• Both habitat change and local lek structure influence patterns of spatial loss and recovery in a black grouse population

      Geary, Matthew; Fielding, Alan H.; Marsden, Stuart J.; University of Chester; Manchester Metropolitan University (Springer, 2015-05-23)
      Land use change is a major driver of declines in wildlife populations. Where human economic or recreational interests and wildlife share landscapes this problem is exacerbated. Changes in UK black grouse Tetrao tetrix populations are thought to have been strongly influenced by upland land use change. In a long-studied population within Perthshire, lek persistence is positively correlated with lek size, and remaining leks clustered most strongly within the landscape when the population is lowest, suggesting that there may be a demographic and/or spatial context to the reaction of the population to habitat changes. Hierarchical cluster analysis of lek locations revealed that patterns of lek occupancy when the population was declining were different to those during the later recovery period. Response curves from lek-habitat models developed using MaxEnt for periods with a declining population, low population, and recovering population were consistent across years for most habitat measures. We found evidence linking lek persistence with habitat quality changes and more leks which appeared between 1994 and 2008 were in improving habitat than those which disappeared during the same period. Generalised additive models (GAMs) identified changes in woodland and starting lek size as being important indicators of lek survival between declining and low/recovery periods. There may also have been a role for local densities in explaining recovery since the population low point. Persistence of black grouse leks was influenced by habitat, but changes in this alone did not fully account for black grouse declines. Even when surrounded by good quality habitat, leks can be susceptible to extirpation due to isolation.
    • A call to action for climate change research on Caribbean dry forests

      Nelson, Howard P.; Devenish-Nelson, Eleanor S.; Rusk, Bonnie L.; Geary, Matthew; Lawrence, Andrew J.; Department of Biological Sciences, University of Chester; Grenada Dove Conservation Programme, St. Georges, Grenada (Springer, 2018-04-20)
      Tropical dry forest (TDF) is globally one of the most threatened forest types. In the insular Caribbean, limited land area and high population pressure have resulted in the loss of over 60% of TDF, yet local people’s reliance on these systems for ecosystem services is high. Given the sensitivity of TDF to shifts in precipitation regimes and the vulnerability of the Caribbean to climate change, this study examined what is currently known about the impacts of climate change on TDF in the region. A systematic review (n = 89) revealed that only two studies addressed the ecological response of TDF to climate change. Compared to the rapidly increasing knowledge of the effects of climate change on other Caribbean systems and on TDF in the wider neotropics, this paucity is alarming given the value of these forests. We stress the need for long-term monitoring of climate change responses of these critical ecosystems, including phenological and hotspot analyses as priorities.
    • Camera Traps Confirm the Presence of the White-naped Mangabey Cercocebus lunulatus in Cape Three Points Forest Reserve, Western Ghana

      Stanley, Christina R.; Nolan, Ryan; Welsh, Adam; Dempsey, Andrea; Mono, Joseph Cudjoe; Osei, David; Hartley, Matt; Geary, Matthew; University of Chester; West African Primate Conservation Action; The Forestry Commission of Ghana; Zoo and Wildlife Solutions Ltd (IUCN/SSC Primate Specialist Group, 2019)
      The white-naped mangabey Cercocebus lunulatus is severely threatened by logging, mining, and hunting. In the last decade, wild populations have been confirmed in just three forested areas in Ghana and a handful of sites in neighboring Côte d’Ivoire and Burkina Faso. Sightings of this species were recently reported in a fourth area in Ghana, the Cape Three Points Forest Reserve, a forest patch in western Ghana, 60 km from the nearest recorded wild population, which is in the Ankasa Conservation Area. We deployed 14 camera traps across 21 different locations throughout the reserve, with the intention of confirming the presence of this species. Images of the white-naped mangabey were captured at four locations, consolidating recent evidence for a fourth sub-population of this species in Ghana and providing only the second-ever photograph of a wild member of this species in the country. We observed evidence of numerous illegal anthropogenic activities in the reserve, which threaten these mangabeys, and we make recommendations for the protection of the reserve, essential for the conservation of this highly endangered species.
    • Combining bioacoustics and occupancy modelling for improved monitoring of rare breeding bird populations

