Climate change-induced increases in air temperature pose a substantial risk to birds inhabiting arid environments. Terrestrial endotherms, such as birds, can respond to high temperatures by moving to cooler microsites, increasing heat dissipation behaviour and/or suppressing activity. Previous studies have suggested that larger bird species may have a greater suppression of activity (e.g. foraging) than smaller species at high air temperatures. However, this body mass effect may be confounded by drinking behaviour, since different species have diverse drinking ecologies. Using four species of lark that inhabit the Tankwa Karoo National Park, I investigated whether foraging activity and other heat-influenced behaviours were influenced by body mass or drinking behaviour when comparisons were constrained within a single family. These lark species were: Red-capped Lark (24 g), Spikedheeled Lark (25 g), Karoo Lark (29 g) and Large-billed Lark (45 g). There was a two-fold difference in body mass between the lightest (Red-capped Lark) and the heaviest (Large-billed Lark). Moreover, two of these lark species drink surface water (drinking larks; Red-capped and Large-billed Lark) and two do not (non-drinking larks; Spike-heeled and Karoo Lark). I also collected data on other passerines present in the Tankwa Karoo for comparison to the larks. Black bulb thermometers were used to measure the thermal landscape and a combination of instantaneous scan samples and focal observations to record bird behaviour. Black bulb temperatures were as much as 8.16 °C cooler in shaded than in sunny locations. Similarly, black bulb temperatures were as much as 8.02 °C cooler off the ground than on the ground. The results from scan sample data showed limited support that foraging was negatively correlated (although non-significant) with mass between lark species as temperatures increased; however, data from focal observations suggested larks that obtain all water from food had a greater reduction in foraging as temperatures increase than larks that drink free surface water. Within scan samples, heat dissipation and shade-seeking behaviour appeared to be more strongly influenced by whether the species drinks free surface water or not than by differences in body mass. Furthermore, drinking larks dissipate heat at lower temperatures and seek shade at higher temperatures than non-drinking larks. Foraging intensity was higher in the sunny microsites as compared to shaded microsites for all species, suggesting that drinking larks might gain an energetic benefit due to increased heat tolerance. Therefore, non-drinking species may be vulnerable to foraging-thermoregulation trade-offs under climate change. However, ongoing drying trends in the Tankwa Karoo and reduced availability of surface water may make drinking species more vulnerable to climate change in the future than non-drinking species.

Earth psychosomatically shrinks with each passing technological feat as persons and thoughts, continents apart, relay information with coherent conversation. Advances in satellite uplink speed, signal coverage, transportation methodologies, et cetera culminates a planet whose habitats, when distance is measured in time, no longer appear as weeks apart, but only a few hours worth of travel. Population continues to rise while Earth slowly wilts from the human_s stampeding footprint. In the context of humanity's relatively brief existence, number of trees is fewer nowadays than ever recorded. Atmospheric carbon parts per million is at an all-time high. Habitable land slowly dwindles along coasts as sea levels continue to rise. Evidence of climate change and studies on the depletion of the ozone layer forebode a grim future for surface dwelling. As humanity continues to expand, the given density of continents can only rise, resulting in hubris and apocalyptical outcomes lest stagnation occurs. While natural disasters and war may cull population rates and expansion, another solution exists within the duration before extrasolar expansion: subaqueous habitation. Oceans compromise over 71% of Earth_s surface, meaning expanding settlements into the deep blue more than triples habitable land. Natural disasters, such as tornadoes, meteorites, electrical storms, drought, heavy snowfall, wildfire, nuclear detonation, haboobs, and surface burning lessen in their hazardous effect with the absence of land. Other present disasters, including hurricanes, submerged volcanoes, torrential currents, landslides, earthquakes, tsunamis, death stranding, and pollution dictate the concepts building design must adhere in order to create habitable living. Furthermore, the effects which sensory deprivation (namely from the absence of light and wide-open spaces) have on inhabitants must be remedied through fabricated scenarios. These may include Virtual Reality, and artificial islands. In terms of expansion, design then must decide whether to unction as a grouping of pods, or a single society a la L_Unite d_habitation. Submersible vehicles may be used to travel from one structure to another, gather resources, and function similarly to vehicles on preset roads. This opens up the possibility of multiple underwater cities, and pathing networks spanning inbetween continents. In the far future, vehicles may be designed for traversing land and underwater terrain. In sum, the highly unexplored ocean provides alleviation to Earth_s near-distant carrying capacity until mankind undergoes planetary exodus. / 0 / SPK / specialcollections@tulane.edu

