Despite considerable progress since the turn of the century, the fight against malaria has stalled in the last few years. There are two main obstacles to the disappearance of the disease: resistance of mosquitoes to insecticides and their ability to avoid core vector control measures by feeding upon animals, feeding outdoors or resting outdoors. Recognizing that both these phenomena are heavily influenced by environmental variations in the abundance of natural resources that mosquitoes need to survive, notably mammalian blood sources and surface water, this project aims to characterize the malaria control opportunities and obstacles that arise from biodiversity conservation efforts across Africa. Our overall goal is to bring the fight against malaria one step closer to elimination while also fostering improved management of wildlife conservation areas.

Population-stabilizing portfolio effects of fine-scale environmental variations in natural resource availability to malaria vector mosquitoes; Characterization and implications for malaria vector control strategies

Deo Kavishe, Research Scientist at the Ifakara Health Institute in Tanzania and PhD candidate at the UCC School of Biological, Earth & Environmental Sciences charging his light traps to see if he can find fully -susceptible wild type variants of malaria vector mosquitoes surviving far away from people and our insecticides in the ILUMA Wildlife Management Area in southern Tanzani

Deo Kavishe, Research Scientist at the Ifakara Health Institute in Tanzania and PhD candidate at the UCC School of Biological, Earth & Environmental Sciences, successfully field tests his new invention: A ventilated backpack with passive evaporative cooling, for long distance transportation of live mosquitoes across large tracts of wilderness that will only be accessible on foot when the rains come. His mosquitoes all survived a 4-day, 60km hike across the ILUMA Wildlife Management Area, including this typical pristine piece of Miombo woodland along the road marking its eastern boundary with Nyerere National Park.

Lily Duggan, Masters’ Degree candidate at the School of Biological, Earth & Environmental Sciences at UCC takes the wildlife surveys she is piloting across the ILUMA Wildlife Management Area in collaboration with the Ifakara Health Institute and Sokoine University of Agriculture into the dense groundwater forest along the south bank of the Kilombero Valley.

Katrina Walsh, Masters’ Degree candidate at the School of Biological, Earth & Environmental Sciences at UCC collaborating with the Ifakara Health Institute and Sokoine University of Agriculture, finds abundant malaria vector mosquito larvae in dry season water hole frequented by African Buffalo, which we suspect they rely on as a source of blood deep in the ILUMA Wildlife Management Area, where humans and livestock are essentially absent.

Climate action at grass roots level: Village Game Scouts from the ILUMA Wildlife Management Area, a community-based conservation and rural development organization, deliver on the environmental protection objectives of our study by destroying a charcoal burning mound encountered during our collaborative pilot surveys of mosquitoes, wildlife and vegetation cover with the Ifakara Health Institute and Sokoine University of Agriculture.

Several bicycles, a motorbike and large quantities of charcoal and timber confiscated by the Village Game Scouts who escorted us through the ILUMA Wildlife Management Area during one of our pilot surveys of mosquitoes and wildlife.

Dr Fidelma Butler from the UCC School of Biological Earth and Environmental Sciences sets off across the extensive Bonde la Mdaba floodplain in the ILUMA Wildlife Management Area while piloting and fine-tuning wildlife surveys in collaboration with the Ifakara Health Institute and Sokoine University of Agriculture.

ILUMA Village Game Scout Mzee Kimboga points out a Warthog footprint at a dry season water hole, in amongst many others left by African Buffalo, to students Maureen Daffa from the College of Forestry, Wildlife and Tourism at Sokoine University of Agriculture (Left) and Lily Duggan from the UCC School of Biological, Earth and Environmental Sciences (Right).

Home sweet home: Our central camp at Msakamba Banda Mbili, where we will establish a field insectary and office for this collaborative project with the Ifakara Health Institute and Sokoine University of Agriculture, and also a new centre of operations for the Village Game Scouts who implement the conservation functions of the ILUMA Wildlife Management Area.

A few months later, our camp at Msakamba Banda Mbili transformed into a field insectary for rearing and experimenting on wild-caught malaria vector mosquitoes, as well as a fully developed centre of operations for the ILUMA Wildlife Management Area Village Game Scouts.