      Abrahams, Carlos; Geary, Matthew; Baker Consultants Ltd; Nottingham Trent University; University of Chester
      Effective monitoring of rare and declining species is critical to enable their conservation, but can often be difficult due to detectability or survey constraints. However, developments in acoustic recorders are enabling an important new approach for improved monitoring that is especially applicable for long-term studies, and for use in difficult environments or with cryptic species. Bioacoustic data may be effectively analysed within an occupancy modelling framework, as presence/absence can be determined, and repeated survey events can be accommodated. Hence, both occupancy and detectability estimates can be produced from large, coherent datasets. However, the most effective methods for the practical detection and identification of call data are still far from established. We assessed a novel combination of automated clustering and manual verification to detect and identify heathland bird vocalizations, covering a period of six days at 44 sampling locations Occupancy (Ψ) and detectability (p ) were modelled for each species, and the best fit models provided values of: nightjar Ψ=0.684, p=0.740, Dartford warbler Ψ=0.449 p=0.196 and woodlark Ψ=0.13 p=0.996. Including environmental covariates within the occupancy models indicated that tree, wetland and heather cover were important variables, particularly influencing detectability. The protocol used here allowed robust and consistent survey data to be gathered, with limited fieldwork resourcing, allowing population estimates to be generated for the target bird species. The combination of bioacoustics and occupancy modelling can provide a valuable new monitoring approach, allowing population trends to be identified, and the effects of environmental change and site management to be assessed.
    • Hen Harrier Circus cyaneus nest sites on the Isle of Mull are associated with habitat mosaics and constrained by topography

      Geary, Matthew; Haworth, Paul F.; Fielding, Alan H.; University of Chester; Haworth Conservation Ltd. (Taylor & Francis, 2018-02-07)
      Capsule: Hen Harrier on the Isle of Mull, UK, are associated with habitat mosaics consisting of moorland, scrub and forestry but avoid grazed land, suggesting that forested habitats could be managed sympathetically for Hen Harrier in the future should the current UK population increase. Aims: To use distribution modelling to investigate nesting habitat associations using a long term dataset for Hen Harrier on Mull. Methods: We develop area-interaction models using a LASSO penalty to explore the distribution of 102 Hen Harrier nest sites in relation to habitat and topography. Our model is then successfully validated in tests using data for 70 nest sites from subsequent years. Results: Our model is effective in predicting suitable areas for Hen Harrier nest sites and indicates that Hen Harriers on Mull are found in habitat mosaics below 200 m asl. Hen Harrier nest intensity is positively associated with increasing proportions of moorland and scrub, open canopy forestry and closed canopy forestry. Nest intensity is negatively associated with increasing proportions of grazed land. Conclusion: Hen Harrier avoid grazed areas but are relatively tolerant of other habitat combinations. These findings are supported by previous observations of Hen Harrier habitat use and have implications for the recovery of some Hen Harrier SPA populations and future forest management. Open canopy forest and forest mosaics could potentially be incorporated into landscape-scale conservation plans for Hen Harriers using the population in Mull as an example.
    • Interpreting predictive maps of disease, highlighting the pitfalls of species distribution models in epidemiology

      Wardrop, Nicola A.; Geary, Matthew; Osborne, Patrick E.; Atkinson, Peter M.; University of Southampton ; University of Chester / University of Southampton ; University of Southampton ; University of Southampton (University of Naples, 2014-11-01)
      The application of spatial modelling to epidemiology has increased significantly over the past decade, delivering enhanced understanding of the environmental and climatic factors affecting disease distributions and providing spatially continuous representations of disease risk (predictive maps). These outputs provide significant information for disease control programmes, allowing spatial targeting and tailored interventions. However, several factors (e.g. sampling protocols or temporal disease spread) can influence predictive mapping outputs. This paper proposes a conceptual framework which defines several scenarios and their potential impact on resulting predictive outputs, using simulated data to provide an exemplar. It is vital that researchers recognise these scenarios and their influence on predictive models and their outputs, as a failure to do so may lead to inaccurate interpretation of predictive maps. As long as these considerations are kept in mind, predictive mapping will continue to contribute significantly to epidemiological research and disease control planning.
    • Recapture rates and habitat associations of White-faced Darter Leucorhinnia dubia on Fenn's and Whixall Moss, Shropshire, UK

      Davies, Rachel; von Hardenberg, Achaz; Geary, Matthew; Conservation Biology Research Group, Department of Biological Sciences, University of Chester, CH1 4BJ (British Dragonfly Society, 2018-10-01)
      Land-use change and habitat loss are important drivers of biodiversity decline at both global and local scales. To protect species from the impacts of land-use change it is important to understand the population dynamics and habitat associations across these scales. Here we present an investigation into the survival and habitat preferences of Leucorrhinia dubia at the local scale at Fenn’s and Whixall Moss, Shropshire, UK. We used mark-release-recapture methods to investigate survival and used sightings of individual dragonflies along with habitat data to investigate habitat preference. We found that survival between capture-visits was very low and that L. dubia showed a clear preference for the open moss habitat on this site. In both cases, we found that the detectability, either through sightings or recaptures, was potentially very low and suggest that this should be taken into account in future analyses. We suggest that by encouraging recorders to submit complete lists and to repeat visits to sites detectability could be easily estimated for dragonfly species and incorporating this into analyses would improve estimates fo population trends and habitat associations.
    • A review of tropical dry forest ecosystem service research in the Caribbean – gaps and policy-implications

