Tag: Frances White

Male Affiliation as an Alternative Mating Strategy in Japanese Macaques

Presenter: Katherine Jones − Anthropology

Faculty Mentor(s): Frances White

Session: (In-Person) Poster Presentation

In non-human primates, dominance is often considered the primary strategy for securing mating opportunities. However, while dominance is certainly an influential factor in an individual’s reproductive success, the ability to form and maintain strong social relationships serves a similar purpose, especially for those individuals who are unable to hold a high dominance rank. Social bonding is predictive of cooperation, higher rates of tolerance, lower rates of aggression, and reproductive success. Japanese macaques (Macaca fuscata) form complex inter-male social networks, with an individual’s position in the network potentially impacting their reproductive success. In this study, we aimed to examine the inter-relatedness of dominance, positive male-male relationships, and reproductive success. Using behavioral data collected at the Oregon National Primate Research Center, we calculated simulated rank orders and constructed social networks based on grooming interactions between adult males. We then investigated correlations between the number of infants a male sired and the male’s age, dominance rank, and social network positionality. Although the most dominant male was more reproductively successful than many lower-ranking individuals, the male with the most offspring was one who had a more central position within the social network. These findings offer a preliminary model for better understanding male social bonding as an alternative mating strategy.

Intragroup Dominance Hierarchies of Domestic Female Llamas in a Long-Term Herd

Presenter: Skye Grubb − Anthropology

Faculty Mentor(s): Larry Ulibarri, Frances White

Session: (In-Person) Poster Presentation

This study examines the presence of a dominance hierarchy among females of an established domestic llama herd. To examine this, a group of thirteen female llamas and one male cria were fed high-quality food in clumped distributions. Their agonistic interactions were observed and recorded using a continuous recording method separated into one minute intervals, as well as a combination of focal animal sampling and scan sampling. A variety of factors including age, long-term health, established time within the herd, proximity, size, frequency of aggression, and reproductive success were examined regarding contribution to the linear dominance hierarchy. Centrality and physical positions within the herd social structure were also considered during analysis of rank. Upon the construction of the original dominance hierarchy, tests of linearity were performed to establish the potential of reversals and changes in the hierarchy over the period of roughly six months. A fairly linear dominance hierarchy has been constructed, showing three distinct groupings of females in terms of general proximity. The majority of reversals occurred in the higher positions of the hierarchy, with individuals lower in the hierarchy interacting aggressively only minimally.

Left Handedness in a Captive bonobo Group

Presenters: Tabatha Rood, Klaree Boose and Frances White

Mentor: Frances White

PM Poster Presentation

Poster 40

Handedness in great apes is related to laterality and cognitive development. Previous studies report a right-handed bias in 9 ape studies. This study observed a group of 16 captive bonobos (Pan paniscus) at the Columbus zoo that was presented with an artificial, baited termite mound. Data was collected from narrated video tapes taken June 29, 2011 – August 31, 2011. Handedness was recorded for 592 fishing and poking bouts by 14 bonobos. Following prior studies, handedness was defined from the percentage of bouts that were done with only the left hand, with 60% or more being left-handed and 40% or less being right-handed. This study group showed a left hand bias among individuals; 9 with left-handed bias (66.7% to 100% of tasks) and 6 with right-handed bias (39.4% to 0% of tasks). The group showed more left-handed (n=311) than right-handed (n=281) bouts, with 93 bouts involving both hands. Right-handed bouts were longer in duration, averaging 113 seconds, with left-handed bouts averaging 79 seconds. The frequency of left and right-handed bouts by individuals was compared to an expectation calculated from the 60% right-handed and 40% left-handed criteria from previous studies using a Replicated Goodness of Fit test and found to be significantly different (G=37.743, p<0.001) with significant heterogeneity (G=171.649, p < 0.001). We conclude that this group of bonobos is predominantly left-handed.

Variation of Dental Calculus in Captive Macaques

Presenters: Colin Oliveira, Daniel Vermillion and Lauren Moore

Mentor: Frances White

PM Poster Presentation

Poster 34

Dental calculus in nonhuman primates varies with diet, ecology, and immune health. As in humans, monkeys with excessive dietary carbohydrates can accumulate calculus buildup over time, although there is little information on variation of this dental pathology within nonhuman primates. Focusing on the variance between sexes and species, we scored the presence and severity of dental calculus in 91 skeletal specimens of captive adult Macaca mulatta (N=33) and Macaca fascicularis (N=58). An adult only sample was established to partially control for variance in calculus due to age, adult defined as erupted M3. Calculus was scored on each tooth from 0 to 3, with 0 as “none present” and 3 indicating “over 50% of surface affected”. Each side was scored independently. Missing teeth were evaluated for apparent causation of tooth loss. Most teeth exhibited some degree of dental calculus, but all four incisors were the most heavily calcified in both species. The anterior labial surfaces were the most impacted. The frequency of premortem canine removal in our sample prevented us from examining this trait in neighboring dentition. The least calcified were the M3s, probably due to the difference in eruption time between the incisors and the molars. We performed a one-way ANOVA on the total sample, and found no significant difference in calculus buildup between females and males for either species. We did find differences between the two species (F = 27.63, p<0.0001) with M. fascicularis exhibiting significantly more calculus.

