Tag: Stephen Frost

Comparison of Measures of Inter-individual Affiliation among Ring-Tailed Lemurs (Lemur catta)

Presenter: Leslie Gotuaco

Mentors: Stephen Frost and Frances White, Anthropology

Poster: 25

Major: Environmental Science 

Primatologists use a number of behavioral measures to assess patterns of affiliation and aggressions in groups of primates. These patterns can, however, vary greatly within a species with behavioral context. Lemurs, for example, are well known for the importance of context in the variation of aggression in feeding and non-feeding contexts as seen in both female dominance and female feeding priority. This study examined whether there are also variations in affiliation between feeding and non-feeding contexts. One of these measures, grooming, is widely accepted as a mechanism for social bonding, but it is not an appropriate measure for affiliation during feeding. We therefore used co-feeding as a measure of affiliation during feeding. We then used a non-parametric multivariate statistical comparison to see if the patterns of affiliation are consistent between these two contexts. We studied a group of semi-free-ranging ring-tailed lemurs on St. Catherine’s Island, Georgia and collected 188 hours of behavioral data. Observations used focal animal sampling and all occurrence sampling of social behavior. We calculated indices for grooming and co-feeding for all possible pairs of individuals. A Mantel test was used to determine the correlation between the two affiliative measures. We found a significant correlation between our measures (r = 0.7509, t = 8.635, p < 0.0001). These results demonstrate that affiliation patterns seen in non-feeding contexts are consistent with affiliation during feeding.

Captive Female Bonobos (Pan paniscus) Tend to Be More Social during Tool Use than Males

Presenter: Daniel Goodkin-Gold

Mentors: Stephen Frost and Frances White, Anthropology

Poster: 24

Major: Anthropology 

Tool use occurs in several non-human species. Within the genus Pan, chimpanzees (P. troglodytes) exhibit tool use in both the wild and captivity. Tool use in bonobos (P. pansiscus) has been documented in captivity and suggested to occur in the wild. Recent comparative studies of chimpanzees and gorillas propose that social tolerance may facilitate the acquisition of tool use behavior. We previously reported that captive bonobos use tools in smaller social groups than gorillas and chimpanzees, which suggests that the number of neighbors does not play an integral role in tool use acquisition in bonobos. Here we investigate sex and age differences in these small social groups. Data were collected between June and August 2011. Subjects were 16 bonobos housed at the Columbus Zoo and Aquarium, where an artificial termite mound was placed in their outdoor exhibit and baited daily. All occurrences of tool use at the mound and of the individuals present were videotaped and coded. Party size and composition were later determined for each fishing bout. Females fished in larger groups (avg.=1.8 individuals) than males (avg.=1.3 individuals) (n=9, F=4.38, p<0.05). While there was no difference between adult and subadult males, adult females fished in significantly larger groups than subadult females (n=5, F=26.03, p < 0.0001). These results support previous knowledge of bonobo sociality in that females are more socially cohesive and males tend to be more solitary.

Comparing Morphometric Methods in Macaca mulatta crania

Presenter: Rachel Glenzer

Mentors: Stephen Frost and Frances White, Anthropology

Poster: 23

Major: Biological Anthropology 

We compared the precision of a relatively new method for collecting three-dimensional landmarks, 3D photogrammetry with Agisoft Photoscan, to that of two other well-known methods: Microscribe 3DX and Nextengine Laser Scanner. Landmark editor was used to place landmarks on laser and photoscans. Two crania (one male, one female) of Macaca mulatta from the University of Oregon Comparative Primate Collection were digitized by two users, (RG) and (KC), who each collected 10 replications with all three methods using a well-established 45 landmark protocol. The 120 replications were then analyzed with generalized Procrustes analysis (GPA) in Morpheus with scale restored. An external scale factor was applied to the photoscans to make them consistent. To assess the overall magnitude and patterning of the three different methods, the Principle Component Analysis (PCA) and scores were compared. PC 1 (46 % variance) separated the two specimens. PC 2 (16 % variance) separated the two specimens by user. PC 3 (6 % variance) sorted the Microscribe from the other methods. There is some significant separation within user based on method (P < .0001), but this was much smaller in magnitude than the other factors. Among the three methods, the laser scans had the best precision (0.42 mm), followed by photoscans (0.67 mm), and least precise was microscribe (0.62 mm). Our results indicate that photoscan is as precise as well-known methods.

