Biological, Earth and Environmental Sciences - Masters by Research Theses

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The influence of community-defined land use plans and de facto land use practices on the relative abundance and distribution of large wild mammals in a community-based Wildlife Management Area in southern Tanzania
(University College Cork, 2023) Duggan, Lily; Killeen, Gerry; Butler, Fidelma; Mombo, Felister; AXA Research Fund
This study investigates the relationship between community-defined land use plans and de facto land use practices, and the influence of the latter on the relative abundance and distribution of large wild mammals in a community-based Wildlife Management Area (WMA) adjacent to Nyerere National Park (NNP) in southern Tanzania. The WMA model represents a relatively new approach to community-based conservation in Tanzania, in which local villages set aside part of their land for wildlife conservation and manage that resource collectively, so that their stakeholder communities can leverage economic and social benefits from income-generating activities like tourism. The Ifakara-Lupiro-Mangula (ILUMA) WMA acts as a key buffer zone between the fully domesticated habitats of the villages to the north and west, and Nyerere National Park to the east. All observed signs of wildlife and human activity were recorded across 32 locations inside ILUMA and in the permanent settlements and national park that border it to the west and east, respectively. For the great majority of wild mammal species, surveys around water bodies within a 2km radius of suitable camping locations proved more sensitive than those along transects between them. The latter transect surveys were only more sensitive for Sable and Spotted Hyena, which are known to routinely commute considerable distances across their home ranges, and for Greater Kudu that seldom drink surface water. Across much of ILUMA WMA, in areas where agreed land use plans were not adhered to, rampant cattle herding and land clearing for cultivation of rice and other tillage crops were associated with reductions in wildlife richness and biodiversity, as well as overall ecosystem integrity. Many unauthorised human activities were recorded inside ILUMA, such as livestock herding, charcoal burning and agriculture, and, where they occur at a high density, wildlife populations are negatively affected. Although all these activities impact wildlife to some degree, cattle herding had the most severe negative effect on wildlife (Species Richness, P=0.002, Simpson’s Index of Diversity, P=0.0022) and ecosystem integrity (P <<0.0001). Nevertheless, several well-managed authorised human settlements within the WMA, where fishing is the primary authorised livelihood, support thriving wildlife populations and pristine land cover, so human settlement per se was not found to be associated with reductions of any of these composite indices (P≥0.4532), except for the novel subjective natural ecosystem integrity index (P=0.0256). Correspondingly, the best conserved parts of the WMA were those closest to the national park to the east and the fishing villages to the north, where compliance with agreed land use plans is highest. Overall, this study illustrates how well-managed WMAs can host resident local communities undertaking selective and appropriately regulated natural resource extraction activities, while maintaining a rich and diverse local wildlife population and acting as an effective buffer zone between fully domesticated areas of human habitation and pristine environments such as national parks. Furthermore, this study also developed and evaluated a novel method for synthesizing consensus subjective impressions of the investigators and intuitively expressing them in semi-quantitative format as a readily interpreted subjective natural ecosystem integrity index that accounts for all aspects of land use, wildlife and human activities. Crucially, however, this alternative to statistical syntheses of extensive, formally collected survey data is intuitively accessible to all manner of stakeholders, including relevant communities, and should be far better suited to routine programmatic monitoring through participatory approaches.