Pace of Early Epiphyseal Fusion in Captive Macaca

Presenters: Samantha Buckley and Sarah Walker

Mentor: Frances White

PM Poster Presentation

Poster 6

Epiphyseal fusion is an important developmental indicator in all mammals. Among cercopithecids, the sequence of epiphyseal fusion is known but the pacing of these fusions is uncertain. The pace at which the fusion occurs is a window into the growth of an animal that the fusion sequence alone cannot provide. The pace and sequence of epiphyseal fusion in long bones are reported here from a sample of 23 Macaca mulatta from the UO Grand collection, consisting of captive juveniles of known age. We scored 33 epiphyses on 25 bones, including all major long bones, the pelvis, and metapodials. We scored the epiphyses as “0” if there was no fusion, “1” if the joint is fusing, and “2” if the epiphysis has completely fused to the diaphysis. All specimens were scored by two coders to ensure intercoder reliability. Only scores with full agreement were included. Because we scored epiphyses in the process of fusing, we are able to comment on the pace of fusion within M. mulatta more than previous studies. Results indicate that metapodial fusion has begun by birth, but continues to fuse until 60 months. Our only explanation for their typical exclusion from fusion charts is because metapodials fuse so early. Addi- tionally, by twelve months, five other epiphyses have begun to fuse: proximal and distal humeral epiphyses, proximal tibia, femoral head, and the greater trochanter. Our results agree with those previously reported by Cheverud (1981). Our sample is younger, allowing us to add new data especially on metapodial fusion.

Evaluating 2D and 3D Methods of Measuring Fluctuating Asymmetry of Primate Skulls

Presenters : Colin Oliveira, Lauren Moore

Mentor : Frances White

Major : Anthropology

Poster 36

Morphological fluctuating asymmetry (FA), particularly cranial FA, can be used as an indicator of past developmental instability or environmental stress. Primate FA has been measured using a variety of two and three dimensional methods either directly from speci- mens or from images. We compared the effectiveness of three methods of calculating FA: Microscribe readings of three dimensional landmarks on the specimen, two dimensional landmarks measured from photographic superimposition using tpsDig, and linear distances using digital calipers on the specimen. Three observers used each of the three methods on two Macaca fuscata skulls, one that appeared asymmetrical and one that appeared symmetrical, using 5 midline points and 7 bilateral points for 5 replicates. Measure- ments taken by each method were compared between the two specimens. Measurement in 3D space via Microscribe exhibited no sig- nificant interaction term, no significant difference between observers (F=1.22, df 2,24, p=0.3119), and significant difference between specimens (F=5.56, df 1,24, p<0.05). Measurement of 2D distances from photographs via tpsDIG exhibited no significant interaction term, significant difference between observers (F=9.78, df 2,24, p<0.001), and significant difference between specimens (F=10.80, df 1,24, p<0.01). Measurement of linear distances via digital calipers exhibited no significant interaction term, no significant difference between observers, and no significant difference between specimens.

Sutural Methodology for Determining Age in Rhesus Monkeys (Macaca mulatta)

Presenter: Julia Arenson

Mentor: Frances White

Poster: 1

Major: Anthropology 

Cranial sutures are frequently used to determine age in forensic and bioarchaeological contexts. However, these methods are mostly only utilized in human populations, and a lack of comparative data for non-human primates makes visualizing the evolution of growth patterns difficult. This project documents cranial suture fusion in rhesus monkeys (Macaca mulatta) as a marker of development. To develop a standardized methodology, I used Meindl and Lovejoy’s (1985) established 0-3 point scale for human ectocranial fusion, and scored sutures all over the cranium that were included in Wang et al.’s research (2006). My sample included osteological specimens with known ages from the UO Comparative Primate Osteological Collection, ranging from 0 to over 14 years, totaling15 specimens (5 females and 10 males). Total percentage fusion of each region of the skull, divided into facial, neurocranial, and basicranial regions, revealed which areas correlated positively with age, while analysis of scoring precision over 10 trials of the same specimens showed which sutures were not scored reliably. Sutures on the neurocranium and face gave the best age correlates, while sutures within the eye orbit and the squamosal suture were not consistently scored. To best estimate the age of an osteological specimen, the findings suggest a focus on sutures of the face and neurocranium. Developing comparative methods to evaluate growth patterns can allow researchers to identify the changes and consistencies of important life history events within both human and nonhuman primate evolution.

