Tag: Colin Brand

The Effect of Visitors in Comparison to the Effect Of Keepers On Zoo-Housed Chimpanzees and Mandrills at the Oregon Zoo

Presenter(s): Nora Sawyer − Anthropology

Faculty Mentor(s): Frances White, Colin Brand

Poster 129

Research Area: Social Science

Captive primates can interact with or be affected by either caretakers or visitors. These interactions may have a positive, neutral, or negative effect on individual animals. Most research on this topic has focused on the interaction between animals and visitors, with many studies finding an overall negative impact of zoo visitors on individual welfare. However, a few studies have also demonstrated no effect or even positive effects of visitors and visitor interactions. This research project uses continuous focal animal sampling to measure the effects of keeper and visitor presence on four chimpanzees (Pan troglodytes) and four mandrills (Mandrillus sphinx) at the Oregon Zoo. Behaviors that are typically considered to be indicative of stress or negative welfare, including pacing, rocking, and hair plucking will be recorded. Crowd size and interactions with visitors will be classified as positive, negative, or neutral. I predict that larger crowd sizes will be associated with high frequencies of negative welfare indicators. Additionally, keeper presence and interactions will reduce the occurrence of these indicators.

Abundance, Density, and Diet of Duikers at Lomako, DRC

Presenter(s): Troi Feinberg − General Science

Faculty Mentor(s): Frances White, Colin Brand

Poster 65

Research Area: Natural Science

Duikers are a widespread family of tiny forest-living antelope that occur across sub-Saharan Africa. While approximately 22 species have been identified, little is known about the biology and behavior of many of these species due to their solitary and reclusive nature. Additionally, these species are sensitive to human disturbance and are often among the first species to be hunted and relocate. The objective of this study was to characterize the abundance and density of duikers inhabiting the forest near the N’dele field site in the Lomako Forest Reserve, Democratic Republic of Congo. Auditory or visual observation of duikers was recorded using all-occurrence sampling over nine months from 1983-1984. We also analyzed stomach contents of animals taken by hunters from outside the study area to gain insight on their diets. We encountered three species of duiker at the field site: Cephalophus weynsi, Cephalophus silvicultor, and Philantomba monticola. We detected C. weynsi 63 times, C. silvicultor once, and P. monticola 35 times. A preliminary estimate of overall density was 4.075 per sq. km. across all species. This result is comparable to duiker densities in other protected areas. Analyses of stomach contents (N=6) revealed that C. weynsi consumed at least 23 different plant species, including the following most prevalent food items: Celtis tessmanii, Dialium sp., and Landolphia congolensis. These data contribute to our broader understanding of duiker biology and are useful for monitoring trends in population size and density at this location over time.

Dominance Hierarchies Are Not Linear in Semi-Free Ranging Black and White Ruffed Lemurs (Varecia variegata)

Presenter(s): India Brock − Biological Anthropology, Environmental Science

Co Presenter(s): Nora Sawyer

Faculty Mentor(s): Frances White, Colin Brand

Poster 6

Research Area: Primate Behavioral Ecology

Dominance rank and the linearity of social hierarchies have important consequences for social behavior in many species, including many primates. Of particular interest are lemurs, which are the only taxonomic primate group that exhibits female feeding priority and social dominance in multiple genera, including Varecia. Previous research has revealed significantly linear dominance hierarchies in some female dominant species (Lemur catta) but not others (Propithecus verreauxi). Here, we investigate the dominance linearity of another female dominant lemur species: the black and white ruffed lemur. We predicted the dominance hierarchy to be significantly linear both before and after rank changes. We collected behavioral data on semi- free ranging ruffed lemurs (N=8) housed at the Duke Primate Center. We used all-occurrence sampling to record interactions between individuals between Sep 1991 and Mar 1993. We constructed dominance matrices using decided interactions and split the data into one of three time periods based on the eviction of a dominant female. We calculated the dominance linearity (h’) for each time period. Contrary to our prediction, we found no significance difference in linearity across any of the time periods: Pre-Event (h’=0.37, ns), Event (h’=0.33, ns) Post-Event (h’= 0.33, ns). This study demonstrates that ruffed lemurs exhibit a more shallow hierarchy more similar to P. verreauxi than to L. catta.

Niche Separation Between Three Sympatric Lemur Species at Berenty Reserve, Madagascar

Presenter(s): Erick Wonderly

Faculty Mentor(s): Frances White & Colin Brand

Poster 50

Session: Sciences

One of the central goals of ecology is to understand niche differentiation: how different species use the same environment in different enough ways so as to coexist. Typically, this is tested by examining dietary overlap between species. The Lemuriformes, lemurs and their relatives, provide an interesting test of niche differentiation given the antiquity of this superfamily and subsequent adaptation to various unoccupied niches. In this study we first tested for dietary overlap in feeding ecology among three lemur species: Ring-tailed lemur (Lemur catta), Verreaux’s sifaka (Propithecus verreauxi), and Brown lemurs (Eulemur fulvus rufus), at Berenty Nature Reserve, Madagascar. We also considered the degree to which species can monopolize a food source from other species. We analyzed 1,988.16 hours of feeding and social behavior data collected by Alison Jolly between 1988-89 and 1992-93. We found consistent, substantial overlap in the diets of all three lemur species across all four study periods. The majority of aggressive intergroup encounters were within species. Between species encounters rarely resulted in aggression and exclusion from a feeding patch. Collectively, these results suggest greater dietary overlap than previously considered in these taxa and that niche separation beyond lemurs occurs beyond feeding contexts.

