Phyllis Lee - Academia.edu (original) (raw)

Papers by Phyllis Lee

Research paper thumbnail of Fecundity and population viability in female zoo elephants: problems and possible solutions

Animal Welfare

We previously reported that African (Loxodonta africana) and Asian (Elephas maximus) female eleph... more We previously reported that African (Loxodonta africana) and Asian (Elephas maximus) female elephants in European zoos have shorter adult lifespans than protected conspecifics in range countries. This effect was the cause of greatest concern in Asian elephants, and risk factors within this species included being zoo-born, transferred between zoos, and possibly removed early from the mother. Here, we investigate these risk factors further; assess fecundity and sustainability in European zoos; and propose testable hypotheses as to the causes of these animals’ problems. Although imported wild-born Asian elephants live longer than zoo-born conspecifics, being imported when juvenile or adult appears no more protective than being imported in infancy, suggesting that the benefits of being wild- rather than zoo-born are conferred early in life. Zoo-born Asian neonates are significantly heavier than those born to working animals in range countries, with a possible tendency to be fatter. In z...

Research paper thumbnail of Unravelling the evolutionary function of communities

Research paper thumbnail of Procedural rights for nature – a pathway to sustainable decarbonisation?

Research paper thumbnail of Play in Elephants: Wellbeing, Welfare or Distraction?

Animals, 2020

We explore elephant play behaviour since (a) play has been proposed to represent a potential welf... more We explore elephant play behaviour since (a) play has been proposed to represent a potential welfare indicator; and (b) play has been associated with long-term survival in the wild. We categorised play into four types, and investigate both social (gentle, escalated-contact) and non-social (lone-locomotor, exploratory-object) play from observations made on wild (Asian N = 101; African N = 130) and captive (Asian N = 8; African N = 7) elephant calves ranging in age from birth to five years. Social play was the most frequent type of play among immature elephants, accounting for an average of 3%–9% of active time. Non-social play accounted for an additional 1%–11% of time. The most time spent in play was seen in captive Asian calves, particularly at the ages of 1–6 months, while wild African calves spent the least time in play overall, even though they had the greatest number and most diverse range of play partners available. We assessed calf energetics using time spent suckling, restin...

Research paper thumbnail of Ivory crisis: Growing no-trade consensus

Science (New York, N.Y.), Apr 20, 2018

In their Perspective, “Breaking the deadlock on ivory” (15 December 2017, p. [1378][1]), D. Biggs... more In their Perspective, “Breaking the deadlock on ivory” (15 December 2017, p. [1378][1]), D. Biggs et al. propose steps to enhance unity around the African elephant poaching crisis. We support their recommendations for dialogue among African elephant range states. However, the Perspective

Research paper thumbnail of Elephant resource-use traditions

Animal Cognition, 2015

African elephants (Loxodonta africana) use unusual and restricted habitats such as swampy clearin... more African elephants (Loxodonta africana) use unusual and restricted habitats such as swampy clearings, montane outcrops and dry rivers for a variety of social and ecological reasons. Within these habitats, elephants focus on very specific areas for resource exploitation, resulting in deep caves, large forest clearings and sand pits as well as long-established and highly demarcated routes for moving between resources. We review evidence for specific habitat exploitation in elephants and suggest that this represents socially learned cultural behaviour. Although elephants show high fidelity to precise locations over the very long term, these location preferences are explained neither by resource quality nor by accessibility. Acquiring techniques for exploiting specific resource sites requires observing conspecifics and practice and is evidence for social learning. Elephants possess sophisticated cognitive capacities used to track relationships and resources over their long lifespans, and they have an extended period of juvenile dependency as a result of the need to acquire this considerable social and ecological knowledge. Thus, elephant fidelity to particular sites results in traditional behaviour over generations, with the potential to weaken relationships between resource quality and site preferences. Illustrating the evidence for such powerful traditions in a species such as elephants contributes to understanding animal cognition in natural contexts.