The Namaqualand area in the North Western Cape, South Africa is unique in comparison to other similar semi-arid areas of the world. It has a high biodiversity and endemism and is consequently an area of interest for a growing number of conservation initiatives. Climate plays an important role in influencing the phenology and growth of the vegetation in the area. Remote sensing techniques were used to reveal the vegetation patterns in the greater Namaqualand area and to relate them to climatic variables. To do this we used the normalised difference vegetation index (NDVI) to relate biomass to altitude, rainfall and vegetation type. Each vegetation type in the area had a unique temporal signature and the climatic variables influencing the summer rainfall and winter rainfall vegetation types differed significantly from each other. Mean annual NDVI was significantly correlated to precipitation and potential evapotranspiration (PET) (r = 0.60, -0.63 respectively). A multiple regression model explained 52% of the variance when Mean Annual NDVI was related to climatic variables. Mean NDVI in August (the month of maximum NDVI in most of Namaqualand) was significantly related to PET and the current plus two previous months of precipitation (r = -0.72 and 0.74 respectively). A multiple regression model for mean NDVI in August and climatic variables explained almost 58% of the variance. The results suggest that NDVI can be used successfully as a measure of growth and phenology in the Namaqualand area and that NDVI could be used in climate models, drought prediction, desertification predictions and a number of other applications in the future.

This thesis is a qualitative ethnographic study of innovations implemented by Mr Zephaniah Phiri Maseko, a smallholder farmer from Zvishavane, rural Zimbabwe. Ethnographic data provides insight and lessons of his practices for rethinking existing strategies for adaptation to climate change. The concept of adaptation is probed i n relationship to the closely related concepts of vulnerability, resilience and innovation. This study also explores the concept of conviviality and argues that Mr Phiri Maseko's adaptation to climate hinges on mediating barriers between local and exogenous knowledge systems. Ethnographic fieldwork aided by an analytical framework of resilience makes clear that his farming practices are informed by a realisation that dualisms are problematic. His innovations are a way of building resilience to climate change and his practices demonstrate the interdependencies in a socio - ecological system. This study argues that innovations by smallholders play a complementary role to interventions by outsiders in the discourse of adaptation to climate in the drylands of southern Zimbabwe. Mr Phiri Maseko harvested water as a way of adapting to climate variability. I argue that he offered tangible adaptive climate strategies through his innovations that "marry water and soil so that it won't elope and run - off but raise a family" on his plot. His agricultural practices are anchored on the Shona concept of hurudza (an exceptionally productive farmer). This thesis explores the concept and practices of uhurudza , to suggest that the latter - day hurudza (commercial farmer) as embodied by Mr Phiri Maseko offered an important set of resources for the development of climate adaptation strategies in the region. Therefore, his activities call for a revisit of the notion of hurudza based on grain harvested, one that includes consistent income generated from selling farm produce. His innovations demonstrate elements of conviviality, resilience, accommodating local knowledge as well as ideas he learnt from various educational institutions in order to adapt to climate variability. This thesis explores the usefulness of Mr Phiri Maseko's innovations for other smallholder farmers in the Zvishavane area who have replicated it. I demonstrate that due to the success of his innovations, uptake has been high underpinning the fact that these smallholders appear to be managing to adapt to climate variability. This ethnographic study of smallholder farmers' adoption of innovations to climate highlights the "complex interplay" of multiple factors that act as barriers to uptake. Such interplay of multiple stressors increases the vulnerability of smallholders. I conclude by arguing that in as much as the skewed colonial land policy impoverished the smallholder farmers, Mr Phiri Maseko nonetheless redefined himself as a latter - day hurudza and thus breaks free from the poverty cycle by 'conjuring ingenious' ways of reducing vulnerability to climate. I do not suggest that his innovations offer a 'silver bullet' solution to the insecure rural livelihoods of smallholder farmers; nevertheless, they are a source of hope in an environment of uncertainty.

