AHEAD Update – April / May / June 2019
Dear AHEAD Colleagues:
* Welcome to the latest issue of the AHEAD Update. As always, if you would like to post an item in the next Update, please just send it to us – thanks.
There is a lot of thought-provoking science on humanity's dismantling of critical ecosystems in this Update – it seemed worth sharing these recent pieces in case you missed them. The critical importance of maintaining and/or restoring habitat connectivity is more clear than ever.
* Cross-Boundary Human Impacts Compromise the Serengeti-Mara Ecosystem (2019) Veldhuis MP, Ritchie ME, Ogutu JO, Morrison TA, Beale CM, Estes AB, Mwakilema W, Ojwang GO, Parr CL, Probert J, Wargute PW, Hopcraft JGC, Olff H. Science, https://doi.org/10.1126/science.aav0564 – Protected areas provide major benefits for humans in the form of ecosystem services, but landscape degradation by human activity at their edges may compromise their ecological functioning. Using multiple lines of evidence from 40 years of research in the Serengeti-Mara ecosystem, we find that such edge degradation has effectively "squeezed" wildlife into the core protected area and has altered the ecosystem's dynamics even within this 40,000-square-kilometer ecosystem. This spatial cascade reduced resilience in the core and was mediated by the movement of grazers, which reduced grass fuel and fires, weakened the capacity of soils to sequester nutrients and carbon, and decreased the responsiveness of primary production to rainfall. Similar effects in other protected ecosystems worldwide may require rethinking of natural resource management outside protected areas.
* A Century of Decline: Loss of Genetic Diversity in a Southern African Lion-Conservation Stronghold (2019) Dures SG, Carbone C, Loveridge AJ, Maude G, Midlane N, Aschenborn O, Gottelli D. Diversity and Distributions, https://doi.org/10.1111/ddi.12905 – There is a dearth of evidence that determines the genetic diversity of populations contained within present-day protected areas compared with their historical state prior to large-scale species declines, making inferences about a species' conservation genetic status difficult to assess. The aim of this paper was to demonstrate the use of historical specimens to assess the change in genetic diversity over a defined spatial area. Like many other species, African lion populations (Panthera leo) are undergoing dramatic contractions in range and declines in numbers, motivating the identification of a number of lion-conservation strongholds across East and southern Africa. We focus on one such stronghold, the Kavango-Zambezi transfrontier conservation area (KAZA) of Botswana, Namibia, Zambia and Zimbabwe. We compare genetic diversity between historical museum specimens, collected during the late 19th and early 20th century, with samples from the modern extant population. We use 16 microsatellite markers and sequence 337 base pairs of the hypervariable control region (HVR1) of the mitochondrial genome. We use bootstrap resampling to allow for comparisons between the historical and modern data. We show that the genetic diversity of the modern population was reduced by 12%-17%, with a reduction in allelic diversity of approximately 15%, compared to historical populations, in addition to having lost a number of mitochondrial haplotypes. We also identify a number of "ghost alleles" in the historical samples which are no longer present in the extant population. We argue a rapid decline in allelic richness after 1895 suggests the erosion of genetic diversity coincides with the rise of a European colonial presence and the outbreak of rinderpest in the region. Our results support the need to improve connectivity between protected areas in order to prevent further loss of genetic diversity in the region.
* Cascading Impacts of Large-Carnivore Extirpation in an African Ecosystem (2019) Atkins JL, Long RA, Pansu J, Daskin JH, Potter AB, Stalmans ME, Tarnita CE, Pringle RM. Science, https://doi.org/10.1126/science.aau3561 – Populations of the world's largest carnivores are declining and now occupy mere fractions of their historical ranges. Theory predicts that when apex predators disappear, large herbivores become less fearful, occupy new habitats, and modify those habitats by eating new food plants. Yet experimental support for this prediction has been difficult to obtain in large-mammal systems. After the extirpation of leopards and African wild dogs from Mozambique's Gorongosa National Park, forest-dwelling antelopes [bushbuck (Tragelaphus sylvaticus)] expanded into treeless floodplains, where they consumed novel diets and suppressed a common food plant [waterwort (Bergia mossambicensis)]. By experimentally simulating predation risk, we demonstrate that this behavior was reversible. Thus, whereas anthropogenic predator extinction disrupted a trophic cascade by enabling rapid differentiation of prey behavior, carnivore restoration may just as rapidly reestablish that cascade.