Research paper thumbnail of People and protected areas: a study of local perceptions of wildlife crop-damage conflict in an area bordering the Selous Game Reserve, Tanzania

Oryx, 2003

This paper presents an analysis of perceived describe on-farm patterns of crop-damage. Comparison... more This paper presents an analysis of perceived describe on-farm patterns of crop-damage. Comparison of the two data sets indicates a disjunction between the patterns of wildlife crop-damage in relation to an onfarm assessment of damage in an area bordering the nature of the wildlife crop-damage conflict as perceived by local villagers, and as it actually occurs in the study Selous Game Reserve (SGR) in southeastern Tanzania. Data from an attitudinal questionnaire survey of 202 area. This disjunction is discussed in relation to the eCect of extreme damage events on local people's views, the households in four villages are used to examine local perceptions of wildlife crop-damage in terms of relative opportunity costs involved in guarding farm plots against crop-damage, and the tenure arrangements for wild-impact and which wildlife species were responsible. We explore the influence of wildlife crop-damage on attitudes life that define the relationship with the state wildlife management authority. to the adjacent game reserve. Data on the frequency of crop-damage events and estimated severity of impacts, recorded during a 6-month programme of crop-damage Keywords Crop-damage, Selous Game Reserve, Tanzania, wildlife conflict. monitoring in one of the survey villages, are used to the major cause of human-wildlife conflict, particularly

Research paper thumbnail of Status of Zanzibar Red Colobus and Sykes's Monkeys in Two Coastal Forests in 2005

Primate Conservation, 2013

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Research paper thumbnail of The reproductive success of vervet monkeys

A current mirror amplifier is supplied input current through the terminal conventionally common t... more A current mirror amplifier is supplied input current through the terminal conventionally common to its input and output circuits, which input current is split into two portions related as the gain of the current mirror amplifier. Either or both of these portions may be utilized as an output current.

Research paper thumbnail of The influence of forage, protected areas, and mating prospects on grouping patterns of male elephants

Behavioral Ecology, 2014

Factors affecting social group size in mammals are relatively well studied for females, but less ... more Factors affecting social group size in mammals are relatively well studied for females, but less is known about determinants of group size for males, particularly in species that live in sexually segregated groups. Male grouping patterns are thought to be driven more by spatial and temporal dispersion of mating opportunities than by food resources or predation risk. We evaluated the influence of 3 factors on male group sizes and number of males in mixed-sex groups in African elephants; forage availability (using Normalized Difference Vegetation Index, a satellite-based indicator of primary productivity), anthropogenic mortality risk (using distance of elephants from a protected area center), and mating opportunities (using the number of males in mixed-sex groups with and without estrous females). Using zero-truncated negative binomial regressions and a model-selection approach, we found that male elephants occurred in larger groups where primary productivity was higher and where they were further from a protected area center. However, we found an interaction between primary productivity and anthropogenic mortality risk: at low primary productivity, elephants formed larger groups further away from a protected area center, but did less so at higher primary productivity. This pattern suggests that male elephants are sensitive to seasonal variation in potential anthropogenic mortality risk, by remaining in smaller groups when risk is low, but forming larger groups when risk is high. Mating opportunities also led to an increase in male numbers in mixed-sex groups, but its relative influence on male grouping was less important because mating opportunities were rare.

Research paper thumbnail of Capuchin monkeys with similar personalities have higher-quality relationships independent of age, sex, kinship and rank

Animal Behaviour, 2015

contributed to variation in the affiliative and agonistic relationships of pairs of brown capuchi... more contributed to variation in the affiliative and agonistic relationships of pairs of brown capuchin monkeys, Sapajus apella. Capuchins that were more similar in Neuroticism had higher affiliative relationship scores, while capuchins that were more similar in Sociability shared overall higherquality relationships (i.e. the difference between the dyad's affiliative and agonistic scores). These effects were independent of age, sex, kinship and rank, suggesting that certain aspects of the psychology of these animals may contribute uniquely to the quality of their social relationships.