Rapid regrowth of the miombo woodland that had been illegally cleared for rice farming occuring around Msakamba Mbili as encroachment pressure eases, turning the recovering hardwood forest back into a natural high capacity carbon sink. In only a year since the new camp was established, these saplings have grown over our heads and the wildlife has returned. Elephants are daily visitors from June to August, while Zebra, hartebeest, sable and duiker are now commonly seen in this recovering habitat, and resident leopard are often heard on patrol.

Fly camping along a seasonal stream bed in the pleasant shade of mature miombo woodland, to collect wild malaria vector mosquitoes from a pristine natural habitat with minimal insecticide pressure. Every two days this mobile mosquito collection team moves on foot to a new survey location in the ILUMA Wildlife Management Area, carrying everything they need with them because there is no vehicle access during much of the rainy season.

Science on the fly: Lily Duggan enters the latest data while she and Katrina Walsh, both MSc candidates at the UCC School of Biological, Earth & Environmental Sciences, shelter from a rain shower.

While our main focus is upon mosquitoes that feed on large wild herbivores, they do have some competition in ILUMA Wildlife Management Area: A lioness killed this kongoni (Lichtenstein’s Hartebeest) about 200 meters from our fly camp and hyenas finished off most of the skeleton, leaving only the skull, large leg bones and a little skin.

During her surveys of wildlife abundance and illegal human encroachment, Lily Duggan (MSc candidate UCC at the School of Biological, Earth & Environmental Sciences) UCC enjoys an animated explanation of how the water mongoose carries around the stone it uses to smash open crabs on a wooden anvil like this one, kindly provided by Octavian Mrope and Mzee Kimboga, both of whom are Village Game Scouts at the ILUMA Wildlife Management Area.

Katrina Walsh, MSc candidate at the School of Biological, Earth & Environmental Sciences collects Anopheles malaria vector mosquito larvae from a pool in the bottom of a seasonal stream bed in the ILUMA Wildlife Management Area. Live larvae and adult mosquitoes are then transported on foot back to our central insectary at Msakamba Banda Mbili by a team of Village Game Scouts who complete the round trip of up to 40km every 2 days.  

Back at Msakamba Banda Mbili, Deo Kavishe, Research Scientists at IHI and PhD candidate at the UCC School of Biological, Earth & Environmental Sciences collects pupae of the malaria vector mosquito Anopheles arabiensis which were reared from larvae obtained from natural habitats across the ILUMA Wildlife Management Area, so that they can emerge into a cage as adults whose offspring may be tested for susceptibility to pyrethroid insecticides.

Deo Kavishe, Research Scientists at IHI and PhD candidate at the UCC School of Biological, Earth & Environmental Sciences, transfers fed adult mosquitoes into large cages with oviposition cups containing moist cotton and filter paper, so that their eggs can be collected and then reared to adulthood for insecticide susceptibility testing.

Rogath Msoffe, Research Scientist at the Ifakara Health Institute and Masters’ Degree candidate at the Nelson Mandela African Institute of Science and Technology, and Cassandra Le Bellicard, BSc candidate at l’Institut Agro in Montpellier and visiting Erasmus student at the UCC School of Biological, Earth & Environmental Sciences, surveying the fine scale dynamics of malaria vector larval habitats around a large water hole regularly frequented by elephant and buffalo in the ILUMA Wildlife Management Area.

Lily Duggan and Katrina Walsh, both MSc candidates at the UCC School of Biological, Earth & Environmental Sciences in Ireland and resident guest scientists at the Ifakara Health Institute in Tanzania literally on the trail of the rather dangerous wild beast that we suspect sustains refugia populations of malaria vectors in conservation areas, where opportunities to feed on blood from humans and cattle are limited.

Of course, working in one of Tanzania’s amazing wild ecosystems requires careful attention to detail and safety protocols, especially when moving around on foot and fly camping for weeks at a time. Here’s a selection of tracks and signs from the wanderings of Lucia Tarimo (Sokoine University of Agriculture), Lily Duggan and Katrina Walsh, all MSc candidates at the UCC School of Biological, Earth & Environmental Sciences and resident guest scientists at the Ifakara Health Institute. Sometimes discretion is the better part of valour, especially in vegetation cover as dense as this.

Chalky hyena faeces, composed largely of powdered bone.

Fresh tracks of a large buffalo.

Fresh tracks of a pride of lions somewhere immediately ahead along the road. 

