Long-term historical and projected herbivore population dynamics in Ngorongoro crater, Tanzania

Factors influencing wildlife roadkill in the Ngorongoro Conservation Area, Northern, Tanzania

Globally, extension of road network is among the major threats affecting different fauna survival. Roads traversing protected areas, usually harm wildlife species (e.g., wildlife roadkill). Wildlife roadkill is of global conservation concern and has been reported to occur in different protected areas worldwide. Very little information on the problem is currently available in the Ngorongoro Conservation Area (NCA). The purpose of this study was to identify factors that affect wildlife roadkill in the NCA. The 82-kilometer main road from Lodoare to Golini served as the study's transects. Data was collected for a duration of one year from July 2021 to June 2022. Vehicle moving with a speed limit of 20km/hr were used during the data collection. The survey started early in the morning from 07:00 am to 06:00 pm and employed both direct and opportunistic encounter observations for recording wildlife roadkill incidences. The results revealed that 85 individual animals belonging to 21 families, i.e., 5 mammalian, 3 reptilian, and 10 bird orders were recorded killed within one year period in the area. These animals comprised 26 different species, which included 10 mammalian, 5 reptilian, and 11 bird species. Moreover, more birds (69.4%) than mammals (18.8%) and reptiles (11.8%) were found killed in the area. Additionally, the night jars (Caprimulgus europaeus; 30.6%) followed by black rat (Rattus rattus; 7.1%) and chameleon (Chamaeleo chamaeleon; 3.5%) were the most frequently recorded killed species in the area. Furthermore, wildlife roadkills did not differ significantly between seasons (p = 0.371) and time of day (e.g., morning vs. afternoon; p = 0.652) but differed significantly between their body size (e.g., small, medium, and large; p < 0.001) and habitat types (e.g., grassland, woodland, shrubland, wooded grassland, forest; p = 0.005). The study recommends punishments and penalties for overspeeding drivers and installing cameras, speed limits, and signboards along the highway to alert drivers to reduce speed. Further, providing regular education to road users on the impacts of roadkill within the ecosystem is critical.

Spatial and seasonal group size variation of wild mammalian herbivores in multiple use landscapes of the Ngorongoro Conservation Area, Tanzania

Group sizes of wild herbivores can be indicators of ecosystem health and proxies for individual and population fitness, particularly in areas where human activities have become increasingly common. We recorded 176 single- and multi-species groups of wild herbivores in human-dominated landscapes of the Ngorongoro Conservation Area (NCA) during dry and wet seasons. We analyzed how wild herbivore group sizes were affected by: (1) season, (2) distance to fully protected area (NCA crater) and to streams, (3) distance to human settlements, and (4) numbers of livestock. Group sizes were generally larger during the wet season than during the dry season and varied seasonally with distance to NCA crater, streams, and human settlements. During the wet season, larger groups were observed further away from the NCA crater whereas the opposite pattern was apparent during the dry season. Average wild herbivore group sizes increased by about three-fold with increasing distance from the streams during the dry season but were invariant to streams during the wet season. Furthermore, during the dry season, group sizes were larger close to settlements but varied little with distance to settlements during the wet season. While livestock presence did not directly affect wild herbivore group size, distance to settlements, streams and distance to the Ngorongoro crater in interaction with rainfall seasonality did. We conclude that the NCA crater functions as a key resource area for wild herbivores such as wildebeest (Connochaetes taurinus) and zebra (Equus quagga burchelli) during the dry season, highlighting the need for its full protection status in this Man and Biosphere reserve.

Integrating stakeholders' perspectives and spatial modelling to develop scenarios of future land use and land cover change in northern Tanzania

Rapid rates of land use and land cover change (LULCC) in eastern Africa and limited instances of genuinely equal partnerships involving scientists, communities and decision makers challenge the development of robust pathways toward future environmental and socioeconomic sustainability. We use a participatory modelling tool, Kesho, to assess the biophysical, socioeconomic, cultural and governance factors that influenced past (1959-1999) and present (2000-2018) LULCC in northern Tanzania and to simulate four scenarios of land cover change to the year 2030. Simulations of the scenarios used spatial modelling to integrate stakeholders' perceptions of future environmental change with social and environmental data on recent trends in LULCC. From stakeholders' perspectives, between 1959 and 2018, LULCC was influenced by climate variability, availability of natural resources, agriculture expansion, urbanization, tourism growth and legislation governing land access and natural resource management. Among other socio-environmental-political LULCC drivers, the stakeholders envisioned that from 2018 to 2030 LULCC will largely be influenced by land health, natural and economic capital, and political will in implementing land use plans and policies. The projected scenarios suggest that by 2030 agricultural land will have expanded by 8-20% under different scenarios and herbaceous vegetation and forest land cover will be reduced by 2.5-5% and 10-19% respectively. Stakeholder discussions further identified desirable futures in 2030 as those with improved infrastructure, restored degraded landscapes, effective wildlife conservation, and better farming techniques. The undesirable futures in 2030 were those characterized by land degradation, poverty, and cultural loss. Insights from our work identify the implications of future LULCC scenarios on wildlife and cultural conservation and in meeting the Sustainable Development Goals (SDGs) and targets by 2030. The Kesho approach capitalizes on knowledge exchanges among diverse stakeholders, and in the process promotes social learning, provides a sense of ownership of outputs generated, democratizes scientific understanding, and improves the quality and relevance of the outputs.