Papers by Colleen Schaffner
Proceedings. Biological sciences, Jan 30, 2018
Groups of animals (including humans) may show flexible grouping patterns, in which temporary aggr... more Groups of animals (including humans) may show flexible grouping patterns, in which temporary aggregations or subgroups come together and split, changing composition over short temporal scales, (i.e. fission and fusion). A high degree of fission-fusion dynamics may constrain the regulation of social relationships, introducing uncertainty in interactions between group members. Here we use Shannon's entropy to quantify the predictability of subgroup composition for three species known to differ in the way their subgroups come together and split over time: spider monkeys (), chimpanzees () and geladas (). We formulate a random expectation of entropy that considers subgroup size variation and sample size, against which the observed entropy in subgroup composition can be compared. Using the theory of set partitioning, we also develop a method to estimate the number of subgroups that the group is likely to be divided into, based on the composition and size of single focal subgroups. Ou...
Archives of sexual behavior, 2018
Homosexual behavior is defined as genital contact or genital manipulation between same-sex indivi... more Homosexual behavior is defined as genital contact or genital manipulation between same-sex individuals. In nonhuman primates, it may regulate social relationships by serving as a means of reconciliation, tension alleviation, or alliance formation. Grappling is a rare and complex behavior, which most frequently occurs between same-sex individuals of the genus Ateles and can include mutual manipulation of the genitalia. Here we report three cases of penile-anal intromission during grappling between wild male spider monkeys living in the natural protected area of Otoch Ma'ax Yetel Kooh, Mexico. In all the observed cases, the same adult male was the actor. To our knowledge, this is the first report of penile-anal intromission between males in any New World primate species.
The role of sucrose and sensory systems in fruit selection and consumption of Ateles geoffroyi in Yucatan, Mexico
Journal of Tropical Ecology, 2015
Chapter 7: Causes, consequences and mechanisms of reconciliation: the role of cooperation
Cooperation in Primates and Humans Mechanisms and Evolution 2006 Isbn 978 3 540 28374 4 Pags 121 136, 2006
Meeting the Assumptions: Testing Line-Transect Methodology for Estimating Spider Monkey Density in the Otoch Ma’Ax Yetel Kooh Protected Area
ABSTRACT
Evolutionary Biology: Mechanisms and Trends, 2012
Opsins provide an excellent model system for studying evolutionary interconnections at genetic, p... more Opsins provide an excellent model system for studying evolutionary interconnections at genetic, phenotypic and behavioural levels. Primates have evolved a unique ability for trichromatic colour vision from a dichromatic mammalian ancestor. This was accomplished via allelic differentiation (e.g. most New World monkeys) or gene duplication (e.g. Old World primates) of the middle to long-wavelength sensitive (M/LWS) opsin gene. However, questions remain
Primatology Monographs, 2011
American journal of primatology, Jan 25, 2015
In species with a high degree of fission-fusion dynamics group members may differ in the use of t... more In species with a high degree of fission-fusion dynamics group members may differ in the use of the group home range to reduce food competition. Such differential use may result in distinct individual core areas. We studied core area quality and overlap among 21 female spider monkeys belonging to the same group over a period of 4 years. Core areas ranged between 62 and 161 ha with a mean overlap of 56% between any given two females. Only a small portion (mean = 3 ha) of each individual core area was used exclusively. No single part of the home range was used as core area by all females, and only an area of less than 1 ha was used as part of the core area by 20 of the 21 females. The time a female spent in the group (i.e., group tenure) was associated with characteristics of the core areas: the longer the group tenure, the better the quality of her core area. In addition, the longer the time two females spent together in the same group, the larger the overlap between their individual...
