Lydia M Hopper
Biographic Data
| ID | 193180 |
|---|---|
| NAME | Lydia M Hopper |
| GIVEN NAMES | Lydia M |
| FAMILY NAME | Hopper |
| SIGNATURE | HOPPER L M |
| AFFILIATIONS | Lincoln Park Zoo |
| ORCID | 0000-0001-5953-3264 |
| VERIFIED | Yes |
| TOTAL WORKS | 25 |
| TOTAL CITATIONS | 1 |
| AUTHOR COUNT | 25 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2009 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 1 |
No Response to Inconsistently Experienced Inequity in Four Primate Species
Understanding when and how nonhuman primates respond to inequity is essential for uncovering the evolutionary roots of human fairness. Previous studies have shown that some species will refuse to participate or refuse rewards in some contexts when outcomes are unequal, but in these studies, subjects experienced inequity on every trial. This is likely not a realistic reflection of daily life, and we do not know whether these responses persist when…
A Collaborative, Multi‐Institutional Growth Standard for Dam‐Reared Infant Rhesus and Pigtail Macaques ( Macaca mulatta and Macaca nemestrina ) in Research Settings
A multicenter study was undertaken to generate new weight‐for‐age growth standards to monitor the growth of infant rhesus and pigtail macaques in research breeding colonies. Previously, single institutions have developed reference growth curves, under the assumption of linear growth, for infants raised in certain settings with a limited scope of benefit to outside institutions. Weight and health records from seven research institutions across the…
Pigtail Macaque ( Macaca nemestrina ) Performance Differs Across Multiple Cognitive Domains in Comparison to Rhesus Macaques ( Macaca mulatta )
Rhesus and pigtail macaques are closely related and have similar social structures, yet differences in their behavior, socio‐ecology, and personality have been observed, although not systematically documented. Given these differences, it is important to assess pigtail macaque cognition independently, rather than relying on rhesus macaque findings as a proxy. To gain a better understanding of pigtail macaque cognition, we used a battery of three c…
Exploring the Utility of the Gut Microbiome as a Longitudinal Health Monitoring Tool in Sanctuary Chimpanzees ( Pan troglodytes )
The primary goal of captive primate management is to ensure optimal health and welfare of the animals in our care. Given that the gut microbiome interacts closely with host metabolism, immunity, and even cognition, it represents a potentially powerful tool for identifying subtle changes in health status across a range of body systems simultaneously. However, thus far, it has not been widely tested or implemented as a monitoring tool. In this stud…
When the Lights Go Out: Studying Sex Differences in Sleep Latency, Sleep Quality, and Social Behavior in Captive Rhesus Macaques ( Macaca mulatta ) Over a 24‐h Period
Assessments of nonhuman primate (NHP) affiliation are typically restricted to daytime behavior. There is, however, a growing interest in understanding NHP behavior and welfare over the 24‐h period. To assess the sleep quality and sociality of rhesus macaques, we measured the time it took pair‐housed macaques to fall asleep (sleep latency), the proportion of time macaques spent asleep at night, and whether these behaviors were mediated by sex and …
Creating connection: Greeting and Leave-Taking Behavior in Nonhuman Primates
The impact of housing on birth outcomes in breeding macaque groups across multiple research centers
Demand for nonhuman primates in research has increased over the past several years, while nonhuman primate supply remains a challenge in the United States. Global nonhuman primate supply issues make it increasingly important to maximize domestic colony production. To explore how housing conditions across primate breeding colonies impact infant survival and animal production more broadly, we collected medical records from 7959 rhesus macaques ( Ma…
What is unique about the human eye? Comparative image analysis on the external eye morphology of human and nonhuman great apes
Primatology in zoos: Studying behavior, cognition, and welfare
Primatological research in zoos is increasing globally. Such research allows scientists to study primate biology, behavior, and cognition while helping to advance the welfare of captive primates. Moreover, zoos welcome millions of visitors annually, which creates unique opportunities for public engagement with this research. Reflecting the importance of zoos in the field of primatology, the articles in this special issue showcase the range of pri…
Nonhuman primate abnormal behavior: Etiology, assessment, and treatment
Across captive settings, nonhuman primates may develop an array of abnormal behaviors including stereotypic and self‐injurious behavior. Abnormal behavior can indicate a state of poor welfare, since it is often associated with a suboptimal environment. However, this may not always be the case as some behaviors can develop independently of any psychological distress, be triggered in environments known to promote welfare, and be part of an animal's…