Research paper thumbnail of The influence of social structure, habitat, and host traits on the transmission of Escherichia coli in wild elephants

PloS one, 2014

Social structure is proposed to influence the transmission of both directly and environmentally t... more Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by h...

Research paper thumbnail of Impact of social context on female reproductive function in a group of captive olive baboons (Papio anubis)

Research paper thumbnail of Reproductive energetics in primates: how costly are babies?

Our recent studies of infant captive baboons (Garcia et al., 2008; 2009) found that infant to mat... more Our recent studies of infant captive baboons (Garcia et al., 2008; 2009) found that infant to maternal mass was positively associated with reproductive parameters, e.g. duration of postpartum amenorrhea and interbirth interval. Baboon mothers resumed cycling and reconceived when their infants attained a relatively consistent threshold mass, as predicted from interspecific life history theory. We suggested that the duration of investment acted as a facultative adjustment to infant growth rates, and depended on maternal physical and social characteristics, such as size and dominance rank. What was surprising was the relatively low energetic costs associated with reproduction; mothers' intake and energy expenditure measured by the DLW method (Rosetta et al., 2011) did not closely predict the time to resumption of cycling. Energy expenditure was correlated with maternal body mass both during early lactation and after the resumption of cycling and there was a relationship between maternal energy expenditure and infant growth rates; mothers with rapidly growing infants had higher energy expenditure than did those with slowly growing infants. Here we place these results on infant growth and reproductive energetics into a broader primate life history perspective, and explore the question of how costly are non-human primate infants? I partition expenses into time costs and energy costs and look at each of these over the early phase of growth, using the baboon model.

Research paper thumbnail of Quantifying forest elephant social structure in Central African bai environments

Research paper thumbnail of Consumption of CycadsEncephalartos hildebrandtiiby Zanzibar Red ColobusProcolobus kirkii

Journal of East African Natural History, 2011

BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting... more BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.

Research paper thumbnail of Development and sexual selection in primates

Sexual Selection in Primates

Research paper thumbnail of “Specialist” Primates Can Be Flexible in Response to Habitat Alteration

Primates in Fragments, 2013

An increasing number of fi eld studies on behavioral adaptations and learning suggest that a capa... more An increasing number of fi eld studies on behavioral adaptations and learning suggest that a capacity for fl exibility in local responses to disturbance could buffer some so-called specialists against that disturbance. We discuss how specialization, rather than an intrinsic species trait, appears to be moderated by fl exible and learned behavior and may not represent a useful trait in comparative analyses of extinction vulnerability. Furthermore, the use of primate species as indicators of the effects of disturbance on communities needs to be balanced with data on their capacity to adjust behaviorally. We present recent examples of innovative and fl exible behavior in primate taxa, some of which have traditionally been viewed as highly specialized, for example species of red colobus. We also highlight research gaps in the ecological specialization-behavioral fl exibility domain.

Research paper thumbnail of African Elephant Play, Competence and Social Complexity

Animal Behavior and Cognition, 2014

Play in African elephants (Loxodonta africana) is a lifelong activity, with both males and female... more Play in African elephants (Loxodonta africana) is a lifelong activity, with both males and females engaging in a variety of forms of play into their 40s and 50s. Play represents a potentially enriching social and physical activity for elephants, but also one with energetic costs and other risks. Having followed a cohort of individually recognized elephants from birth to adulthood in Amboseli, Kenya, we suggest here some long-term consequences for the role of play in the development of social and physical skills in elephants. Playful elephant calves appeared to be individuals with greater capacity to resist growth insults or stresses and had a reduced risk of dying as adults. The sexes differed in the social contexts and consequences of their early play experiences. Juvenile males used play as a mechanism to enable relaxed contacts with relative strangers, providing vital physical and behavioral information about future friends, associates and reproductive competitors. Females, by contrast, used play as one of the many mechanism for sustaining their social, protective and leadership roles within families.