Blood host preferences and competitive inter-species dynamics within an African malaria vector species complex inferred from signs of animal activity around aquatic larval habitats distributed across a gradient of fully domesticated to fully pristine ecosystems in southern Tanzania
(University College Cork, 2023) Walsh, Katrina; Killeen, Gerard; Butler, Fidelma; Kaindoa, Emmanuel; AXA Research Fund; University College Cork
The effectiveness of current first-choice vector control interventions on the semi-zoophagic vector Anopheles arabiensis are limited, among other things, by insecticide resistance and their ability to acquire non-human bloodmeals. Across much of southern Tanzania, in areas where humans and cattle are readily available, it is the predominant member sibling species of the Anopheles gambiae complex. However, little is known about its population dynamics or blood utilization behaviours in pristine natural ecosystems, where these known preferred hosts are scarce or completely absent. This study investigated larval habitat occupancy and species composition of the An. gambiae complex, together with the availability of various potential mammalian blood host species, across a gradient of fully domesticated to fully pristine ecosystems in southern Tanzania. Potential aquatic habitats were surveyed at 40 locations encompassing permanent human settlements, a community-owned Wildlife Management Area with varying degrees of human activity, and Nyerere National Park (NNP), which had very little. To investigate the effects of potential host availability on the species composition of the complex, all direct observations, tracks and signs of humans, livestock and wild animals observed around the surveyed larval habitats were recorded in parallel. The resulting data were analysed by logistic regression using generalized linear mixed models. Odds of habitat occupancy by An. gambiae complex larvae decreased by 62% (P<0.0001) across the full range of natural ecosystem integrities observed, from fully domesticated to completely pristine areas, suggesting that the availability of suitable blood hosts had a modest effect on overall habitat utilization by this taxon. However, while only An. arabiensis, a key vector of residual malaria transmission, was found in fully domesticated ecosystems, its non-vector sibling species An. quadriannulatus also occurred in conserved areas and dominated the most pristine natural ecosystems. The proportion of An. arabiensis versus An. quadriannulatus was positively associated with the number of times humans and/or cattle (P=0.0007) were detected at a location and negatively associated with distance inside NNP and away from human settlements (P<0.0001). Nevertheless, An. arabiensis was found even in absolute pristine environments that were >40km away from any signs of human or livestock, suggesting this species can survive on blood from one or more wild animal species. High proportions of An. quadriannulatus inside NNP were positively associated with the number of times impala were detected (P<0.0001), suggesting they may be a preferred blood source for this non-vector, giving it a competitive advantage over An. arabiensis where this antelope is abundant. Despite being detected less frequently, bushpig were also positively associated with high proportions of An. quadriannulatus, suggesting they provide a second preferred blood source, particularly in the miombo woodlands of the buffer zone where impala were scarce. Overall, it seems that the availability of preferred hosts influences the competitive balance between these sibling species and that refugia populations of An. arabiensis can persist in wild areas, thus presenting both challenges and opportunities for control interventions: While such refuge populations deep inside pristine conservation area may confound attempts to repeat historical successes with eliminating this species from areas outside its natural range, it may also constitute a reservoir of diverse, unselected genomes with original wild-type insecticide susceptibility traits that could repopulate areas around human settlements that had otherwise been considered lost from the natural gene pool.
Urban trees and biodiversity in Cork city
(University College Cork, 2022) Marron, Caoimhe; Lettice, Eoin; Doyle Prestwich, Barbara
Biodiversity is poorly quantified in urban landscapes and is not effectively incorporated into urban planning and policymaking. Land-use change (e.g., urbanisation) is one of the key drivers of biodiversity loss. Furthermore, urbanisation is expected to increase from 50 to 70% by 2050. The CSO reported a 0.6% decrease of residents living in highly rural areas of Ireland (2011-2016), including a 5.5% increase in residents living in independent urban towns. Urban trees have a broad range of ecosystem services; it is likely that many of these services will become increasingly important due to climate change pressures (e.g., changing climatic conditions, extreme natural occurrences). This thesis examines the role of urban trees/green spaces in supporting the biodiversity of other taxa (lichens, invertebrates, birds, and ground vegetation) in Cork city. There was a total of 102 individual trees studied across 6 Cork city sites, including the UCC arboretum (n=26); Cork city Marina (n=12); the Atlantic Pond (n=17); Kennedy Park (n=11); The Lee Fields (n=18); Fitzgerald’s Park (n=18). A full survey of all 4 taxa was conducted per tree, including the use of sticky traps for invertebrates; quadrat sampling for both vegetation and lichens; and observational point-counts for birds. There were no significant differences/associations between the species richness of the various taxa and the species of tree. This could be due to a limited number of replicate trees, which can be expected with an observational-based approach. However, community-level analyses have shown significant variations in the taxa communities among the 6 sites (p<0.001 for all taxa). These data suggest that the type of urban site is significantly associated with biotic community composition. Additionally, the research investigates the relationship that microclimate (light intensity and temperature) and canopy openness have with urban tree species. Microclimate data loggers were deployed at the base of all trees for each experiment and hemispherical canopy images were taken to determine canopy openness in Fitzgerald’s Park. In general, there were no, or little associations found between microclimate data, canopy openness and biodiversity. Thus, the assessment of the hypothesis that microclimate conditions impact taxa communities was inconclusive. Overall, the study supported the hypothesis that urban trees and green spaces support a large variety of individuals from other taxa and provides a baseline for biodiversity in Cork city, specifically regarding future studies and urban planning.