Rogath Msoffe, Research Scientist at Ifakara Health Institute and MSc candidate at Nelson Mandela African Institute of Science and Technology, takes a break from his field work to presenting his recently published study at the Pan-African Mosquito Control Association annual conference in Kigali, Rwanda. His detailed work in collaboration with local communities demonstrates how participatory approaches to installation of insecticidal mosquito screens in typical rural houses could more effectively tackle malaria transmission, and also allow us to manipulate of mosquito genetics at population level with affordable combinations of complementary insecticides. Specifically, our hope is that we may be able to use such insecticide combinations to back-select for insecticide-susceptibility among malaria mosquito populations, which depends in turn on those ancestral wild-type traits surviving among refuge populations in pristine wilderness areas at the fringes of human settlements, such as the ILUMA Wildlife Management Area.

Meanwhile, back in the ILUMA Wildlife Management Area, Lily Duggan (MSc candidate at the UCC School of Biological, Earth & Environmental Sciences) works late into the night collecting wild mosquitoes in pristine wild habitat, where we suspect they find refuge away from insecticide pressure.

Perhaps the most important things we’ve learned so far through our collaboration with the ILUMA Wildlife Management Area are (1) Just a little bit of collectively managed income from visiting tourists and researchers can go a long way in isolated rural communities, (2) They are broadly supportive of devolved conservation areas and engage in community-based governance when given the opportunity, and (3) Sustainable business models, transparent stewardship and partnership with local government will be vital to their long term success. Here an elected community representative on the governance body of the ILUMA Wildlife Management Area shares wonderfully impassioned views about all this at a recent stakeholder meeting, following a transparent explanation of how our project has shared resources with this community-based conservation body, presented by Mr Deo Kavishe, IHI Research Scientist and UCC PhD Candidate.

Encouragingly, the views of community representatives were decisively backed up by the District Commissioner for Ulanga, Mh Ngolo Malenya (Left), who explained the role of the ILUMA WMA in the Tanzanian government's overall conservation and development plan for the Kilombero Valley as a whole. Also, the Regional Natural Resources Officer for Morogoro, Mh Joseph Chua (Right), explained the importance of making this devolved model for community-based governance and management work for the villages around the conservation area.

And here’s what contributions to sustainable business models may look like for these vital fringe conservation areas: young and adventurous visitors, like UCC undergraduates Alice Twiss and Cassandra Le Belicard, with modest budgets but enough time over the summer to learn about the intricacies of tropical ecology and the practical challenges of conservation in rural Africa .

Being an adventure of course, there are always surprizes: On her first evening of camping in the wilderness, the team of ILUMA Village Game Scouts looking after Alice had to make enough noise to deter an approaching herd of elephants.

Also fascinating to huddle around the safety of a big fire and listen in on the spectacular territorial vocalizations of the local lion pride, who were kind enough on this occasion to leave something for the pot after making a kill nearby.

In addition to providing invaluable revenue for the ILUMA Wildlife Management Area and jobs for Village Game Scouts, simply having legal income-generating activities ongoing in the conservation area performs a conservation function because various forms of illegal encroachment (charcoal burning, timber harvesting, meat poaching, cattle herding and farming) are most readily carried out of sight and out of mind. This photo captures a common occurrence in which a bicycle has been rapidly abandoned inside the conservation area by an unknow person who was clearly startled when he/she heard the research team and their Village Game Scout escorts coming.  

We are therefore monitoring long terms trends in wildlife abundance and habitat integrity, including forest cover. Here Lucia Tarimo, Research Assistant at Sokoine University of Agriculture and MSc candidate at the UCC School of Biological, Earth & Environmental Sciences, and UCC BSc candidate Alice Twiss, appear happy to have preliminarily marked, tagged and measured their first tree in their first plot in our first forest survey in the ILUMA Wildlife Management Area.

Publications:

Killeen, G.F. & T.E. Reed (2018) The portfolio effect cushions mosquito populations and malaria transmission against vector control interventions. Malaria Journal. 17: 291; https://malariajournal.biomedcentral.com/articles/10.1186/s12936-018-2441-z

Smeller, D.S., Courchamp, F. & G.F. Killeen (2020) Biodiversity loss, emerging pathogens and human health risks. Biodiversity and Conservation. 29: 3095–3102; https://link.springer.com/article/10.1007/s10531-020-02021-6