Fitz Seminars: 2013

Unless otherwise specified, seminars are held on Tuesdays at in the Niven Library (Zoology Building). If you would like to be reminded of forthcoming seminars, or have any related queries, please contact Hilary Buchanan.

PhD proposal presentation:

The physiological ecology of nocturnal birds exposed to high daytime environmental temperatures: energy and water balance in two southern African caprimulgids during summer. Ryan O'Connor, PhD student, U. Pretoria

Date: Monday September 2, 2013
Time: 13h00
Venue: Niven Library

Caprimulgid birds often roost and nest in open microsites, and may hence experience intense solar radiation and resultant high operative temperatures. Additionally, because of their crepuscular and nocturnal habits, caprimulgids remain inactive and experience zero preformed water intake during the hottest parts of the day. Consequently, they must evaporate water to avoid hyperthermia when roosting or incubating, but at the potential risk of dehydration. For species inhabiting hot, arid environments, the risk of dehydration will be exacerbated given the scarcity of water resources. Moreover, global average surface and ocean temperatures are on the rise with significant increases in the frequency, intensity, and duration of heat waves considered likely. Thus, caprimulgids represent an intriguing taxon for investigating physiological tolerance limits under high operative temperatures, and may potentially be valuable for modelling climate change impacts on other avian taxa. Using two southern African caprimulgids as focal species, namely Freckled Nightjars (Caprimulgus tristigma) and Rufous-cheeked Nightjars (Caprimulgus rufigena), I plan to investigate how caprimulgids maintain energy and water balance under thermal conditions among the most challenging experienced by any endotherm, and what the future implications of global warming are for caprimulgids and other nocturnal birds in hot habitats. To try and answer these over-arching questions my project focuses on five specific aims, including: 1) empirically determining relationships between evaporative water loss, metabolic rate, body temperature and high air temperature, 2) quantifying daily water flux and field metabolic rates in free-ranging birds over a range of temperatures, 3) measuring variation in core body temperature of free-ranging birds, including comparisons of incubating vs. non-incubating birds, 4) determining the role of available drinking water on nest success, evaporative water loss and total body water and, 5) determining the thermoregulatory demands of incubation.

Smelling home in the wind: the study of olfactory homing in petrels Gaia Dell'Ariccia, CEFE-CNRS, Montpellier, France

Date: Wednesday September 4, 2013
Time: 13h00
Venue: Niven Library

ABSTRACT: Animals use their sensory abilities to perceive and exploit their environment, and to interact with their conspecifics and other species. Although the sense of smell in birds has been largely neglected in the past, recent studies are bringing new evidence that olfaction plays a fundamental role in the ecology of at least some bird species, and especially petrels. However, the response to olfactory cues is not homogeneous between petrel species. For example, the olfactory recognition of the nest is performed only by nocturnal species while the diurnal ones use sight. These findings reflect species-specific divergences in lifestyles and ecology suggesting that odour responsiveness too is linked to specific lifestyles. In order to understand the adaptive and evolutive importance of the use of olfaction, we investigated and compared the homing behaviour of different petrel species. We performed different experiments, i.e. Y-maze choice tests in the colony and GPS tracking, to evaluate the homing behaviour and the use of smell in nest recognition in different petrel species in relation to their environments and lifestyles.

BIOGRAPHY: Gaia Dell’Ariccia is an Italian post-doctorate at the Center of Evolutionary and Functional Ecology of the French National Centre for Scientific Research (CEFE-CNRS) in Montpellier, France. She is a behavioral ecologist working on the use of olfaction in birds for a number of behaviours, ranging from foraging to homing, and to nests and partner recognition. After completing her masters studies at the University of Rome, Gaia conducted her PhD at the University of Zurich (Switzerland) on the influences of sociality and experience on avian navigation abilities using homing pigeon as a model species. She is currently finalizing a post-doctorate in Montpellier in the team of Francesco Bonadonna, studying the olfactory ecology of various petrel species with a comparative approach between Mediterranean and Atlantic populations.

MSc proposal presentation: The effects of urbanisation and microhabitat on Kelp Gulls in Plettenberg Bay Minke Witteveen

Date: Thursday August 15, 2013
Time: 13h00
Venue: Niven Library
Speaker: Minke Witteveen, MSc student

The human population is increasing rapidly, as is contemporary urbanisation. Coastal areas are especially developed, with high population density and economic activities. Temperature increases, sea level rise and climate change is putting added pressure on coastal ecosystems. Despite various negative impacts of these factors on many seabird species, some have adapted and subsequently increased in number. There are 51 species of gull worldwide and of these 18 have subspecies or populations that are increasing; many of these are due to their ability to adapt to human activities. Seabird breeding and nesting sites are often specifically chosen according to habitat variables, which have been shown to affect breeding success and adult survivorship. Climate change, sea level rise and on-going urbanisation will alter the habitat available for nesting. The Kelp Gull has a wide distribution throughout the southern hemisphere, and is increasing in certain areas of the Eastern Cape region of South Africa. This research aims to determine the extent of the influence of urbanisation and microhabitat on the breeding biology, foraging behaviour and thermoregulation of Kelp Gulls nesting at Keurbooms River and Robberg Peninsula, Plettenberg Bay, Western Cape.