South Africa comprises almost 10% of known plant species and also has the only arid zone "hotspot" defined worldwide, namely the succulent Karoo. Anthropogenic climate change predictions for South Africa suggest rapid climate change in the next 50 years will have adverse effects on its vegetation biomes. This study shows how the aborescent succulent, Aloe pillansii, has a limited distribution due significantly to environmental and climatic variables and therefore it is potentially at risk given anthropogenic climate change predictions. The total South African A. pillansii population investigated is made up of 1202 individuals and is found in the Richtersveld, which is part of the Succulent Karoo. The A. pillansii individuals were sampled in terms of their height and geographical position and then defined into subpopulations by a distance of 2 kms of separation. The sub-populations were then evaluated in terms of their respective environmental and climatic variables acquired from a CCWR database for South Africa using Arc View 3.2. The sub-population size class distributions were also constructed so that population dynamics and recruitment could be investigated. The results show how the A. pillansii sub-populations are limited to a specific environmental and climatic range. The sub-populations group along similar environmental and climatic variables with the healthiest sub-populations found at lower elevation, higher temperatures and higher Potential Evapo-Transpiration. The climatic range of A. pillansii is also evident from the range of its environmental and climatic variables and the associated unhealthy sub-populations that lie on the extremes of this range. Recruitment was found to correlate strongly with the environmental and climatic variables, % winter rainfall and elevation, suggesting it is moisture limited. The evidence found in this study of A. pillansii 's specific environmental and climatic distribution may have negative implications for its future survival and conservation especially with present indications of anthropogenic climate change.

The effects of environmental warming on the reproductive performance of birds are most easily studied in desert habitats where birds already experience air temperatures (Tₐs) close to their upper thermal tolerance. Many desert birds coincide breeding with periods of food availability triggered by rainfall during the summer season. Daily maximum air temperatures (ₘₐₓ) during the Kalahari summer season frequently reach the lower forties (°C) and recent years have been characterised by reduced rainfall and increased Tₐ. Breeding Southern Yellow-billed Hornbills (Tockus leucomelas) could be particularly vulnerable to high Tₐ due to their breeding strategy whereby the females are confined to the nest cavity for most of the nesting period. During this time their male partners are solely responsible for food provisioning, which imposes a considerable energetic demand. In this thesis, I investigated the extent to which Tₐ affects the ability and willingness of breeding males to provision their female partners and offspring. And consequently, the extent to which male investment and the thermal environment affect female body mass (Mb) and chick development rates in Southern Yellowbilled Hornbills in the Kalahari. During three consecutive hornbill breeding seasons (October - March, between 2012 and 2015), I collected life history data during 50 breeding attempts by 32 hornbill pairs. At the study site, Southern Yellow-billed Hornbills readily breed in artificial nest boxes and this allowed me to assess the internal nest climate using temperature and relative humidity loggers which were placed in most of the nests. The male hornbills in the study population were semi-habituated which facilitated behavioural observations. Weather data were recorded at an on-site weather station. Morphometric data from females and chicks were collected on a daily basis at selected nests and perch scales installed at nest entrances recorded Mb data of the provisioning males. From chick hatching to chick fledging, I observed the behaviour of the males during 30-min focal follows and focussed on foraging behaviour, prey allocation decisions (nest versus self), microsite use and thermoregulatory behaviour. Male hornbills spent more than half of their time panting at Tₐs above 34.5 °C. Days on which this threshold temperature was exceeded were therefore described as 'hot days'. The male hornbills experienced trade-offs on hot days between foraging efficiency and panting behaviour, indicating that the additional cost of thermoregulation and high Tₐ affected foraging success (Chapter 2). Males would always provision larger prey items to the nest and consumed the smaller prey items themselves. As Tₐ increased, the males increased their foraging effort, but caught fewer and smaller prey items overall, reducing the total biomass they provisioned to the nest as well as the biomass they consumed. As a result, males were unable to maintain their Mb on days when Tₐ exceeded 37.9 °C (Chapter 3). A similar effect of hot days on Mb maintenance was observed in females and chicks within the nest. Independent of chick age, females departed the nest when their Mb reached a lower limit of 189.3 ± SD 18.1 g. The females would then aid the males in nest provisioning, however the negative effect of increasing ₘₐₓ on provisioning rate was still evident; i.e. females were not able to compensate for reduced male provisioning rates on hot days. High Tₐs during the nesting period resulted in smaller and lighter fledglings and overall reduced the probability of a successful nesting attempt (Chapter 4). A thermal imaging experiment revealed that the large beak of hornbills (both males and females) plays an important role in non-evaporative heat loss. Hornbills were observed to dissipate up to 19.9 % of the total non-evaporative body heat loss via the beak. This water-saving mechanism can be highly advantageous to hornbills living in arid regions where water availability is limited (Chapter 5). Lastly, a comparison of the results of the current study with those of a study on the same hornbill population carried out between 2008 and 2011 revealed that mean ₘₐₓ as well as rainfall during the nesting period had an important impact on overall hornbill reproductive effort and success (Chapter 6). Long-lived species are expected to prioritise future reproductive opportunities over current broods. However, the predicted scenario for the Kalahari is that high Tₐs become more extreme and periods of drought become more frequent. Therefore, I predict an increased risk of breeding failure among Southern Yellow-billed Hornbills in the future which could affect the persistence of this population.