* New Book - Corridor Ecology (2nd Ed): Linking Landscapes for Biodiversity Conservation and Climate Adaptation (2019) Hilty JA, Keeley ATH, Lidicker Jr WZ, Merenlender AM, Island Press, 368 pp. – Migrating wildlife species across the globe face a dire predicament as their traditional migratory routes are cut off by human encroachment. Forced into smaller and smaller patches of habitat, they must compete more aggressively for dwindling food resources and territory. This is more than just an unfortunate side effect of human progress. As key species populations dwindle, ecosystems are losing resilience and face collapse, and along with them, the ecosystem services we depend on. Healthy ecosystems need healthy wildlife populations. One possible answer? Wildlife corridors that connect fragmented landscapes. This new and expanded second edition of Corridor Ecology: Linking Landscapes for Biodiversity Conservation and Climate Adaptation captures the many advances in the field over the past ten years. It builds on concepts presented in the first edition on the importance and practical details of maintaining and restoring land connectivity. For more details, see https://islandpress.org/books/corridor-ecology-second-edition.
* Wildlife Disease Association (WDA) 68th Annual International Conference, Tahoe City, California, USA, August 4-9, 2019 – This conference provides an interdisciplinary setting for wildlife health, conservation and management practitioners from around the world to exchange ideas, share best practices and give formal presentations on the latest in wildlife health. WDA includes many different professional specialties and you do not need to be a WDA member to participate. All interested individuals are invited to attend. Students also play a prominent role in the conference, with an entire day dedicated exclusively to student presentations. WDA encourages student participation, sponsoring several conference travel grants and student awards including two scholarships, a research recognition travel award, a best student presentation award, and a best student poster award. For more information, please see https://wda2019.ucdavis.edu.
* Global Foot and Mouth Disease Research Alliance (GFRA) Scientific Meeting, October 29-31, 2019, Bangkok, Thailand – GFRA is a worldwide association of animal health research organizations that are involved in combating foot and mouth disease (FMD). Its aim is to build a global alliance of partners to generate and share knowledge - in a virtual FMD laboratory - to develop tools that can better combat the threat of disease. They invite you to "save the date" and join them at this year's scientific meeting focused on "Advancing FMD Research by Bridging the Gaps with Novel Tools." For more information, see https://www.ars.usda.gov/GFRA/index.htm, or contact Wilna Vosloo at firstname.lastname@example.org.
Again, if you have items for the next AHEAD Update, please just let us know – thanks.
"What is AHEAD?" Animal & Human Health for the Environment And Development was launched at the 2003 IUCN World Parks Congress in Durban, South Africa. By assembling a ‘dream team’ of veterinarians, ecologists, biologists, social and economic scientists, agriculturists, wildlife managers, public health specialists and others from across East and southern Africa, we were fortunate to have tapped into some of the most innovative conservation and development thinking on the African continent – and AHEAD was born. Since then, a range of programs addressing conservation, health, and concomitant development challenges have been launched with the support of a growing list of implementing partners and donors who see the intrinsic value of the One World, One Health approach. AHEAD is a convening, facilitative mechanism, working to create enabling environments that allow different and often competing sectors to literally come to the same table and find collaborative ways forward to address challenges at the interface of wildlife health, livestock health, and human health and livelihoods. We convene stakeholders; help delineate conceptual frameworks to underpin planning, management and research; and provide technical support and resources for projects stakeholders identify as priorities. AHEAD recognizes the need to look at health and disease not in isolation but within a given region's environmental and socioeconomic context.
All the best,
Steve & Shirley