An evaluation of thermal imaging as a welfare monitoring tool for captive chimpanzees
Chimpanzees in Context: A Comparative Perspective on Chimpanzee Behavior, Cognition, Conservation, and Welfare
The relationship between personality, season, and wounding receipt in zoo‐housed Japanese macaques ( Macaca fuscata ): A multi‐institutional study
It is important to those managing Japanese macaques ( Macaca fuscata ) in captive settings to understand predictors of wounding. While studies have demonstrated that season (breeding or nonbreeding) and sex predict rates of wounding received by zoo‐housed Japanese macaques, we investigated whether individual differences in personality ratings also might explain some of the observed interindividual variance in wounding. Such patterns were previous…
Using a Touchscreen Paradigm to Evaluate Food Preferences and Response to Novel Photographic Stimuli of Food in Three Primate Species (Gorilla gorilla gorilla, Pan troglodytes, and Macaca fuscata)
Understanding the Behavior of Sanctuary-Housed Chimpanzees During Public Programs
At zoos, and some sanctuaries, members of the public can observe the resident animals. Examining the characteristics and consequences of this type of human–animal encounter is important to understand public education and engagement as well as animal behavior and welfare. Zoos typically have a large and consistent visitor presence, and researchers report mixed findings regarding the effects of the visiting public on the behavior of resident primat…
Foraging in a social setting: A comparative analysis of captive gorillas and chimpanzees
Testing the weekend effect hypothesis: Time of day and lunar phase better predict the timing of births in laboratory‐housed primates than day of week
The weekend effect hypothesis proposes that captive primates are more likely to give birth during times of low disturbance and reduced staff activity. The hypothesis specifically predicts that laboratory‐housed primates will be more likely to give birth during the weekend than weekdays when staff activity is reduced. To date, support for the weekend effect hypothesis has been mixed and based on studies with relatively few subjects. To further exa…
A unique zoo‐sanctuary collaboration for chimpanzees
The effect of captivity on the primate gut microbiome varies with host dietary niche
Despite careful attention to animal nutrition and wellbeing, gastrointestinal distress remains relatively common in captive non‐human primates (NHPs), particularly dietary specialists such as folivores. These patterns may be a result of marked dietary differences between captive and wild settings and associated impacts on the gut microbiome. However, given that most existing studies target NHP dietary specialists, it is unclear if captive environ…
Chimpanzees copy dominant and knowledgeable individuals: Implications for cultural diversity
Chimpanzees create and modify probe tools functionally: A study with zoo‐housed chimpanzees
Chimpanzees (Pan troglodytes) use tools to probe for out-of-reach food, both in the wild and in captivity. Beyond gathering appropriately-sized materials to create tools, chimpanzees also perform secondary modifications in order to create an optimized tool. In this study, we recorded the behavior of a group of zoo-housed chimpanzees when presented with opportunities to use tools to probe for liquid foods in an artificial termite mound within thei…
The Next Direction for Primatology? A Commentary on Setchell (2013)
Developing a comprehensive and comparative questionnaire for measuring personality in chimpanzees using a simultaneous top‐down/bottom‐up design
One effective method for measuring personality in primates is to use personality trait ratings to distill the experience of people familiar with the individual animals. Previous rating instruments were created using either top-down or bottom-up approaches. Top-down approaches, which essentially adapt instruments originally designed for use with another species, can unfortunately lead to the inclusion of traits irrelevant to chimpanzees or fail to…
An Evaluation of the Efficacy of Video Displays for Use With Chimpanzees ( P an troglodytes )
Video displays for behavioral research lend themselves particularly well to studies with chimpanzees ( P an troglodytes ), as their vision is comparable to humans’, yet there has been no formal test of the efficacy of video displays as a form of social information for chimpanzees. To address this, we compared the learning success of chimpanzees shown video footage of a conspecific compared to chimpanzees shown a live conspecific performing the sa…
Emulation, imitation, over-imitation and the scope of culture for child and chimpanzee
We describe our recent studies of imitation and cultural transmission in chimpanzees and children, which question late twentieth-century characterizations of children as imitators, but chimpanzees as emulators. As emulation entails learning only about the results of others' actions, it has been thought to curtail any capacity to sustain cultures. Recent chimpanzee diffusion experiments have by contrast documented a significant capacity for copyin…
