228 Works

Gambia Tobacco Survey 2017

Mongolia Illicit Cigarette Data 2017-2018.

Georgia Tobacco Survey 2017

OHS-LFS Consistent Series Weights 1994-2007

Nicola Branson

Employers and Self Employed Series 2001-2013

Data from: A tight balance between natural selection and gene flow in a southern African arid-zone endemic bird

Ângela Maria Ribeiro, Penn Lloyd & Rauri C. K. Bowie
Gene flow is traditionally thought to be antagonistic to population differentiation and local adaptation. However, recent studies have demonstrated that local adaptation can proceed provided that selection is greater than the homogenising effects of gene flow. We extend these initial studies by combining ecology (climate), phenotype (body size), physiological genetics (oxidative phosphorylation genes) and neutral loci (nuclear microsatellites and introns) to test whether selection can counter-balance gene flow and hence promote local adaptation in a...

Data from: Host-parasite arms races and rapid changes in bird egg appearance

Claire N. Spottiswoode & Martin Stevens
Coevolutionary arms races are a powerful force driving evolution, adaptation, and diversification. They can generate phenotypic polymorphisms which render it harder for a coevolving parasite or predator to exploit any one individual of a given species. In birds, egg polymorphisms should be an effective defense against mimetic brood parasites, and are extreme in the African tawny-flanked prinia (Prinia subflava) and its parasite the cuckoo finch (Anomalospiza imberbis). Here we use models of avian visual perception...

Data from: Pair complementarity influences reproductive output in the polymorphic black sparrowhawk (Accipiter melanoleucus)

Gareth Tate, Petra Sumasgutner, Ann Koeslag & Arjun Amar
How multiple morphs are maintained within populations of colour polymorphic bird species remains a challenging question in evolutionary ecology. In some systems, differential productivity or survival between morphs are thought to play a role. Here we examine key demographic parameters between the two discrete adult morphs that characterise the polymorphic black sparrowhawk Accipiter melanoleucus. Using long-term breeding and survival data from a population on the Cape Peninsula, South Africa, we test for differences in reproductive...

Data from: Bouldering: an alternative strategy to long-vertical climbing in root-climbing hortensias

Carolina Granados Mendoza, Sandrine Isnard, Tristan Charles-Dominique, Jan Van Den Bulcke, Nick P. Rowe, Joris Van Acker, Paul Goetghebeur & Marie-Stéphanie Samain
In the Neotropics, the genus Hydrangea of the popular ornamental hortensia family is represented by climbing species that strongly cling to their support surface by means of adhesive roots closely positioned along specialized anchoring stems. These root-climbing hortensia species belong to the nearly exclusive American Hydrangea section Cornidia and generally are long lianescent climbers that mostly flower and fructify high in the host tree canopy. The Mexican species Hydrangea seemannii, however, encompasses not only long...

Data from: Dietary studies in birds: testing a non-invasive method using digital photography in seabirds

Davide Gaglio, Timothée Cook, Maëlle Connan, Peter G. Ryan & Richard B. Sherley
Dietary studies give vital insights into foraging behaviour, with implications for understanding changing environmental conditions and the anthropogenic impacts on natural resources. Traditional diet sampling methods may be invasive or subject to biases, so developing non-invasive and unbiased methods applicable to a diversity of species is essential. We used digital photography to investigate the diet fed to chicks of a prey-carrying seabird and compared our approach (photo-sampling) to a traditional method (regurgitations) for the greater...

Data from: Flexibility in the duration of parental care: female leopards prioritise cub survival over reproductive output

Guy A. Balme, Hugh S. Robinson, Ross T. Pitman & Luke T. B. Hunter
1.Deciding when to terminate care of offspring is a key consideration for parents. Prolonging care may increase fitness of current offspring, but it can also reduce opportunities for future reproduction. Despite its evolutionary importance, few studies have explored the optimal duration of parental care, particularly among large carnivores. 2.We used a 40-year dataset to assess the trade-offs associated with the length of maternal care in leopards in the Sabi Sand Game Reserve, South Africa. We...

Data from: Factors associated with leucism in the common blackbird (Turdus merula)

Lucía Izquierdo, Robert L. Thomson, José I. Aguirre, Alazne Díez-Fernández, Bruno Faivre, Jordi Figuerola & Juan Diego Ibáñez-Álamo
Leucism is the total or partial lack of melanins in the skin and associate structures (i.e. hair or feathers). Little is known about the factors influencing this chromatic aberration although some local studies suggest that there is an effect of habitat, age and sex. To test these hypotheses and expand our knowledge on leucism, we carried out a large‐scale study using common blackbirds (Turdus merula) as our model species. Given the poor information available on...