Morphological Signals and Mating Systems: Comparing Measures of Cranial Fluctuating Asymmetry and Second-to-Fourth Digit Ratio in Primates

Presenter: Kelsey Clarke

Mentors: Stephen Frost and Frances White, Anthropology

Poster: 12

Major: Anthropology

Fluctuating Asymmetry (FA) has been hypothesized to be related to testosterone levels and mating strategies; typically males are more asymmetrical than females. Second-to-fourth digit ratio (2D:4D) is correlated with developmental testosterone levels. Using 2D:4D and cranial FA from 19 primates, we compare the relationship between these variables to their respective mating systems. Forty-five landmarks were digitized using a Microscribe- 3DX© for 345 male and 307 female crania. Cranial FA was measured by calculating the Procrustes’ distance between each individual and its mirror-image. Mating systems, classified by intensity and frequency of male aggression, and sex-specific 2D:4D were taken from published studies. Cranial FA and 2D:4D were compared using parametric correlation. Two-way ANOVA of sex and species with a priori multiple comparisons between mating systems was used to examine variation in individual FA. Cranial FA and 2D:4D were correlated (r=-0.460,P<0.05). Cranial FA significantly differed among species (F=64.84,N=19,P<0.05), but there was no difference between sexes (F=1.08,ns) and no sex-species interaction (F=1.24,ns). Multiple comparisons grouping species by mating systems within this ANOVA showed significant differences between pair-bonded and non-pair bonded (F=30.79,P<0.05), between low intensity and high intensity (F=136.76,P<0.05) within non-pair bonded, and between low frequency and high frequency (F=154.62,P<0.05) within high intensity and non-pair bonded. These results support the hypothesis that cranial FA is correlated with testosterone and the variance in male aggression among mating systems.

Bergmann’s Rule in Skull Size and Clinical Variation in Skull Shape of Wild Versus Captive fascicularis Group Macaques

Presenter: Julia Arenson

Mentors: Frances White and Stephen Frost, Anthropology

Poster: 1

Major: Anthropology

Bergmann’s rule predicts that body size increases with distance from the equator. This pattern has been noted in wild macaque populations, but relocated captive populations have not been examined for this cline. Captive populations provide an opportunity to analyze whether Bergmann’s rule is influenced more by natural selection or phenotypic plasticity. Forty-five 3D cranial landmarks were collected using a Microscribe-3DX on a sample of 251 adult crania of wild Macaca fascicularis, M. cyclopis, M. fuscata and M. mulatta with known provenience, as well as 18 captive M. mulatta from Beaverton, OR (lat=45.5) and 40 from Cayo Santiago, Puerto Rico (lat=18.2). Cranial centroid size was calculated for each specimen as a proxy measure of body size. The covariation between shape and geography was assessed with a 2-Block Partial Least Squares (2B-PLS) analysis. Regression analyses were used to predict the expected latitudes for the captive samples based on size and shape. For wild macaques, distance from the equator was significantly correlated with both size (males R2=0.370; p=0.00; females R2=0.475; p=0.00) and shape (pooled sex R2=0.51, p=0.00). Predicted latitudes based on cranial sizes (Beaverton=38.0; Cayo Santiago=44.9) were higher than the current captive locations but were lower when based on shape (Cayo Santiago=13.3; Beaverton=8.5). These results suggest the latitudinal pattern of skull shape and size in wild fascicularis group macaques is more influenced by phenotypic plasticity than natural selection.

Measuring Finger Ratios in Hands and Bones: Testing the Reliability and Accuracy of Post-mortem Methods of Second-to-Fourth Digit Ratio Assessment in Primates