Emulation, imitation, over-imitation and the scope of culture for child and chimpanzee
We describe our recent studies of imitation and cultural transmission in chimpanzees and children, which question late twentieth-century characterizations of children as imitators, but chimpanzees as emulators. As emulation entails learning only about the results of others' actions, it has been thought to curtail any capacity to sustain cultures. Recent chimpanzee diffusion experiments have by contrast documented a significant capacity for copyin…
An Evaluation of the Efficacy of Video Displays for Use With Chimpanzees ( P an troglodytes )
Video displays for behavioral research lend themselves particularly well to studies with chimpanzees ( P an troglodytes ), as their vision is comparable to humans’, yet there has been no formal test of the efficacy of video displays as a form of social information for chimpanzees. To address this, we compared the learning success of chimpanzees shown video footage of a conspecific compared to chimpanzees shown a live conspecific performing the sa…
Developing a comprehensive and comparative questionnaire for measuring personality in chimpanzees using a simultaneous top‐down/bottom‐up design
One effective method for measuring personality in primates is to use personality trait ratings to distill the experience of people familiar with the individual animals. Previous rating instruments were created using either top-down or bottom-up approaches. Top-down approaches, which essentially adapt instruments originally designed for use with another species, can unfortunately lead to the inclusion of traits irrelevant to chimpanzees or fail to…
The Next Direction for Primatology? A Commentary on Setchell (2013)
Chimpanzees copy dominant and knowledgeable individuals: Implications for cultural diversity
Chimpanzees create and modify probe tools functionally: A study with zoo‐housed chimpanzees
Chimpanzees (Pan troglodytes) use tools to probe for out-of-reach food, both in the wild and in captivity. Beyond gathering appropriately-sized materials to create tools, chimpanzees also perform secondary modifications in order to create an optimized tool. In this study, we recorded the behavior of a group of zoo-housed chimpanzees when presented with opportunities to use tools to probe for liquid foods in an artificial termite mound within thei…
Foraging in a social setting: A comparative analysis of captive gorillas and chimpanzees
Testing the weekend effect hypothesis: Time of day and lunar phase better predict the timing of births in laboratory‐housed primates than day of week
The weekend effect hypothesis proposes that captive primates are more likely to give birth during times of low disturbance and reduced staff activity. The hypothesis specifically predicts that laboratory‐housed primates will be more likely to give birth during the weekend than weekdays when staff activity is reduced. To date, support for the weekend effect hypothesis has been mixed and based on studies with relatively few subjects. To further exa…
A unique zoo‐sanctuary collaboration for chimpanzees
The effect of captivity on the primate gut microbiome varies with host dietary niche
Despite careful attention to animal nutrition and wellbeing, gastrointestinal distress remains relatively common in captive non‐human primates (NHPs), particularly dietary specialists such as folivores. These patterns may be a result of marked dietary differences between captive and wild settings and associated impacts on the gut microbiome. However, given that most existing studies target NHP dietary specialists, it is unclear if captive environ…
Using a Touchscreen Paradigm to Evaluate Food Preferences and Response to Novel Photographic Stimuli of Food in Three Primate Species (Gorilla gorilla gorilla, Pan troglodytes, and Macaca fuscata)
Understanding the Behavior of Sanctuary-Housed Chimpanzees During Public Programs
At zoos, and some sanctuaries, members of the public can observe the resident animals. Examining the characteristics and consequences of this type of human–animal encounter is important to understand public education and engagement as well as animal behavior and welfare. Zoos typically have a large and consistent visitor presence, and researchers report mixed findings regarding the effects of the visiting public on the behavior of resident primat…
An evaluation of thermal imaging as a welfare monitoring tool for captive chimpanzees
Chimpanzees in Context: A Comparative Perspective on Chimpanzee Behavior, Cognition, Conservation, and Welfare
The relationship between personality, season, and wounding receipt in zoo‐housed Japanese macaques ( Macaca fuscata ): A multi‐institutional study
It is important to those managing Japanese macaques ( Macaca fuscata ) in captive settings to understand predictors of wounding. While studies have demonstrated that season (breeding or nonbreeding) and sex predict rates of wounding received by zoo‐housed Japanese macaques, we investigated whether individual differences in personality ratings also might explain some of the observed interindividual variance in wounding. Such patterns were previous…