Social interactions, social relationships and the social system of spider monkeys
Behavior, Ecology and Evolution of the Genus Ateles, 2008
Molecular Ecology, 2014
New World monkeys exhibit prominent color vision variation due to allelic polymorphism of the lon... more New World monkeys exhibit prominent color vision variation due to allelic polymorphism of the long-to-middle wavelength (L/M) opsin gene. The known spectral variation of L/M opsins in primates is broadly determined by amino acid composition at three sites: 180, 277 and 285 (the "three-sites" rule). However, two L/M opsin alleles found in the black-handed spider monkeys (Ateles geoffroyi) are known exceptions, presumably due to novel mutations. The spectral separation of the two L/M photopigments is 1.5 times greater than expected based on the "three-sites" rule. Yet the consequence of this for the visual ecology of the species is unknown, as is the evolutionary mechanism by which spectral shift was achieved. In the present study, we first examine L/M opsins of two other Atelinae species, the long-haired spider monkeys (A. belzebuth) and the common woolly monkeys (Lagothrix lagotricha). By a series of site-directed mutagenesis, we show that a mutation Y213D (tyrosine to aspartic acid at site 213) in the ancestral opsin of the two alleles enabled N294K, which occurred in one allele of the ateline ancestor, and increased the spectral separation between the two
Adaptive Explanation for the Origins of the Anthropoidea (Primates) Urinary Steroid and Gonadotropin Excretion Across the
A new explanation for the origin of the primate suborder Anthropoidea is presented. Functional an... more A new explanation for the origin of the primate suborder Anthropoidea is presented. Functional analyses of the forward-facing orbits, postorbital septum and retinal fovea are used to reconstruct the morphological and ecological contexts in which these features are most likely to have ...
Previous studies of wild marmosets and tamarins provide conflicting evidence regarding the nature... more Previous studies of wild marmosets and tamarins provide conflicting evidence regarding the nature of 3 polyandrous groups. One perspective supports a monopolizing strategy on the part of males as only 4 one male is observed to mate when the female is ovulating and it is that male that has a preferential 5 relationship with the female. The alternative perspective suggests that polyandry is facultative as 6 observations indicate that reproductive opportunities occur more or less evenly among the males and 7 no preferential relationship between the males and the female is evident. We tested these competing 8 hypotheses in male marmosets (Callithrix kuhlii) by forming 5 polyandrous groups consisting of 2 9 related males and 1 unrelated female. We monitored male behavior and levels of urinary testosterone 10 (T) and cortisol (CORT) across the first 80 days of group formation and contrasted them with similar 11 measures in males housed in monogamous groups. We found little evidence that males in polyandrous 12 groups exercised a mating monopoly of the female and no evidence for overt competition between 13 polyandrous males. We did find two behavioral differences between the 2 types of males: 14 polyandrous males were less often in proximity and copulated more often with the female than 15 monogamous males. Our findings suggest that polyandry is facultative in newly-formed groups of 16 marmosets. This appears to be the case for three reasons. First, males may use sperm competition 17 rather than overt competition. Second, it may take longer for relationships to develop between the 18 female and the males in polyandrous groups compared to monogamous groups. Thus, there is not 19 sufficient time for a preferential relationship to develop between the female and one of the males. 20 Third, the cost of infant care is sufficiently high to demand that group members 'get along' when 21 groups are small and reproductive benefits are shared. 22 23
Preliminary validation of a cortisol assay in Spider Monkeys at Chester Zoo
3rd Annual Symposium on Zoo Research Preliminary validation of a cortisol assay in Spider Monkeys... more 3rd Annual Symposium on Zoo Research Preliminary validation of a cortisol assay in Spider Monkeys at Chester Zoo 1 2 3 Chester Zoological Gardens, Chester, UK; Department of Psychology, Chester College of Higher Education, Chester, UK; Department of Biology & ...
Aggression and Post-conflict Behavior in Red-bellied Tamarins (S̲a̲g̲u̲i̲n̲u̲s̲ L̲a̲b̲i̲a̲t̲u̲s̲)
Wild and zoo experiences: The benefits of integrating behavioural research from captivity and the field
Fission-fusion societies and cognitive evolution
The context, direction and intensity of spider monkey aggression in zoos
Significance of trichromatic color vision in fruit foraging of spider monkeys [in japanese]. Significado de la visión del color tricromático en el forrajeo de frutas en los monos colorados [en japonés]
1. Editorial: Science in Places Editorial: Science in Places (pp. 539-540)
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Papers by Colleen Schaffner