People

Lab Head

Dr John Lesku

leskuI’m interested in most things related to sleep.  Using behavioural observations, accelerometry for remote monitoring and neurophysiological recording techniques, I seek to provide insight into how sleep and sleep functions have evolved in different types of animals, from flatworms to birds and mammals.  I also study how ecological factors (e.g., predation risk, reproduction) influence the amount, composition, depth and timing of sleep.  Most recently, these interests have expanded to include how anthropogenic light pollution influences sleeping brain activity in mammals (with Dr Kylie Robert) and birds (with Dr Therésa Jones).

I completed my B.Sc. in zoology at the University of Guelph (Canada) in 2002.  I then did a MSc with Drs Charles Amlaner and Steven Lima at Indiana State University (USA) (2003-2006).  This work consisted mostly of phylogenetic comparative analyses of sleep quotas as a means for testing interspecific support for various non-exclusive hypotheses for the functions of sleep.  These, and other, studies provided evidence that the risk of predation can reduce the amount of rapid eye movement (REM) sleep over both evolutionary and ecological timescales, in prey.  From there I joined the Avian Sleep Group of Dr Niels Rattenborg at the Max Planck Institute for Ornithology – Seewiesen (Germany).  My PhD focused on the evolution and regulation of sleep states in birds (2007-2011).  I stayed in Seewiesen for the remainder of 2011 as a postdoc – a part of what has been the most fulfilling collaboration of my career.  Working with Drs Rattenborg and Mihai Valcu, and Prof Dr Bart Kempenaers, we studied breeding pectoral sandpipers on the tundra in Barrow, Alaska; work that provided the first direct evidence that sleep loss can be evolutionarily adaptive.  For my contributions to this group effort, I was given the Young Investigator Award by the Sleep Research Society (USA).  After 5 wonderful years in Germany, I took up a University Postdoctoral Research Fellowship at The University of Western Australia (2012).  Soon thereafter I was offered a continuing position at La Trobe University, which I commenced in 2013.  From 2014-03/2017, I was an Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) Research Fellow.  In December 2016, I was promoted to Senior Lecturer.

 

Postgraduate Students

Erika Zaid – Reproductive sleeplessness in dasyurid marsupials

zaidSleep is a prominent part of animal life, but our understanding of the adaptive value of sleep remains incomplete.  Even though it is generally thought that reduced performance is an inevitable outcome of sleep loss, some animals may perform well on little sleep when ecological demands favour extended periods of wakefulness.  One of the best mammal candidates for such sleeplessness is antechinus, as these marsupials die synchronously after just one intense mating season.  My project, based in the Otways, examines the activity patterns of dusky antechinus in a real-world environment in and outside the breeding season, and quantifies the concentration of various hormones that may predict activity levels.  Furthermore, to provide insight into sleep evolution and function, my research seeks to determine relatedness among animals to see whether the most active males sire more offspring.  I am co-mentored by Dr Kylie Robert also at La Trobe University and Dr Niels Rattenborg at the Max Planck Institute for Ornithology, Seewiesen, Germany.

Anne Aulsebrook – Impacts of artificial night lighting on circadian rhythms in urban birds

aulsebrookIncreasing artificial light at night (ALAN) is one of the most rapid and pervasive changes to our natural environment.  Nevertheless, the consequences of ALAN for wildlife are only beginning to be understood.  A likely impact of ALAN is the disruption of endogenous daily rhythms, or circadian rhythms, including the sleep-wake cycle.  My research investigates the impacts of ALAN on the circadian rhythms of two urban bird species, the black swan (Cygnus atratus) and the pigeon (Columba livia).  Wild swans at Albert Park Lake are well-studied, individually identifiable, exposed to artificial night lights, and ideal for investigating impacts of ALAN in a natural or semi-natural environment.  Meanwhile, pigeons are an ideal model species for studying the impacts of ALAN in a more controlled, laboratory setting.  My project is co-supervised by Prof Raoul Mulder and Dr Therésa Jones at The University of Melbourne.

Michael Kelly – The behavioural and physiological indicators of sleep in sharks

mkSleep is a conspicuous behaviour in the lives of most animals, and is intimately tied to activity patterns, circadian rhythms and changes in metabolic rate.  Sleep is of great importance to us as humans and is found in all terrestrial vertebrates and many invertebrates studied so far.  However, questions of whether, how and when, many aquatic animals, including sharks, engage in this enigmatic behavioural and physiological state remains unclear.

My dissertation aims to answer these long standing questions by integrating investigations of behavioural patterns of inactivity, circadian rhythms, and the influences of environmental factors, with the assessment of physiological indicators of sleep (heart and respiratory rates, muscle tone) and recordings of brain activity in sharks.  I will search for signs of sleep in representatives of benthic sharks (buccal pumping species which can remain motionless on the sea floor for extended periods of time) and pelagic species (ram ventilating sharks) that must swim continuously to keep water flowing over their gills.  Overall, this comprehensive and multidisciplinary approach will help characterise sleep in sharks for the first time and provide new insights into sleep evolution and how the physiological demands associated with different respiratory strategies influence if and how sharks obtain their daily sleep.  I am co-supervised by Prof Shaun Collin at The University of Western Australia, Perth, Dr Jennifer Rodger (UWA) and Prof Jelle Atema at Boston University and Woods Hole Oceanographic Institution.

 

Honours Students

Brayden Redwood

Chris Vapp

 

Research Assistants

Shaun Blackburn – Shaun’s focus is scoring electrophysiological and accelerometry recordings from birds.

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Rowan Jacques-Hamilton – Rowan is applying machine learning techniques to avian electrophysiolgy in an effort to “make Shaun redundant”.  [Quote courtesy of R.J-H.]

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Former Honours Students

Linh Ly – Activity patterns in jellyfish

Alicia Dimovski – Artificial light pollution: shifting spectral wavelengths to mitigate ecological and health consequences in a nocturnal mammal

Shauni Omond – Searching for sleep in an evolutionarily simple bilaterian

Danielle Eastick – The thermoregulatory role of the southern cassowary’s (Casuarius casuarius) casque

Michael Kelly – Unilateral eye closure as an anti-predator behavior in juvenile saltwater crocodiles (Crocodylus porous)

Laura Tieri – Absence of local sleep homeostasis-like patterns under isoflurane anaesthesia in the pigeon (Columba livia)