Author
Caroline Ross
Other affiliations: Durham University, University of Surrey, University College London
Bio: Caroline Ross is an academic researcher from University of Roehampton. The author has contributed to research in topics: Population & Animal ecology. The author has an hindex of 29, co-authored 57 publications receiving 2440 citations. Previous affiliations of Caroline Ross include Durham University & University of Surrey.
Topics: Population, Animal ecology, Sexual swelling, Sexual selection, Predation
Papers published on a yearly basis
Papers
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TL;DR: It is shown that the major determinant of sex differences in energetic costs is body size dimorphism, and, in highly sexually dimorphic species, in the long term, the energetic costs are often greater for females, but, when male body size exceeds female body size by 60% or more, male energetic Costs are greater than those for females.
Abstract: Female mammals bear the energetic costs of gestation and lactation. Therefore, it is often assumed that the overall energetic costs are greater for females than they are for males. However, the energetic costs to males of intrasex competition may also be considerable, particularly if males maintain a much larger body size than females. Using data from 19 non‐human primates, this paper examines the relationship between male and female energetic costs both in the short term (daily energy expenditure) and the long term (the energetic cost of producing a single offspring). It is shown that the major determinant of sex differences in energetic costs is body size dimorphism. In the long term, the energetic costs are often greater for females, but, when male body size exceeds female body size by 60% or more, male energetic costs are greater than those for females. That is, in highly sexually dimorphic species the energetic costs of gestation and lactation for the females are matched by the energetic costs to the males of maintaining a large body size.
143 citations
TL;DR: There is no strong evidence that diet is directly linked to BMR, although a low BMR may be found in species with folivorous diets, and some predictions are made about the relative BMRs that should be found for other species whose BMR is, as yet, unknown.
Abstract: The relationship between basal metabolic rate (BMR), body weight and diet is examined for primates. Contrary to the results reported in several recent works, there is no strong evidence that diet is directly linked to BMR, although a low BMR, relative to body weight, may be found in species with folivorous diets. There is some evidence that nocturnal haplorhine species have a relatively low BMR, but strepsirhines appear to have a uniformly low relative BMR regardless of their primary activity period. The evolution of BMR in primates is discussed in the light of these findings. Some predictions are made about the relative BMRs that should be found for other species whose BMR is, as yet, unknown.
127 citations
TL;DR: It is found that this parameter is negatively correlated with body weight, so that larger primate species consistently have a lower rmax than do smaller species, and pre-natal maternal investment (MI) is found to correlate highly with BMR, even after the removal of body weight effects.
Abstract: The intrinsic rate of natural increase (rmax) is calculated for 58 primate species. It is found that this parameter is negatively correlated with body weight, so that larger primate species consistently have a lower rmax than do smaller species. Although there is no apparent link between the raw value of rmax and environmental predictability, a relationship between a high rmax, relative to body weight, and an unpredictable environment is found to exist. However, there is no relationship between a predictable environment and either the raw value of rmax, or the relative rmax. After body size effects are removed, rmax is not correlated with basal metabolic rate (BMR). Pre-natal maternal investment (MI) is found to correlate highly with BMR, even after the removal of body weight effects. MI does not correlate either with rmax or with environmental predictability. Diet appears to have little influence either on rmax on MI, but there is some indication that folivores have both a high relative rmax and a high relative MI. These results are discussed in the light of theories of life-history strategy evolution.
125 citations
TL;DR: Although riding may have some energetic and reproductive costs, its repeated evolution in the Primates suggests that it also has some benefits, the most likely being a reduced mortality risk for carried infants.
Abstract: Few mammalian orders carry their infants clinging to the mother's fur. I investigated the evolution of carrying behavior in primates and the life-history and ecological correlates of infant care patterns. Primates are ideal for the study as there is variation in infant care patterns. Primate infants are left hidden in nests or parked in trees, both of which strategies I term parking, and are carried orally or ride clinging to the mother's fur: riding. Infant carrying has evolved several times in the Primates and, once evolved, it has been conserved. Significant energetic costs of riding are indicated as riding species maintain smaller home ranges than those of non-riders of the same body size. With body size and phylogenetic influences taken into account, riders appear to incur a reproductive cost by weaning and breeding later than parkers. Although riders do not have lower birth rates than those of parkers, their later age at first reproduction leads to their having a lower reproductive rate, measured by the intrinsic rate of population increase. Precociality of infants is not correlated with either riding or nesting behavior. Although non-nesting species have larger litter sizes, their infants are not significantly smaller, nor are their neonatal brains relatively smaller. Although riding may have some energetic and reproductive costs, its repeated evolution in the Primates suggests that it also has some benefits, the most likely being a reduced mortality risk for carried infants.
124 citations
TL;DR: It is shown that swelling color and size vary independently, and that, consistent with results in other species, swelling size contains information about the timing of ovulation and the fertile period, however, it is shownthat swelling color does not contain such information.
124 citations
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TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
14,171 citations
TL;DR: An analysis of variability in body mass indicates that the coefficient of variation for body mass increases with increasing species mean mass.
1,198 citations
TL;DR: This review demonstrates the value of applying a multilevel evolutionary-developmental approach to the analysis of a central feature of human phenotypic variation: LH strategy, and converging lines of evidence support core assumptions of the theory.
Abstract: The current paper synthesizes theory and data from the field of life history (LH) evolution to advance a new developmental theory of variation in human LH strategies. The theory posits that clusters of correlated LH traits (e.g., timing of puberty, age at sexual debut and first birth, parental investment strategies) lie on a slow-to-fast continuum; that harshness (externally caused levels of morbidity-mortality) and unpredictability (spatial-temporal variation in harshness) are the most fundamental environmental influences on the evolution and development of LH strategies; and that these influences depend on population densities and related levels of intraspecific competition and resource scarcity, on age schedules of mortality, on the sensitivity of morbidity-mortality to the organism’s resource-allocation decisions, and on the extent to which environmental fluctuations affect individuals versus populations over short versus long timescales. These interrelated factors operate at evolutionary and developmental levels and should be distinguished because they exert distinctive effects on LH traits and are hierarchically operative in terms of primacy of influence. Although converging lines of evidence support core assumptions of the theory, many questions remain unanswered. This review demonstrates the value of applying a multilevel evolutionary-developmental approach to the analysis of a central feature of human phenotypic variation: LH strategy.
1,027 citations
TL;DR: This paper compares patterns of mortality from natural populations of mammals with a variety of life histories and finds that, after removing the effects of body weight, mortality is the best predictor of variation in life-history traits.
Abstract: Recent comparative studies point to the importance of mortality schedules as determinants in the evolution of life-history characteristics. In this paper, we compare patterns of mortality from natural populations of mammals with a variety of life histories. We find that, after removing the effects of body weight, mortality is the best predictor of variation in life-history traits. Mammals with high levels of natural mortality tend to mature early and give birth to small offspring in large litters after a short gestation, before and after body size effects are factored out. We examine the way in which life-history traits relate to juvenile mortality versus adult mortality and find that juvenile mortality is more highly correlated with life-history traits than is adult mortality. We discuss the necessity of distinguishing between extrinsic sources of mortality (e.g. predation) and mortality caused by intrinsic sources (e.g. costs of reproduction), and the role that ecology might play in the evolution of patterns of mortality and fecundity. We conclude that these results must be explained not simply in the light of the demographic necessity of balancing mortality and fecundity, but as a result of age-specific costs and benefits of reproduction and parental investment. Detailed comparative studies of mortality patterns in natural populations of mammals offer a promising avenue towards understanding the evolution of life-history strategies.
1,003 citations
01 Jan 2002
847 citations