Maternally-transferred thyroid hormones and life-history variation in birds

Bin-Yan Hsu Hsu, Veli-Matti Pakanen, Winnie Boner, Blandine Doligez, Tapio Eeva, Ton Groothuis, Erkki Korpimäki, Toni Laaksonen, Asmoro Lelono, Pat Monaghan, Tom Sarraude, Robert Thomson, Jere Tolvanen, Barbara Tschirren, Rodrigo Vásquez & Suvi Ruuskanen
1. In vertebrates, thyroid hormones (THs) play an important role in the regulation of growth, development, metabolism, photoperiodic responses and migration. Maternally transferred THs are important for normal early-phase embryonic development when embryos are not able to produce endogenous THs. Previous studies have shown that variation in maternal THs within the physiological range can influence offspring phenotype. 2. Given the essential functions of maternal THs in development and metabolism, THs may be a mediator of...

Data from: Urbanization is associated with increased breeding rate, but decreased breeding success in an urban population of near-threatened African Crowned Eagles (Stephanoaetus coronatus)

Colleen Downs, Shane McPherson, Rebecca Muller, Petra Sumasgutner & Arjun Amar
Urban areas can be attractive to certain species because of increased food abundance and nesting availability which in turn may increase productivity or breeding rates. However, there are also potential costs associated with urban living such as higher nest failure, poorer body condition or increased prevalence of disease. These costs may result in species trading off the number of young produced against the condition of their young. African Crowned Eagles (Stephanoaetus coronatus) are a rare...

Epiphytic bryophyte diversity and range distributions along an elevational gradient in Marojejy, Madagascar

Lovanomenjanahary Marline, Claudine Ah-Peng & Terry Hedderson
Describing spatial variation in species richness and understanding its links to ecological mechanisms are complementary approaches for explaining geographical patterns of richness. The study of elevational gradients holds enormous potential for understanding the factors underlying global diversity. This paper investigates the pattern of species richness and range-size distribution of epiphytic bryophytes along an elevational gradient in Marojejy National Park, North-east Madagascar. The main objectives are to describe bryophyte species composition and endemism in Marojejy National...

Heat dissipation behaviour of birds in seasonally hot, arid-zones: are there global patterns?

Nicholas Pattinson, Michelle Thompson, Michael Griego, Grace Russell, Nicola Mitchell, Rowan Martin, Blair Wolf, Ben Smit, Susan Cunningham & Andrew McKechnie
Quantifying organismal sensitivity to heat stress provides one means for predicting vulnerability to climate change. Birds are ideal for investigating this approach, as they display quantifiable fitness consequences associated with behavioural and physiological responses to heat stress. We used a recently developed method that examines correlations between readily-observable behaviours and air temperature (Tair) to investigate interspecific variation in avian responses to heat stress in seasonally hot, arid regions on three continents: the southwestern United States,...

The role of shade in maintaining alternative stable states between open- and closed-canopy vegetation

Simon Power, G. Anthony Verboom, William Bond, Kirsten Packer & Michael Cramer
Fire is commonly identified as strong driver of alternative stable states such as adjacent open- versus closed-canopy vegetation types. The absence of open-canopy species from closed-canopy understoreys, where light availability is low and dynamic, however, suggests shade tolerance is an integral determinant of such vegetation boundaries. While the importance of light dynamics between alternative stable states has been acknowledged, the physiological mechanisms behind sun versus shade-tolerance are unclear. Here we investigated the differences in light...

Data from: A predictive model for improving placement of wind turbines to minimise collision risk potential for a large soaring raptor

Megan Murgatroyd, Willem Bouten & Arjun Amar
1. With the rapid growth of wind energy developments worldwide, it is critical that the negative impacts on wildlife are considered and mitigated. This includes minimising the numbers of large soaring raptors which are killed when they collide with wind turbines. 2. To reduce the likelihood of raptor collisions, turbines should be placed at locations which are least used by sensitive species. For resident or breeding species, this is often delineated crudely through the use...

Strengthening Resilience Across Scales: Moving Cities beyond COVID-19

Andrea Lampis

Data from: Quantifying the environmental limits to fire spread in grassy ecosystems

Ann Carla Staver, Anabelle Cardoso, Sally Archibald, William Bond, Corli Coetsee, Matthew Forrest, Navashni Govender, David Lehmann, Loic Makaga, Nokukhanya Mpanza, Josue Edzang Ndong, Aurelie Koumba Pambo, Tercia Strydom, David Tilman & Peter Wragg
Modeling fire spread as an infection process is intuitive: an ignition lights a patch of fuel, which infects its neighbor, and so on. Infection models produce non-linear thresholds, whereby fire spreads only when fuel connectivity and infection probability are sufficiently high. These thresholds are fundamental both to managing fire and to theoretical models of fire spread, whereas applied fire models more often apply quasi-empirical approaches. Here, we resolve this tension by quantifying thresholds in fire...

An umbrella review protocol of the evidence syntheses to inform vaccination practices and policies against COVID-19 pandemic in Africa

Krisna Els, Benjamin Kagina & Edina Amponsah-Dacosta
In Africa, the rollout of COVID-19 vaccines is slower than in high income settings. Furthermore, in Africa, the rollout started in the first quarter of 2021 compared with earlier periods (December 2020 and January 2021) in high income settings. Optimal COVID-19 vaccination rollout in Africa should be guided by context-specific and up to date available evidence. We conducted an umbrella review to identify, analyze and characterize the evidence synthesis that is available and has the...

UCT researchers

Maggie Marx
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