Presenter: Josie Beavers

Co-Presenters: Enrique Gomez

Faculty Mentor: Frances White, Stephen Frost

Presentation Type: Poster 46

Primary Research Area: Science

Major: Biological Anthropology

The ratio of length of the second digit to fourth digit indicates individual exposure to gonadal hormones in utero (Manning 2002). 2D:4D is therefore used as a proxy for prenatal androgen exposure; a lower 2D:4D indicates more prenatal androgen exposure, and a higher 2D:4D indicates less prenatal androgen exposure (Manning 2002). The most accurate way to measure 2D:4D is to measure from the proximal crease to the most distal end of the digit in living and recently deceased individuals (Manning 2002). However, in many cases an individual may be mummified or decomposed prior to measuring 2D:4D. Our research seeks to determine the accuracy of different 2D:4D measurement methods by comparing obtained 2D:4D values from the fully fleshed, skinned, disarticulated, and articulated phalangeal bones of the same rhesus macaque individual (Macaca mulatta). We also determined if the position of the hand (i.e. flattened palm or curled fingers) yielded significantly different 2D:4D ratios. Our findings indicate that the 2D:4D values obtained in all flattened measurements closely correlated (r = 0.997 – 0.999), but the measurements obtained from the curled hands were not as closely correlated (r = 0.962 – 0.982). These results suggest that 2D:4D measurements on articulated bones are most closely correlated to the fully fleshed 2D:4D measurement. These findings will allow scientists to more accurately obtain 2D:4D measurements on non-living specimens in the future.

Cranial Morphometric Analysis on Pygathrix nemaeus and Pygrathrix cinerea

Presenter(s): Carly Pate − Anthropology

Faculty Mentor(s): Larry Ulibarri, Frances White, Stephen Frost

Poster 137

Research Area: Anthropology

This study analyzes cranial morphometric distinction between Pygathrix species. Endangered Pygathrix nemaeus and Critically Endangered Pygathrix cinerea are endemic to Southeast Asia. They are threatened with extinction due to hunting and habitat fragmentation. While generally understudied, osteological analysis on these species are also uncommon due to lack of specimen collections or accessibility. Although their ranges partially overlap, it is possible to distinguish species based on genotypic and phenotypic pelage differences. However, distinctions of skeletal morphology have not been quantified. Pygathrix phylogeny has been debated, with a recent cranial morphometric analysis showing no distinction between species detected through linear measures. Using 3D photogrammetric methods and linear measures, cranial data was collected on an osteological collection of confiscated and captive red-shanked doucs, P. nemaeus, (n=43) and grey-shanked doucs, P. cinerea, (n=23), from the Endangered Primate Rescue Center, Cuc Phuong National Park, Vietnam. Five linear cranial measures indicate no sexual dimorphism between P. cinerea males and females, (n=24, n=19) or between P. nemaeus males and females, (n=17, n=6). One linear measure, anterior foramen magnum to the superior most point on sagittal suture, allowed distinction between species among males, (F 4.37, P<0.05) and among females, (F 10.06, P <0.05). These results indicate a cranial morphometric variation among species. Further 3D shape analysis will continue to explore this distinguishability. Intra- and interspecies variation analyzed morphometrically by 3D photogrammetry can aid in understanding the impacts of species- specific factors such as social structure and feeding ecology on cranial morphological variation.

3D GM study of effects of age on cranial shape large-bodied Papionins, using molar wear as a proxy for age

Presenter(s): Andrea Quintanilla—Anthropology

Faculty Mentor(s): Stephen Frost, Evan Simons

Session: Prerecorded Poster Presentation

Primate cranial shape in relation to age, sex and taxonomy is a growing topic of research, with large- bodied Old World monkeys being among the most studied using geometric morphometrics (GM) and used as models for human cranial shape variation . Ontogenetic changes to skull shape from juveniles to adults are well studied, but those that occur during adulthood are less well known: a twenty-year old is still an adult, but their skull could differ in shape compared to that of a sixty-year old . In this project, we used GM and multivariate analyses to observe changes of cranial shape that occur with post-adult aging . Forty-five 3D landmarks were collected with a Microscribe 3DX digitizer on a sample of 347 wild-collected baboon (Genus Papio) crania, and subjected to generalized Procrustes analysis using the Geomorph package in Rstudio; this superimposes the data and standardizes geometric size, but leaves shape differences . The resulting Procrustes shape coordinates were adjusted for size and sex with multivariate regression analysis to mitigate the effects of allometry and dimorphism . These adjusted coordinates were then regressed against upper third molar wear stage as a proxy for age, using multivariate tests for significance . Principal components analysis was used to summarize the resulting shape space . Results demonstrated that there is a significant effect of molar wear stage on cranial shape, even after accounting for size and sex differences, but it is a subtle effect that accounts for approximately 1% of shape variance . In the future, we will investigate causes of this shape change .