Field Notes #18: The Burning Question

Text by Hannah Hilden-Reid

We are now roughly one year out from the start of our project at the Akaka site, in Ranomafana National Park (RNP), Madagascar. It has been an incredible year, filled with a plethora of challenges but always coupled with some really amazing successes. This project, aimed at examining the impact of fire disturbance on faunal species residing within fire-sensitive ecosystems, began in June of 2025. We aim to investigate the ecological impacts of fire on Eulemur rubriventer (red-bellied lemur) and Eulemur rufifrons (red-fronted brown lemur), both medium-bodied, frugivorous, arboreal, and cathemeral primates endemic to Madagascar. We are hoping to learn more about how this major fire event influences these sympatric lemur species’ feeding behavior, movement ecology, and activity patterns within RNP’s Akaka site, beginning five months post-fire and continuing for approximately 18 months. Short-term observations will generate insights into direct behavioral shifts, while long-term monitoring will inform our understanding of population-level dynamics and potential mechanisms for forest recovery. Akaka has experienced a series of disturbances for decades; at present, it consists primarily of secondary forest having been impacted by logging, mining, human settlement, previous fires, and a high prevalence of invasive plant species. Unfortunately, pre-fire baseline data are unavailable for the Akaka site, but we are aiming to assess our findings relative to those of E. rubriventer and E. rufifrons groups at Valohoaka, a second site within RNP representing undisturbed primary forest, which will serve as a pseudo-control for this study.

Local village of Vohiparara, located near the Akaka Site in Ranomafana National Park, Madagascar.

In June of 2026, our first order of business was creating our amazing team: our research assistant, Naly; our two Centre ValBio (CVB) technicians, Manana and Vololona; our two local Vohiparara guides, Nirina and Gerard; and our highly skilled (and very patient) CVB cook, Njato. With our team assembled, we made our way into the forest, searching for a suitable camp deep enough into the forest, just outside of the local village of Vohiparara, in close proximity to known groups of our study species, and nearest to the most recent fire that occurred at the end of 2024 and into early 2025.

Once our tents were up, our tarp-covered kitchen constructed, and our pit toilet dug, it was time to build the infrastructure of data collection. With the expertise of all of our guides, but especially Nirina and Gerard, who were most familiar with the forest, we began constructing our ten one-kilometer transects throughout the area. This process was laborious and tedious, taking an entire twelve-day expedition to complete and resulting in many slips and falls by (almost exclusively) me. But once completed, we were able to effectively perform our faunal transect and phenology surveys. Additionally, we constructed sixty vegetation plots in an effort to measure forest composition, structure, and regeneration in this period post-fire.

Akaka Site impacted by recent fire and former illegal mining efforts

We were also getting our feet wet with polishing our focal follow and scan sampling protocols of the resident lemur groups in the area, with each field team member playing a different role in the process (GPS tracking, data recording, lemur locating, plant identification, and feeding-tree tagging). Finally, in August of 2025, we welcomed the GPS collaring team, led by veterinarian Haja, with extensive experience collaring lemurs all over Madagascar. His veterinary team, accompanied by representatives from CVB, Madagascar National Parks (MNP), and CAFF/CORE (Malagasy research oversight committee), were successful in capturing and affixing GPS collars to six lemurs at Akaka (four E. rubriventer and two E. rufifrons). These collars will be used to record GPS locations and acceleration events over 24-hour periods, allowing us to measure daily and nightly travel distance, activity rates, and Autocorrelated Kernel Density Estimation (AKDE) of home ranges across spatial and temporal scales.

Furthermore, we have successfully mapped the burn boundary in the northern portion of the field site using our GPSs. This mapping allows us to delineate the unburned area from the burned area, compare vegetation structure inside and outside the burned zone, and plan future sampling and monitoring within this boundary.​

Severe damage to vegetation in the wake of the Ranomafana Fire occurring late December of 2024 into early January 2025

Unfortunately, we have documented several threats to biodiversity during our fieldwork. These include fire impacts, including substantial vegetation loss, canopy thinning, and reduced ground as well as canopy cover. We also recorded signs of human activity, including novel footpaths, cut vegetation, and active gold mining holes. Additionally, the site shows a high abundance of invasive species, most notably strawberry guava (Psidium cattleianum). We will continue to document these ongoing threats as our study continues.
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We are officially approaching our twenty-ninth expedition, with the hope of continuing this study to the end of the year. I could not be happier with the progress we have made and can’t wait to see what we ultimately discover! It has been a pleasure to be a guest in this unique and magical place, surrounded by some of the most extraordinary wildlife and people. ​