David Morgan

We present Zamba, an open source Python package designed to streamline camera trap data processing through machine learning. Zamba supports inference and custom model training for species classification on videos and images, as well as depth estimation inference for videos.

Tropical rainforests are complex mosaics of different forests types, each with its own biodiversity and structure. Efforts to characterize and map diversity and composition of tropical forests are vital at both local and larger scales in order to improve conservation strategies and accurately monitor anthropogenic threats. However, despite advances in remote sensing, classifying and mapping forest types remains a significant challenge and remotely sensed classifications in the tropics often treat forests as a single category. Here, we used Sentinel-2 data, and a high-quality ground reference dataset, to map monodominant Gilbertiodendron dewevrei forest, a unique forest type in central Africa. We used a random forest classifier, and spectral, vegetation, and textural indices, to map G. dewevrei forest across the Sangha Trinational, a network of national parks in central Africa. The overall accuracy of our classification was 83% when evaluated against an independently sampled reference test dataset, successfully distinguishing this monodominant forest from the spectrally similar terre firme mixed forest present throughout much of the study area. The gray level co-occurrence matrix (GLCM) textural metrics proved the most important factors for distinguishing G. dewevrei forest, due to the homogenous canopy texture created by this monodominant species. In conclusion, our study illustrates that freely available Sentinel-2 data hold promise for mapping distinct forest types in tropical forests, particularly when they exhibit structural and textural differences, as seen in monodominant and mixed forests, and provided that high-quality ground reference data are available.

How populations adapt to their environment is a fundamental question in biology. Yet, we know surprisingly little about this process, especially for endangered species, such as nonhuman great apes. Chimpanzees, our closest living relatives, are particularly notable because they inhabit diverse habitats, from rainforest to woodland-savannah. Whether genetic adaptation facilitates such habitat diversity remains unknown, despite it having wide implications for evolutionary biology and conservation. By using newly sequenced exomes from 828 wild chimpanzees (388 postfiltering), we found evidence of fine-scale genetic adaptation to habitat, with signatures of positive selection in forest chimpanzees in the same genes underlying adaptation to malaria in humans. This work demonstrates the power of noninvasive samples to reveal genetic adaptations in endangered populations and highlights the importance of adaptive genetic diversity for chimpanzees.

Existing protected areas are anchors for conservation. Safeguarding flora and fauna within their peripheral areas is essential to maintaining their integrity and to potential increases to the area under effective conservation. With the decline in tropical forests, initiatives to increase the area of undisturbed forests under strict protection, particularly those neighboring protected areas, is of critical importance. Applied research has informed such land-management decisions for areas surrounding the Nouabalé-Ndoki National Park (NNNP) in Republic of Congo since the park’s inception three decades ago. Here, we present results of the first systematic line transect survey of great ape nests conducted in the Djéké Triangle, a 100 km² unlogged continuous forest in the Kabo Forestry Management Unit adjacent to the NNNP. Distance sampling methods applied along 26 line transects on two different occasions (2016 and 2018, with total effort of 69.4 km) provided density estimates of 0.75 (95% confidence interval (CI) 0.52–1.09) and 0.61 (95% CI 0.40–0.92) chimpanzees/km² and 2.15 (95% CI 1.36–3.40) and 1.19 (95% CI 0.78–1.82) gorillas/km² for each of the two surveys, respectively. Estimated ape densities were compared to others across the landscape. The findings provide a unique baseline in an area that supports ongoing behavioral research and future gorilla tourism opportunities in the Djéké Triangle. More importantly, results provided empirical evidence of the environmental value and strategic conservation importance supporting inclusion of the Djéké Triangle into the NNNP in 2023. These long-term monitoring results inform best-practice standards and ape tourism certification.