Research paper thumbnail of Wild Western Lowland Gorillas Signal Selectively Using Odor

Research paper thumbnail of Fecundity and population viability in female zoo elephants: problems and possible solutions

Animal Welfare

We previously reported that African (Loxodonta africana) and Asian (Elephas maximus) female eleph... more We previously reported that African (Loxodonta africana) and Asian (Elephas maximus) female elephants in European zoos have shorter adult lifespans than protected conspecifics in range countries. This effect was the cause of greatest concern in Asian elephants, and risk factors within this species included being zoo-born, transferred between zoos, and possibly removed early from the mother. Here, we investigate these risk factors further; assess fecundity and sustainability in European zoos; and propose testable hypotheses as to the causes of these animals’ problems. Although imported wild-born Asian elephants live longer than zoo-born conspecifics, being imported when juvenile or adult appears no more protective than being imported in infancy, suggesting that the benefits of being wild- rather than zoo-born are conferred early in life. Zoo-born Asian neonates are significantly heavier than those born to working animals in range countries, with a possible tendency to be fatter. In z...

Research paper thumbnail of Unravelling the evolutionary function of communities

Research paper thumbnail of Procedural rights for nature – a pathway to sustainable decarbonisation?

Research paper thumbnail of Play in Elephants: Wellbeing, Welfare or Distraction?

Animals, 2020

We explore elephant play behaviour since (a) play has been proposed to represent a potential welf... more We explore elephant play behaviour since (a) play has been proposed to represent a potential welfare indicator; and (b) play has been associated with long-term survival in the wild. We categorised play into four types, and investigate both social (gentle, escalated-contact) and non-social (lone-locomotor, exploratory-object) play from observations made on wild (Asian N = 101; African N = 130) and captive (Asian N = 8; African N = 7) elephant calves ranging in age from birth to five years. Social play was the most frequent type of play among immature elephants, accounting for an average of 3%–9% of active time. Non-social play accounted for an additional 1%–11% of time. The most time spent in play was seen in captive Asian calves, particularly at the ages of 1–6 months, while wild African calves spent the least time in play overall, even though they had the greatest number and most diverse range of play partners available. We assessed calf energetics using time spent suckling, restin...

Research paper thumbnail of Ivory crisis: Growing no-trade consensus

Science (New York, N.Y.), Apr 20, 2018

In their Perspective, “Breaking the deadlock on ivory” (15 December 2017, p. [1378][1]), D. Biggs... more In their Perspective, “Breaking the deadlock on ivory” (15 December 2017, p. [1378][1]), D. Biggs et al. propose steps to enhance unity around the African elephant poaching crisis. We support their recommendations for dialogue among African elephant range states. However, the Perspective

Research paper thumbnail of Elephant resource-use traditions

Animal Cognition, 2015

African elephants (Loxodonta africana) use unusual and restricted habitats such as swampy clearin... more African elephants (Loxodonta africana) use unusual and restricted habitats such as swampy clearings, montane outcrops and dry rivers for a variety of social and ecological reasons. Within these habitats, elephants focus on very specific areas for resource exploitation, resulting in deep caves, large forest clearings and sand pits as well as long-established and highly demarcated routes for moving between resources. We review evidence for specific habitat exploitation in elephants and suggest that this represents socially learned cultural behaviour. Although elephants show high fidelity to precise locations over the very long term, these location preferences are explained neither by resource quality nor by accessibility. Acquiring techniques for exploiting specific resource sites requires observing conspecifics and practice and is evidence for social learning. Elephants possess sophisticated cognitive capacities used to track relationships and resources over their long lifespans, and they have an extended period of juvenile dependency as a result of the need to acquire this considerable social and ecological knowledge. Thus, elephant fidelity to particular sites results in traditional behaviour over generations, with the potential to weaken relationships between resource quality and site preferences. Illustrating the evidence for such powerful traditions in a species such as elephants contributes to understanding animal cognition in natural contexts.

