Understanding continent-wide variation in vulture ranging behavior to assess feasibility of Vulture Safe Zones in Africa: Challenges and possibilities

Protected areas are intended as tools in reducing threats to wildlife and preserving habitat for their long-term population persistence. Studies on ranging behavior provide insight into the utility of protected areas. Vultures are one of the fastest declining groups of birds globally and are popular subjects for telemetry studies, but continent-wide studies are lacking. To address how vultures use space and identify the areas and location of possible vulture safe zones, we assess home range size and their overlap with protected areas by species, age, breeding status, season, and region using a large continent-wide telemetry datasets that includes 163 individuals of three species of threatened Gyps vulture. Immature vultures of all three species had larger home ranges and used a greater area outside of protected areas than breeding and non-breeding adults. Cape vultures had the smallest home range sizes and the lowest level of overlap with protected areas. Rüppell\u27s vultures had larger home range sizes in the wet season, when poisoning may increase due to human-carnivore conflict. Overall, our study suggests challenges for the creation of Vulture Safe Zones to protect African vultures. At a minimum, areas of 24,000 km2 would be needed to protect the entire range of an adult African White-backed vulture and areas of more than 75,000 km2 for wider-ranging Rüppell\u27s vultures. Vulture Safe Zones in Africa would generally need to be larger than existing protected areas, which would require widespread conservation activities outside of protected areas to be successful

Detecting and predicting forest degradation: A comparison of ground surveys and remote sensing in Tanzanian forests

Funder: Critical Ecosystem Partnership Fund; Id: http://dx.doi.org/10.13039/100013724Funder: Global Environment Facility; Id: http://dx.doi.org/10.13039/100011150Funder: Danish International Development Agency; Id: http://dx.doi.org/10.13039/501100011054Funder: Scottish Government’s Rural and Environment Science and Analytical Services DivisionFunder: Finnish International Development AgencyFunder: Leverhulme Trust; Id: http://dx.doi.org/10.13039/501100000275Societal Impact Statement: Large areas of tropical forest are degraded. While global tree cover is being mapped with increasing accuracy from space, much less is known about the quality of that tree cover. Here we present a field protocol for rapid assessments of forest condition. Using extensive field data from Tanzania, we show that a focus on remotely‐sensed deforestation would not detect significant reductions in forest quality. Radar‐based remote sensing of degradation had good agreement with the ground data, but the ground surveys provided more insights into the nature and drivers of degradation. We recommend the combined use of rapid field assessments and remote sensing to provide an early warning, and to allow timely and appropriately targeted conservation and policy responses. Summary: Tropical forest degradation is widely recognised as a driver of biodiversity loss and a major source of carbon emissions. However, in contrast to deforestation, more gradual changes from degradation are challenging to detect, quantify and monitor. Here, we present a field protocol for rapid, area‐standardised quantifications of forest condition, which can also be implemented by non‐specialists. Using the example of threatened high‐biodiversity forests in Tanzania, we analyse and predict degradation based on this method. We also compare the field data to optical and radar remote‐sensing datasets, thereby conducting a large‐scale, independent test of the ability of these products to map degradation in East Africa from space. Our field data consist of 551 ‘degradation’ transects collected between 1996 and 2010, covering >600 ha across 86 forests in the Eastern Arc Mountains and coastal forests. Degradation was widespread, with over one‐third of the study forests—mostly protected areas—having more than 10% of their trees cut. Commonly used optical remote‐sensing maps of complete tree cover loss only detected severe impacts (≥25% of trees cut), that is, a focus on remotely‐sensed deforestation would have significantly underestimated carbon emissions and declines in forest quality. Radar‐based maps detected even low impacts (<5% of trees cut) in ~90% of cases. The field data additionally differentiated types and drivers of harvesting, with spatial patterns suggesting that logging and charcoal production were mainly driven by demand from major cities. Rapid degradation surveys and radar remote sensing can provide an early warning and guide appropriate conservation and policy responses. This is particularly important in areas where forest degradation is more widespread than deforestation, such as in eastern and southern Africa

Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation

Range and population expansion as tools to reduce the extinction risk in a 'critically endangered' primate : kipunji Rungwecebus kipunji