Global climatic processes which control the interannual variability of summer rainfall over South Africa are studied. Monthly and seasonal rainfall variations are analysed with respect to fluctuations in sea surface temperature (SST), outgoing longwave radiation (OLR) and tropospheric winds. OLR is used as a proxy for convective intensity and for the identification of areas of sympathy and opposition to convection over South Africa. Wind data (and derived parameters) are employed to explore large- scale tropical dynamical structures. Plausible explanations are offered for the observed associations. A change in sign of the correlation structure from the October/November rainfall regime to the December through March regime is indicative of a shift from downstream advective processes (Atlantic side) to a teleconnection-type of behaviour (Indian Ocean side). Rainfall variations during the late summer months show significant (and negative) links with SST fluctuations within the equatorial/tropical Pacific and Indian Ocean areas and are consistent with results obtained in analyses with respect to OLR fluctuations. December OLR in the Western Equatorial Indian Ocean is associated with a large portion of the variance in late summer rainfall, and points to a possible relation with the evolution of the Indian monsoon. The positive association implies that reduced cloudiness off the eastern coast of equatorial Africa in the spring precedes above normal mid- and late- summer rainfall over South Africa. Vertical mass overturnings are investigated through the velocity potential and derived parameters (the Zonal Circulation and Meridional Circulation Indices). The results suggest that the vertical tropospheric cells are among the important associated components which modulate climate across southern Africa, and that broad scale flows have an impact upon regional circulation cells. Evaluation of the vertical circulations with respect to wet and dry composites reveals that the Walker-type cell which connects a branch over the Indian Ocean gradually forms after November and reaches peak development in February. A slight increase of SST in the Central Equatorial Indian Ocean (CEI) modifies the Walker cell anomaly leading to below normal summer rainfall over South Africa. Additional thermodynamic inputs in the CEI region are conducive to deeper convection, hence elevated outflow signatures are observed in the velocity potential and related fields. It is conjectured that the teleconnections between South Africa, the CEI and the remote Pacific Ocean regulate the depth of moisture influx and convergence over South Africa. Based on the results of this study, it is believed that empirical models could be designed for long-range prediction of summer rainfall anomalies over the central interior of South Africa.

In an attempt to determine why trees and grasses are able to coexist in savannas, Walter (1971) first proposed the root niche separation model for savannas which suggests that trees and grasses have differential access to water due to spatial differences in their rooting profiles. Subsequent studies in various savannas around the world have found that this is often not the case. In the central region of the Kruger National Park February & Higgins (2010) found that trees and grasses root at the same depths within the soil profile. In this study I determine whether the existence of fine roots in the soil profile necessarily indicates root activity. I also aim to determine the effect of increased water and nitrogen availability on root activity of trees and grasses. Pits of 20 x 20 em were dug to a depth of 40 em in plots that were either irrigated with the equivalent of 30 ml of rainfall per month or left without irrigation. This study was performed at the end of the rainfall season. I found that trees and grasses root at the same depths under moist and dry edaphic conditions as well as in plots with increased nitrogen. Tree roots are however, significantly more active than grass roots in non-irrigated plots. Temporal separation in root activity therefore seems to be a factor that allows for the coexistence of trees and grasses in savanna ecosystems.