The Nouabalé–Ndoki National Park (NNNP) in Republic of Congo has become a beacon for conservation in Central Africa. This manuscript documents the arrival of primatologists, the establishment of field stations and major discoveries in primate behavior and ecology. Field stations were strategically established to study primate behavior in a variety of different contexts from stationary platforms to forest follows of habituated groups. The implementation of new technologies and analyses have also been a hallmark of research at Ndoki. Scientists are shaping a new era in primatology at NNNP by building on past successes and promoting the next generation of Congolese conservationists to address environmental challenges. Results have proven crucial in discussions with government and industry and led to conservation gains such as the inclusion of the intact forests of the Goualougo and Djéké Triangles into the NNNP. The research stations have also become essential for developing a long-term certified sustainable international gorilla tourism program. Despite the many advancements for conservation such as increased protection of forests, development of internationally recognized protocols and large-scale capacity building initiatives, there are reasons for considerable concern in the near- and long-term for primates and their forest habitats in the Ndoki landscape. To address these concerns, we emphasize the long history of forming partnerships with local communities. We also discuss shared overlap featuring multicultural and environmental use of forest resources that is likely to be crucial in championing the conservation of the Ndoki forests for the next 25 years and beyond.

While there is growing recognition of the importance of traditional knowledge in science, these perspectives remain underrepresented in research publications. However, the synthesis of these approaches has tremendous potential to improve our understanding of wildlife and ecosystems. Toward realizing this aim, we combined local traditional knowledge with molecular classification techniques to investigate “soil scratching” behavior in western lowland gorillas in two localities in Republic of Congo, the Goualougo Triangle and the Djéké Triangle. Daily observations of four gorilla groups for nearly a decade revealed that soil scratching is a foraging strategy to access a deer truffle species, identified here as Elaphomyces labyrinthinus. We also conducted group scans to calculate the time gorillas spent foraging for deer truffles and video focal observations to assess foraging efficiency. There was considerable variation in soil scratching across groups. It was most common in Buka’s group, followed by Kingo’s group and Mététélé’s group. Truffle foraging was rarely observed in the Loya-Makassa group. While the overall distribution of deer truffles seemingly determines the occurrence of this behavior across populations, we found indications of social influences on soil scratching within populations. For example, an adult female transferred from a group in which the behavior was rare to another group where it is common and adjusted her frequencies of soil scratching to that of her new group. Finally, these findings were included in an ecological impact assessment of the Djéké Triangle that prompted conservation managers to shift the location of tourism-associated construction to safeguard this putative cultural behavior.

Conservation funding is currently limited; cost‐effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID‐19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km ² than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These “earth observatories” provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly.

Planning is a type of problem solving in which a course of future action is devised via mental computation. Potential advantages of planning for tool use include reduced effort to gather tools, closer alignment to an efficient tool design, and increased foraging efficiency. Chimpanzees (Pan troglodytes troglodytes) in the Goualougo Triangle use a variety of different types of tools. We hypothesized that procurement strategy (brought to the termite nest, manufactured or acquired at the termite nest, or borrowed from others) reflects planning for current needs, with tool transport behavior varying by tool type and by age and sex class. It is also possible that chimpanzees anticipate the need for tools at future times, which would be evidenced by transporting multiple tool types for a sequential task. One year of video recordings at termite nests were systematically screened for tool procurement; data comprised 299 tool procurement events across 66 chimpanzees. In addition, we screened video recordings of leaf sponging and honey gathering, which resulted in another 38 procurement events. Fishing probes, which are typically used during a single visit, were typically transported to termite nests, while puncturing tools, which are durable and remain on site, were more often acquired at termite nests. Most tools transported in multiples were fishing probes, perhaps in anticipation that a single probe might not last through an entire foraging bout or might be transferred to another chimpanzee. We further documented that chimpanzees transported tool sets, comprising multiple different tool types used in sequence. Mature chimpanzees transported tools more often than did immatures. These observations suggest that chimpanzees plan tool use flexibly, reflecting the availability of raw materials and the likelihood that specific tool types will be needed for particular tasks. Developmental studies and further integration of behavioral, spatial, and archaeological data will help to illuminate the decision making and time depth of planning associated with tool technologies in living primates and hominin ancestors.