Human Activity and Forest Degradation Threaten Populations of the Nigeria–Cameroon Chimpanzee (Pan troglodytes ellioti) in Western Cameroon

Increased human activities such as commodity-led deforestation, extension of agriculture, urbanization, and wildfires are major drivers of forest loss worldwide. In Cameroon, these activities cause a loss of suitable primate habitat and could ultimately threaten the survival of chimpanzees (Pan troglodytes). We derived independent estimates of the population size of the Endangered Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) in Kom-Wum Forest Reserve, Cameroon, and surrounding unprotected forest areas through 1) direct observations, 2) camera trapping, 3) distance sampling, 4) marked nest counts, and 5) standing crop nest counts. In addition, we georeferenced signs of chimpanzee and human activity along line transects. We used a generalized linear mixed model to predict the occurrence of chimpanzees in response to edge length (measured as the perimeter of core forest patches), core area of forest patches (measured as area of forest patches beyond an edge width of 100 m), habitat perforation (measured as the perimeter of nonforested landscape within core forest patches), patch size(measured as area of forest patches), and forest cover. Chimpanzee density estimates ranged from 0.1 (direct observation) to 0.9 (distance sampling) individuals km−2 depending on estimation method with a mean nest group size of 7 ± 5.4 (SD). The mean encounter rate for signs of chimpanzee activity was significantly higher in mature forests (2.3 signs km−1) than in secondary forests (0.3 signs km−1) and above 1000 m elevation (4.0 signs km−1) than below 1000 m (1.0 signs km−1). The mean encounter rate for signs of human activity was significantly higher in secondary (8.0 signs km−1) than in mature forests (0.9 signs km−1). Secondary forests, habitat perforation, and edge length had a significant negative effect on the occurrence of chimpanzee signs. Overall, human activity and forest degradation affected the number of observed chimpanzee signs negatively. Regular antipoaching patrols and reforestation programs in degraded areas could potentially reduce threats to populations of endangered species and may increase suitable habitat area.Projekt DEALPeer Reviewe

Erhaltungszustand und Ökologie des Nigeria–Kamerun Schimpansen im Kom–Wum Waldreservat, Nord–West Region, Kamerun

