction......Page 259
Hunter–gatherer responses to seasonality......Page 260
The primate context......Page 263
Individual variation among human foragers......Page 265
Methods......Page 266
Temporality in resources and foraging behavior......Page 267
Explaining contemporary variability......Page 271
Hypothesis 2......Page 272
Hypothesis 4......Page 274
Discussion and conclusions......Page 276
References......Page 280
Part IV Seasonality, reproduction, and social organization......Page 283
Introduction: types of seasonality......Page 285
Recognizing income versus capital breeding......Page 290
Evaluation......Page 296
Predictions......Page 301
Evaluation: conception and food abundance......Page 303
Evaluation: fat accumulation during pregnancy......Page 306
Evaluation: sensitivity to food scarcity during pregnancy and abortion......Page 307
Evaluation: interannual variation in birth rates......Page 308
Discussion......Page 310
References......Page 314
Introduction......Page 323
Measures of birth seasonality......Page 324
Hypotheses for birth seasonality......Page 326
Choice of variables......Page 336
Results......Page 337
Timing of births relative to expected plant productivity......Page 344
Utility of r measure......Page 351
Effects of diet versus body size on birth seasonality......Page 352
Geographic variation in the narrowness of the birth peak......Page 353
Birth timing and energy availability......Page 354
Birth timing and female reproductive strategies......Page 355
Challenges for the future......Page 357
Data sources for birth data......Page 358
Climatic data......Page 359
Statistical considerations......Page 360
Appendix 11.2......Page 361
References......Page 362
Introduction......Page 367
Fluctuations in fruit availability: continental differences......Page 368
Changes in diet composition and energy intake, and the impact of fallback foods......Page 369
Energy expenditure and energy balance......Page 374
Reproductive responses to energetic status......Page 375
Summary of energetic and reproductive responses......Page 378
Recommendations for comparative studies......Page 383
Implications for hominin evolution......Page 385
References......Page 388
Introduction......Page 395
Social factors influencing human birth seasonality......Page 396
Climatological factors influencing human birth seasonality......Page 397
Energetic factors influencing female fecundity......Page 400
Birth seasonality in the western Toba community of Vaca Perdida......Page 403
Energetics and birth seasonality in other great apes......Page 406
Adaptive significance of the connection between energetics and female fecundity......Page 408
Summary......Page 409
References......Page 410
Introduction......Page 417
Indirect effects: seasonality and male competition......Page 419
Direct effects: seasonality and body size......Page 421
Morphological data......Page 422
Behavioral/ecological data......Page 424
Analyses......Page 425
Environmental seasonality and female body size......Page 426
Environmental seasonality and sexual dimorphism......Page 427
Environmental seasonality and group size......Page 430
Reproductive seasonality, group size, and dimorphism......Page 432
Direct effects......Page 433
Indirect effects......Page 436
Seasonality, dimorphism, and hominins......Page 437
Conclusions......Page 438
References......Page 448
Part V Seasonality and community ecology......Page 459
Introduction......Page 461
Seasonality and community composition......Page 463
Seasonality and the number of primate species......Page 467
Community biomass......Page 470
Frugivore biomass......Page 472
Discussion......Page 474
References......Page 476
Introduction......Page 481
Early Tertiary environments and early primates......Page 482
Tarsiers: denizens of Old World rainforests past and present......Page 486
Early catarrhines and hominoids: at home in the rainforests and woodlands......Page 488
The Miocene faunal turnover and the rise of Old World monkeys......Page 491
Environmental seasonality and the rise of hominins......Page 494
Conclusions......Page 495
References......Page 497
Part VI Seasonality and human evolution......Page 503
Introduction......Page 505
Climatic patterns......Page 506
Habitats......Page 510
Seasonality......Page 513
Hominin diets......Page 520
Early hominins......Page 522
Early Homo......Page 523
Homo erectus......Page 524
Later Homo species and the evolution of hunting......Page 525
Conclusions......Page 527
References......Page 528
Introduction......Page 535
Astronomical control of solar radiation......Page 537
Modern climate and seasonality in Equatorial Africa......Page 542
Evidence of orbital forcing and seasonality in Equatorial Africa......Page 546
Proxies for paleoseasonality......Page 548
Climate change and evolution of Equatorial African ecosystems......Page 549
Summary......Page 550
References......Page 551
Introduction......Page 559
Primate responses to seasonal food scarcity: the importance of behavioral flexibility......Page 560
Seasonal food scarcity and reproduction: energy balance and conception......Page 569
The impact of seasonality on social organization and sexual dimorphism......Page 572
Conclusions......Page 575
The impact of seasonality on extinct primates and humans......Page 576
Conclusions......Page 582
References......Page 583
Index......Page 587