Research paper thumbnail of People and protected areas: a study of local perceptions of wildlife crop-damage conflict in an area bordering the Selous Game Reserve, Tanzania

Oryx, 2003

This paper presents an analysis of perceived describe on-farm patterns of crop-damage. Comparison... more This paper presents an analysis of perceived describe on-farm patterns of crop-damage. Comparison of the two data sets indicates a disjunction between the patterns of wildlife crop-damage in relation to an onfarm assessment of damage in an area bordering the nature of the wildlife crop-damage conflict as perceived by local villagers, and as it actually occurs in the study Selous Game Reserve (SGR) in southeastern Tanzania. Data from an attitudinal questionnaire survey of 202 area. This disjunction is discussed in relation to the eCect of extreme damage events on local people's views, the households in four villages are used to examine local perceptions of wildlife crop-damage in terms of relative opportunity costs involved in guarding farm plots against crop-damage, and the tenure arrangements for wild-impact and which wildlife species were responsible. We explore the influence of wildlife crop-damage on attitudes life that define the relationship with the state wildlife management authority. to the adjacent game reserve. Data on the frequency of crop-damage events and estimated severity of impacts, recorded during a 6-month programme of crop-damage Keywords Crop-damage, Selous Game Reserve, Tanzania, wildlife conflict. monitoring in one of the survey villages, are used to the major cause of human-wildlife conflict, particularly

Research paper thumbnail of Status of Zanzibar Red Colobus and Sykes's Monkeys in Two Coastal Forests in 2005

Primate Conservation, 2013

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Research paper thumbnail of The reproductive success of vervet monkeys

A current mirror amplifier is supplied input current through the terminal conventionally common t... more A current mirror amplifier is supplied input current through the terminal conventionally common to its input and output circuits, which input current is split into two portions related as the gain of the current mirror amplifier. Either or both of these portions may be utilized as an output current.

Research paper thumbnail of The influence of forage, protected areas, and mating prospects on grouping patterns of male elephants

Behavioral Ecology, 2014

Factors affecting social group size in mammals are relatively well studied for females, but less ... more Factors affecting social group size in mammals are relatively well studied for females, but less is known about determinants of group size for males, particularly in species that live in sexually segregated groups. Male grouping patterns are thought to be driven more by spatial and temporal dispersion of mating opportunities than by food resources or predation risk. We evaluated the influence of 3 factors on male group sizes and number of males in mixed-sex groups in African elephants; forage availability (using Normalized Difference Vegetation Index, a satellite-based indicator of primary productivity), anthropogenic mortality risk (using distance of elephants from a protected area center), and mating opportunities (using the number of males in mixed-sex groups with and without estrous females). Using zero-truncated negative binomial regressions and a model-selection approach, we found that male elephants occurred in larger groups where primary productivity was higher and where they were further from a protected area center. However, we found an interaction between primary productivity and anthropogenic mortality risk: at low primary productivity, elephants formed larger groups further away from a protected area center, but did less so at higher primary productivity. This pattern suggests that male elephants are sensitive to seasonal variation in potential anthropogenic mortality risk, by remaining in smaller groups when risk is low, but forming larger groups when risk is high. Mating opportunities also led to an increase in male numbers in mixed-sex groups, but its relative influence on male grouping was less important because mating opportunities were rare.

Research paper thumbnail of Capuchin monkeys with similar personalities have higher-quality relationships independent of age, sex, kinship and rank

Animal Behaviour, 2015

contributed to variation in the affiliative and agonistic relationships of pairs of brown capuchi... more contributed to variation in the affiliative and agonistic relationships of pairs of brown capuchin monkeys, Sapajus apella. Capuchins that were more similar in Neuroticism had higher affiliative relationship scores, while capuchins that were more similar in Sociability shared overall higherquality relationships (i.e. the difference between the dyad's affiliative and agonistic scores). These effects were independent of age, sex, kinship and rank, suggesting that certain aspects of the psychology of these animals may contribute uniquely to the quality of their social relationships.