Kipunji Rungwecebus kipunji, a Tanzanian endemic and Africa's rarest monkey, was only discovered in 2003. It was subsequently categorised as 'critically endangered' on the IUCN Red List, with 93% of the population found in the degraded Mt Rungwe and Livingstone forests (RL) of the Southern Highlands. Aspects of kipunji ecology and habitat characteristics were investigated for the RL population to inform future evidence-based conservation, and more specifically to look at how range and population expansion can be used as tools to reduce the extinction risk of a 'critically endangered' species. Habitat use models developed for kipunji suggested that they are able to tolerate some forest disturbance, such as a fragmented canopy, as long as this is associated with specific tree communities at mid to lower altitudes. Predictions of habitat suitability suggest there is little room for expansion within forests around the known kipunji range (RL extent of occurrence = 42 km"), although the original habitat in areas south of the current range, now deforested, would have been highly suitable. From these results, improving habitat quality and connectivity inside the forest, and reforesting parts of the former range outside of the forest, would be needed to facilitate range expansion. Twenty three kipunji groups were studied to record demographic data testing a partial count method, used as a response to the problems of estimating age-sex ratios for shy, cryptic and arboreal animals. This method demonstrated potential as a quick and simple way to collect baseline population data. Kipunji demographics indicate a 'healthy' population composition (based on current numbers of adult females to males, females with infants, and proportion of infants per group) that is stable, if not increasing. There is no evidence so far to suggest that kipunji group size changes along a gradient of forest disturbance, although some demographic parameters are inversely correlated with forest disturbance and may be linked to resource availability. The 22-month foraging ecology study demonstrated that kipunji have a wide, diverse and predominantly fruit-rich diet. Fruit consumption was correlated with fruit availability which showed a peak during the wet season, and a period of fruit scarcity in the driest months (August-October). During this period, three fallback foods (unripe fruits, mature leaves and pith) were widely consumed. α diversity and evenness of diet was remarkably similar across months, but there was high β diversity in diets across months at the cusp of wet and dry seasons, and during periods of low fruit availability This suggests considerable dietary adaptability to fluctuating resources, which may act to buffer against further forest disturbance. Tree species associated with relatively undisturbed forest were significantly more important in the diet, especially in the dry season, than those of disturbed forests. Regeneration of key trees appeared healthy except in two important Ficus species. Patterns of home range use showed that temporal and spatial patterns were linked to fruit availability. An expansion of the range occurred with low fruit availability in the dry season, and a longer dry season daily path length was associated with an increase in diversity of fruits in the diet. Activity budgets changed between seasons with a greater proportion of time spent feeding in the dry season. Kipunji exhibited long ranging patterns of home range use, rarely returning to the same site on successive days, which probably facilitated resource monitoring and/or allowed dietary switching as fruit scarcity increased during 'leaner' periods. The main pressures on kipunji in the forest are from logging, charcoal production and hunting. Retributive hunting on the forest edge also occurred in response to crop raiding of maize (and to a lesser extent legumes and potatoes) by kipunji and Moloney's white-collared monkey. This was a localised problem in the wet season months (December to April), and was predicted primarily by the presence of maize, and not habitat measures, suggesting that reforestation schemes at the forest boundary might not necessarily increase the incidence of crop raiding. Mitigation measures should include methods that create physical barriers/buffer zones between maize and the forest edge. The matrix habitat adjacent to the RL forests was dominated by agriculture, interspersed with some small forest patches and single trees, which may be useful as 'links' in the landscape. Matrix habitat immediately bordering the forest was very different from forest within the reserve, and this 'hard edge' means that reforestation to create 'extra' kipunji habitat would basically start from nothing. Kipunji habitat creation which seeks to relieve pressure on the forest and directly benefit communities is likely to be supported as 95% of villagers interviewed were willing to become involved in tree planting/reforestation schemes. Reforesting 800 ha, which may be sufficient for an 'extra' 500 kipunji (almost 50% of the total current population), could cost $491,400 based on current land prices, a relatively modest sum with potentially significant outcomes for a threatened species, but feasibility of such a scheme might be limited by socio-political factors.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Herpetofauna of Montane Areas of Tanzania. 4. Amphibians and Reptiles of Mahenge Mountains, with Comments on Biogeography, Diversity, and Conservation

The Mahenge Mountains are located in the Eastern Arc Mountains, part of a global biodiversity hotspot. Few amphibian and reptile surveys have been conducted in this area, with only one study of the submontane forest zone. This previous study revealed a characteristic endemic Eastern Arc amphibian and reptile forest fauna. New studies outlined here extend the sampling time considerably and the geographical coverage (including Mselezi Forest Reserve). These studies reveal a remarkable diversity of amphibians and reptiles increasing known faunal diversity considerably, including several putative new species that await further taxonomic verification. Biogeographical analyses using Bray-Curtis indices show Mahenge clusters with the geographically close Udzungwa Mountains and Southern Highlands (non–Eastern Arc highland fragment including Mt. Rungwe). This clustering of areas suggests an interesting biogeographical history and deserves special attention in the future. In light of the remarkable amphibian and reptile diversity, conservation of Mahenge habitats, in particular Sali Forest Reserve, is desperately required

Understanding continent-wide variation in vulture ranging behavior to assess feasibility of Vulture Safe Zones in Africa:challenges and possibilities

Protected areas are intended as tools in reducing threats to wildlife and preserving habitat for their long-term population persistence. Studies on ranging behavior provide insight into the utility of protected areas. Vultures are one of the fastest declining groups of birds globally and are popular subjects for telemetry studies, but continent-wide studies are lacking. To address how vultures use space and identify the areas and location of possible vulture safe zones, we assess home range size and their overlap with protected areas by species, age, breeding status, season, and region using a large continent-wide telemetry datasets that includes 163 individuals of three species of threatened Gyps vulture. Immature vultures of all three species had larger home ranges and used a greater area outside of protected areas than breeding and non-breeding adults. Cape vultures had the smallest home range sizes and the lowest level of overlap with protected areas. Rüppell's vultures had larger home range sizes in the wet season, when poisoning may increase due to human-carnivore conflict. Overall, our study suggests challenges for the creation of Vulture Safe Zones to protect African vultures. At a minimum, areas of 24,000 km2 would be needed to protect the entire range of an adult African White-backed vulture and areas of more than 75,000 km2 for wider-ranging Rüppell's vultures. Vulture Safe Zones in Africa would generally need to be larger than existing protected areas, which would require widespread conservation activities outside of protected areas to be successful