Land use, REDD+ and the status of wildlife populations in Yaeda Valley, northern Tanzania

Abstract

REDD+ projects primarily focus on reducing carbon emissions from deforestation and forest degradation in developing countries. These projects are regularly evaluated against their core objective of conserving carbon stocks, but their contribution to biodiversity conservation has rarely been assessed. To assess the conservation value of the area and the relative performance of a REDD+ land use plan in Yaeda Valley, a semi-arid savannah ecosystem in northern Tanzania, we implemented an annual wildlife monitoring scheme. Based on direct sightings and indirect signs of wildlife, obtained from stratified walking transects conducted annually from 2015–2018, we estimated annual trends of mammal species richness and wildlife densities in three REDD+ and three non-REDD+ land-use strata. Our surveys document a near complete mammal community in the area. Species accumulation curves, and subsequent statistical comparisons, indicated highest mammal species richness in the woodland habitats (both REDD+ and non REDD+ strata) as compared to more human and livestock impacted areas, and suggested constant species richness from 2015–2018. To estimate stratum- and year-specific livestock and wildlife densities (cattle, donkey, goat and sheep combined, Thomson’s gazelle, Kirk’s dik-dik) and wildlife sign densities (aardvark, bushbuck, bushpig, Kirk’s dik dik, eland, elephant, Maasai giraffe, greater kudu, hyena, impala, lesser kudu, warthog, wildebeest, Plains zebra), we fitted species-specific detection functions in a distance sampling framework. Species-specific densities varied between 2015 and 2018 and showed substantial increases and occasional declines in other species-stratum combinations. However, population growth rates were not systematically associated with specific land-use strata. Although our results do not explicitly provide evidence that REDD+ land-use plans directly co-benefit wildlife conservation, they show that REDD+ areas have the potential to maintain intact wildlife assemblages. To ensure effective long-term conservation outcomes, we advocate for a more formal integration of wildlife conservation goals in the REDD+ scheme.

Hunter-Gatherers in context: Mammal community composition in a northern Tanzania landscape used by Hadza foragers and Datoga pastoralists

“…Lions are frequently heard in Tli'ika but their populations densities are very low, and so while they are present, were not detected by the camera traps [65]. On a positive note, our photo capture of the wild dog (Lycaon pictus) confirms the presence of this endangered species in the study area [32,64]. These comparisons underline the general consensus that a combination of multiple survey methods is necessary to…”

“…Employing participatory camera-trap monitoring [33], we describe the mammal species detected in the area centered upon a favored camping location of Hadza hunter-gatherers. This study builds upon previous research in which mammal communities across the wider study area were estimated using indirect (animal signs) evidence [32]. The status of wildlife populations is a vital concern to the Hadza community and is valuable for modeling the ecology of hunting and gathering in the region.…”

“…In East Africa, scholars have observed widely varying human impacts upon wildlife communities. In areas subject to human land-uses such as dense settlement, agriculture and pastoralism, some communities of large mammals show signs of low species richness and density, while others exhibit species richness and densities similar to nearby protected areas [16,[23][24][25][26][27][28][29][30][31][32]. Cultural and economic differences among human communities are clearly implicated in such patterns, but poorly understood.…”

Land Use and Access in Protected Areas: A Hunter’s View of Flexibility

“…This approach enabled us to derive meaning from relevant accounts of the hunter. A transect walk has the merit of enabling the researcher to cope with challenges in interactive platforms and of disclosing different viewpoints about a given area [42][43][44]. A transect walk is also a useful means for site mapping [42].…”

Community‐based wildlife management area supports similar mammal species richness and densities compared to a national park

“…Assessing the performance of conservation areas requires monitoring of suitable biological variables over time, ideally in comparison to appropriate spatial baselines (Geldmann et al, ; Schmeller et al, ). When wildlife is readily observable, assessing, and estimating species richness of large mammal assemblages and population densities of specific species over time can be performed simultaneously (Kiffner et al, ; Kiffner, Nagar, Kollmar, & Kioko, ; Schuette et al, ). This combined approach offers advantages over focusing solely on species richness (Cromsigt, van Rensburg, Etienne, & Olff, ; Msuha, Carbone, Pettorelli, & Durant, ; Treydte, Edwards, & Suter, ), on one or few snapshot assessments of species' densities (Caro, ; Waltert, Meyer, & Kiffner, ), or on population trends of selected species (Kiffner et al, ; Ogutu et al, ).…”