      Nelson, Howard; Devenish-Nelson, Eleanor; Rusk, Bonnie; Geary, Matthew; Lawrence, Andrew; University of Chester;University of Edinburgh; Grenada Dove Conservation Programme
      Tropical dry forests (TDFs) are globally threatened, yet remain poorly studied. In the Caribbean, the most biodiverse of island biodiversity hotspots, TDFs have structural properties distinct from the Neotropical mainland and are important to local communities for ecosystem services. We undertook a systematic review (n = 186) of ecosystem services literature of Caribbean TDF. Only 19.89% qualified for inclusion, with the majority (56.76%) from primary literature. Research on supporting services (31.14%), particularly primary production was predominant. Most studies (70.97%) took a biophysical perspective and quantification focused on the supply of ecosystem services (43.00%), while measurement of wellbeing benefits were uncommon. Geographic coverage of all studies was patchy originating from only nine of 28 independent countries and dependent territories. Our findings highlight a lack of research, while accentuating the value of grey literature in quantifying cultural services. Of concern, are gaps in air- and water-related services and the importance of TDF to human health. To move from biophysical assessments to a broader portfolio of ecosystem services studies, research on Caribbean TDF should be collaborative and strategic. Such gaps and research biases suggest opportunities for evidence-led policy-making. These lessons are relevant for mainstreaming ecosystem services into decision-making in Small Island Developing States.
    • Scenario-Led Habitat Modelling of Land Use Change Impacts on Key Species

      Geary, Matthew; Fielding, Alan H.; McGowan, Philip J. K.; Marsden, Stuart J.; University of Chester, Manchester Metropolitan University; Newcastle University (PLOS, 2015-11-16)
      Accurate predictions of the impacts of future land use change on species of conservation concern can help to inform policy-makers and improve conservation measures. If predictions are spatially explicit, predicted consequences of likely land use changes could be accessible to land managers at a scale relevant to their working landscape. We introduce a method, based on open source software, which integrates habitat suitability modelling with scenario-building, and illustrate its use by investigating the effects of alternative land use change scenarios on landscape suitability for black grouse Tetrao tetrix. Expert opinion was used to construct five near-future (twenty years) scenarios for the 800 km2 study site in upland Scotland. For each scenario, the cover of different land use types was altered by 5–30% from 20 random starting locations and changes in habitat suitability assessed by projecting a MaxEnt suitability model onto each simulated landscape. A scenario converting grazed land to moorland and open forestry was the most beneficial for black grouse, and ‘increased grazing’ (the opposite conversion) the most detrimental. Positioning of new landscape blocks was shown to be important in some situations. Increasing the area of open-canopy forestry caused a proportional decrease in suitability, but suitability gains for the ‘reduced grazing’ scenario were nonlinear. ‘Scenario-led’ landscape simulation models can be applied in assessments of the impacts of land use change both on individual species and also on diversity and community measures, or ecosystem services. A next step would be to include landscape configuration more explicitly in the simulation models, both to make them more realistic, and to examine the effects of habitat placement more thoroughly. In this example, the recommended policy would be incentives on grazing reduction to benefit black grouse.
    • Seasonality of Plasmodium falciparum transmission: a systematic review