Research paper thumbnail of The influence of social structure, habitat, and host traits on the transmission of Escherichia coli in wild elephants

PloS one, 2014

Social structure is proposed to influence the transmission of both directly and environmentally t... more Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by h...

Research paper thumbnail of Impact of social context on female reproductive function in a group of captive olive baboons (Papio anubis)

Research paper thumbnail of Reproductive energetics in primates: how costly are babies?

Our recent studies of infant captive baboons (Garcia et al., 2008; 2009) found that infant to mat... more Our recent studies of infant captive baboons (Garcia et al., 2008; 2009) found that infant to maternal mass was positively associated with reproductive parameters, e.g. duration of postpartum amenorrhea and interbirth interval. Baboon mothers resumed cycling and reconceived when their infants attained a relatively consistent threshold mass, as predicted from interspecific life history theory. We suggested that the duration of investment acted as a facultative adjustment to infant growth rates, and depended on maternal physical and social characteristics, such as size and dominance rank. What was surprising was the relatively low energetic costs associated with reproduction; mothers' intake and energy expenditure measured by the DLW method (Rosetta et al., 2011) did not closely predict the time to resumption of cycling. Energy expenditure was correlated with maternal body mass both during early lactation and after the resumption of cycling and there was a relationship between maternal energy expenditure and infant growth rates; mothers with rapidly growing infants had higher energy expenditure than did those with slowly growing infants. Here we place these results on infant growth and reproductive energetics into a broader primate life history perspective, and explore the question of how costly are non-human primate infants? I partition expenses into time costs and energy costs and look at each of these over the early phase of growth, using the baboon model.

Research paper thumbnail of Quantifying forest elephant social structure in Central African bai environments

Research paper thumbnail of Consumption of CycadsEncephalartos hildebrandtiiby Zanzibar Red ColobusProcolobus kirkii

Journal of East African Natural History, 2011

BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting... more BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.

Research paper thumbnail of Development and sexual selection in primates

Sexual Selection in Primates

Research paper thumbnail of “Specialist” Primates Can Be Flexible in Response to Habitat Alteration

Primates in Fragments, 2013

An increasing number of fi eld studies on behavioral adaptations and learning suggest that a capa... more An increasing number of fi eld studies on behavioral adaptations and learning suggest that a capacity for fl exibility in local responses to disturbance could buffer some so-called specialists against that disturbance. We discuss how specialization, rather than an intrinsic species trait, appears to be moderated by fl exible and learned behavior and may not represent a useful trait in comparative analyses of extinction vulnerability. Furthermore, the use of primate species as indicators of the effects of disturbance on communities needs to be balanced with data on their capacity to adjust behaviorally. We present recent examples of innovative and fl exible behavior in primate taxa, some of which have traditionally been viewed as highly specialized, for example species of red colobus. We also highlight research gaps in the ecological specialization-behavioral fl exibility domain.

Research paper thumbnail of African Elephant Play, Competence and Social Complexity

Animal Behavior and Cognition, 2014

Play in African elephants (Loxodonta africana) is a lifelong activity, with both males and female... more Play in African elephants (Loxodonta africana) is a lifelong activity, with both males and females engaging in a variety of forms of play into their 40s and 50s. Play represents a potentially enriching social and physical activity for elephants, but also one with energetic costs and other risks. Having followed a cohort of individually recognized elephants from birth to adulthood in Amboseli, Kenya, we suggest here some long-term consequences for the role of play in the development of social and physical skills in elephants. Playful elephant calves appeared to be individuals with greater capacity to resist growth insults or stresses and had a reduced risk of dying as adults. The sexes differed in the social contexts and consequences of their early play experiences. Juvenile males used play as a mechanism to enable relaxed contacts with relative strangers, providing vital physical and behavioral information about future friends, associates and reproductive competitors. Females, by contrast, used play as one of the many mechanism for sustaining their social, protective and leadership roles within families.

Research paper thumbnail of Wild Western Lowland Gorillas Signal Selectively Using Odor