Thesis advisor: Philip E. Strahan / The dissertation consists of two essays on corporate finance, banking, and political economy. The first chapter studies how partisan-driven views about climate change affect institutional investors’ investment in assets that are exposed to climate risk. The second chapter examines how unexpected political chaos can affect politically active companies in a negative way. In “Climate Change, the Partisan Divide, and Exposure to Climate Risk”, I study how partisan-driven beliefs about climate change affect the distribution of climate risk across mortgage lenders. Using wildfires to capture climate exposure, I find that Republican-leaning lenders are more likely to approve mortgage applications in high wildfire risk areas than Democratic-leaning lenders. This difference in approval rates is only evident among second-lien and jumbo mortgage applications, highlighting how securitization affects risk-taking incentives. Lastly, Republican-leaning lenders originate more climate-exposed second-lien and jumbo loans and thus hold more wildfire risk. The findings suggest that dispersion over climate change beliefs affects how institutional investors hold climate risks, potentially affecting financial stability. In “Downsides of Corporate Political Spending: Evidence from Mass Shootings”, I study the negative impacts of corporate political spending on firm outcomes. Using data from 20 years of mass shootings, I find that when mass shootings take place, companies that primarily donate to pro-gun-rights politicians experience negative stock price reactions and worse operating performance. The negative impacts on companies’ bottom line are stronger when incidents are deadlier. The decline in operating performance reverses within a couple of years. The findings are not driven by firms contributing to Republican politicians. Similarly, using Summary of Deposits data from FDIC, I find that banks primarily donating to pro-gun-rights politicians also experience higher deposit outflows around mass shootings. After incidents, firms significantly reduce corporate political donations to pro-gun-rights politicians. Overall, my findings highlight negative impacts on companies resulting from their political spending being disapproved by stakeholders. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Carroll School of Management. / Discipline: Finance.

Global climate change models indicate that a rise in temperature and reduction in rainfall in the Western Cape Province of South Africa is inevitable and unavoidable. Within the Western Cape lies the Cape Floristic Region (CFR); a biodiversity hotspot with high levels of endemism. This includes its freshwater fish assemblage. Whereas the current greatest threats to native fish biodiversity are habitat degradation and invasion by non-native species, predicted climate change is likely to further impact fish communities negatively. As a master abiotic variable in aquatic ecosystems; temperature influences the fitness, behaviour, and life-histories of aquatic biota. Thermal alteration may therefore affect sensitive fish species. The upper thermal limit, determined via the critical thermal method, has been validated as a measure of thermal sensitivity. To better understand the impacts of climate change on the native fish of the CFR, upper thermal limits (critical thermal maxima/CTmax) were determined for seven native species of freshwater fish. Thermal preferences were also determined for five of these species using the acute gradient tank approach to elucidate thermal habitat preferences. Species that were identified by the IUCN as vulnerable, endangered, or critically endangered were selected from the four main families of native fish in the CFR (Anabantidae, Austroglanidae, Cyprinidae, and Galaxiidae), from four Rivers. Overall, Cape galaxias (Galaxias zebratus), Breede River redfin (Pseudobarbus burchelli), Berg River redfin (Pseudobarbus burgi), Clanwilliam redfin (Pseudobarbus calidus), and fiery redfin (Pseudobarbus phlegethon) were found to be most sensitive to increased temperature (CTmax= 29.8-32.7⁰C). Clanwilliam rock-catfish (Austroglanis gilli) and Cape kurper (Sandelia capensis) were found to be moderately sensitive (CTmax= 33.0-35.3⁰C). Similar trends were found using the thermal preference approach as CTmax and thermal preference were found to correlate well. The results were related to in-situ water temperature, which influenced both parameters. Thermal tolerances and preferences of all the native species exceed that of invasive salmonids (Onchorynchus mykiss and Salmo trutta). However, non-native centrarchids (Micropterus spp.) are more thermally tolerant, indicating an increase in threat by warm adapted non-natives. These data suggest that species interactions and distributions are likely to undergo substantial changes in response to elevated water temperature.