      Reiner, Robert C.; Geary, Matthew; Atkinson, Peter M.; Smith, David L.; Gething, Peter W.; 1 Fogarty International Center, National Institutes of Health, Bethesda, MD, USA 2 Department of Epidemiology and Biostatistics, Indiana University School of Public Health, Bloomington, IN, USA 3 Department of Entomology, University of California, Davis, CA, USA 4 Department of Biological Sciences, University of Chester, Chester, UK 5 Faculty of Science and Technology, Engineering Building, Lancaster University, Lancaster LA1 4YR, UK 6 Faculty of Geosciences, University of Utrecht, Heidelberglaan 2, Utrecht, 3584 CS, The Netherlands 7 School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, Belfast BT7 1NN, Northern Ireland, UK 8 Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK 9 Center for Disease Dynamics, Economics and Policy, Washington, DC, USA 10 Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, UK (BioMed Central, 2015-09-15)
      Background Although Plasmodium falciparum transmission frequently exhibits seasonal patterns, the drivers of malaria seasonality are often unclear. Given the massive variation in the landscape upon which transmission acts, intra-annual fluctuations are likely influenced by different factors in different settings. Further, the presence of potentially substantial inter-annual variation can mask seasonal patterns; it may be that a location has “strongly seasonal” transmission and yet no single season ever matches the mean, or synoptic, curve. Accurate accounting of seasonality can inform efficient malaria control and treatment strategies. In spite of the demonstrable importance of accurately capturing the seasonality of malaria, data required to describe these patterns is not universally accessible and as such localized and regional efforts at quantifying malaria seasonality are disjointed and not easily generalized. Methods The purpose of this review was to audit the literature on seasonality of P. falciparum and quantitatively summarize the collective findings. Six search terms were selected to systematically compile a list of papers relevant to the seasonality of P. falciparum transmission, and a questionnaire was developed to catalogue the manuscripts. Results and discussion 152 manuscripts were identified as relating to the seasonality of malaria transmission, deaths due to malaria or the population dynamics of mosquito vectors of malaria. Among these, there were 126 statistical analyses and 31 mechanistic analyses (some manuscripts did both). Discussion Identified relationships between temporal patterns in malaria and climatological drivers of malaria varied greatly across the globe, with different drivers appearing important in different locations. Although commonly studied drivers of malaria such as temperature and rainfall were often found to significantly influence transmission, the lags between a weather event and a resulting change in malaria transmission also varied greatly by location. Conclusions The contradicting results of studies using similar data and modelling approaches from similar locations as well as the confounding nature of climatological covariates underlines the importance of a multi-faceted modelling approach that attempts to capture seasonal patterns at both small and large spatial scales. Keywords: Plasmodium falciparum ; Seasonality; Climatic drivers
    • Street-level green spaces support a key urban population of the threatened Hispaniolan Parakeet Psittacara chloropterus

      Geary, Matthew; Celia, Brailsford; Laura, Hough; Fraser, Baker; Simon, Guerrero; Yolanda, Leon; Nigel, Collar; Stuart, Marsden; University of Chester; Manchester Metropolitan University; Autonomous University of Santo Domingo; Instituto Tecnológico de Santo Domingo; BirdLife International
      While urbanisation remains a major threat to biodiversity, urban areas can sometimes play an important role in protecting threatened species, especially exploited taxa such as parrots. The Hispaniolan Parakeet Psittacara chloropterus has been extirpated across much of Hispaniola, including from most protected areas, yet Santo Domingo (capital city of the Dominican Republic) has recently been found to support the island’s densest remaining population. In 2019, we used repeated transects and point-counts across 60 1 km2 squares of Santo Domingo to examine the distribution of parakeets, identify factors that might drive local presence and abundance, and investigate breeding ecology. Occupancy models indicate that parakeet presence was positively related to tree species richness across the city. N-Mixture models show parakeet encounter rates were correlated positively with species richness of trees and number of discrete ‘green’ patches (> 100 m2) within the survey squares. Hispaniolan Woodpecker Melanerpes striatus, the main tree-cavity-producing species on Hispaniola, occurs throughout the city, but few parakeet nests are known to involve the secondary use of its or other cavities in trees/palms. Most parakeet breeding (perhaps 50‒100 pairs) appears to occur at two colonies in old buildings, and possibly only a small proportion of the city’s 1,500+ parakeets that occupy a single roost in street trees breed in any year. Our models emphasise the importance of parks and gardens in providing feeding resources for this IUCN Vulnerable species. Hispaniola’s urban centres may be strongholds for populations of parakeets and may even represent sources for birds to recolonise formerly occupied areas on the island.
    • White-faced Darter distribution is associated with coniferous forests in Great Britain

      Geary, Matthew; von Hardenberg, Achaz; Conservation Biology Research Group, Department of Biological Science, University of Chester, Chester, CH1 4BJ (Wiley, 2020-08-11)
      Abstract 1) Understanding of dragonfly distributions is often geographically comprehensive but less so in ecological terms. 2) White-faced darter (Leucorhinnia dubia) is a lowland peatbog specialist dragonfly which has experienced population declines in Great Britain. White-faced darter are thought to rely on peat-rich pool complexes within woodland but this has not yet been empirically tested. 3) We used dragonfly recording data collected by volunteers of the British Dragonfly Society from 2005 to 2018 to model habitat preference for white-faced darter using species distribution models across Great Britain and, with a more detailed landcover dataset, specifically in the North of Scotland. 4) Across the whole of Great Britain our models used the proportion of coniferous forest within 1km as the most important predictor of habitat suitability but were not able to predict all current populations in England. 5) In the North of Scotland our models were more successful and suggest that habitats characterised by native coniferous forest and areas high potential evapotranspiration represent the most suitable habitat for white-faced darter. 6) We recommend that future white-faced darter monitoring should be expanded to include areas currently poorly surveyed but with high suitability in the North of Scotland. 7) Our results also suggest that white-faced darter management should concentrate on maintaining Sphagnum rich pool complexes and the maintenance and restoration of native forests in which these pool complexes occur.