Increased human activity, such as deforestation, is a major driver of biodiversity loss worldwide. In Cameroon, these activities could ultimately threaten the survival of the Nigeria-Cameroon chimpanzee, but knowledge of their abundance and ecology in the Kom - Wum Forest Reserve in Cameroon is still lacking. This research aimed to estimate the population size of this chimpanzee subspecies and assess threats, investigate nesting behaviour, identify suitable habitats, determine feeding habits and document the tools used for food acquisition. Research was conducted using line transects during two seasons: wet (May-September 2018) and dry (November 2019-March 2020). Population size and threats were assessed by georeferencing signs of chimpanzees and human activity along line transects. Nesting behaviour was investigated by recording the characteristics of nesting trees along line transects and mapping their distribution in ArcGIS. Suitable habitat was identified by relating chimpanzee presence signs to local environmental variables related to relief, vegetation and human impact using the Maximum Entropy Species Distribution Model (MaxEnt). Feeding habits were investigated by direct examination of chimpanzee faeces, and tool use was documented by observation and measurement of tools in situ. The reserve is home to up to 83 chimpanzees. Signs of chimpanzee activity were significantly higher in mature forest than in secondary forest, and above 1000 m than below 1000 m. Hunting was the main threat to chimpanzees, and the occurrence of chimpanzee signs decreased significantly with increasing human activity. Chimpanzees preferred tall, mature forest trees at higher elevations with slopes for nesting, and avoided areas near villages and bare land. Only 8% of the study area was suitable chimpanzee habitat. Fruit dominated the chimpanzees' diet, but they also consumed leaves and fruit pith, especially during the dry season. There was also indirect evidence that chimpanzees used tools to consume driver ants (genus Dorylus). Seasonality significantly affected the size of tools used by chimpanzees for driver ant predation. They preferred to use thicker and shorter tools for driver ant predation during the rainy season, whereas longer and thinner tools were used during the dry season. The results of this research highlight the need to reduce poaching and deforestation to protect the remaining chimpanzee population and suitable habitat in the reserve and surrounding unprotected forest. High-elevation and mature forests are critical for chimpanzee conservation and should be a high priority for protection. This research has filled the knowledge gap on what little was known about the abundance and ecology of Nigeria-Cameroon chimpanzees.Die erhöhte menschliche Aktivität, wie etwa die Abholzung, ist weltweit ein bedeutender Faktor für den Verlust an Biodiversität. In Kamerun könnten diese Aktivitäten letztendlich das Überleben des Nigeria-Kamerun-Schimpansen gefährden, doch das Wissen über ihre Häufigkeit und Ökologie im Kom-Wum-Waldreservat in Kamerun ist noch unzureichend. Diese Forschung zielt darauf ab, die Populationsgröße dieser Schimpansen-Unterart zu schätzen, Bedrohungen zu bewerten, das Nestbauverhalten zu untersuchen, geeignete Lebensräume zu identifizieren, Fressgewohnheiten festzustellen und Werkzeuge zur Nahrungsbeschaffung zu dokumentieren. Die Forschung nutzte Linientransekte in zwei Jahreszeiten: Regenzeit und Trockenzeit. Populationsgröße und Bedrohungen wurden durch die Georeferenzierung von Schimpansen- und menschlichen Aktivitätszeichen entlang der Linientransekte bewertet. Das Nestbauverhalten wurde durch Aufzeichnung der Merkmale von Nestbäumen entlang der Linientransekte untersucht und in ArcGIS kartiert. Geeignete Lebensräume wurden durch die Beziehung von Schimpansenpräsenzzeichen zu lokalen Umweltvariablen im Zusammenhang mit Relief, Vegetation und menschlichem Einfluss mithilfe des Maximum Entropy Species Distribution Model (MaxEnt) identifiziert. Fressgewohnheiten wurden durch direkte Untersuchung von Schimpansenkot erforscht, und der Werkzeuggebrauch wurde durch Beobachtung und Messung von Werkzeugen vor Ort dokumentiert. Das Reservat beherbergt bis zu 83 Schimpansen. Zeichen für Schimpansenaktivität waren signifikant häufiger im ausgewachsenen Wald als im Sekundärwald und über 1000 m höher als unter 1000 m. Die Hauptbedrohung für Schimpansen war die Jagd, und das Auftreten von Schimpansenzeichen nahm signifikant mit zunehmender menschlicher Aktivität ab. Schimpansen bevorzugten hohe, ausgewachsene Waldbäume in höheren Lagen mit Neigungen zum Nestbau und mieden Gebiete in der Nähe von Dörfern und Brachland. Nur 8% des Untersuchungsgebiets waren geeigneter Schimpansenlebensraum. Obst dominierte die Ernährung der Schimpansen, doch sie konsumierten auch Blätter und Fruchtsaft, besonders während der Trockenzeit. Es gab auch indirekte Hinweise darauf, dass Schimpansen Werkzeuge zur Konsumierung von Treiberameisen verwendeten. Die Jahreszeit beeinflusste die Größe der Werkzeuge für die Treiberameisenprädation signifikant. Während der Regenzeit bevorzugten sie dickere und kürzere Werkzeuge, während sie während der Trockenzeit längere und dünnere Werkzeuge nutzten. Die Ergebnisse dieser Forschung unterstreichen die Notwendigkeit, Wilderei und Abholzung zu reduzieren, um die verbleibende Schimpansenpopulation und geeigneten Lebensraum im Reservat und den umliegenden ungeschützten Wäldern zu schützen. Hochgelegene und ausgewachsene Wälder sind entscheidend für den Schutz der Schimpansen und sollten eine hohe Priorität für den Schutz haben. Diese Forschung hat die Wissenslücke über die Häufigkeit und Ökologie der Nigeria-Kamerun-Schimpansen geschlossen

Evaluating urban land-use demarcation and implementation for various urban functions using GIS and survey-based data: The case of Abuja City, Nigeria

Urban planning implementation is a crucial process of urban planning to improve, attain, and maintain urban sustainability globally. However, the implementation process for land use demarcated for various urban functions is being confronted by various challenges in the Global South. This study aims to integrate questionnaire surveys of urban and regional planning experts and Geographic Information Systems (GIS), in order to investigate the level of urban planning implementation of land use demarcated for various urban functions to support strategic actions for urban sustainability. Using Abuja, Nigeria, as a case study, an urban plan, urban impervious surface map, and questionnaire data were collected, and an integrated method analysis, including qualitative and quantitative (descriptive, Euclidean Distance Modelling, and Linear Regression Modelling) was deployed. Key findings show that the vast majority of experts in urban and regional planning perceive the implementation of all land use for various urban functions to be between moderate and very high levels, except that of industrial land use perceived to be between moderate and low levels. GIS findings show that, while land uses demarcated for transportation, commercial, educational, and institutional functions are positively and significantly associated with the urban impervious surface, industrial land use and urban green spaces are negatively associated. Findings show that abuse of official privileges by distorting master plans, political interference, compromise by public servants, and inadequate funding are key challenges for urban planning implementation on land use demarcated for various urban functions. The findings in this study are crucial for strategic decision makers in urban planning to improve the implementation process for various urban land-use functions and urban sustainability in the Global South, in general, and in sub-Saharan Africa, in particular