The past: Historical mapping project
What can old maps tell us about the future?
For over five decades, researchers in Kibale National Park, Uganda mapped where and how far primates traveled. These hand-drawn maps represent an extraordinary scientific archive, documenting five species - red-tailed monkeys, blue monkeys, grey-cheeked mangabeys, black-and-white colobus, and red colobus monkeys - across two long-term research sites: Ngogo and Kanyawara.
In my dissertation, I focus on reconstructing the movement behavior of red-tailed monkeys. With the help of undergraduate research assistants, I scan, georeference, and digitize historical ranging maps collected between 1970 and 2007, and integrate them with modern GPS data collected between 2007 and 2026. By combining these movement data with long-term climate records and feeding observations collected alongside the original maps, I examine how primates adjusted their home ranges as environmental conditions and population dynamics changes over time.
Beyond this dissertation chapter, we aim to preserve the data of all five species. In collaboration with the computer science department, I am developing a machine learning approach to automate map digitization. This will allow us to expand the project beyond red-tailed monkeys to the other primate species in Kibale - and eventually to additional field sites - making decades of ecological data accessible for future research and conservation.
The present: Predictors of territorial gains and losses in red-tailed monkeys (Cercopithecus ascanius)
Why do some groups expand their ranges while others shrink?
Using GPS data from the Ngogo Monkey Project in Kibale National Park, I examine how the home ranges of red-tailed monkeys change over time. Although primate groups often occupy the same general area for many years, the intensity with which they use different parts of their home range can shift over shorter time scales.
To understand what drives these changes, I analyzed movement, ecological, and behavioral data from six red-tailed monkey groups between 2008 and 2019. I tested whether home range changes were influenced by factors such as group size, resource availability, energy balance, and intergroup encounters with neighboring groups.
The results challenge some traditional assumptions about territorial dynamics. Larger groups tended to lose home range area rather than expand it, suggesting that coordination within large groups may be difficult and can lead to collective action problems. Smaller and intermediate-sized groups were more likely to expand their ranges when ecological opportunities arose.
Together, these findings highlight how social dynamics and group coordination can shape how primates use space, sometimes more strongly than simple numerical advantage. I presented the results of this project as a poster at the Animal Behavior Conference 2023 in Portland and as a conference talk at the Midwest Primate Interest Group (MPIG) Conference 2023. The results are currently in preparation for publication in Animal Behaviour.
The present: Mapping the invisible - Using movement ecology as a window into energetic condition
What does daily movement reveal about an animal's internal internal energetic condition?
In this chapter, I test whether movement behavior can act as a window into energetic condition. Animals must balance energetic costs of locomotion with the benefits of finding food. When energy intake exceeds expenditure, individuals may move more and explore their environment; when energy is limited, they may reduce movement to conserve energy.
To investigate this relationship, I link movement patterns - including daily travel distance, group spread, and individual locomotor effort - to a panel of non-invasive biomarkers that reflect energetic condition, such as urinary C-peptide, ketones, creatinine, nitrogen stable isotopes, fecal glucocorticoids, and thyroid hormones.
I compare red-tailed monkey groups across three Ugandan forest sites that differ in ecological conditions and competition: the groups at Ngogo in Kibale National Park live in prestine forest and experience strong within- and between-group competition, as well as between species competition; the Rwengobe group occupies a regenerating forest fragment in Rwengobe, just outside of Kibale, experiences minimal competition; and the Mabira groups live in a more disturbed forest with intermediate competition between groups and between species. Together, these sites allow me to test how internal energetic condition and external ecological and social pressures interact to shape primate movement.
The future: Movement in a human-altered world
How does human disturbance reshape animal movement?
As forests become fragmented and human activity increases, primates must navigate noise and fragmented habitats. In this chapter, I use satellite imagery, LiDAR forest structure data, and advanced movement models to test how red-tailed monkeys adjust their paths under anthropogenic pressure.
Understanding these responses helps predict which populations are most vulnerable - and which are more resilient.