Variability Selection Hypothesis, Weed Macaques, and Body Size Variance

Presenter: Harry Sullivan

Mentors: Andrea Eller and Frances White, Biology

Poster: 61

Major: Biology 

Variability Selection Hypothesis (VSH) proposes that early Homo gained adaptive benefit from being flexible in novel or unpredictable climates. Increased intra-taxon variation in body size and the expansion of geographic ranges in early Homo populations suggests greater phenotypic and developmental plasticity. Similar levels of ecological flexibility have been documented in some species of macaques, earning them the moniker of “weed species”. We compare body size variance between weed and non-weed macaques to determine whether intrataxon variation in body size positively correlates with ecological flexibility, as proposed by the VSH. We used two sources of body size data for all available taxa: original data on postcranial osteological body size estimators (seven species, n=49), and published body masses for nineteen species. Fourteen osteometric body size estimators on the humerus, radius, ulna, femur, and tibia were included. All estimators show a tight correlation with body mass: R2 values range from 0.79 to 0.95 with a mean of 0.9. Variance per estimator per species was calculated, as proxies for body mass variance. Averaged estimator variances in non-weed species range from 1.71-11.34, but only 2.26-4.36 within weed species. This data analysis indicates that weed macaques do not exhibit more intrataxon body size variance than non-weeds. Macaques are under-utilized ecological referents for human evolution, and this genus’ diversity is informative for understanding the role of adaptive flexibility in primate evolution generally.

Normal as Found: Opportunities and Challenges in Developing a Necropsy Protocol for Evolutionary Veterinary Medicine

Presenter: Carly Pate

Co-Presenters: Andrea Eller and Ulirike Streicher

Mentors: Frances White and Lawrence Ulibarri, Anthropology

Poster: 50

Major: Anthropology and General Science

Evolutionary veterinary medicine is a burgeoning field, applying evolutionary perspectives to comparative and veterinary data. Because evolutionary research focuses on natural variation across species, veterinary medicine is
an obvious partner for understanding nonhuman anatomy. To meet this goal, cross-disciplinary work is required, but we need to be able to compare and exchange data. Utilizing the comparative collections in the University of Oregon Primate Osteology Lab, and in collaboration with both an evolutionary biologist and a wildlife veterinarian, we present a protocol that is designed for many vertebrate species and includes procedures for collecting normal and pathological variation. Published necropsies are surprising rare. Veterinary necropsies tend to be pathology- based, whereas anthropologists’ are focused on normal variation within and between species. The protocols cited and described in veterinary medicine tend to be particular to a single species and do not document repeatable procedures. Anthropological research tends to focus solely on the anatomical area of interest. We are developing a protocol using a uniform and explicit technique, so that the data can be analyzed and compared across disciplines. We pay particular attention to tissues that have evolutionary significance in their degree of variance like fat, skeletal muscle, brain weight, gastro-intestinal tract and bone. We include placental mammals, marsupials, and reptiles in our initial phase of data collection. This protocol will be utilized for ongoing comparative research.

An Interspecific Comparison of Variance in Sex-Based Developmental Markers

Presenter: Kyle Morley

Mentors: Andrea Eller and Frances White, Anthropology

Poster: 47

Major: Anthropology 

Sexual dimorphism varies with the degree of male-male competition among primates. Changes in body size of both sexes are well known during ontogeny, but less is known about how osteological developmental markers vary under differing levels of sexual selection. Male-male competition is reflected in a species’ body size sex ratio: humans are reported to have a 1.2 ratio, while rhesus macaques have a 1.6 ratio. We predict greater results for larger bodies and canines in macaque males compared to macaque females and humans as well as greater growth marker variation among macaque males than in these other groups. We documented dental eruption and epiphyseal fusion in 292 macaque skeletal specimens and compared the data to over 25,000 individuals using published human population data. Two-way ANOVAs without replication were used to test whether species had similar variation in dental eruption and fusion time. The two species had significantly different eruption variation (males F=33.71, df=15,1, p <0.0001; females F=119.06, df =15,1, p <0.0001) with macaques more variable than humans. Both species also had different ranges in fusion time (F=7.28, df=13,1, p <0.05) with macaque males more variable than human males. The results support our prediction that macaque males show the greatest variation in these growth markers. Interspecies comparisons of developmental plasticity, such as this study, allow for inferences on how growth variation is affected by sexual selection.