The ecology and phylogeography of the common lizard (Zootoca vivipara) in Ireland
(University College Cork, 2023) Lyne, Linda; Butler, Fidelma; Ramsay, Ruth; European Regional Development Fund
Ireland has only one native terrestrial reptile, the common lizard Zootoca vivipara. Many people are unaware of its presence in Ireland and little research has been conducted on the species here. However, understanding the ecology of the common lizard in Ireland could greatly help with the conservation of our only native lizard. Here we show that records of common lizards in Ireland are predominantly from coastal areas and that it occupies smaller microhabitats, such as banks or stone walls, which potentially have microclimates that offer advantages for thermoregulation. Using records of Z. vivipara sightings from the National Biodiversity Data Centre, this research identified data gaps within the distribution of Z. vivipara in Ireland, but it is uncertain if these gaps are explained by unsuitable habitat type or low sampling effort. In addition, distribution of records were found to be centred around coastal areas and sites popular with human outdoor recreation. Recorder bias, habitat suitability, and coastal sunshine hours were identified as potential factors influencing the distribution of records. A focused study on the Iveragh Peninsula, in the south-west of Ireland, observed Z. vivipara from habitat types such as upland peatland/heath (23%), gardens (17%) and old stone walls/ruins (16%). Wind speed, air temperature, and relative humidity were environmental parameters examined in this research to investigate the influence of microclimates within the microhabitats which lizards occupy. Wind speed was found to be significantly lower at ground level (P<0.05) compared to 2m height, and thus, wind may have an influence on where lizards are found within habitats. In addition, through genetic analysis, we confirm for the first time, that Irish Z. vivipara belong to the Western viviparous clade. This brings Irish phylogeographic research on the species up to date with similar research in other parts of the species’ range. We also identify that unique haplotypes are present in Ireland and that unique lineages also exist within geographically disparate populations here. Additional genetic sampling is recommended to fully understand how Z. vivipara colonised Ireland post-glacially. It is recommended that a long-term study is established to perform focused surveys for lizard presence/absence in areas where data gaps occur in sightings records of the species in Ireland. This focused study should also identify reasons for data gaps, such as habitat suitability or recorder effort. A population dynamics and behavioural study is needed to examine how environmental parameters influence Z. vivipara presence/absence in certain habitats. Finally, additional samples for genetic sequencing would greatly benefit the research into the different haplotypes identified in this study. A more geographically widespread range of samples, including from off-shore islands, would aid in understanding how Z. vivipara arrived and dispersed in Ireland.
Biodiversity, people, and logistics: the balancing act of urban park management
(University College Cork, 2023) Horan, Sadhbh; Harrison, Simon; Lettice, Eoin
In a time when global populations are moving to urban centres, the need for adequate green spaces in towns and cities for the health of both people and nature is paramount. The management of such spaces in Ireland is idiosyncratic and requires investigation. Multiple studies have tried to quantify the key influences to take into consideration when managing an urban park and for this thesis it was determined that the intersection of biodiversity, people and logistics encompassed theses influences. The aim of this study was to determine how best to manage parks in terms of habitat, amenity and management choice, based on the three selected influences. Diversity of vascular plants and fungi were assessed at six parks in Cork city. In addition, park user questionnaires and SOPARC (System for Observing Play and Recreation in Communities) observations were made to quantify people’s park use and opinions. Finally, in order to determine what systems were already in place, structured interviews were undertaken with individuals and organisations who manage urban parks in Ireland. Results show that dry meadow is the optimal choice of habitat for Irish parks due to it high level of biodiversity, its popularity among park visitors, and its compatibility with park amenities however the choice of habitat needs to take abiotic and social factors into account also. Basic amenities such as footpaths and litter bins were preferred over elaborate ones such as outdoor exercise equipment, while overall, recreational facilities were more popular than sports facilities. Logistically, in urban centres where a park management sector was present, it was often underfunded and understaffed, and so while the progress made by these groups is commendable, they are simply not rigorous enough to sustain the growing number and need for urban parks in Ireland. Urban green spaces require a complex understanding of each of the three influences highlighted in this study both across urban centres and within individual parks and cities in order for optimal management to take place.

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