Reliability and accuracy of post-mortem methods of manual 2D:4D assessment in primates Kendall Soriano, Sarah Brown, Enrique Gomez, Colin M. Brand, Frances J. White

Presenter(s): Kendall Soriano

Co Presenter(s): Sarah Brown

Faculty Mentor(s): Frances White & Colin Brand

Poster 31

Session: Sciences

The ratio of the length of the second to the fourth digitis[AH1] related to levels of prenatal hormone in exposure, specifically testosterone. A lower 2D:4D ratio indicates higher levels of prenatal androgen exposure, and a higher ratio indicates lower levels. Digit length is typically measured from the proximal crease to the most distal end of the digit in living and post-mortem individuals. However, post-mortem processes such as desiccation or decomposition can affect both landmark identification and accuracy of the measure. Digit length can also be measured on osteological specimens, but there is little information on how these measures compare to post- mortem measures. This study compares post-mortem measurements with osteological measurements taken on the same specimens. Here, we compared these measures across multiple primate species (N=40. We also examined the 2D:4D ratio in a macaque foot. First, using a caliper, measurements of the 3 segments in each digit were taken of a fully fleshed foot. Then, after removal of skin and flesh, measurements were taken of bones and tendons. Lastly, measurements of only bones were recorded after removal of tendons. This technique was shown to be an effective way of analyzing digit measurements as the results indicate clear differences in the ratio of digit sizes. This study demonstrates that the disarticulated measurement is the most accurate osteological method of estimating post-mortem 2D:4D. We want to take our knowledge of the relation between 2D:4D ratio and prenatal hormone exposure and apply it to across various other primate species.

Literature Review: The Abundance and Density of Duiker in Lomako, DRC

Presenter(s): Troi Feinberg

Faculty Mentor(s): Frances White & Colin Brand

Poster 130

Session: Social Sciences & Humanities

Duikers are a widespread family of tiny, forest-living antelope that inhabit sub-Saharan Africa. While approximately 22 species have been identified, little is known about the biology and behavior of many of these species due to their solitary and reclusive nature. Additionally, these species are sensitive to human disturbance and are often among the first species to be hunted and relocated. Population density estimates relate to how a population responds to anthropogenic, biological, and environmental factors. Duikers play a vital role in the ecological health of the forest environment they inhabit as active seed dispersers. Therefore, duiker population density also correlates with the forest health of that tropical region. From 1983-1984, we characterized the abundance and density of duikers inhabiting the forest near the N’dele field site in the Lomako Forest Reserve in the Democratic Republic of Congo, using all-occurrence sampling with standard line-transect methodology. A preliminary estimate of an overall density of 2.46 per sq. km. across all species. We examined scientific reports to conclude why the duiker population in DRC was lower than other populations in nearby regions during 1983-1984: the behavioral crypticity of the species, hunting trends in wildlife and local communities, and cross section of demographic changes over several decades. Monitoring trends such as population size and density of duikers gives insight on how human disturbance affects these animals’ behaviors and contributes to future conservation plans for the species

Dating App Use Is Associated with Less Sexual Restrictedness in Both Men and Women

Presenter(s): Mariah Bloom

Faculty Mentor(s): Lawrence Sugiyama & Colin Brand

Poster 107

Session: Social Sciences & Humanities

30 million Americans use dating technologies. Location-based real time dating (LBRTD) apps (e.g., Tinder) allow users to access photos and short profiles of potential mates in real time, indicate interest, and communicate and arrange meetings if desired. Sexual strategies theory posits humans evolved multiple mating strategies, contextually deployed based on relevant costs and benefits. We hypothesized LBRTDs alter perceived costs and benefits of different mating strategies, leading to different patterns of sexual behavior. We administered a Qualtrics survey to UO undergraduates about dating app usage, and measures including sex, STMs, LTMs, perceptions and their Socio-sexual Orientation (SOI, indicative of STM (high SOI) vs LTM (low SOI) attitudes, preferences, and behaviors). Responses of self-identified heterosexual respondents (N=126) were analyzed. General linear models show app use associated with higher SOI (β = 0.09, p < 0.001), but not sex or self-perceived attractiveness. Number of STMs was higher for males than females (β = 4.82 p < 0.05), and positively related to SOI (β = 0.09, p < 0.01). Conversely, SOI was a negative predictor of LTMs (β = -0.04, p < 0.05). App-using men had more STMs and LTMs than non-app users. Women app users and non-users did not differ in STMs or LTMs. Thus we find mixed support for our predictions. Because sample women are near peak fertility, with high mate value, they likely can act on short-term mating desires regardless of dating app usage.