Fynbos Endemic Birds: Densities and distributions in relation to vegetation structure and weather by Dr Alan Lee

Date: Thursday June 13
Time: 13h00
Venue: Niven Library
Speaker: Dr Alan Lee, PostDoctoral Fellow, Percy FitzPatrick Institute and SANBI Climate Change and BioAdaptation Division

The Fynbos Biome is home to six (1/3rd) of South Africa's endemic bird species. The biome is vulnerable to climate change as there is little room to move in order to maintain current temperature space. Increase in fire frequencies have been reported, and changes in rainfall patterns are also projected. Loss of suitable range was predicted for a suite of Fynbos bird species nearly 10 years ago, and a recent review of South African Bird Atlas Project data hinted that the predictions made were becoming a reality as Fynbos endemic birds were faring poorly compared to generalist species. I present preliminary data on bird occurrence and density in relation to environmental variables and surrogate variables for climate in terms of temperature and aridity gradients. These variables will be useful in determining density and distributions under future climate change scenarios for some of South Africa's most important bird species.

Field metabolic rate in seabirds - influence, limits and consequences Dr Jonathan Green, University of Liverpool

Date: Monday, April 15, 2013
Time: 13h00
Venue: Niven Library
Speaker: Dr Jonathan Green, University of Liverpool

With their predictable life-histories and tractability, seabirds make excellent models for studies of energy metabolism. Using examples from the literature, field work on macaroni penguins at Bird Island and studies of seabirds in Australia, this seminar will address what leads to variability in field metabolic rate at the inter-specific and intra-specific levels. I will discuss limits to metabolism in terms of theory on optimal and maximal rates of energy expenditure, and the role of the ‘prudent parent’. Finally I will talk about how an understanding of field metabolic rate can help us to predict the impacts of environmental change and understand differences between individuals in their phenotypic quality.

About the speaker: Jon Green did his undergraduate degree in Zoology at the University of Cambridge, then a PhD and postdoc with Pat Butler at the University of Birmingham focussing on the energetics and behaviour of macaroni penguins breeding at South Georgia. He then did a fellowship at La Trobe University, Melbourne, Australia, focussing on little penguins and Australasian gannets. Since 2008 he has been a lecturer in Marine Biology at the University of Liverpool with interests now including all aspects of seabird ecology, physiology and behaviour with an increasing focus on applied issues.

Management of Egyptian Geese on golf courses Dr Rob Little, PFIAO

Date: Friday, April 12, 2013
Time: 13h00
Venue: Niven Library
Speaker: Dr Rob Little, Manager, DST/NRF Centre of Excellence, PFIAO

The number of Egyptian Geese Alopochen aegyptiaca has increased in the Western Cape Province, South Africa, during the past few decades and they are allegedly perceived as a problem on golf courses. Attitudes towards the geese on golf courses in the province have however not been empirically assessed. We surveyed the residents and members of the Steenberg Golf Estate, Cape Town, to evaluate perceptions towards Egyptian Geese on the estate. A standardized, anonymous questionnaire was sent to 548 estate residents and non-resident golfing members. Of the 112 respondents, the majority (92 or 84%) considered that geese are a problem on the estate. The ranking of the perceived problem was; 16 (15%) minimal problem, 34 (33%) moderate problem and 54 (52%) severe problem. The majority also considered that the goose population should be reduced by 50% or more (90 or 86% of all respondents). Most control measures used to reduce the problem have been unsuccessful. We then investigated environmental management options by determining which landscape features attract geese to certain areas within golf courses and cause them to avoid others. Goose vigilance levels were lower in favoured areas than in avoided areas regardless of group size and thus provided a surrogate for perceived safety, suggesting that geese are attracted to some areas because they perceive them to be environments with relatively low predation risk. The landscape features which attract Egyptian geese were proximity to water (<100 m), large open patches of ground (>1.5 ha), and a large area-to-edge ratio of the patch (>0.003 ha/m). These landscape elements should be considered during the design of golf courses and can be modified on existing golf courses to render habitat structures less attractive to geese. Importantly, the level of the goose problem at any one particular golf course is a consequence of the intrinsic properties of that course and is not influenced by the extent of the problem at nearby golf courses.

Risk taking behaviour in a changing world Anders Pape Møller, Laboratoire d'Ecologie, Systematique et Evolution, CNRS, Paris

Date: Tuesday, March 19, 2013
Time: 13h00
Venue: Niven Library
Speaker: Anders Pape Møller, Laboratoire d'Ecologie, Systematique et Evolution, CNRS, Paris

All animals face a trade-off between foraging and fleeing because predators and the risk of predation are ubiquitous. Hence individuals have to optimize the distance at which they take flight from an approaching predator, resulting in a characteristic flight distance of each individual being tuned to maximise fitness. Flight distance being defined as the distance at which an individual takes flight is an empirical measure of this risk. Indeed, individuals with short flight distances run large risks of predation, showing a link between behaviour and fitness. Because individuals of different age-classes and sexes living at different latitudes differ in residual reproductive value, this should result in predictable differences in risk taking behaviour. Flight distance should also have consequences at the population level, with species composed of individuals with short fight distances being more successful invaders. Furthermore, species with short flight distances should be better able to cope with human disturbance, resulting in such species having increasing population trends. Such species should constitute prime examples of adaptation to human proximity, while rare species that take flight at long distances should face ever-increasing risk of declining populations and ultimately extinction.