What is unique about the human eye? Comparative image analysis on the external eye morphology of human and nonhuman great apes
Primatology in zoos: Studying behavior, cognition, and welfare
Primatological research in zoos is increasing globally. Such research allows scientists to study primate biology, behavior, and cognition while helping to advance the welfare of captive primates. Moreover, zoos welcome millions of visitors annually, which creates unique opportunities for public engagement with this research. Reflecting the importance of zoos in the field of primatology, the articles in this special issue showcase the range of pri…
Nonhuman primate abnormal behavior: Etiology, assessment, and treatment
Across captive settings, nonhuman primates may develop an array of abnormal behaviors including stereotypic and self‐injurious behavior. Abnormal behavior can indicate a state of poor welfare, since it is often associated with a suboptimal environment. However, this may not always be the case as some behaviors can develop independently of any psychological distress, be triggered in environments known to promote welfare, and be part of an animal's…
The impact of housing on birth outcomes in breeding macaque groups across multiple research centers
Demand for nonhuman primates in research has increased over the past several years, while nonhuman primate supply remains a challenge in the United States. Global nonhuman primate supply issues make it increasingly important to maximize domestic colony production. To explore how housing conditions across primate breeding colonies impact infant survival and animal production more broadly, we collected medical records from 7959 rhesus macaques ( Ma…
Pigtail Macaque ( Macaca nemestrina ) Performance Differs Across Multiple Cognitive Domains in Comparison to Rhesus Macaques ( Macaca mulatta )
Rhesus and pigtail macaques are closely related and have similar social structures, yet differences in their behavior, socio‐ecology, and personality have been observed, although not systematically documented. Given these differences, it is important to assess pigtail macaque cognition independently, rather than relying on rhesus macaque findings as a proxy. To gain a better understanding of pigtail macaque cognition, we used a battery of three c…
Exploring the Utility of the Gut Microbiome as a Longitudinal Health Monitoring Tool in Sanctuary Chimpanzees ( Pan troglodytes )
The primary goal of captive primate management is to ensure optimal health and welfare of the animals in our care. Given that the gut microbiome interacts closely with host metabolism, immunity, and even cognition, it represents a potentially powerful tool for identifying subtle changes in health status across a range of body systems simultaneously. However, thus far, it has not been widely tested or implemented as a monitoring tool. In this stud…
When the Lights Go Out: Studying Sex Differences in Sleep Latency, Sleep Quality, and Social Behavior in Captive Rhesus Macaques ( Macaca mulatta ) Over a 24‐h Period
Assessments of nonhuman primate (NHP) affiliation are typically restricted to daytime behavior. There is, however, a growing interest in understanding NHP behavior and welfare over the 24‐h period. To assess the sleep quality and sociality of rhesus macaques, we measured the time it took pair‐housed macaques to fall asleep (sleep latency), the proportion of time macaques spent asleep at night, and whether these behaviors were mediated by sex and …
Creating connection: Greeting and Leave-Taking Behavior in Nonhuman Primates
No Response to Inconsistently Experienced Inequity in Four Primate Species
Understanding when and how nonhuman primates respond to inequity is essential for uncovering the evolutionary roots of human fairness. Previous studies have shown that some species will refuse to participate or refuse rewards in some contexts when outcomes are unequal, but in these studies, subjects experienced inequity on every trial. This is likely not a realistic reflection of daily life, and we do not know whether these responses persist when…
A Collaborative, Multi‐Institutional Growth Standard for Dam‐Reared Infant Rhesus and Pigtail Macaques ( Macaca mulatta and Macaca nemestrina ) in Research Settings
A multicenter study was undertaken to generate new weight‐for‐age growth standards to monitor the growth of infant rhesus and pigtail macaques in research breeding colonies. Previously, single institutions have developed reference growth curves, under the assumption of linear growth, for infants raised in certain settings with a limited scope of benefit to outside institutions. Weight and health records from seven research institutions across the…
Primate Behavior and Ecology (23 works) · Biology (17 works) · Psychology (14 works) · Ecology (10 works) · Computer Science (9 works) · Primate (9 works) · Zoology (7 works) · Animal Behavior and Welfare Studies (6 works) · Social Psychology (6 works) · Human-Animal Interaction Studies (5 works)